A rolling friction reduction device for rock mechanics and geotechnical engineering tests

Abstract

The invention relates to the technical field of rock mechanics and geotechnical engineering test devices, and in particular to a rolling friction reduction device used in rock mechanics and geotechnical engineering tests, comprising a movable plate, a fixed plate, an elastic connector and a rolling friction reduction body. The movable plate and the fixed plate are stacked, and the movable plate is composed of a plurality of movable blocks arranged. The movable blocks and the fixed plate, and adjacent movable blocks are connected respectively by elastic connectors. Rolling friction reduction bodies are also provided respectively between the opposite surfaces of the movable blocks and the fixed plate, and between the opposite surfaces of adjacent movable blocks. Under the action of external force, the fixed plate and each movable block constituting the movable plate produce corresponding coordinate position rolling dislocation, and the friction reduction direction is not restricted. Point contact rolling friction reduction is utilized to meet the requirements of bidirectional ultra-low friction reduction, and the elastic connector of the rolling friction reduction device has an automatic reset function, and when the external force disappears, the friction reduction device can be automatically reset and restored.

Description

Technical Field

[0001] The invention relates to the technical field of rock mechanics and geotechnical engineering test devices, and in particular to a rolling friction reduction device applied to rock mechanics and geotechnical engineering tests. Background Art

[0002] In rock mechanics tests, there is often a large friction between the specimen boundary and the bearing pad. The resulting boundary friction effect will greatly affect the accuracy and reliability of the test results, especially in some compression model tests. The specimens used are often cast model specimens such as sand and concrete, and the specimen surface is rough and not smooth. During the compression process, the deformation of the specimen will cause a large friction force on the boundary surface, resulting in an uneven stress distribution inside the specimen, which in turn affects the accuracy of the test.

[0003] At present, the most common boundary friction reduction method used in model tests is to apply silicone oil or other greasy lubricating materials between the force transmission plate in contact with the model and the test bench, and then cover it with a layer of polytetrafluoroethylene film, or add a layer of grease and a layer of polytetrafluoroethylene film. The low friction coefficient between the two layers of polytetrafluoroethylene film is used to reduce friction. There are also friction reduction measures such as placing a "rolling bearing + load-bearing plate + load-bearing block" type friction reduction box between the loading head and the model. However, for larger-sized model tests, due to the large boundary area of ​​the model and the uneven force, the deformation of the model boundary is bound to be inconsistent. The surface contact friction reduction may cause the film to be torn due to the inconsistent deformation, and the friction reduction effect is not ideal. The rolling bearing type friction reduction box is a linear contact rolling friction reduction, and its friction reduction direction is limited, which is difficult to meet the requirements of large-area boundary bidirectional friction reduction.

[0004] Therefore, how to effectively and practically reduce the boundary friction of the model specimen is a key factor in whether the test is practical and achieves the expected results. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a rolling friction reduction device applied to rock mechanics and geotechnical engineering tests, which utilizes point-contact rolling friction reduction to meet the requirements of bidirectional ultra-low friction reduction. The rolling friction reduction device has an automatic reset function, and can automatically reset and restore the friction reduction device when the external force disappears.

[0006] In order to achieve the above-mentioned invention object, the present invention adopts the following technical solutions:

[0007] A rolling friction reduction device used in rock mechanics and geotechnical engineering tests, the friction reduction device is arranged between a test specimen and a bearing pad, and comprises a movable plate, a fixed plate, an elastic connector and a rolling friction reduction body. The movable plate and the fixed plate are stacked, the movable plate is composed of a plurality of movable blocks, the movable blocks and the fixed plate, and adjacent movable blocks are connected respectively by elastic connectors, and rolling friction reduction bodies are respectively provided between the opposite surfaces of the movable block and the fixed plate, and between the opposite surfaces of adjacent movable blocks to reduce the friction between the opposite surfaces.

[0008] Furthermore, the elastic connecting member is a spring supporting member.

[0009] Furthermore, the elastic connecting member includes a movable leaf spring, a spring shaft, and a movable and static leaf spring. The movable leaf spring is arranged between adjacent movable blocks, and the movable and static leaf springs are arranged between the movable block and the fixed plate. The two ends of the movable leaf spring are respectively connected to the adjacent movable blocks through the spring shaft, and the two ends of the movable and static leaf springs are respectively connected to the movable block and the fixed plate through the spring shaft.

[0010] Furthermore, the rolling friction-reducing body is a spherical rolling body, which includes a spherical rolling body A and a spherical rolling body B. A groove A is provided on the surface of the movable block relative to the fixed plate, the spherical rolling body A is embedded in the groove A, and the part of the spherical rolling body A away from the groove A protrudes from the groove A and contacts the fixed plate. A groove B is provided on the surface of the movable block relative to the adjacent movable block, and a sleeve is embedded in the groove B. The spherical rolling body B, a spring seat and a friction-reducing spring are sequentially arranged in the sleeve from the outside to the inside. One side of the spring seat is fixedly connected to the friction-reducing spring, and the other side of the spring seat contacts the spherical rolling body B. The friction-reducing spring is in a compressed state. The end of the friction-reducing spring away from the spring seat is fixed to the inner wall of the bottom of the groove B through a spring shaft, and the part of the spherical rolling body B away from the spring seat protrudes from the groove B and contacts the adjacent movable block.

[0011] Furthermore, the spherical rolling body is a steel ball.

[0012] Furthermore, fillers are provided between the movable block and the fixed plate, between adjacent movable blocks, and between the spherical rolling body and the movable block and the fixed plate, and the fillers are used for lubrication and friction reduction.

[0013] Furthermore, the filler is a lubricant made of lubricating material.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. When the present invention is applied to rock mechanics model test, the friction reduction device is placed between the specimen and the bearing pad, the fixed plate is against the bearing pad, and the movable plate is against the specimen. Since the fixed plate and the movable plate are independent of each other, the movable blocks constituting the movable plate produce corresponding coordinate position rolling dislocation under the action of external force, which adapts to the uneven force deformation of the specimen model boundary, converts the boundary friction into point contact rolling friction, greatly reduces the friction coefficient, reduces the boundary friction force, and achieves the purpose of two-way ultra-low friction reduction;

[0016] 2. Compared with the commonly used surface contact friction reduction method, the present invention does not have the situation that the film or other materials are torn due to the uncoordinated deformation and affect the test. The point contact rolling friction better adapts to the uneven force deformation of the specimen model boundary. Compared with the linear contact rolling friction reduction such as the rolling bearing friction reduction box, the friction reduction direction is not restricted. Each unit active block can be rolled and dislocated in multiple directions under the action of external force, meeting the requirements of two-way ultra-low friction reduction.

[0017] 3. The present invention is used for geotechnical mechanics and geotechnical engineering tests to improve the corresponding test stress environment, achieve effective friction reduction in the test, and reduce the influence of boundary friction effect on the accuracy and reliability of the test results, providing a more advanced means for geotechnical mechanics and geotechnical engineering tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a side structural schematic diagram of the present invention;

[0019] Figure 2 yes Figure 1 Schematic diagram of the structure of the middle BB section;

[0020] Figure 3 yes Figure 1 Schematic diagram of the half-section structure of the middle movable plate in direction A;

[0021] Figure 4 This is a schematic diagram of the side view structure of the present invention in working state;

[0022] In the above figure: 1-movable plate; 1.1-movable block; 2-fixed plate; 3-movable leaf spring; 4-spring shaft; 5-movable and static leaf spring; 6-spherical rolling body A; 7-spherical rolling body B; 8-sleeve; 9-spring seat; 10-friction reducing spring; 11-test specimen; 12-bearing pad. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Combined with Figure 1-4 The invention describes in detail a rolling friction reduction device for rock mechanics and geotechnical engineering tests, wherein the friction reduction device is arranged between a test specimen 11 and a bearing pad 12, and is characterized in that it comprises a movable plate 1, a fixed plate 2, an elastic connector and a rolling friction reduction body, wherein the movable plate 1 and the fixed plate 2 are stacked, and the movable plate 1 is composed of a plurality of movable blocks 1.1 arranged in an arranged manner, wherein the movable blocks 1.1 and the fixed plate 2 and the adjacent movable blocks 1.1 are respectively connected by elastic connectors, and the opposite surfaces of the movable blocks 1.1 and the fixed plate 2 and the opposite surfaces of the adjacent movable blocks 1.1 are respectively connected by elastic connectors. Corresponding rolling friction reducing bodies are provided to reduce the friction between the relative surfaces. During the test, the fixed plate 2 is abutted against the bearing pad 12, and the movable plate 1 is abutted against the test specimen 11. Since the fixed plate 2 and the movable plate 1 are independent of each other, the various movable blocks 1.1 constituting the movable plate 1 produce corresponding rolling dislocation of coordinate positions under the action of external force, elastic connecting parts and rolling friction reducing bodies, which adapts to the uneven force deformation of the boundary of the test specimen 11, converts the boundary friction into point contact rolling friction, greatly reduces the friction coefficient, reduces the boundary friction, and achieves the purpose of two-way ultra-low friction reduction.

[0025] The elastic connecting member is a spring support member. The setting of the elastic connecting member enables the fixed plate 2 and the movable block 1.1 to move relative to each other under the action of external force, and can automatically reset when the external force disappears.

[0026] The elastic connecting member includes a movable leaf spring 3, a spring shaft 4, and a movable and static leaf spring 5. The movable leaf spring 3 is arranged between adjacent movable blocks 1.1, and the movable and static leaf spring 5 is arranged between the movable block 1.1 and the fixed plate 2. The two ends of the movable leaf spring 3 are respectively connected to the adjacent movable blocks 1.1 through the spring shaft 4, and the two ends of the movable and static leaf spring 5 are respectively connected to the movable block 1.1 and the fixed plate 2 through the spring shaft 4. The movable leaf spring 3 is arranged to ensure that the adjacent movable blocks 1.1 can move relative to each other under the action of external force, and can automatically reset when the external force disappears. The movable and static leaf spring 5 is arranged to ensure that the fixed plate 2 and the movable block 1.1 can move relative to each other under the action of external force, and can automatically reset when the external force disappears. Point contact rolling friction reduction is utilized to meet the requirements of bidirectional ultra-low friction reduction. When the external force disappears, it can automatically reset to restore the friction reduction device.

[0027] The rolling anti-friction body is a spherical rolling body, and the spherical rolling body includes a spherical rolling body A6 and a spherical rolling body B7. A groove A is provided on the surface of the movable block 1.1 relative to the fixed plate 2, and the spherical rolling body A6 is embedded in the groove A, and the part of the spherical rolling body A6 away from the groove A protrudes from the groove A and contacts the fixed plate 2. A groove B is provided on the surface of the movable block 1.1 relative to the adjacent movable block 1.1, and a sleeve 8 is embedded in the groove B. The spherical rolling body B7, a spring seat 9 and a friction-reducing spring 10 are sequentially arranged in the sleeve 8 from the outside to the inside, one side of the spring seat 9 is fixedly connected to the friction-reducing spring 10, and the other side of the spring seat 9 contacts the spherical rolling body B7, and the friction-reducing spring 10 is away from the spring seat 9. One end of the seat 9 is fixed to the inner wall of the bottom of the sleeve 8 through the spring shaft 4, the anti-friction spring 10 is in a compressed state, the part of the spherical rolling body B7 away from the spring seat 9 protrudes from the groove B and contacts the adjacent movable block 1.1, and the spherical rolling body A6 ensures point-contact rolling friction reduction between the fixed plate 2 and the movable block 1.1. Due to the large pulling force of the dynamic and static leaf springs 5, the spherical rolling body A6 will not fall off from the groove A when rolling. The spherical rolling body B7 ensures point-contact rolling friction reduction between the adjacent movable blocks 1.1. The setting of the sleeve 8 and the anti-friction spring 10 prevents the spherical rolling body B7 from falling off from the groove B when subjected to a large external force. At the same time, when the external force disappears, the spherical rolling body B7 can automatically reset.

[0028] The spherical rolling element is a steel ball.

[0029] Fillers are provided between the movable block 1.1 and the fixed plate 2, between adjacent movable blocks 1.1, and between the spherical rolling body and the movable block 1.1 and the fixed plate 2. The fillers are lubricants made of lubricating materials, preferably butter, silicone oil or other greasy lubricants, which are used for lubrication and friction reduction.

[0030] The working process of the present invention is as follows:

[0031] (1) Before assembling the friction reducing device of the present invention, all parts should be strictly rinsed and the moving parts such as steel balls and springs should be coated with butter filler;

[0032] (2) After the anti-friction device is assembled, it is placed on the bearing pad 12 before the test begins. The test specimen 11 is directly placed at the center of the movable plate 1. The fixed plate 2 is used to abut against the bearing pad 12. The movable plate 1 abuts against the test specimen 11. At this time, the test has not yet started, there is no external force, and the anti-friction device does not work;

[0033] (3) Start the test. During the test, the model of the test specimen 11 may produce boundary stress deformation under the action of external force. The external force acts on the anti-friction device through the test specimen 11. At this time, the spherical rolling body A6 and the spherical rolling body B7 built in the anti-friction device roll under the action of the external force. The dynamic and static leaf springs 5, the dynamic leaf springs 3 and the anti-friction springs 10 will produce elastic deformation, causing the movable block 1.1 to produce offset rolling in the coordinate position, adapting to the unevenness of the boundary stress of the test specimen 11 model, reducing the friction coefficient, and transforming the original sliding friction between the test specimen 11 and the bearing pad 12 into point contact rolling friction and elastic deformation, effectively restoring the original stress state of the test specimen 11 and reducing the loss of the test specimen 11;

[0034] (4) After the test is completed and the external force disappears, the elastically deformed dynamic and static plate connecting spring 5, the dynamic plate connecting spring 3 and the friction reducing spring 10 will automatically reset and restore, driving the movable block 1.1 to return to the original coordinate position, thereby driving the automatic recovery of the entire friction reducing device.

[0035] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "front", "back" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention. In the present invention, it should also be noted that the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, an integrally formed connection, a mechanical connection, or an indirect connection through an intermediate medium, and the specific meaning of the terms in this utility model can be understood according to the specific circumstances.

[0036] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any reference numerals in the claims should not be regarded as limiting the claims involved.

[0037] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A rolling friction reduction device for rock mechanics and geotechnical engineering tests, the friction reduction device being arranged between a test specimen (11) and a bearing pad (12), and characterized in that: The invention comprises a movable plate (1), a fixed plate (2), an elastic connecting member and a rolling friction reducing body. The movable plate (1) and the fixed plate (2) are stacked and arranged. The movable plate (1) is composed of a plurality of movable blocks (1.1) arranged in an arranged manner. The movable blocks (1.1) and the fixed plate (2) and adjacent movable blocks (1.1) are connected respectively by elastic connecting members. The elastic connecting members comprise a movable plate spring (3), a spring shaft (4), and a movable and static plate spring (5). The movable plate spring (3) is arranged between adjacent movable blocks (1.1). The spring (5) is arranged between the movable block (1.1) and the fixed plate (2), the two ends of the movable plate spring (3) are respectively connected to the adjacent movable block (1.1) through the spring shaft (4), the two ends of the movable and stationary plate spring (5) are respectively connected to the movable block (1.1) and the fixed plate (2) through the spring shaft (4), and rolling friction reducing bodies are respectively arranged between the opposing surfaces of the movable block (1.1) and the fixed plate (2) and between the opposing surfaces of adjacent movable blocks (1.1) to reduce the friction between the opposing surfaces, and the rolling friction reducing bodies are The spherical rolling body comprises a spherical rolling body A (6) and a spherical rolling body B (7), a groove A is provided on the surface of the movable block (1.1) relative to the fixed plate (2), the spherical rolling body A (6) is embedded in the groove A, and a portion of the spherical rolling body A (6) away from the groove A protrudes out of the groove A and contacts the fixed plate (2), a groove B is provided on the surface of the movable block (1.1) relative to the adjacent movable block (1.1), a sleeve (8) is embedded in the groove B, and the sleeve (8) is sequentially provided from the outside to the inside. A spherical rolling body B (7), a spring seat (9) and a friction-reducing spring (10) are provided. The friction-reducing spring (10) is in a compressed state. One side of the spring seat (9) is fixedly connected to the friction-reducing spring (10). The other side of the spring seat (9) contacts the spherical rolling body B (7). One end of the friction-reducing spring (10) away from the spring seat (9) is fixed to the inner wall of the bottom of the groove B through a spring shaft (4). The part of the spherical rolling body B (7) away from the spring seat (9) protrudes from the groove B and contacts the adjacent movable block (1.1).

2. A rolling friction reduction device for rock mechanics and geotechnical engineering tests according to claim 1, characterized in that: The spherical rolling element is a steel ball.

3. A rolling friction reduction device for rock mechanics and geotechnical engineering tests according to claim 1, characterized in that: Fillers are provided between the movable block (1.1) and the fixed plate (2), between adjacent movable blocks (1.1), and between the spherical rolling body and the movable block (1.1) and the fixed plate (2) for lubrication and friction reduction.

4. A rolling friction reduction device for rock mechanics and geotechnical engineering tests according to claim 3, characterized in that: The filler is a lubricant made of lubricating material.

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