A quick-mount axial extensometer

Abstract

The application belongs to the technical field of rock mechanics testing, and relates to an axial extensometer capable of being quickly installed. The application comprises two clamping assemblies arranged at intervals along an axial direction and an auxiliary rod connecting the two clamping assemblies; the clamping assembly comprises a mounting shell, an inner ring rotatably mounted in the mounting shell and a clamping plate arranged in a radial sliding mode, the inner ring drives the clamping plate to radially translate through a transmission structure; a bidirectional locking assembly is arranged on the inner ring. The bidirectional locking assembly has a first state and a second state: when in the first state, the bidirectional locking assembly is expanded to the mounting shell to lock the inner ring; when in the second state, the bidirectional locking assembly releases the locking of the mounting shell and is synchronously expanded to be fixed to the end of the auxiliary rod. Through the state switching of the bidirectional locking assembly, the installation of the auxiliary rod and the unlocking of the inner ring are cooperatively operated, the synchronous clamping of the upper and lower clamping assemblies can be realized by pushing the auxiliary rod, reverse operation can lock the clamping state and remove the auxiliary rod, and the application has the advantages of high installation efficiency, good centering precision and the like.

Description

Technical Field

[0001] This invention belongs to the field of rock mechanics testing technology and relates to an axial extensometer that can be quickly installed. Background Technology

[0002] In the field of indoor rock mechanics testing equipment, the study of rock deformation characteristics has always been at the core and crucial level. As an indispensable parameter for in-depth analysis of rock mechanical properties, the accuracy of rock deformation characteristics measurement directly affects the depth and breadth of our understanding of rock mechanical behavior. In practical scientific research and experimental work, the acquisition of rock strain mainly relies on the accurate measurement of deformation sensors. Therefore, for deformation sensors to perform at their best, a suitable and efficient installation device is particularly important.

[0003] Currently, in rock mechanics testing, traditional axial extensometers require the upper clamp to be positioned and fixed first, and then the lower clamp to be installed using a positioning rod. This process is time-consuming for a single sample and necessitates multiple people working together or repeated operations by a single person. In batch rock tests, frequent step-by-step operations reduce experimental efficiency and prolong the testing cycle.

[0004] To address the above problems, this invention proposes an axial extensometer that can be installed quickly. Summary of the Invention

[0005] To address the problems existing in the background art, the present invention proposes an axial extensometer that can be installed quickly.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: an axial extensometer that can be quickly installed, comprising two clamping assemblies spaced apart and an auxiliary rod connecting the two clamping assemblies;

[0007] The clamping assembly includes a mounting shell, an inner ring, and a plurality of clamping plates that are radially slidable relative to the mounting shell. The inner ring is rotatably mounted inside the mounting shell, and the inner ring drives the plurality of clamping plates to translate radially simultaneously.

[0008] The inner ring is provided with a two-way locking component; when the two-way locking component is in the first state, it expands and tightens against the mounting shell to lock the inner ring.

[0009] When the bidirectional locking assembly switches to the second state, it releases the locking of the mounting shell and simultaneously tightens and fixes itself to the end of the auxiliary rod.

[0010] Furthermore, a top cover is fixedly provided on the mounting shell, and the inner ring is rotatably connected between the mounting shell and the top cover; the top cover has a plurality of radially extending limiting grooves, and a clamping plate is slidably provided in each limiting groove; the inner ring has inclined grooves corresponding to the limiting grooves one by one; a sliding rod is slidably provided in each inclined groove, and the sliding rod is fixedly connected to the corresponding clamping plate.

[0011] Furthermore, the outer circumferential surface of the mounting housing is symmetrically provided with clearance grooves; the bidirectional locking assembly includes a fixing rod symmetrically arranged on the outer circumferential surface of the inner ring, a threaded rod fixed to the outer end of the fixing rod, and a threaded sleeve threadedly connected to the outside of the threaded rod; the threaded rod is slidably disposed in the corresponding clearance groove.

[0012] Furthermore, the two ends of the threaded rod are respectively provided with an outer conical surface and an inner conical surface in the axial direction; the two ends of the threaded sleeve are respectively provided with a first expansion section and a second expansion section, and the first expansion section has a first inclined surface that mates with the outer conical surface, and the second expansion section has a second inclined surface that mates with the inner conical surface.

[0013] When the threaded sleeve is screwed outward, when the bidirectional locking assembly is in the first state, the inner conical surface pushes the second expansion section to expand outward and tighten between the mounting shell and the upper cover; at this time, the bidirectional locking assembly is in the first state.

[0014] When the bidirectional locking assembly switches to the second state, the threaded sleeve is screwed inward, causing the second expansion section to disengage from the inner conical surface, while the first expansion section is squeezed outward by the outer conical surface.

[0015] Furthermore, both ends of the auxiliary rod are provided with locking holes; the first expansion section of the threaded sleeve is inserted into the corresponding locking hole, and after being pushed and expanded by the outer conical surface, it comes into close contact with the inner wall of the locking hole to complete the fixation.

[0016] Furthermore, both the mounting shell and the upper cover are provided with mounting holes for mounting the extensor, and the inner ring is provided with an arc-shaped hole, with the mounting holes and the arc-shaped hole corresponding in the axial direction.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. By setting up a two-way locking component, the installation of the auxiliary rod, the unlocking and locking of the inner ring are integrated into the same screwing operation of the threaded sleeve. The operator only needs to screw the threaded sleeve once to complete both the fixing of the auxiliary rod and the unlocking of the inner ring at the same time, and screwing it in the opposite direction once can complete both the disassembly of the auxiliary rod and the locking of the inner ring at the same time, which improves the installation efficiency and the detection efficiency of rock samples.

[0019] 2. The two ends of the auxiliary rod are connected to the bidirectional locking components of the two clamping assemblies. When the auxiliary rod is pushed to rotate, the inner rings of the two clamping assemblies are forced to move synchronously, causing all clamping plates to move synchronously, thus clamping the upper and lower pressure blocks simultaneously and improving installation efficiency. Furthermore, the two clamping assemblies remain parallel throughout the entire clamping process, eliminating the need for individual leveling adjustments and avoiding uneven clamping force or measurement errors caused by misalignment.

[0020] 3. The auxiliary rod is connected to the first expansion section via a locking hole, eliminating the need for bolts or clips and allowing for quick installation and removal. Furthermore, by selecting auxiliary rods of different lengths, the distance between the two clamping components can be quickly adjusted to accommodate rock samples of varying heights.

[0021] 4. The operation process is simple and easy to understand, with fewer steps, reducing reliance on the operator's experience and improving the stability and reliability of the experiment. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 In this invention Figure 1 Enlarged view of part A;

[0024] Figure 3 This is a schematic diagram of the clamping component in this invention;

[0025] Figure 4 This is an exploded structural diagram of the mounting shell, inner ring, and upper cover in this invention;

[0026] Figure 5 This is a schematic diagram of the clamping plate in this invention;

[0027] Figure 6 This is a schematic diagram of the inner ring structure in this invention;

[0028] Figure 7 In this invention Figure 6 Enlarged view of part B;

[0029] Figure 8 This is a top view of the inner ring in this invention;

[0030] Figure 9 In this invention Figure 8 Enlarged view of part C;

[0031] Figure 10 This is a schematic diagram of the auxiliary rod of the present invention.

[0032] In the diagram: 1. Clamping assembly; 101. Mounting shell; 102. Relief groove; 103. Inner ring; 104. Inclined groove; 105. Fixing rod; 106. Threaded rod; 107. Outer conical surface; 108. Inner conical surface; 109. Threaded sleeve; 110. First expansion section; 111. Second expansion section; 112. Top cover; 113. Limiting groove; 114. Slide rod; 115. Clamping plate; 116. Mounting hole; 117. Arc-shaped hole; 2. Extensor; 3. Auxiliary rod; 4. Locking hole. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] like Figures 1-10 As shown, the technical solution adopted by the present invention is as follows: A quick-installing axial extensometer includes two clamping assemblies 1 spaced apart along the axial direction and an auxiliary rod 3 connecting the two clamping assemblies 1. In actual testing, the extensometer 2 is detachably installed between the two clamping assemblies 1 to precisely measure the relative displacement between the two clamping assemblies 1. To adapt to different testing requirements, the auxiliary rod 3 can be equipped with various lengths, allowing testers to select the appropriate length based on the axial length of the rock sample to be tested.

[0035] The two clamping components 1 have the same structure. The structure of one clamping component 1 will be described in detail below.

[0036] The clamping assembly 1 includes a mounting shell 101, a top cover 112, an inner ring 103, and multiple clamping plates 115. The mounting shell 101 is a disc-shaped shell, and its upper part is fixedly connected to the top cover 112 by screws or clips. An annular cavity is formed between the mounting shell 101 and the top cover 112, and the inner ring 103 is rotatably mounted in the annular cavity, that is, the inner ring 103 can rotate freely relative to the mounting shell 101 and the top cover 112. The mounting shell 101, the top cover 112, and the inner ring 103 are coaxially arranged.

[0037] The upper cover 112 has multiple radially extending limiting grooves 113, which penetrate the thickness direction of the upper cover 112, and are evenly distributed around the circumference of the upper cover 112. A clamping plate 115 is slidably disposed within each limiting groove 113. The inner end face of the clamping plate 115 is used to contact the outer peripheral surface of the testing machine's pressure block, thereby clamping the pressure block.

[0038] The inner ring 103 has inclined grooves 104 corresponding to the limiting grooves 113. The inclined grooves 104 form an acute angle with the radial direction of the inner ring 103, for example, 30° to 60°. That is, one end of the inclined groove 104 is inclined towards the axis of the inner ring 103. A slide rod 114 is slidably disposed in each inclined groove 104, and the slide rod 114 slides along the extension direction of the inclined groove 104. Figure 5 As shown, the upper end of the slide rod 114 is fixedly connected to the corresponding clamping plate 115. Specifically, the slide rod 114 and the clamping plate 115 can be connected by welding or threading, or they can be integrally formed.

[0039] When the inner ring 103 rotates relative to the mounting shell 101, the side wall of the inclined groove 104 pushes the slide rod 114 to move along the inclined groove 104. Since there is an angle between the inclined groove 104 and the radial direction, the slide rod 114 is displaced in the radial direction, thereby driving the clamping plate 115 to move inward or outward along the limiting groove 113 (i.e., the radial direction).

[0040] Specifically, when the inner ring 103 rotates in one direction, all clamping plates 115 move radially inward simultaneously, thereby clamping the pressure block. When the inner ring 103 rotates in the opposite direction, all clamping plates 115 move radially outward simultaneously, thereby releasing the pressure block.

[0041] A bidirectional locking assembly is provided on the inner ring 103. Two relief grooves 102 are symmetrically formed on the outer circumferential surface of the mounting shell 101, which radially penetrate the side wall of the mounting shell 101 to accommodate the bidirectional locking assembly. When the bidirectional locking assembly is in the first state, it expands and tightens against the mounting shell 101 to lock the inner ring 103. When the bidirectional locking assembly switches to the second state, it releases the lock on the mounting shell 101 and simultaneously expands and tightens to fix itself to the end of the auxiliary rod 3.

[0042] In this embodiment, the bidirectional locking assembly includes two fixing rods 105 symmetrically arranged on the outer circumferential surface of the inner ring 103, a threaded rod 106, and a threaded sleeve 109 threadedly connected to the threaded rod 106. The fixing rods 105 extend radially outward along the inner ring 103, and their inner ends are fixedly connected to the inner ring 103. Each fixing rod 105 has a threaded rod 106 fixedly connected to its outer end, and the threaded rod 106 is coaxially arranged with the corresponding fixing rod 105. The threaded rod 106 has an external thread.

[0043] The threaded rod 106 is slidably disposed in the relief groove 102 of the mounting housing 101. The threaded rod 106 can move within the relief groove 102 along the rotation direction of the inner ring 103, thereby allowing the inner ring 103 to rotate within a certain angle range without being interfered with by the mounting housing 101.

[0044] The threaded rod 106 has an outer conical surface 107 at the end furthest from the inner ring 103, i.e., the outer end, and the diameter of the outer conical surface 107 gradually decreases in the direction away from the inner ring 103. The threaded rod 106 has an inner conical surface 108 at the end closest to the inner ring 103, i.e., the inner end, and the diameter of the inner conical surface 108 gradually decreases in the direction close to the inner ring 103.

[0045] The threaded sleeve 109 is a hollow sleeve open at both ends, with internal threads on its inner wall to mate with the external threads of the threaded rod 106. For example... Figure 7 As shown, the threaded sleeve 109 has a first expansion section 110 and a second expansion section 111 at its two ends. The first expansion section 110 is located at the end of the threaded sleeve 109 away from the inner ring 103, and the second expansion section 111 is located at the end of the threaded sleeve 109 closer to the inner ring 103. Both the first expansion section 110 and the second expansion section 111 are axially slotted elastic claw structures that can expand or contract radially when subjected to force.

[0046] The first expansion section 110 has a first inclined surface inside that mates with the outer conical surface 107, and the taper of the first inclined surface matches the taper of the outer conical surface 107. The second expansion section 111 has a second inclined surface inside that mates with the inner conical surface 108, and the taper of the second inclined surface matches the taper of the inner conical surface 108.

[0047] When the threaded sleeve 109 is screwed onto the threaded rod 106, its axial position changes, thereby altering the contact state between the first expansion section 110 and the outer conical surface 107, as well as the contact state between the second expansion section 111 and the inner conical surface 108.

[0048] Both ends of the auxiliary rod 3 are provided with locking holes 4, which cooperate with the first expansion section 110 of the threaded sleeve 109, allowing the first expansion section 110 to be smoothly inserted into the locking hole 4. Furthermore, when the first expansion section 110 expands, it abuts against the inner wall of the locking hole 4, thereby connecting the auxiliary rod 3 and the threaded sleeve 109 together, connecting the two clamping assemblies 1 together, and keeping the two clamping assemblies 1 parallel.

[0049] The second expansion section 111 is used to mate with the mounting housing 101 and the top cover 112. When the second expansion section 111 expands, it abuts against the mounting housing 101 and the top cover 112, thereby locking the inner ring 103 onto the mounting housing 101 and preventing the inner ring 103 from rotating relative to the mounting housing 101.

[0050] To facilitate the axial through-mounting of the extensor 2, such as Figure 3 and Figure 4As shown, both the mounting housing 101 and the top cover 112 have axially aligned mounting holes 116. Correspondingly, the inner ring 103 has a corresponding arc-shaped hole 117. During installation, the extender 2 can pass through the arc-shaped hole 117 and eventually extend into the mounting hole 116 on the mounting housing 101. Because the arc-shaped hole 117 provides circumferential clearance, even when the inner ring 103 rotates a certain angle relative to the mounting housing 101, the extender 2 can still pass through the arc-shaped hole 117 and extend into the mounting hole 116 on the mounting housing 101.

[0051] Working principle: Initially, the bidirectional locking assembly is in the first state. At this time, the second expansion section 111 of the threaded sleeve 109 is rotated outward to the maximum distance. Under the action of the inner conical surface 108, the second expansion section 111 is in an open state. The second expansion section 111 is tightened between the mounting shell 101 and the top cover 112 to lock the inner ring 103, prevent the inner ring 103 from rotating, and prevent the clamping plate 115 from sliding accidentally, thereby facilitating the transportation and transfer of the clamping assembly 1.

[0052] When testing is required, first select a suitable auxiliary rod 3 according to the length of the rock sample to be tested. When installing the auxiliary rod 3, fit the locking hole 4 of the auxiliary rod 3 onto the first expansion section 110 of the corresponding threaded sleeve 109. Next, use a screwdriver to insert into the slot at the end of the first expansion section 110 and screw the threaded sleeve 109 to move it closer to the inner ring 103 (i.e., inward). At this time, the second expansion section 111 gradually disengages from the inner conical surface 108, releasing the tension on the mounting shell 101 and the top cover 112, and the inner ring 103 returns to a state of free rotation.

[0053] Simultaneously, the first expansion section 110 gradually fits onto the outer conical surface 107, which forces the first expansion section 110 to expand radially, making the outer peripheral surface of the first expansion section 110 in close contact with the inner wall of the locking hole 4, thus completing the connection between the auxiliary rod 3 and the clamping assembly 1. At this time, the bidirectional locking assembly is in the second state.

[0054] Since the length of the auxiliary rod 3 is fixed and both ends are rigidly connected to the clamping assembly 1, the mounting shells 101 and the top cover 112 of the two clamping assemblies 1 are forced to remain parallel to each other and with a fixed distance, without the need for additional centering adjustment.

[0055] Next, the rock sample to be tested is placed between the upper and lower pressure blocks of the testing machine (not shown in the figure). Then, the assembled extensometer is placed over the upper pressure block, the rock sample, and the lower pressure block, so that the upper clamping component 1 is located on the outer periphery of the upper pressure block and the lower clamping component 1 is located on the outer periphery of the lower pressure block.

[0056] Subsequently, the auxiliary rod 3 is pushed by hand to rotate relative to the mounting housing 101 around the central axis of the extensometer. Since the auxiliary rod 3 is fixedly connected to the inner ring 103 through the first expansion section 110, threaded sleeve 109, threaded rod 106, and fixing rod 105, the rotation of the auxiliary rod 3 will drive the inner rings 103 on both sides to rotate synchronously in the same direction. When the inner ring 103 rotates, the inclined groove 104 on it pushes the slide rod 114 to slide along the inclined groove 104. Due to the guiding effect of the inclined groove 104, the slide rod 114 drives the clamping plate 115 to move inward along the limiting groove 113. As the auxiliary rod 3 continues to push, all the clamping plates 115 synchronously retract inward until the upper clamping plate 115 clamps the outer peripheral surface of the upper pressure block, and the lower clamping plate 115 clamps the outer peripheral surface of the lower pressure block. At this time, the two clamping components 1 complete the clamping action simultaneously, and due to the forced constraint of the auxiliary rod 3, the two clamping components 1 always remain parallel and do not need to be adjusted one by one.

[0057] To facilitate observation of the horizontal state, a level (not shown in the figure) can be installed on the side of the mounting housing 101 or the top cover 112. Only the level on one of the clamping components 1 needs to be observed. Moreover, both clamping components 1 clamp simultaneously, effectively improving the installation efficiency of the extensometer.

[0058] After the clamping plate 115 clamps the pressure block, use a screwdriver to unscrew the threaded sleeve 109 in the opposite direction to move it outward. At this time, the first expansion section 110 disengages from the outer conical surface 107 and contracts radially, releasing the tension connection with the locking hole 4, and the auxiliary rod 3 can be easily removed. Simultaneously, the second expansion section 111 re-contacts with the inner conical surface 108 and is stretched open, tightening again between the mounting shell 101 and the upper cover 112, locking the inner ring 103, so that the clamping plate 115 remains in a clamping state on the pressure block and will not loosen.

[0059] Then, the extensor 2 is installed between the two clamping components 1, and then the external testing machine can be started to conduct the testing experiment on the rock sample.

[0060] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An axial extensometer that can be quickly installed, characterized in that: It includes two clamping components (1) spaced apart and an auxiliary rod (3) connecting the two clamping components (1); The clamping assembly (1) includes a mounting shell (101), an inner ring (103), and a plurality of clamping plates (115) that are radially slidably disposed relative to the mounting shell (101). The inner ring (103) is rotatably mounted inside the mounting shell (101), and the inner ring (103) drives the plurality of clamping plates (115) to translate radially simultaneously. A two-way locking assembly is provided on the inner ring (103); when the two-way locking assembly is in the first state, it expands against the mounting shell (101) to lock the inner ring (103); When the bidirectional locking assembly switches to the second state, it releases the lock on the mounting shell (101) and simultaneously tightens and fixes itself to the end of the auxiliary rod (3).

2. The axial extensometer that can be quickly installed according to claim 1, characterized in that: A top cover (112) is fixedly installed on the mounting shell (101), and an inner ring (103) is rotatably connected between the mounting shell (101) and the top cover (112). The top cover (112) has a plurality of radially extending limiting grooves (113), and a clamping plate (115) is slidably installed in each limiting groove (113). The inner ring (103) has inclined grooves (104) that correspond one-to-one with the limiting grooves (113). A sliding rod (114) is slidably installed in each inclined groove (104), and the sliding rod (114) is fixedly connected to the corresponding clamping plate (115).

3. The axial extensometer that can be quickly installed according to claim 2, characterized in that: The mounting housing (101) has symmetrical relief grooves (102) on its outer peripheral surface; the bidirectional locking assembly includes a fixed rod (105) symmetrically arranged on the outer peripheral surface of the inner ring (103), a threaded rod (106) fixed to the outer end of the fixed rod (105), and a threaded sleeve (109) threadedly connected to the outside of the threaded rod (106); the threaded rod (106) is slidably arranged in the corresponding relief groove (102).

4. The axial extensometer that can be quickly installed according to claim 3, characterized in that: The threaded rod (106) has an outer conical surface (107) and an inner conical surface (108) axially arranged at both ends; the threaded sleeve (109) has a first expansion section (110) and a second expansion section (111) at both ends, and the first expansion section (110) has a first inclined surface that mates with the outer conical surface (107) inside, and the second expansion section (111) has a second inclined surface that mates with the inner conical surface (108) inside; When the threaded sleeve (109) is screwed outward, the inner conical surface (108) pushes the second expansion section (111) to expand outward and tighten between the mounting shell (101) and the upper cover (112); at this time, the bidirectional locking assembly is in the first state; When the bidirectional locking assembly switches to the second state, the threaded sleeve (109) is screwed inward, causing the second expansion section (111) to disengage from the inner conical surface (108), while the first expansion section (110) is squeezed outward by the outer conical surface (107).

5. An axial extensometer that can be quickly installed according to claim 4, characterized in that: Both ends of the auxiliary rod (3) are provided with locking holes (4); the first expansion section (110) of the threaded sleeve (109) is inserted into the corresponding locking hole (4), and after being pushed and expanded by the outer conical surface (107), it is in close contact with the inner wall of the locking hole (4) to complete the fixation.

6. The axial extensometer that can be quickly installed according to claim 2, characterized in that: The mounting shell (101) and the upper cover (112) are both provided with mounting holes (116) for mounting the extensor (2), and the inner ring (103) is provided with an arc-shaped hole (117). The mounting holes (116) and the arc-shaped hole (117) are axially aligned.

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