Rock compression-resistant end face flatness testing device

Abstract

The utility model relates to the technical field of rock engineering experiments, and mainly discloses a rock compression-resistant end face flatness testing device, which comprises a leveling base, a vertical rod, a dial indicator and a sample clamp, leveling bolts are arranged at four corners of the base to establish an absolute horizontal reference plane, the vertical rod is vertically fixed on the base, and the sample clamp is connected with a fixed seat through a rotating rod. Clamping bolts which are uniformly distributed in the circumferential direction of the rotating rod are adaptive to fixation of test pieces with different sizes, the dial indicator is mounted on the sliding seat through a three-axis universal bracket, a ball is embedded at the tail end of a measuring head to reduce friction loss, a spring locking mechanism is arranged in the rotating rod, and the rotating rod is self-locked and positioned after being pressed and rotated; according to the utility model, the height difference interference of the test piece is eliminated through the reference surface separation design, the double-end-face rapid detection is realized by combining the overturning clamping mechanism, the problems of reference surface deviation, tedious operation and easy damage of the measuring head in the traditional method are solved, and the rock end face flatness detection precision and efficiency are obviously improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of rock engineering experiment, concretely is a rock compressive end face flatness testing arrangement. BACKGROUND

[0002] Rock uniaxial compressive strength test is the core test project in the field of geotechnical engineering, and its precision directly affects engineering safety evaluation. According to the requirements of "Highway Engineering Rock Test Regulations" JTG 3431-2024, the end face flatness tolerance of the test piece needs to be less than 0.05mm. Flatness refers to the state that all elements of a surface are on a plane, and the tolerance control of flatness 0.05mm required by "Highway Engineering Rock Test Regulations" is the form and position tolerance that limits the allowable uneven error of a surface.

[0003] The conventional operation directly places the test piece on the detection platform, first determines the height of the test piece, measures the height difference of multiple points by moving the dial gauge to determine the flatness, and then reverses the test piece and repeats the above operation. The height range is required to be less than 0.05mm, so as to ensure that the rock test piece meets the requirements. Two kinds of devices for detecting rock flatness disclosed in Chinese invention patents CN117329954A and CN106247908B both directly measure the flatness by placing the test piece directly on the detection platform.

[0004] In the actual rock cutting and grinding process, it is very small that the two compressive planes are completely parallel, and the actual parallel error exceeds 0.5mm. This direct placement on the platform test method, the inclination of the platform contact surface will cause the measurement reference surface to deviate from the theoretical plane, so that the flatness measurement value contains the system error introduced by the overall height difference of the test piece, so that the flatness is measured to be larger, and even exceeds the requirement.

[0005] The current standard requires that the test piece needs to be repeatedly turned over and measured multiple times for verification, and the clamping mechanism of the prior art cannot realize the rapid turning and positioning of the test piece. The operator needs to manually release the clamp, adjust the angle of the test piece, and then fix it again, which takes a long time to detect.

[0006] In addition, the traditional dial gauge probe is a rigid contact structure, which is subjected to friction resistance and vibration impact when sliding on the rock surface, causing the measuring rod to deform and even the internal gear set to be stuck. Especially for test pieces containing quartz, feldspar and other hard minerals, the wear rate of the probe is significantly increased. UTILITY MODEL CONTENTS

[0007] The utility model discloses a rock compression resistance end face flatness testing device which establishes an absolute horizontal reference plane through a leveling base, clamps the test piece through a sample clamp that is turned over by 180 degrees, and the turned over test surface is parallel to the absolute horizontal reference plane as a measurement reference, so that the height difference caused by the non-parallel test piece can be eliminated, and the sample clamp is convenient to turn over, the ball type measuring head is not easy to be damaged, and the measurement accuracy of the dial gauge is improved.

[0008] To achieve the above object, the utility model adopts the following technical scheme: a rock compression resistance end face flatness testing device, which comprises a base, a vertical rod, a dial gauge and a sample clamp.

[0009] Through the above technical scheme, the horizontal bubble is placed above the base, the absolute horizontal reference plane is established through the leveling bolts at the bottom of the base, then the second sliding seat is slid to the bottom and fixed, the bottom surface of the sample clamp contacts or does not contact the upper plane of the base, then the test piece is placed in the sample clamp, the test piece is clamped and fixed through the sample clamp, at this time, the bottom surface of the test piece can be ensured to be parallel to the plane of the base, then the second sliding seat is vertically slid along the vertical rod, after being vertically moved to the appropriate position, the rotating rod at one end of the sample clamp is adjusted, so that the sample clamp is turned over by 180 degrees, the bottom surface of the test piece is turned over as the test surface, at this time, the test surface can be ensured to be parallel to the absolute horizontal reference plane, so the measurement result of the test surface is the accurate value of the flatness of the end surface of the test piece.

[0010] The further scheme of the utility model is that the sample clamp is cylindrical, and a plurality of clamping bolts are vertically and circumferentially arranged on the side wall of the sample clamp along the radial direction.

[0011] Preferably, the clamping bolt is provided with four clamping bolts.

[0012] The further scheme of the utility model is that a plurality of guide rails are circumferentially arranged on the side wall of the vertical rod along the axial direction of the vertical rod, and corresponding guide grooves are arranged in the first sliding seat and the second sliding seat, and the guide rails are matched with the guide grooves.

[0013] Preferably, the guide rail and the guide groove are both provided as two.

[0014] Further scheme of the utility model lies in, the ball is embedded in the measuring head bottom end of dial gauge, and the measuring head bottom end is provided with lock nut, the opening degree of measuring head bottom end is adjusted through the lock nut, and the tightness of ball is adjusted and the ball is replaced.

[0015] Further scheme of the utility model lies in, the universal support includes first connecting rod, second connecting rod and third connecting rod, one end of first connecting rod is connected with first sliding seat universally, the other end of first connecting rod is rotatably connected with one end of second connecting rod, the other end of second connecting rod is universally connected with one end of third connecting rod, and the other end of third connecting rod is provided with vertical hole for installing dial gauge.

[0016] Further scheme of the utility model lies in, the rotating rod is provided with guide cylinder, the guide cylinder is arranged along the diameter direction of rotating rod, the guide cylinder is provided with spring inside, the both ends of guide cylinder are provided with locking head, the locking head is slidably connected with guide cylinder, one end of locking head extends outside rotating rod, and the other end of locking head is limited in guide cylinder, the fixing base is provided with positioning hole corresponding with locking head, and locking head is convenient to extend.

[0017] Further scheme of the utility model lies in, the first sliding seat is provided with lock bolt between the first sliding seat and the vertical rod, the second sliding seat is provided with lock bolt between the second sliding seat and the vertical rod, and the rotating rod is provided with lock bolt between the rotating rod and the fixing base, and the tightness between the two is adjusted through the lock bolt.

[0018] Compared with the prior art, the utility model has the advantages of:

[0019] The utility model provides a kind of rock compression end face flatness testing device, and the influence of the height difference of test piece itself on measurement is completely isolated by establishing absolute horizontal datum plane by leveling bolt.Sample clamp 180 ° overturn, and the surface to be measured is automatically parallel to datum plane, eliminate the virtual increase of measurement value caused by test piece inclination in traditional method, ensure that flatness detection result truly reflects end face appearance;The independent adjustment function of four groups of clamping bolts makes the device compatible with the flatness detection of various shapes test pieces such as cylinder and cube;Locking mechanism between rotating rod and fixing base realizes the single-action overturning of sample clamp "pressing-rotating-self locking", shortens positioning operation time, cooperates with the quick positioning function of universal support, and single end face multi-point measurement can be completed within 2 minutes, which significantly improves batch detection efficiency;Ball structure at the bottom of measuring head converts sliding friction into rolling friction, reduces the wear rate of measuring head, and improves detection accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a front view of the testing device of this utility model;

[0022] Figure 2 This is a top view of the testing device of this utility model;

[0023] Figure 3 This is a side view of the testing device of this utility model;

[0024] Figure 4 This utility model Figure 2 A cross-sectional view along the AA direction;

[0025] Figure 5 This utility model Figure 4 A magnified view of a portion of point A in the middle;

[0026] Figure 6 This utility model Figure 4 A magnified view of a portion of point B in the middle.

[0027] In the diagram, 1. Base; 2. Leveling bolt; 3. Upright pole; 4. Universal bracket; 5. Dial indicator; 6. First sliding seat; 7. Second sliding seat; 8. Fixed seat; 9. Rotating rod; 10. Sample clamp; 11. Locking bolt; 12. Clamping bolt; 13. Level bubble; 14. First connecting rod; 15. Second connecting rod; 16. Third connecting rod; 17. Guide rail; 18. Specimen; 19. Probe; 20. Ball bearing; 21. Locking nut; 22. Guide cylinder; 23. Spring; 24. Locking head; 25. Guide groove. Detailed Implementation

[0028] A rock compressive end face flatness testing device includes a base 1, a pole 3, a dial indicator 5, and a sample clamp 10.

[0029] like Figure 1 As shown, the base 1 is square, and leveling bolts 2 are provided at the four corners of the base 1. The upright 3 is perpendicular to the base 1 and fixed above the base 1. The level bubble 13 can be placed directly in the center of the base 1 or integrated into the groove in the center of the base 1. The base 1 and the upright 3 are connected by a flange embedded connection, and six bolts are evenly distributed around the circumference of the flange to ensure that the error between the axis of the upright 3 and the reference plane of the base 1 is ≤0.01°.

[0030] The dial gauge 5 is installed on the first sliding seat 6 through the universal support 4, and the first sliding seat 6 is arranged above the vertical rod 3. The first sliding seat 6 is in sliding connection with the vertical rod 3.

[0031] Specifically, as shown in the figure, Figure 4 The universal support 4 comprises a first connecting rod 14, a second connecting rod 15 and a third connecting rod 16. One end of the first connecting rod 14 is in universal connection with the first sliding seat 6, and the other end of the first connecting rod 14 is in rotary connection with one end of the second connecting rod 15. The other end of the second connecting rod 15 is in universal connection with one end of the third connecting rod 16, and the other end of the third connecting rod 16 is provided with a vertical hole for installing the dial gauge 5. The first connecting rod 14 is connected with the first sliding seat 6 through a ball hinge, and a rotary joint with a scale disc is arranged between the second connecting rod 15 and the third connecting rod 16.

[0032] As shown in the figure, Figure 1 , Figure 2 One end of the sample clamp 10 is provided with a rotary rod 9, and the other end of the rotary rod 9 is in rotary connection with a fixed seat 8. The fixed seat 8 is arranged on a second sliding seat 7, and the second sliding seat 7 is arranged below the first sliding seat 6. The second sliding seat 7 is in sliding connection with the vertical rod 3. Specifically, the sample clamp 10 is made of cylindrical carbon steel, and a plurality of clamping bolts 12 are vertically and circumferentially arranged on the side wall of the sample clamp 10 along the radius direction. In this embodiment, the clamping bolts 12 are provided with four groups. The four groups of clamping bolts 12 are circumferentially and uniformly distributed at an angle of 90° along the sample clamp 10, and the ends of the bolts are provided with buffer washers. The device is suitable for non-destructive clamping of cylindrical specimens 18 with a diameter of φ50-80mm and a height-diameter ratio of 2.0 and cubic specimens 18 with a diameter of 50-70mm.

[0033] As shown in the figure, Figure 2 A plurality of guide rails 17 are circumferentially and uniformly arranged on the side wall of the vertical rod 3 along the axis direction of the vertical rod 3, and corresponding guide grooves 25 are arranged in the first sliding seat 6 and the second sliding seat 7. The guide rails 17 are matched with the guide grooves 25.

[0034] Preferably, the guide rails 17 and the guide grooves 25 are both provided with two groups. Specifically, the surface of the vertical rod 3 is processed with double-row square guide rails 17, and the surface of the guide rails 17 is plated with hard chromium. The inner part of the sliding seat is provided with a matching guide groove 25, so as to ensure that the first sliding seat 6 and the second sliding seat 7 are in over-positioning constraint when moving up and down.

[0035] As shown in the figure, Figure 5As shown, the bottom end of the measuring head 19 of the dial gauge 5 is provided with a ball 20. Specifically, the ball 20 is embedded in the bottom end of the measuring head 19 of the dial gauge 5, and the bottom end of the measuring head 19 is provided with a locking nut 21. The bottom end face of the measuring head 19 is provided with a spherical groove, and the outer wall of the bottom of the measuring head 19 is symmetrically slotted at both ends to allow the bottom of the measuring head 19 to be opened and closed. The ball 20 is placed in the spherical groove, and the upper end of the bottom of the measuring head 19 is threaded. The locking nut 21 is threadedly connected to the upper end of the bottom of the measuring head 19. The opening degree of the bottom end of the measuring head 19 is adjusted by the locking nut 21, which is used to adjust the tightness of the ball 20 and replace the ball 20.

[0036] As shown in the drawings, Figure 6 As shown, the rotating rod 9 is provided with a guide cylinder 22, which is arranged along the diameter direction of the rotating rod 9. The guide cylinder 22 is provided with a spring 23 inside. The two ends of the guide cylinder 22 are provided with locking heads 24, which are slidably connected with the guide cylinder 22. One end of the locking head 24 extends out of the rotating rod 9, and the other end of the locking head 24 is limited in the guide cylinder 22. The fixed seat 8 is provided with a positioning hole corresponding to the locking head 24, which facilitates the extension of the locking head 24. The locking head 24 is made of tungsten steel, and the end is processed into a 120° conical surface, which forms a self-centering locking with the positioning hole of the fixed seat 8. When the sample clamp 10 is turned over, the locking head 24 is compressed and retracted, and after being rotated by 180°, the spring 23 pushes the locking head 24 to embed into the positioning hole, realizing zero-gap positioning.

[0037] The first sliding seat 6 and the vertical rod 3, the second sliding seat 7 and the vertical rod 3, and the rotating rod 9 and the fixed seat 8 are all provided with locking bolts 11, which are used to adjust the tightness between the two.

[0038] Through the above technical scheme, the operation process of the device is as follows: first, place the horizontal bubble 13 above the base 1, and place the horizontal bubble 13 in the center of the base 1, and observe the position of the bubble. If the bubble deviates from the central area, adjust the four corner leveling bolts 2 in turn until the bubble is stably positioned in the central ring. An absolute horizontal reference surface is established through the leveling bolts 2 at the bottom of the base 1.

[0039] Then, slide the second sliding seat 7 to the bottom and fix it, so that the bottom surface of the sample clamp 10 contacts or does not contact the upper plane of the base 1. Then, place the test piece 18 in the sample clamp 10, clamp and fix the test piece 18 through the sample clamp 10, loosen the clamping bolts 12, and place the test piece 18 into the inner cavity of the sample clamp 10. Tighten the clamping bolts 12 in diagonal order until the gasket is slightly deformed.

[0040] At this time, the bottom surface of the test piece 18 is parallel to the plane of the base 1, and then the second sliding seat 7 is vertically slid along the vertical rod 3, and after being vertically moved to a suitable position, the rotating rod 9 at one end of the test sample clamp 10 is adjusted to make the test sample clamp 10 flip by 180°, the test sample clamp 10 is pressed downward to lock the head 24, and the locking head 24 is compressed back to the guide cylinder 22. The test sample clamp is rotated counterclockwise by 180° until a "click" sound is heard, the locking head 24 is popped out under the action of the spring 23, and is embedded in the positioning hole of the fixed seat 8 to complete self-locking, and the bottom surface of the test piece 18 is flipped as a to-be-measured surface, at this time, it can be ensured that the to-be-measured surface is parallel to the absolute horizontal reference surface;

[0041] Therefore, the measurement result of the to-be-measured surface is the accurate value of the flatness of the end surface of the test piece 18. Then the first sliding seat 6 is moved, the first sliding seat 6 is slid to the upper part of the vertical rod 3, and the rotating joint locking knob of the universal support 4 is loosened. The angle of the second connecting rod 15 is adjusted, the ball 20 of the measuring head 19 of the dial gauge 5 lightly touches the center of the to-be-measured surface of the test piece 18. The locking nut 21 is tightened to fix the first sliding seat 6;

[0042] The dial gauge 5 is adjusted to 0 or the initial value is recorded, and then the dial gauge 5 is moved on the end surface of the test piece 18 and the value is read, and five detection points (center + four quarter points) are selected along the circumference of the end surface of the test piece 18. The position of the dial gauge 5 is adjusted by adjusting the third connecting rod 16 one by one, the values of the dial gauge 5 at each point are recorded, and the difference between the maximum value and the minimum value is the flatness of the end surface;

[0043] After testing the to-be-measured surface, the above operation is repeated to test the other end surface.

[0044] It is obvious for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the claims involved.

Claims

1. A device for testing the flatness of a rock compressive end face, characterized in that: The device includes a base (1), a pole (3), a dial indicator (5), and a sample holder (10). The base (1) has leveling bolts (2) at its four corners. The pole (3) is perpendicular to the base (1) and fixed above it. The dial indicator (5) is mounted on a first sliding seat (6) via a universal bracket (4). The first sliding seat (6) is located above the pole (3) and is slidably connected to the pole (3). One end of the sample holder (10) is provided with a rotating rod (9), and one end of the rotating rod (9) is rotatably connected to a fixed seat (8). The fixed seat (8) is located on a second sliding seat (7). The second sliding seat (7) is located below the first sliding seat (6) and is slidably connected to the pole (3). The bottom end of the probe (19) of the dial indicator (5) is provided with a ball bearing (20).

2. The rock compressive strength end face flatness testing device according to claim 1, characterized in that: The sample holder (10) is cylindrical, and multiple clamping bolts (12) are arranged perpendicularly to the radial direction and evenly distributed around the circumference on the side wall of the sample holder (10).

3. The rock compressive strength end face flatness testing device according to claim 2, characterized in that: The clamping bolts (12) are provided in four pieces.

4. The rock compressive strength end face flatness testing device according to claim 1, characterized in that: Multiple guide rails (17) are evenly distributed around the side wall of the upright (3) along the axial direction of the upright (3). The first sliding seat (6) and the second sliding seat (7) are provided with corresponding guide grooves (25), and the guide rails (17) cooperate with the guide grooves (25).

5. The rock compressive strength end face flatness testing device according to claim 4, characterized in that: The guide rail (17) and guide groove (25) are both set to 2.

6. The rock compressive strength end face flatness testing device according to claim 1, characterized in that: The ball (20) is embedded in the bottom end of the probe (19) of the dial indicator (5), and the bottom end of the probe (19) is provided with a locking nut (21).

7. A rock compressive strength end face flatness testing device according to any one of claims 1-6, characterized in that: The universal bracket (4) includes a first link (14), a second link (15) and a third link (16). One end of the first link (14) is universally connected to the first sliding seat (6), the other end of the first link (14) is rotatably connected to one end of the second link (15), the other end of the second link (15) is universally connected to one end of the third link (16), and a dial indicator (5) is vertically installed on the other end of the third link (16).

8. The rock compressive strength end face flatness testing device according to claim 1, characterized in that: The rotating rod (9) is provided with a guide cylinder (22), which is arranged along the diameter direction of the rotating rod (9). A spring (23) is provided inside the guide cylinder (22), and locking heads (24) are provided at both ends of the guide. The locking heads (24) are slidably connected to the guide cylinder (22).

9. The rock compressive strength end face flatness testing device according to claim 1, characterized in that: Locking bolts (11) are provided between the first sliding seat (6), the second sliding seat (7) and the upright (3), and between the rotating rod (9) and the fixed seat (8).

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