High-precision earthwork compactness detection device for water conservancy project

Abstract

The invention discloses a hydraulic engineering high-precision earthwork compactness detection device, and relates to the technical field of hydraulic engineering, and the hydraulic engineering high-precision earthwork compactness detection device specifically comprises a bearing plate, a positioning groove is formed in the upper surface of one side of the bearing plate, a soil sampling cutting ring is movably connected to the inner wall of the positioning groove, and positioning plates are symmetrically and fixedly mounted on the upper surface of one side of the bearing plate; movable plates are slidably mounted on the inner walls of the two positioning plates, and mounting rods are fixedly mounted on the outer walls of one sides of the two movable plates. According to the soil sampling device, the connecting plate is arranged on the upper surface of the movable plate and connected with the bottom of the extension spring, the bearing disc can be driven to be attached to the bottom of the soil sampling cutting ring through the acting force of the extension spring, and a soil sample can be effectively prevented from scattering from the bottom in the process that the soil sampling cutting ring completes soil sampling and moves upwards; the quality accuracy degree of earthwork sampling is ensured, and the acquisition accuracy of earthwork compactness data can be effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of water conservancy engineering, and in particular to a high-precision earthwork compaction degree detection device for water conservancy engineering. Background Art

[0002] Water conservancy projects are projects used to control and allocate natural surface water and groundwater. They are built for the purpose of eliminating harm and promoting benefits. By building various hydraulic structures such as dams, dikes, spillways, etc., they achieve multiple goals such as flood control, irrigation, power generation, water supply and shipping. Earth compaction detection is a key step to ensure the quality of water conservancy earthwork projects. The sampling process needs to represent the actual situation of the earthwork project to avoid damaging the structure of the earthwork. The selection of sampling sites should take into account the uniformity and typicality of the earthwork, and the number should be determined according to the scale of the project to ensure the reliability of the test results.

[0003] The earth compaction detection device for water conservancy projects in the prior art usually adopts the form of manual direct soil sampling operation in the process of detecting and sampling the earth compaction in the water conservancy project area. During the upward movement of the soil sample extraction ring knife, the soil sample is easily scattered along the bottom of the ring knife, which reduces the accuracy of obtaining the earth compaction data. The upward movement speed uniformity of the soil sample extraction mechanism is poor, which reduces the stability of soil sample extraction. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a high-precision earth compaction detection device for water conservancy projects, which has the advantages of high soil sample extraction accuracy, high degree of automation and high upward stability of the extraction mechanism. It solves the problem that during the upward movement of the soil sample extraction ring knife, the soil sample is easily scattered along the bottom of the ring knife, which reduces the accuracy of obtaining earth compaction data, and the upward movement speed uniformity of the soil sample extraction mechanism is poor, which reduces the stability of soil sample extraction.

[0005] In order to achieve the above-mentioned purposes of high soil sample extraction accuracy, high degree of automation and high upward stability of the extraction mechanism, the present invention provides the following technical solution: it includes a receiving plate, a positioning groove is provided on the upper surface of one side of the receiving plate, and a soil extracting ring knife is movably connected to the inner wall of the positioning groove, and a positioning plate is symmetrically fixedly installed on the upper surface of one side of the receiving plate, and a movable plate is slidably installed on the inner walls of the two positioning plates, and a mounting rod is fixedly installed on the outer wall of one side of the two movable plates, and the ends of the two mounting rods are rotatably connected to the movable rod, and a receiving plate is fixedly installed on the outer wall of one side of the movable rod, and a limiting groove is symmetrically provided on the upper surface of one side of the receiving plate, and a support plate is fixedly installed on the top of the outer wall of the two positioning plates, and a mounting plate is fixedly installed on the inner upper surface of the two support plates, and a tension spring is provided on the lower surface of the two mounting plates, and a connecting plate is fixedly installed on the upper surface of the two movable plates, and the two connecting plates are connected to the bottom of the tension spring.

[0006] Preferably, a positioning rod is fixedly installed on the upper surface of the receiving plate, and a connecting column is fixedly installed on the middle part of the upper surface of the soil extracting ring knife.

[0007] Preferably, a lifting plate is fixedly mounted on the top end of the connecting column, and positioning holes are symmetrically provided on the upper surface of the lifting plate.

[0008] Preferably, the lower surface of the receiving plate is symmetrically provided with motors, and the upper surface of the lifting plate is symmetrically provided with nuts.

[0009] Preferably, the ends of the output shafts of the two motors are fixedly mounted with lead screws, and the two lead screws are matched with nuts.

[0010] Preferably, a top plate is symmetrically fixedly mounted on the top of the positioning rod, and a positioning ring is fixedly mounted on the lower surface of one side of the two top plates.

[0011] Preferably, a handle is symmetrically fixedly installed on the top of the outer wall of the receiving plate, an extension plate is symmetrically fixedly installed on the bottom of the outer wall of the receiving plate, and positioning sleeves are fixedly installed inside a plurality of the extension plates.

[0012] Preferably, a metal plate is movably connected to the top of the plurality of positioning sleeves, a buried nail is fixedly installed on the lower surface of the plurality of metal plates, and a mounting shaft is rotatably installed on the inner wall of one side of the plurality of extension plates.

[0013] Preferably, a pedal is fixedly mounted on the top of the outer wall on one side of the plurality of installation shafts, and a linkage plate is fixedly mounted on the outer wall on one side of the plurality of installation shafts away from the pedal.

[0014] Preferably, anti-slip strips are symmetrically fixedly installed on the upper surfaces of the plurality of pedals, and positioning blocks are symmetrically fixedly installed on the top of the inner wall of one side of the plurality of extension plates.

[0015] Compared with the prior art, the present invention provides a high-precision earthwork compaction detection device for water conservancy projects, which has the following beneficial effects: 1. The high-precision earth compaction detection device for water conservancy projects is used to support and position the tension spring by arranging a support plate on the top of the positioning plate and cooperating with the mounting plate. A connecting plate is arranged on the upper surface of the movable plate and connected to the bottom of the tension spring. Through the action of the tension spring, the receiving plate can be driven to keep the bottom of the soil sampling ring knife in a fitted state, which can effectively prevent the soil sample from scattering from the bottom of the soil sampling ring knife during the upward movement of the soil sampling, thereby ensuring the quality and accuracy of the earth sampling and effectively improving the accuracy of the acquisition of earth compaction data.

[0016] 2. The high-precision earth compaction detection device for water conservancy projects is used to set a motor on the lower surface of the receiving plate to drive the screw to rotate, and through the adaptation with the nut, it can realize the automatic lifting and lowering adjustment of the lifting plate, which is used for lifting the soil ring knife. At the same time, a top plate is set on the top of the positioning rod, and the positioning ring is driven to correspond to the screw to realize the rotation positioning of the top of the screw. Compared with the traditional manual earth sampling structure, this device has a higher degree of automation, can effectively ensure the uniformity of the rising speed of the soil ring knife, and is more stable for the extraction of internal soil samples.

[0017] 3. The high-precision earth compaction detection device for water conservancy projects is used to support and position the pedal and the linkage plate by setting installation shafts on the inner walls of multiple extension plates, so that the pedal and the linkage plate can rotate and swing along the inner walls of the extension plates, and through the cooperation of the positioning blocks, it is used to position the rotation angle of the linkage plate. By stepping on the pedals, the linkage plates can be used to loosen the buried nails from the ground, thereby realizing rapid separation of the device from the ground, which can effectively improve the convenience of transferring the earth sampling site of the device and make the actual detection operation more flexible. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional front view schematic diagram of the structure of the high-precision earthwork compaction degree detection device for water conservancy projects proposed by the present invention; Figure 2 A three-dimensional bottom-up schematic diagram of the structure of the high-precision earthwork compaction degree detection device for water conservancy projects proposed by the present invention; Figure 3 It is a three-dimensional side cross-sectional schematic diagram of the structure of the high-precision earthwork compaction degree detection device for water conservancy projects proposed by the present invention; Figure 4 It is a three-dimensional front cross-sectional schematic diagram of the structure of the high-precision earthwork compaction degree detection device for water conservancy projects proposed by the present invention; Figure 5 It is a partial three-dimensional cross-sectional schematic diagram of the structure of the high-precision earthwork compaction degree detection device for water conservancy projects proposed by the present invention; Figure 6 It is a partial three-dimensional cross-sectional schematic diagram of the structure of the high-precision earthwork compaction degree detection device for water conservancy projects proposed by the present invention; Figure 7 It is a partial three-dimensional side view schematic diagram of the structure of the high-precision earthwork compaction degree detection device for water conservancy projects proposed by the present invention; Figure 8 It is a partial three-dimensional cross-sectional schematic diagram of the structure of the high-precision earth compaction detection device for water conservancy projects proposed by the present invention.

[0019] In the figure: 1. receiving plate; 2. positioning groove; 3. earth-taking ring knife; 4. positioning plate; 5. movable plate; 6. mounting rod; 7. movable rod; 8. receiving plate; 9. limiting groove; 10. supporting plate; 11. mounting plate; 12. tension spring; 13. connecting plate; 14. positioning rod; 15. connecting column; 16. lifting plate; 17. positioning hole; 18. motor; 19. nut; 20. lead screw; 21. top plate; 22. positioning ring; 23. handle; 24. extension plate; 25. positioning sleeve; 26. metal plate; 27. buried nail; 28. mounting shaft; 29. ​​pedal; 30. linkage plate; 31. anti-slip strip; 32. positioning block. DETAILED DESCRIPTION

[0020] 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.

[0021] See also Figure 1-8, including a receiving plate 1, a positioning groove 2 is provided on the upper surface of one side of the receiving plate 1, and a soil ring knife 3 is movably connected to the inner wall of the positioning groove 2, a positioning plate 4 is symmetrically fixedly installed on the upper surface of one side of the receiving plate 1, and movable plates 5 are slidably installed on the inner walls of the two positioning plates 4, and mounting rods 6 are fixedly installed on the outer walls of one side of the two movable plates 5, and movable rods 7 are rotatably connected to the ends of the two mounting rods 6, and a receiving plate 8 is fixedly installed on the outer wall of one side of the movable rod 7, and a limiting groove 9 is symmetrically provided on the upper surface of one side of the receiving plate 1, and support plates 10 are fixedly installed on the top of the outer walls of the two positioning plates 4, and mounting plates 11 are fixedly installed on the inner upper surfaces of the two support plates 10, and tension springs 12 are provided on the lower surfaces of the two mounting plates 11, and a connecting plate 1 is fixedly installed on the upper surfaces of the two movable plates 5. 3, the two connecting plates 13 are connected to the bottom of the tension spring 12, and a support plate 10 is arranged on the top of the positioning plate 4, and the mounting plate 11 cooperates to support and position the tension spring 12, and a connecting plate 13 is arranged on the upper surface of the movable plate 5, and is connected to the bottom of the tension spring 12. Through the force of the tension spring 12, the receiving plate 8 can be driven to keep in contact with the bottom of the soil ring knife 3, which can effectively prevent the soil sample from scattering from the bottom during the upward movement of the soil sampling ring knife 3, thereby ensuring the quality and accuracy of the soil sampling, and effectively improving the accuracy of the acquisition of the soil compaction data. A positioning rod 14 is fixedly installed on the upper surface of the receiving plate 1, and a connecting column 15 is fixedly installed in the middle of the upper surface of the soil ring knife 3. A lifting plate 16 is fixedly installed on the top of the connecting column 15, and positioning holes 17 are symmetrically opened on the upper surface of the lifting plate 16. A motor 18 is symmetrically provided on the lower surface of the receiving plate 1, and a nut 19 is symmetrically provided on the upper surface of the lifting plate 16. Screws 20 are fixedly installed on the ends of the output shafts of the two motors 18, and the two screws 20 are adapted to the nut 19. A top plate 21 is symmetrically fixedly installed on the top of the positioning rod 14, and a positioning ring 22 is fixedly installed on the lower surface of one side of the two top plates 21. By arranging the motor 18 on the lower surface of the receiving plate 1, it is used to drive the screw 20 to rotate and operate, and by adapting to the nut 19, the lifting plate 16 is driven to automatically lift and lower, which is used for lifting the soil ring knife 3. At the same time, by arranging the top plate 2 on the top of the positioning rod 14 1, and drives the positioning ring 22 to correspond to the screw 20, so as to realize the rotational positioning of the top of the screw 20. Compared with the traditional manual soil sampling structure, the device has a higher degree of automation, can effectively ensure the uniformity of the rising speed of the soil sampling ring knife 3, and is more stable for the internal soil sample extraction. The top of the outer wall of the receiving plate 1 is symmetrically fixed with a handle 23, and the bottom of the outer wall of the receiving plate 1 is symmetrically fixed with an extension plate 24. The interior of multiple extension plates 24 is fixedly installed with a positioning sleeve 25, and the top of multiple positioning sleeves 25 is movably connected with a metal plate 26. The lower surface of multiple metal plates 26 is fixedly installed with buried nails 27. The inner wall of one side of multiple extension plates 24 is rotatably installed with a mounting shaft 28, and the top of one side of the outer wall of multiple mounting shafts 28 is fixedly installed with a pedal 29.A linkage plate 30 is fixedly installed on the outer wall of one side of the multiple installation shafts 28 away from the pedals 29, and an anti-slip strip 31 is symmetrically fixedly installed on the upper surface of the multiple pedals 29. A positioning block 32 is symmetrically fixedly installed on the top of the inner wall of one side of the multiple extension plates 24. The installation shafts 28 are arranged on the inner walls of the multiple extension plates 24 to support and position the pedals 29 and the linkage plate 30, so that the pedals 29 and the linkage plate 30 can rotate and swing along the inner wall of the extension plate 24, and the positioning block 32 is used to position the rotation angle of the linkage plate 30. By stepping on the pedals 29, the linkage plate 30 can be used to loosen the buried nails 27 from the ground, so as to quickly separate the device from the ground, which can effectively improve the convenience of transferring the earthwork sampling site of the device, and make the actual detection operation more flexible.

[0022] The electrical components mentioned in this article are all connected to an external main controller and 220V mains electricity, and the main controller can be a conventional known device for controlling a computer or the like.

[0023] When in use, first fix the receiving plate 1 in the soil sample extraction area according to the actual site conditions of the water conservancy project earth compaction detection area, and set a positioning groove 2 on the upper surface of the receiving plate 1 for clamping and positioning the soil sampling ring knife 3, so that the soil sampling ring knife 3 can be lifted and moved along the receiving plate 1, and place the receiving plate 1 in the water conservancy project earth compaction detection area, and press the soil sampling ring knife 3 downward at a uniform speed so that the original soil is placed inside the soil sampling ring knife 3 for sampling the earth. In this process, a positioning plate 4 is set on the upper surface of the receiving plate 1, and the two positioning plates 4 are located in the same horizontal plane, which are used to support and position the movable plate 5, so that the movable plate 5 can be lifted and moved along the positioning plate 4, and the movable rod 7 is driven to move synchronously through the cooperation of the mounting rod 6. The receiving plate 8 is arranged on the outer wall of the movable rod 7, and the end of the receiving plate 8 is arranged in a conical shape, and can be placed horizontally at the bottom of the device through the cooperation of the limiting groove 9. In the process of the soil sampling ring knife 3 completing the upward movement of the soil sampling, the receiving plate 8 is placed at the bottom of the soil sampling ring knife 3. At the same time, a support plate 10 is arranged on the top of the positioning plate 4, and through the cooperation of the mounting plate 11, it is used to support and position the tension spring 12. A connecting plate 13 is arranged on the upper surface of the movable plate 5, and is connected to the bottom of the tension spring 12. Through the action of the tension spring 12, the receiving plate 8 can be driven to maintain a fit with the bottom of the soil sampling ring knife 3. A positioning rod 14 is arranged on the upper surface of the receiving plate 1, and through the cooperation of the positioning hole 17, it is used to control the lifting The support and positioning of the plate 16 enables the lifting plate 16 to be lifted and moved along the positioning rod 14, and through the cooperation of the connecting column 15, the earth-excavating ring knife 3 is synchronously driven to move. In actual use, a motor 18 is arranged on the lower surface of the receiving plate 1 to drive the screw 20 to rotate, and through the adaptation with the nut 19, the lifting plate 16 is driven to automatically lift and adjust, which is used for the lifting operation of the earth-excavating ring knife 3. At the same time, a top plate 21 is arranged on the top of the positioning rod 14, and the positioning ring 22 is driven to correspond to the screw 20, so as to realize the rotation positioning of the top of the screw 20, and a handle 23 is arranged on the outer wall of the receiving plate 1, so that personnel can hold the equipment to move and adjust the position. In actual use, a plurality of extensions are arranged on the outer wall of the receiving plate 1 The extension plates 24 are arranged in a rectangular array. Positioning sleeves 25 are arranged inside the plurality of extension plates 24, and the metal plates 26 are cooperated to support and position the buried nails 27. By placing the receiving plate 1 in a specific soil compaction detection sampling area, the metal plates 26 are knocked downward to drive the buried nails 27 to be inserted into the ground, thereby achieving a fast connection between the device and the ground. At the same time, mounting shafts 28 are arranged on the inner walls of the plurality of extension plates 24 to support and position the pedals 29 and the linkage plates 30, so that the pedals 29 and the linkage plates 30 can rotate and swing along the inner walls of the extension plates 24, and the positioning blocks 32 are cooperated to position the rotation angle of the linkage plates 30. By stepping on the pedals 29, personnel can cooperate with the linkage plates 30.It is used to drive the buried nail 27 to loosen from the ground, so as to realize the rapid separation of the device from the ground.

[0024] In summary, the high-precision earthwork compaction detection device for water conservancy projects is provided with a receiving plate 8 on the outer wall of the movable rod 7, the end of the receiving plate 8 is provided in a conical shape, and can be placed horizontally at the bottom of the device through the cooperation of the limiting groove 9. In the process of the soil sampling ring knife 3 completing the upward movement of the earthwork sampling, the receiving plate 8 is placed at the bottom of the soil sampling ring knife 3. At the same time, a support plate 10 is provided on the top of the positioning plate 4, and the mounting plate 11 is cooperated to support and position the tension spring 12. A connecting plate 13 is provided on the upper surface of the movable plate 5. The receiving plate 8 is connected to the bottom of the tension spring 12. Through the force of the tension spring 12, the receiving plate 8 can be driven to keep in contact with the bottom of the soil ring knife 3, which can effectively prevent the soil sample from scattering from the bottom during the upward movement of the soil sampling ring knife 3, thereby ensuring the quality and accuracy of the soil sampling, and effectively improving the accuracy of the acquisition of the soil compaction data. By arranging a motor 18 on the lower surface of the receiving plate 1 to drive the lead screw 20 to rotate, and by adapting to the nut 19, the lifting plate 16 can be driven to automatically rise and fall. It is used for lifting the soil ring cutter 3. At the same time, by setting a top plate 21 on the top of the positioning rod 14, and driving the positioning ring 22 to correspond to the screw 20, the rotation positioning of the top of the screw 20 is realized. Compared with the traditional manual earth sampling structure, the device has a higher degree of automation, can effectively ensure the uniformity of the rising speed of the soil ring cutter 3, and is more stable for the internal soil sample extraction. By knocking the metal plate 26 downward, the buried nail 27 can be driven to be inserted into the ground to realize the fastening connection between the device and the ground. At the same time, by extending a plurality of An installation shaft 28 is set on the inner wall of the plate 24, which is used to support and position the pedal 29 and the linkage plate 30, so that the pedal 29 and the linkage plate 30 can rotate and swing along the inner wall of the extension plate 24, and through the cooperation of the positioning block 32, it is used to position the rotation angle of the linkage plate 30. By stepping on the pedal 29, the linkage plate 30 can be cooperated to drive the buried nail 27 to loosen from the ground, thereby realizing the rapid separation of the device from the ground, which can effectively improve the convenience of transferring the earth sampling site of the device, and the actual detection operation is more flexible, which is suitable for popularization.

[0025] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise one" do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0026] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-precision earthwork compaction detection device for water conservancy projects, comprising a receiving plate (1), characterized in that: A positioning groove (2) is provided on the upper surface of one side of the receiving plate (1), and a soil extracting ring knife (3) is movably connected to the inner wall of the positioning groove (2). A positioning plate (4) is symmetrically fixedly installed on the upper surface of one side of the receiving plate (1), and movable plates (5) are slidably installed on the inner walls of the two positioning plates (4). A mounting rod (6) is fixedly installed on the outer walls of one side of the two movable plates (5), and the ends of the two mounting rods (6) are rotatably connected to movable rods (7). A receiving plate (8) is fixedly installed on the outer wall of one side of the movable rod (7). A limiting groove (9) is symmetrically provided on the upper surface of one side of the receiving plate (1), and a support plate (10) is fixedly installed on the top of the outer wall of the two positioning plates (4). A mounting plate (11) is fixedly installed on the inner upper surface of the two support plates (10). A tension spring (12) is provided on the lower surface of the two mounting plates (11). A connecting plate (13) is fixedly installed on the upper surface of the two movable plates (5), and the two connecting plates (13) are connected to the bottom of the tension spring (12).

2. The high-precision earthwork compaction detection device for water conservancy projects according to claim 1 is characterized in that: A positioning rod (14) is fixedly mounted on the upper surface of the receiving plate (1), and a connecting column (15) is fixedly mounted on the middle portion of the upper surface of the soil extracting ring knife (3).

3. The high-precision earthwork compaction detection device for water conservancy projects according to claim 2 is characterized in that: A lifting plate (16) is fixedly mounted on the top end of the connecting column (15), and positioning holes (17) are symmetrically provided on the upper surface of the lifting plate (16).

4. The high-precision earthwork compaction detection device for water conservancy projects according to claim 3 is characterized in that: A motor (18) is symmetrically provided on the lower surface of the receiving plate (1), and a nut (19) is symmetrically provided on the upper surface of the lifting plate (16).

5. The high-precision earthwork compaction detection device for water conservancy projects according to claim 4 is characterized in that: Screws (20) are fixedly mounted on the ends of the output shafts of the two motors (18), and the two screws (20) are matched with the screw nuts (19).

6. The high-precision earthwork compaction detection device for water conservancy projects according to claim 5 is characterized in that: A top plate (21) is symmetrically fixedly mounted on the top of the positioning rod (14), and a positioning ring (22) is fixedly mounted on the lower surface of one side of the two top plates (21).

7. The high-precision earthwork compaction detection device for water conservancy projects according to claim 1 is characterized in that: A handle (23) is symmetrically fixedly mounted on the top of the outer wall of the receiving plate (1), an extension plate (24) is symmetrically fixedly mounted on the bottom of the outer wall of the receiving plate (1), and positioning sleeves (25) are fixedly mounted inside a plurality of the extension plates (24).

8. The high-precision earthwork compaction detection device for water conservancy projects according to claim 7 is characterized in that: The tops of the plurality of positioning sleeves (25) are movably connected with metal plates (26), the lower surfaces of the plurality of metal plates (26) are fixedly mounted with buried nails (27), and the inner walls of one side of the plurality of extension plates (24) are rotatably mounted with mounting shafts (28).

9. The high-precision earthwork compaction detection device for water conservancy projects according to claim 8, characterized in that: A pedal (29) is fixedly mounted on the top of one side outer wall of the plurality of mounting shafts (28), and a linkage plate (30) is fixedly mounted on one side outer wall of the plurality of mounting shafts (28) away from the pedal (29).

10. The high-precision earthwork compaction detection device for water conservancy projects according to claim 9, characterized in that: Anti-slip strips (31) are symmetrically fixedly mounted on the upper surfaces of the plurality of pedals (29), and positioning blocks (32) are symmetrically fixedly mounted on the top of the inner walls of one side of the plurality of extension plates (24).

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