Multifunctional drilling rig for engineering investigation

Abstract

The invention relates to the technical field of geological investigation, in particular to an engineering investigation multifunctional drilling rig which comprises a base, an electric push rod is welded to the outer wall of the top of the base, a sliding seat is welded to the output end of the electric push rod, the sliding seat is inserted into the outer wall of the base in a sliding mode, and a motor is welded to the outer wall of the sliding seat. Through arrangement of the sliding columns, when the threaded sleeve drives the drill rod to further move downwards relative to the lower polished rod section, the abutting heads on the two sliding columns at the lowest position firstly abut against the inclined blocks, the abutting heads slide in the direction away from the axis of the drill rod along the inclined surfaces of the inclined blocks, the sliding columns drive the sampling groove to slide out, and then the sampling groove is matched with rotation of the drill rod; when an inclined block is separated from an abutting head, under the action of a fourth spring, a sliding column drives the sampling groove to be stored in the outer wall of the drill rod again, the sampling effect is achieved, meanwhile, an electric push rod continuously pushes the drill rod to be fed downwards, and the multi-layer sampling effect can be achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of geological exploration, and in particular relates to a multifunctional drilling device for engineering exploration. Background Art

[0002] Engineering survey is a basic construction procedure for the purpose of engineering construction, based on geological observation and research, and according to task requirements, it selects necessary technical means or methods, such as surveying and mapping, geophysical exploration, geochemical prospecting, drilling, pit exploration, sampling testing, geological remote sensing, etc., to obtain underground rock information. Among them, drilling sampling is an important means of obtaining underground rock information.

[0003] However, the existing drilling equipment has a single function and cannot perform multi-layer sampling, resulting in low exploration efficiency. In addition, the existing drilling equipment does not have a hole expansion function. When relevant detection equipment needs to be lowered into the borehole, other hole expansion equipment is required, which greatly affects the exploration efficiency. Summary of the invention

[0004] The purpose of the present invention is to solve the problems in the background technology and to propose a multifunctional drilling device for engineering survey.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A multifunctional drilling device for engineering survey, comprising a base, an electric push rod welded on the top outer wall of the base, a slide seat welded on the output end of the electric push rod, the slide seat is slidably plugged on the outer wall of the base, a motor is welded on the outer wall of the slide seat, an upper polished rod section, a threaded section and a lower polished rod section are sequentially opened on the main shaft of the motor, a threaded sleeve is connected to the outer wall of the threaded section through threaded matching, a drill rod is rotatably plugged on the bottom outer wall of the threaded sleeve, an installation cavity is opened inside the drill rod, and the main shaft of the motor extends to the installation cavity A limit groove is provided on the outer wall of the main shaft of the motor, a limit block is welded on the top of the installation cavity, the limit block is slidably inserted in the limit groove, a plurality of pairs of linearly distributed sliding columns are slidably inserted on the outer wall of the drill rod, an abutment joint is welded on the outer wall of one end of each sliding column close to the installation cavity, a spring four is welded between the outer wall of each abutment joint and the inner wall of the installation cavity, a sampling groove is provided on the outer wall of each sliding column away from the abutment joint, a hole expanding mechanism is provided on the drill rod, and an anti-deflection mechanism is provided in the threaded sleeve.

[0007] In the above-mentioned multifunctional drilling device for engineering survey, the upper polishing rod section and the lower polishing rod section are evenly matched with threaded sleeves, a spring is welded between the outer wall of the threaded sleeve and the outer wall of the sliding seat, a telescopic rod is welded on the outer wall of the sliding seat, and the output end of the telescopic rod is fixed on the outer wall of the threaded sleeve.

[0008] In the above-mentioned multifunctional drilling device for engineering investigation, a soil breaking tip is provided on the outer wall of one end of each sliding column away from the abutment joint.

[0009] In the above-mentioned multifunctional drilling device for engineering survey, a pair of support rods are welded on the outer wall of the bottom end of the lower polished rod section, and an inclined block is slidably inserted on the outer wall of each support rod, and the inclined block is adapted to the abutment joint. A spring 2 is welded between the outer wall of each inclined block and the outer wall of the lower polished rod section, and a avoidance groove is opened on the outer wall of each inclined block, and the avoidance groove is adapted to the sliding column.

[0010] In the above-mentioned multifunctional drilling device for engineering survey, the hole expansion mechanism includes a trigger ring 1, a spring 3 is welded on the top inner wall of the installation cavity, a trigger ring 1 is welded on the other end of the spring 3, the trigger ring 1 is slidably sleeved on the outer wall of the lower light rod section, and the trigger ring 1 is adapted to the bevel block.

[0011] In the above-mentioned multifunctional drilling device for engineering investigation, a pair of symmetrically distributed connecting rods are rotatably plugged into the outer wall of the trigger ring, and a scraper is rotatably plugged into the outer wall of the end of each connecting rod, and the scraper is slidably plugged into the outer wall of the drill rod.

[0012] In the above-mentioned multifunctional drilling device for engineering survey, the anti-deviation mechanism includes a trigger ring 2, a trigger ring 2 is slidably sleeved on the outer wall of the main shaft of the motor, a spring 5 is welded between the outer wall of the trigger ring 2 and the inner wall of the threaded sleeve, a stopper is welded in the limit groove, the stopper and the limit block can avoid each other, and the trigger ring 2 is adapted to the stopper.

[0013] In the above-mentioned multifunctional drilling device for engineering survey, a pair of symmetrically distributed connecting rods 2 are rotatably connected to the outer wall of the trigger ring 2, a slider is rotatably connected to the end wall of each connecting rod 2, and a universal wheel is rotatably connected to the outer wall of each slider.

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

[0015] 1. Sampling: When the threaded sleeve with the drill rod moves further downward relative to the lower polished rod section, the abutment joints on the two lowest sliding columns first abut against the inclined block, and the abutment joints slide along the inclined surface of the inclined block in the direction away from the axis of the drill rod, so that the sliding column drives the sampling slot to slide out, and then cooperates with the rotation of the drill rod, so that the soil sample is squeezed into the sampling slot. When the inclined block is separated from the abutment joint, under the action of spring four, the sliding column drives the sampling slot to be stored in the outer wall of the drill rod again, achieving the sampling effect. At the same time, the electric push rod continuously pushes the drill rod downward to achieve the effect of multi-layer sampling;

[0016] 2. Hole expansion: Through the hole expansion mechanism, when sampling is completed, the threaded sleeve moves to the lower polished rod section. At this time, the inclined block abuts against the trigger ring 1 and pushes it upward. Under the action of the connecting rod 1, the two scrapers move away from the axis of the drill rod. When the drill rod drives the scrapers to rotate, the borehole can be expanded without the need for additional hole expansion equipment.

[0017] 3. Straightening: Through the anti-deflection mechanism, when the threaded sleeve moves to the lower polished rod section, the threaded sleeve drives the trigger ring 2 to abut against the block in the limit groove, so that the block pushes the trigger ring 2 to move upward. Under the action of the connecting rod 2, the two sliders move away from the axis of the drill rod, so that the slider drives the universal wheel to abut against the inner wall of the borehole, thereby achieving the effect of straightening the drill rod and avoiding the deviation of the drill rod during hole expansion. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional schematic diagram of the overall structure of the present invention.

[0019] Figure 2 It is a schematic plan cross-sectional view of the initial state of the overall structure of the present invention.

[0020] Figure 3 It is a three-dimensional schematic diagram of the motor of the present invention.

[0021] Figure 4 for Figure 3 A magnified view of the structure at A.

[0022] Figure 5 It is a three-dimensional schematic diagram of a drill rod of the present invention.

[0023] Figure 6 It is a three-dimensional schematic diagram of the working state of the overall structure of the present invention.

[0024] Figure 7 It is a three-dimensional schematic diagram of the inclined block avoiding position of the present invention.

[0025] Figure 8 It is a plan view schematic diagram of the working state of the scraper and slider of the present invention.

[0026] In the figure: 1. base; 2. slide seat; 21. electric push rod; 22. telescopic rod; 23. threaded sleeve; 24. spring one; 3. motor; 31. threaded section; 32. upper polishing rod section; 321. lower polishing rod section; 33. limit groove; 331. block; 34. support rod; 35. inclined block; 351. avoidance groove; 36. spring two; 4. drill rod; 41. limit block; 42. installation cavity; 5. trigger ring one; 51. spring three; 52. connecting rod one; 53. scraper; 6. sliding column; 61. sampling groove; 62. soil breaking tip; 63. abutment; 64. spring four; 7. trigger ring two; 71. spring five; 72. connecting rod two; 73. slider; 74. universal wheel. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0028] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the 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 orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0029] See also Figure 1-Figure 8 The present invention provides a technical solution: a multifunctional drilling device for engineering survey, comprising a base 1, an electric push rod 21 is welded on the top outer wall of the base 1, a slide seat 2 is welded on the output end of the electric push rod 21, the slide seat 2 is slidably plugged on the outer wall of the base 1, a motor 3 is welded on the outer wall of the slide seat 2, an upper polished rod section 32, a threaded section 31 and a lower polished rod section 321 are sequentially opened on the main shaft of the motor 3, a threaded sleeve 23 is connected to the outer wall of the threaded section 31 through threaded matching, and the threaded sleeve 23 A drill rod 4 is rotatably plugged into the outer wall of the bottom, a mounting cavity 42 is provided inside the drill rod 4, the main shaft of the motor 3 extends into the mounting cavity 42, a limiting groove 33 is provided on the outer wall of the main shaft of the motor 3, a limiting block 41 is welded on the top of the mounting cavity 42, the limiting block 41 is slidably plugged into the limiting groove 33, a plurality of pairs of linearly distributed sliding columns 6 are slidably plugged into the outer wall of the drill rod 4, and a butt joint 63 is welded on the outer wall of one end of each sliding column 6 close to the mounting cavity 42, and the outer wall of each butt joint 63 is Springs 464 are welded between the wall and the inner wall of the installation cavity 42, a sampling groove 61 is provided on the outer wall of each sliding column 6 away from the abutment joint 63, a hole expansion mechanism is provided on the drill rod 4, an anti-bias mechanism is provided in the threaded sleeve 23, the upper polishing rod section 32 and the lower polishing rod section 321 are evenly matched with the threaded sleeve 23, a spring 24 is welded between the outer wall of the threaded sleeve 23 and the outer wall of the slide seat 2, a telescopic rod 22 is welded on the outer wall of the slide seat 2, and the output end of the telescopic rod 22 is fixed to the threaded sleeve 2 3, a ground-breaking tip 62 is provided on the outer wall of one end of each sliding column 6 away from the abutment 63, a pair of support rods 34 are welded on the outer wall of the bottom end of the lower light rod section 321, an inclined block 35 is slidably inserted on the outer wall of each support rod 34, the inclined block 35 is adapted to the abutment 63, a spring 2 36 is welded between the outer wall of each inclined block 35 and the outer wall of the lower light rod section 321, and an avoidance groove 351 is provided on the outer wall of each inclined block 35, and the avoidance groove 351 is adapted to the sliding column 6.

[0030] In the initial state, if Figure 2 As shown, the electric push rod 21 is in a retracted state, the threaded sleeve 23 is located on the upper polishing rod section 32, and the spring 1 24 is in a compressed state, and the lower polishing rod section 321 is located at the bottom of the installation cavity 42.

[0031] When the motor 3 drives the threaded segment 31 to rotate forward, under the limiting action of the telescopic rod 22, the threaded sleeve 23 can move up along the threaded segment 31 to the upper polished rod segment 32; when the motor 3 rotates reversely, the threaded sleeve 23 moves down along the threaded segment 31 to the lower polished rod segment 321.

[0032] The above content is further elaborated: when working, the electric push rod 21 is started to push the slide seat 2 downward, so that the slide seat 2 drives the drill rod 4 to move downward, and the motor 3 is started to rotate forward at the same time. Under the cooperation of the limit groove 33 and the limit block 41, the motor 3 drives the drill rod 4 to rotate, thereby achieving the drilling effect. In the initial state, the sampling groove 61 on the slide column 6 is stored in the outer wall of the drill rod 4, and only the soil breaking tip 62 is exposed to the outside, so that when the drill rod 4 drives the slide column 6 to rotate, the soil breaking tip 62 can improve the soil breaking effect of the drill rod 4. When sampling is required, the motor 3 is controlled to reverse. At this time, under the action of the spring 24, the threaded sleeve 23 cooperates with the threaded section 31, so that the threaded sleeve 23 slowly moves down along the threaded section 31 to the lower polished rod section 321. In this process, the threaded sleeve 23 leads the drill rod 4 to move further downward relative to the lower polished rod section 321, so that the abutment joints 63 on the two lowest slide columns 6 first abut against the inclined block 35, and the abutment joints 6 When the drill rod 4 is in the state of being moved downward, the slide 61 is moved upwards to move the drill rod 4 downwards, and the slide 61 is moved upwards to move the drill rod 4 downwards, so that the drill rod 4 can move upwards and downwards, so that the slide 61 is moved upwards to move the drill rod 4 downwards, and the slide 61 is moved upwards to move the drill rod 4 downwards, so that the drill rod 4 can move upwards and downwards, so that the slide 61 is moved upwards to move the drill rod 4 downwards, and the slide 61 is moved upwards to move the drill rod 4 downwards, so that the slide 6 can move the drill rod 4 upwards, so that the slide 6 can move the drill rod 4 downwards, and the slide 61 is moved upwards to move the drill rod 4 downwards, so that the slide 6 can move the drill rod 4 downwards, and the slide 61 is moved upwards to move the drill rod 4 downwards, so that the slide 6 can move the drill rod 4 downwards, and the slide 61 is moved upwards to move the drill rod 4 downwards, so that the slide 6 can move the drill rod 4 downwards, and the slide 61 is moved upwards to move the drill rod 4 downwards, so that the slide 6 can move the drill rod 4 downwards, and the slide 6 can ...

[0033] Specifically, the reaming mechanism includes a trigger ring 5, a spring 3 51 is welded on the top inner wall of the mounting cavity 42, a trigger ring 5 is welded on the other end of the spring 3 51, the trigger ring 5 is slidably sleeved on the outer wall of the lower light rod section 321, the trigger ring 5 is adapted to the inclined block 35, a pair of symmetrically distributed connecting rods 52 are rotatably plugged into the outer wall of the trigger ring 5, a scraper 53 is rotatably plugged into the outer wall of the end of each connecting rod 52, and the scraper 53 is slidably plugged into the outer wall of the drill rod 4.

[0034] In the initial state, if Figure 2 As shown, under the action of spring three 51, trigger ring one 5 moves downward to pull connecting rod one 52, so that the two scrapers 53 are close to each other and maintain the storage state.

[0035] The above content is further elaborated: after the sampling is completed, the threaded sleeve 23 moves to the lower light rod section 321. At this time, the inclined block 35 abuts against the trigger ring 5 and pushes it upward. Under the action of the connecting rod 52, the two scrapers 53 move away from the axis of the drill rod 4. When the drill rod 4 drives the scrapers 53 to rotate, the effect of expanding the borehole can be achieved without the aid of additional expanding equipment.

[0036] Specifically, the anti-bias mechanism includes a trigger ring 27, which is slidably sleeved on the outer wall of the main shaft of the motor 3, a spring 5 71 is welded between the outer wall of the trigger ring 27 and the inner wall of the threaded sleeve 23, a stopper 331 is welded in the limit groove 33, the stopper 331 and the limiter 41 can avoid each other, the trigger ring 27 and the stopper 331 are adapted to each other, a pair of symmetrically distributed connecting rods 2 72 are rotatably inserted on the outer wall of the trigger ring 27, a slider 73 is rotatably inserted on the end wall of each connecting rod 2 72, and a universal wheel 74 is rotatably inserted on the outer wall of each slider 73.

[0037] In the initial state, if Figure 2 As shown, under the action of spring five 71, trigger ring two 7 moves downward to pull connecting rod two 72, so that the two sliders 73 are close to each other, so that the two universal wheels 74 remain in the storage state.

[0038] The above content is further elaborated: when the threaded sleeve 23 moves to the lower polished rod section 321, the threaded sleeve 23 drives the trigger ring 2 7 to abut against the block 331 in the limit groove 33, so that the block 331 pushes the trigger ring 2 7 to move upward, and under the action of the connecting rod 2 72, the two sliders 73 move in the direction away from the axis of the drill rod 4, so that the slider 73 drives the universal wheel 74 to abut against the inner wall of the borehole, thereby achieving the effect of straightening the drill rod 4 and avoiding the deviation of the drill rod 4 when expanding the hole.

[0039] The working principle and use process of the present invention are as follows: when working, the electric push rod 21 is started to push the slide 2 downward, so that the slide 2 drives the drill rod 4 to move downward, and at the same time, the motor 3 is started to rotate forward. Under the cooperation of the limit groove 33 and the limit block 41, the motor 3 drives the drill rod 4 to rotate, thereby achieving the drilling effect. In the initial state, the sampling groove 61 on the slide column 6 is stored in the outer wall of the drill rod 4, and only the soil breaking tip 62 is exposed to the outside, so that when the drill rod 4 drives the slide column 6 to rotate, the soil breaking tip 62 can improve the soil breaking effect of the drill rod 4. When sampling is required, the motor 3 is controlled to reverse. At this time, the threaded sleeve 23 slowly moves down along the threaded section 31 to the lower polished rod section 32 1. During this process, the threaded sleeve 23 leads the drill rod 4 to move further downward relative to the lower polished rod section 321, so that the abutment joints 63 on the two lowest slide posts 6 first abut against the inclined block 35, and the abutment joints 63 slide along the inclined surface of the inclined block 35 in a direction away from the axis of the drill rod 4, so that the slide post 6 drives the sampling groove 61 to slide out, and then cooperates with the rotation of the drill rod 4, so that the soil sample is squeezed into the sampling groove 61. When the inclined block 35 is separated from the abutment joint 63, under the action of the spring four 64, the slide post 6 drives the sampling groove 61 to be stored in the outer wall of the drill rod 4 again, so as to achieve the sampling effect. At the same time, the electric push rod 21 continuously pushes the drill rod 4 downward to feed, which can achieve The effect of multi-layer sampling is realized. When the inclined block 35 abuts against the trigger ring 1 5, under the action of the reaming mechanism, the inclined block 35 pushes the trigger ring 1 5 to move upward. Under the action of the connecting rod 1 52, the two scrapers 53 move in the direction away from the axis of the drill rod 4. When the drill rod 4 drives the scrapers 53 to rotate, the effect of reaming the borehole can be achieved without the aid of additional reaming equipment. When the stopper 331 abuts against the trigger ring 2 7, under the action of the anti-bias mechanism, the stopper 331 pushes the trigger ring 2 7 to move upward. Under the action of the connecting rod 2 72, the two sliders 73 move in the direction away from the axis of the drill rod 4, so that the slider 73 drives the universal wheel 74 to axially align with the drill rod 4. The inner wall abuts to achieve the effect of straightening the drill rod 4 to avoid the drill rod 4 from deflecting during hole expansion. When the work is completed, the electric push rod 21 is controlled to retract and the motor 3 rotates forward, so that the slide seat 2 and the threaded sleeve 23 drive the drill rod 4 to lift and reset. During this process, the drill rod 4 moves up relative to the lower light rod section 321, so that the avoidance groove 351 on the inclined block 35 abuts against the sliding column 6, so that the sliding column 6 can push the inclined block 35 away along the avoidance groove 351 to achieve the avoidance effect, so that during the resetting process of the drill rod 4, the sliding column 6 will not slip out and cause the sample to fall off. After the drill rod 4 is lifted to the ground, the sliding column 6 is pulled outward to take out the sample.

[0040] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A multifunctional drilling device for engineering survey, comprising a base (1), characterized in that: An electric push rod (21) is welded on the top outer wall of the base (1), a slide seat (2) is welded on the output end of the electric push rod (21), the slide seat (2) is slidably plugged on the outer wall of the base (1), a motor (3) is welded on the outer wall of the slide seat (2), an upper polished rod section (32), a threaded section (31) and a lower polished rod section (321) are sequentially provided on the main shaft of the motor (3), a threaded sleeve (23) is connected to the outer wall of the threaded section (31) by threaded matching, a drill rod (4) is rotatably plugged on the bottom outer wall of the threaded sleeve (23), an installation cavity (42) is provided inside the drill rod (4), the main shaft of the motor (3) extends into the installation cavity (42), and the motor (3) A limit groove (33) is provided on the outer wall of the main shaft, a limit block (41) is welded on the top of the installation cavity (42), and the limit block (41) is slidably inserted in the limit groove (33). A plurality of pairs of linearly distributed sliding columns (6) are slidably inserted on the outer wall of the drill rod (4), and a butt joint (63) is welded on the outer wall of one end of each sliding column (6) close to the installation cavity (42), and a spring four (64) is welded between the outer wall of each butt joint (63) and the inner wall of the installation cavity (42), and a sampling groove (61) is provided on the outer wall of each sliding column (6) away from the butt joint (63). A hole expansion mechanism is provided on the drill rod (4), and an anti-deflection mechanism is provided in the threaded sleeve (23).

2. The multifunctional drilling device for engineering survey according to claim 1, characterized in that: The upper polishing rod section (32) and the lower polishing rod section (321) are evenly matched with the threaded sleeve (23); a spring (24) is welded between the outer wall of the threaded sleeve (23) and the outer wall of the slide seat (2); a telescopic rod (22) is welded on the outer wall of the slide seat (2); and the output end of the telescopic rod (22) is fixed on the outer wall of the threaded sleeve (23).

3. The multifunctional drilling device for engineering survey according to claim 1, characterized in that: A soil breaking tip (62) is formed on the outer wall of one end of each sliding column (6) away from the abutment joint (63).

4. The multifunctional drilling device for engineering survey according to claim 1, characterized in that: A pair of support rods (34) are welded to the outer wall of the bottom end of the lower light rod section (321); a slanted block (35) is slidably inserted on the outer wall of each support rod (34); the slanted block (35) is matched with the abutment joint (63); a spring 2 (36) is welded between the outer wall of each slanted block (35) and the outer wall of the lower light rod section (321); a avoidance groove (351) is opened on the outer wall of each slanted block (35); the avoidance groove (351) is matched with the sliding column (6).

5. The multifunctional drilling device for engineering survey according to claim 1, characterized in that: The hole expansion mechanism comprises a trigger ring 1 (5), a spring 3 (51) is welded on the top inner wall of the installation cavity (42), a trigger ring 1 (5) is welded on the other end of the spring 3 (51), the trigger ring 1 (5) is slidably sleeved on the outer wall of the lower light rod section (321), and the trigger ring 1 (5) is adapted to the inclined block (35).

6. The multifunctional drilling device for engineering survey according to claim 5, characterized in that: A pair of symmetrically distributed connecting rods (52) are rotatably plugged into the outer wall of the trigger ring (5), and a scraper (53) is rotatably plugged into the outer wall of the end of each connecting rod (52), and the scraper (53) is slidably plugged into the outer wall of the drill rod (4).

7. The multifunctional drilling device for engineering survey according to claim 1, characterized in that: The anti-deviation mechanism comprises a trigger ring 2 (7), the trigger ring 2 (7) is slidably sleeved on the outer wall of the main shaft of the motor (3), a spring 5 (71) is welded between the outer wall of the trigger ring 2 (7) and the inner wall of the threaded sleeve (23), a stopper (331) is welded in the limit groove (33), the stopper (331) and the limit block (41) can avoid each other, and the trigger ring 2 (7) and the stopper (331) are adapted.

8. The multifunctional drilling device for engineering survey according to claim 7, characterized in that: A pair of symmetrically distributed connecting rods (72) are rotatably plugged on the outer wall of the trigger ring (7), a slider (73) is rotatably plugged on the end wall of each connecting rod (72), and a universal wheel (74) is rotatably plugged on the outer wall of each slider (73).

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