Stripping device for open pit coal mine

Abstract

The utility model relates to the technical field of coal mining, in particular to a stripping device for an open pit coal mine, which comprises a machine body, a large arm, a small arm and a stripping bucket with adjustable width, the lower end of the large arm is hinged with the machine body, the upper part of the small arm is hinged with the front end of the large arm, the stripping bucket is hinged with the lower end of the small arm, and the stripping bucket comprises a main bucket and two auxiliary buckets. Sliding cavities are formed in the left side and the right side of the main bucket respectively, the two sliding cavities are arranged in a bilateral symmetry mode, the two auxiliary buckets slide in the two sliding cavities in the left-right direction respectively, and the two-way push-pull mechanism can drive the two auxiliary buckets to slide at the same time and is installed in the lower portion of the small arm. The problem that an existing single-bucket excavator is low in stripping efficiency is solved.

Description

Technical Field

[0001] This utility model relates to the field of coal mining technology, specifically to a stripping device for open-pit coal mines. Background Technology

[0002] Open-pit coal mines refer to coal seams deposited on the surface or in shallow layers due to geographical changes. In open-pit coal mining, the overlying rocks and covering materials must first be removed to expose the coal seam for mining. Currently, the commonly used excavating equipment for open-pit coal mining includes single-bucket excavators and multi-bucket excavators, with single-bucket excavators being the most widely used.

[0003] The width of the bucket in existing single-bucket excavators is generally not adjustable, which limits the amount and range of stripping per operation and affects the stripping efficiency of coal mines. To improve the stripping efficiency of single-bucket excavators, it may be necessary to replace the bucket, which not only increases time costs but also affects the continuity of stripping operations. Utility Model Content

[0004] This invention proposes a stripping device for open-pit coal mines, which solves the problem of low stripping efficiency of existing single-bucket excavators.

[0005] To achieve the above objectives, this utility model proposes a stripping device for open-pit coal mines, comprising a body, a boom, a forearm, and a stripping bucket with adjustable width. The lower end of the boom is hinged to the body, the upper part of the forearm is hinged to the front end of the boom, and the stripping bucket is hinged to the lower end of the forearm. The stripping bucket includes a main bucket and two auxiliary buckets.

[0006] The main bucket has sliding cavities on its left and right sides, and the two sliding cavities are symmetrically arranged. The two auxiliary buckets slide in the two sliding cavities in the left and right directions respectively.

[0007] It also includes a bidirectional push-pull mechanism that can simultaneously drive the two auxiliary buckets to slide, and the bidirectional push-pull mechanism is installed inside the lower part of the forearm.

[0008] Preferably, two parallel connecting plates are fixed to the upper surface of the main bucket, and the lower end of the forearm is hinged between the rear ends of the two connecting plates.

[0009] Preferably, the upper cavity wall of the sliding cavity is provided with a sliding groove, and the outer end of the sliding groove is closed.

[0010] The upper surface of the secondary bucket is provided with a slider, which slides within the groove.

[0011] Preferably, the lower part of the forearm is provided with a mounting hole and a lifting hole, the mounting hole is located above the lifting hole, and a partition is provided between the mounting hole and the lifting hole.

[0012] Preferably, the bidirectional push-pull mechanism includes a push-pull rod, a motor, a lifting tube, and a lead screw;

[0013] The motor is installed in the mounting hole, the output shaft of the motor passes vertically through the partition, and the output shaft of the motor rotates relative to the partition;

[0014] The lead screw is vertically arranged and rotates within the lifting hole. The output end of the motor is fixedly connected to the upper end of the lead screw. The lifting tube is sleeved on the body of the lead screw and is threadedly connected to the lead screw.

[0015] The lifting tube is provided with lifting sliders on its front and rear sides respectively, and the two lifting sliders are slidably connected to the front and rear walls of the lifting hole respectively.

[0016] Two push-pull rods are provided symmetrically on the left and right sides. The push-pull rods are inclined. The upper ends of the two push-pull rods are respectively hinged to the left and right sides of the lifting tube, and the lower ends of the push-pull rods are bidirectionally hinged to the upper surface of the auxiliary bucket.

[0017] Preferably, two parallel connecting push plates are fixed to the upper surface of the secondary bucket, and the connecting push plates are close to the outer edge of the secondary bucket.

[0018] Preferably, lifting connecting ears are fixed on the left and right sides of the lifting tube respectively;

[0019] A bidirectional connector is provided between the push-pull rod and the connecting push plate. The bidirectional connector includes a lower connecting lug, a transition plate, and an upper connecting lug.

[0020] The lower connecting ear is fixed to the lower surface of the transition plate, and the upper connecting ear is fixed to the lower surface of the transition plate. The lower connecting ear and the upper connecting ear are perpendicular to each other.

[0021] The push-pull rod has double connecting ears at both ends. The double connecting ears at the upper end of the push-pull rod are hinged to the lifting connecting ear, and the double connecting ears at the lower end of the push-pull rod are hinged to the upper connecting ear.

[0022] The lower connecting lug is hinged between the two connecting push plates.

[0023] Preferably, it also includes a bidirectional telescopic rod, which includes a main rod and two auxiliary rods. The main rod is a tubular rod, and the two auxiliary rods are symmetrically arranged on the left and right sides. The inner ends of the two auxiliary rods slide inside the main rod.

[0024] The main rod passes through the lower end of the forearm and the rear ends of the two connecting plates, and the main rod rotates relative to the lower end of the forearm and the two connecting plates respectively.

[0025] The outer end of the auxiliary rod passes through the lower connecting lug and the two connecting push plates, and the auxiliary rod rotates relative to the lower connecting lug and the two connecting push plates respectively.

[0026] Preferably, the main rod is provided with four limiting plates, the two limiting plates located in the middle abutting against the left and right sides of the lower end of the forearm, and the limiting plates located on both sides abutting against the outer sides of the two connecting plates.

[0027] The auxiliary rod is provided with two limiting plates, which abut against the opposite sides of the two connecting push plates.

[0028] Preferably, a second sliding groove is provided on the inner side wall of the main rod, and the two ends of the second sliding groove are closed.

[0029] The auxiliary rod slides on a slider two on the circumferential side of one end of the main rod, and the slider two slides in the groove two.

[0030] This utility model has the following beneficial effects:

[0031] 1. By using a bidirectional push-pull mechanism to move the two auxiliary buckets on the left and right outwards, the width of the stripping bucket is increased. This increases the amount and range of coal stripping that the stripping bucket can strip at one time, thereby improving the stripping efficiency of the stripping device.

[0032] 2. The two-way telescopic rod, in conjunction with the two-way push-pull mechanism, allows the auxiliary bucket to slide stably. Moreover, as a connecting shaft shared by the main bucket and the auxiliary bucket, the two-way telescopic rod ensures the synchronicity of the swing of the main bucket and the auxiliary bucket, preventing the stripping bucket from jamming during swing.

[0033] 3. The setting of the limit plate can prevent the active arm and the forearm from being displaced in the horizontal direction, and can also prevent the auxiliary rod from causing the main rod to be displaced in the horizontal direction during the sliding process.

[0034] 4. The setting of the second limiting plate can prevent the auxiliary rod from separating from the connecting push plate and the lower connecting ear as the auxiliary rod moves with the connecting push plate. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall structure of the stripping device for open-pit coal mines described in this utility model.

[0036] Figure 2 This is a schematic diagram showing the connection between the boom and the stripping bucket in the stripping device for open-pit coal mines described in this utility model.

[0037] Figure 3 This is a schematic diagram showing the connection between the bidirectional push-pull mechanism and the stripping bucket in the stripping device for open-pit coal mines described in this utility model.

[0038] Figure 4 This is a schematic diagram showing the connection between the bidirectional push-pull mechanism and the forearm in the stripping device for open-pit coal mines described in this utility model.

[0039] Figure 5 This is a schematic diagram showing the connection between the bidirectional telescopic rod and the auxiliary bucket in the stripping device for open-pit coal mines described in this utility model.

[0040] Figure 6 for Figure 5 Enlarged view of point A in the image;

[0041] Figure 7 This is a schematic diagram of the push-pull rod, bidirectional connector, and auxiliary bucket in the stripping device for open-pit coal mines described in this utility model;

[0042] Figure 8 This is a schematic diagram of the main bucket in the stripping device for open-pit coal mines described in this utility model.

[0043] In the diagram: 1. Machine body; 2. Boom; 3. Arm; 31. Mounting hole; 32. Lifting hole; 33. Partition plate; 4. Hydraulic rod one; 5. Hydraulic rod two; 6. Stripping bucket; 61. Main bucket; 611. Connecting plate; 612. Slide cavity; 613. Slide groove one; 62. Secondary bucket; 621. Connecting push plate; 622. Sliding block one; 7. Bidirectional push-pull mechanism; 71. Push-pull rod; 711. Double connecting lug; 72. Motor; 73. Lifting mechanism Pipe; 731, Lifting connecting ear; 732, Lifting slider; 74, Lead screw; 8, Hydraulic rod three; 9, Connecting rod one; 100, Connecting rod two; 200, Two-way connector; 201, Lower connecting ear; 202, Transition plate; 203, Upper connecting ear; 300, Two-way telescopic rod; 310, Main rod; 3101, Limiting plate one; 3102, Slide groove two; 320, Sub-rod; 3201, Limiting plate two; 3202, Slider two. Detailed Implementation

[0044] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, so that those skilled in the art can implement it based on the description.

[0045] This utility model proposes a stripping device for open-pit coal mines, such as... Figure 1 and Figure 2As shown, the device includes a body 1, a large arm 2, a small arm 3, and a peeling bucket 6 with adjustable width. The lower end of the large arm 2 is hinged to the body 1, the upper part of the small arm 3 is hinged to the front end of the large arm 2, and the peeling bucket 6 is hinged to the lower end of the small arm 3. The peeling bucket 6 includes a main bucket 61 and two auxiliary buckets 62. The main bucket 61 has sliding cavities 612 on its left and right sides, and the two sliding cavities 612 are symmetrically arranged. The two auxiliary buckets 62 slide in the two sliding cavities 612 in the left and right directions, respectively. The device also includes a bidirectional push-pull mechanism 7 that can simultaneously drive the two auxiliary buckets 62 to slide. The bidirectional push-pull mechanism 7 is installed in the lower part of the small arm 3.

[0046] like Figure 1 As shown, a hydraulic rod 4 is provided between the boom 2 and the body 1. The cylinder of the hydraulic rod 4 is hinged to the body 1, and the output end of the hydraulic rod 4 is hinged to the boom 2. A hydraulic rod 5 is provided between the upper surface of the boom 2 and the upper end of the forearm 3. The cylinder of the hydraulic rod 5 is hinged to the upper surface of the boom 2, and the output end of the hydraulic rod 5 is hinged to the upper end of the forearm 3.

[0047] like Figure 2 and Figure 8 As shown, two parallel connecting plates 611 are fixed on the upper surface of the main bucket 61, and the lower end of the forearm 3 is hinged between the rear ends of the two connecting plates 611.

[0048] like Figure 2 As shown, a connecting rod 9 is hinged between the front ends of the two connecting plates 611. The connecting rod 9 is inclined. Two parallel connecting rods 100 are hinged to the lower front side of the forearm 3. The free end of the connecting rod 9 is hinged between the free ends of the two connecting rods 100.

[0049] like Figure 2 As shown, a hydraulic rod 3 8 is provided between the main bucket 61 and the forearm 3. The cylinder of the hydraulic rod 3 8 is hinged to the front side of the forearm 3, and the output end of the hydraulic rod 3 8 is hinged to the free end of the connecting rod 9.

[0050] The extension and retraction of hydraulic rod 4 can drive the boom 2 to rise and fall, the extension and retraction of hydraulic rod 5 can drive the forearm 3 to swing back and forth, the extension and retraction of hydraulic rod 8 can drive the connecting rod 100 to swing up and down, and while the connecting rod 100 swings up and down, it can also drive the connecting rod 9 to move up and down. The angle between the connecting rod 9 and the connecting rod 100 changes accordingly. The connecting rod 9 drives the connecting plate 611 to swing up and down, and the angle between the connecting rod 9 and the connecting plate 611 also changes accordingly. The stripping bucket 6 swings accordingly, thus completing the stripping action of the stripping bucket 6.

[0051] like Figure 5 , Figure 7 and Figure 8 As shown, the upper cavity wall of the sliding cavity 612 is provided with a sliding groove 613, and the outer end of the sliding groove 613 is closed.

[0052] The upper surface of the secondary bucket 62 is provided with a slider 622, which slides in the groove 613.

[0053] The slider 622 and the outer closed groove 613 work together to prevent the auxiliary bucket 62 from separating from the main bucket 61.

[0054] like Figure 4 As shown, the lower part of the forearm 3 is provided with a mounting hole 31 and a lifting hole 32. The mounting hole 31 is located above the lifting hole 32, and a partition 33 is provided between the mounting hole 31 and the lifting hole 32.

[0055] like Figure 3 and Figure 4 As shown, the bidirectional push-pull mechanism 7 includes a push-pull rod 71, a motor 72, a lifting tube 73, and a lead screw 74;

[0056] The motor 72 is installed in the mounting hole 31, and the output shaft of the motor 72 passes vertically through the partition 33, and the output shaft of the motor 72 rotates relative to the partition 33.

[0057] The lead screw 74 is vertically arranged and rotates within the lifting hole 32. The output end of the motor 72 is fixedly connected to the upper end of the lead screw 74. The lifting tube 73 is sleeved on the body of the lead screw 74 and is threadedly connected to the lead screw 74.

[0058] The front and rear sides of the lifting tube 73 are respectively provided with lifting sliders 732, and the two lifting sliders 732 are slidably connected to the front and rear hole walls of the lifting hole 32 respectively.

[0059] Two push-pull rods 71 ​​are symmetrically arranged on the left and right sides. The push-pull rods 71 ​​are inclined. The upper ends of the two push-pull rods 71 ​​are respectively hinged to the left and right sides of the lifting tube 73, and the lower ends of the push-pull rods 71 ​​are bidirectionally hinged to the upper surface of the auxiliary bucket 62.

[0060] like Figure 5 and Figure 7 As shown, two parallel connecting push plates 621 are fixed on the upper surface of the secondary bucket 62, with the connecting push plates 621 close to the outer edge of the secondary bucket 62.

[0061] like Figure 4 As shown, lifting connecting ears 731 are fixed on the left and right sides of the lifting tube 73, respectively.

[0062] like Figure 7 As shown, a bidirectional connector 200 is provided between the push-pull rod 71 and the connecting push plate 621. The bidirectional connector 200 includes a lower connecting lug 201, a transition plate 202 and an upper connecting lug 203.

[0063] The lower connecting ear 201 is fixed to the lower surface of the transition plate 202, and the upper connecting ear 203 is fixed to the lower surface of the transition plate 202. The lower connecting ear 201 and the upper connecting ear 203 are perpendicular to each other.

[0064] like Figure 5 and Figure 7 As shown, the push-pull rod 71 has double connecting ears 711 at both ends. The double connecting ears 711 at the upper end of the push-pull rod 71 are hinged to the lifting connecting ear 731, and the double connecting ears 711 at the lower end of the push-pull rod 71 are hinged to the upper connecting ear 203.

[0065] The lower connecting ear 201 is hinged between the two connecting push plates 621.

[0066] like Figure 3 . Figure 5 and Figure 7 As shown, it also includes a bidirectional telescopic rod 300, which includes a main rod 310 and two auxiliary rods 320. The main rod 310 is a tubular rod, and the two auxiliary rods 320 are symmetrically arranged on the left and right sides. The inner ends of the two auxiliary rods 320 slide inside the main rod 310.

[0067] The main rod 310 passes through the lower end of the forearm 3 and the rear ends of the two connecting plates 611, and the main rod 310 rotates relative to the lower end of the forearm 3 and the two connecting plates 611 respectively.

[0068] The outer end of the auxiliary rod 320 passes through the lower connecting lug 201 and the two connecting push plates 621, and the auxiliary rod 320 rotates relative to the lower connecting lug 201 and the two connecting push plates 621 respectively.

[0069] The bidirectional telescopic rod 300, in conjunction with the bidirectional push-pull mechanism 7, enables the auxiliary bucket 62 to slide stably. Furthermore, as a connecting shaft shared by the main bucket 61 and the auxiliary bucket 62, the bidirectional telescopic rod 300 ensures the synchronicity of the swing of the main bucket 61 and the auxiliary bucket 62, preventing the stripping bucket 6 from jamming during swing.

[0070] like Figure 3 , Figure 5 and Figure 6 As shown, the main rod 310 has four limiting plates 3101 on its body. The two limiting plates 3101 in the middle abut against the left and right sides of the lower end of the forearm 3, respectively, and the limiting plates 3101 on both sides abut against the outer sides of the two connecting plates 611, respectively.

[0071] The secondary rod 320 has two limiting plates 3201 on its shaft, and the two limiting plates 3201 abut against the opposite sides of the two connecting push plates 621.

[0072] The setting of the limit plate 3101 can prevent the active arm and the forearm 3 from being relatively displaced in the horizontal direction, and can also prevent the auxiliary rod 320 from causing the main rod 310 to be displaced in the horizontal direction during the sliding process.

[0073] The setting of the limiting plate 3201 can make the auxiliary rod 320 move with the connecting push plate 621, preventing the auxiliary rod 320 from separating from the connecting push plate 621 and the lower connecting lug 201.

[0074] like Figure 5 and Figure 6 As shown, a second sliding groove 3102 is provided on the inner side wall of the main rod 310, and both ends of the second sliding groove 3102 are closed.

[0075] The auxiliary rod 320 slides on the circumferential side of one end of the main rod 310, and the slider 3202 slides in the groove 3102.

[0076] Using this invention, when it is necessary to increase the width of the peeling bucket 6, the motor 72 is started. The motor 72 drives the lead screw 74 to rotate, and the lead screw 74 drives the lifting tube 73 to move downward. The lifting tube 73 drives the upper ends of the two push-pull rods 71 ​​to move downward through the two lifting connecting ears 731. The lower ends of the two push-pull rods 71 ​​move to the left and right respectively. The double connecting ears 711 located at the lower end of the push-pull rods 71 ​​rotate relative to the upper connecting ears 203. At the same time, the two push-pull rods 71 ​​push the two bidirectional connecting parts 200 to move outward through the corresponding upper connecting ears 203. The two lower connecting ears 201 push the corresponding two connecting push plates 621 to move outward respectively. The left and right auxiliary buckets 62 move outward accordingly. Since the two connecting push plates 621 are located between the two limiting plates 3201, the outward movement of the two connecting push plates 621 will drive the corresponding auxiliary rods 320 to move outward. In this way, by increasing the width of the stripping bucket 6, the stripping amount and stripping range of the coal mine at one time can be increased, thereby improving the stripping efficiency of the stripping device.

[0077] Although the embodiments of this utility model have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this utility model. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, this utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A stripping and extraction device for open coal mines, comprising a body (1), a large arm (2), a small arm (3) and a width-adjustable stripping bucket (6), the lower end of the large arm (2) being hinged to the body (1), the upper part of the small arm (3) being hinged to the front end of the large arm (2), the stripping bucket (6) being hinged to the lower end of the small arm (3), characterized in that, The stripping hopper (6) comprises a main hopper (61) and two auxiliary hoppers (62); Two slide cavities (612) are respectively arranged on the left and right sides of the main hopper (61), the two slide cavities (612) are symmetrically arranged, and the two auxiliary hoppers (62) are respectively slidably arranged in the two slide cavities (612) along the left-right direction; A bidirectional push-pull mechanism (7) capable of simultaneously sliding the two auxiliary hoppers (62) is further arranged in the lower part of the small arm (3).

2. The stripping and extraction apparatus for an open cut coal mine as claimed in claim 1 wherein, Two parallel connecting plates (611) are fixed to the upper surface of the main hopper (61), and the lower end of the small arm (3) is hingedly connected between the rear ends of the two connecting plates (611).

3. The stripping and extraction apparatus for open cut coal mines according to claim 1, characterised in that, A slide groove (613) is arranged on the upper cavity wall of the slide cavity (612), and the outer end of the slide groove (613) is closed. A slide block (622) is arranged on the upper surface of the auxiliary hopper (62), and the slide block (622) is slidably arranged in the slide groove (613).

4. The stripping and extraction apparatus for open cut coal mines according to claim 2, characterised in that, An installation hole (31) and a lifting hole (32) are arranged in the lower part of the small arm (3), the installation hole (31) is arranged above the lifting hole (32), and a partition plate (33) is arranged between the installation hole (31) and the lifting hole (32).

5. The stripping and extraction apparatus for an open cut coal mine as claimed in claim 4 wherein, The bidirectional push-pull mechanism (7) comprises a push-pull rod (71), a motor (72), a lifting pipe (73), and a lead screw (74). The motor (72) is arranged in the installation hole (31), the output shaft of the motor (72) vertically penetrates the partition plate (33), and the output shaft of the motor (72) is rotatably arranged opposite to the partition plate (33); The lead screw (74) is vertically arranged and rotatably arranged in the lifting hole (32), the output end of the motor (72) is fixedly connected to the upper end of the lead screw (74), the lifting pipe (73) is sleeved on the rod body of the lead screw (74), and the lifting pipe (73) is threadedly connected to the lead screw (74); Lifting slide blocks (732) are arranged on the front and rear sides of the lifting pipe (73), and the two lifting slide blocks (732) are slidably connected to the front and rear hole walls of the lifting hole (32); The push-pull rod (71) is symmetrically arranged on the left and right sides, the push-pull rod (71) is obliquely arranged, the upper ends of the two push-pull rods (71) are hingedly connected to the left and right sides of the lifting pipe (73), and the lower ends of the push-pull rods (71) are bidirectionally hingedly connected to the upper surface of the auxiliary hopper (62).

6. The stripping and extraction apparatus for an open cut coal mine as claimed in claim 5 wherein, Two left-right parallel connecting push plates (621) are fixed to the upper surface of the auxiliary hopper (62), and the connecting push plates (621) are close to the outer side edges of the auxiliary hopper (62).

7. The stripping and extraction apparatus for an open cut coal mine as claimed in claim 6 wherein, Lifting connecting ears (731) are respectively fixed to the left and right sides of the lifting pipe (73); A bidirectional connecting piece (200) is arranged between the push-pull rod (71) and the connecting push plate (621), and the bidirectional connecting piece (200) comprises a lower connecting ear (201), a transition plate (202), and an upper connecting ear (203). The lower connecting lug (201) is fixed on the lower surface of the transition plate (202), and the upper connecting lug (203) is fixed on the lower surface of the transition plate (202), and the lower connecting lug (201) is perpendicular to the upper connecting lug (203); Both ends of the push-pull rod (71) are respectively provided with double connecting lugs (711), the double connecting lug (711) located at the upper end of the push-pull rod (71) is hinged to the lifting connecting lug (731), and the double connecting lug (711) located at the lower end of the push-pull rod (71) is hinged to the upper connecting lug (203); The lower connecting lug (201) is hinged between the two connecting push plates (621).

8. The stripping and extraction apparatus for an open cut coal mine as claimed in claim 7 wherein, The two-way telescopic rod (300) comprises a main rod (310) and two auxiliary rods (320), the main rod (310) is a tubular rod, the two auxiliary rods (320) are symmetrically arranged, and the inner ends of the two auxiliary rods (320) are slidably arranged in the main rod (310); The main rod (310) penetrates the lower end of the small arm (3) and the rear ends of the two connecting plates (611), and the main rod (310) is relatively rotatable with the lower end of the small arm (3) and the two connecting plates (611) respectively. The outer ends of the auxiliary rods (320) penetrate the lower connecting lug (201) and the two connecting push plates (621), and the auxiliary rods (320) are relatively rotatable with the lower connecting lug (201) and the two connecting push plates (621) respectively.

9. The stripping and extraction apparatus for an open cut coal mine according to claim 8, characterised in that, Four limiting plates one (3101) are arranged on the rod body of the main rod (310), the two limiting plates one (3101) located at the middle portion are respectively abutted against the left and right side surfaces of the lower end of the small arm (3), and the limiting plates one (3101) located at the two sides are respectively abutted against the outer sides of the two connecting plates (611). Two limiting plates two (3201) are arranged on the rod body of the auxiliary rod (320), and the two limiting plates two (3201) are respectively abutted against the side surfaces away from the two connecting push plates (621).

10. The stripping and extraction apparatus for an open cut coal mine according to claim 8, characterised in that, A sliding groove two (3102) is formed in the inner side wall of the main rod (310), and both ends of the sliding groove two (3102) are closed; A sliding block two (3202) is arranged on the circumferential surface of one end of the main rod (310), and the sliding block two (3202) slides in the sliding groove two (3102).

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