A symmetrical retractable mechanical arm

Abstract

The present invention belongs to the technical field of intelligent manufacturing equipment, and discloses a symmetrical telescopic mechanical arm, including a support frame, telescopic mechanical arms are fixedly connected to both sides of the top of the inner cavity of the support frame, and the output end of the telescopic mechanical arm is provided with a counterweight mechanism, and the counterweight mechanism includes a first counterweight box, and the first counterweight box is fixedly connected to the output end of one of the telescopic mechanical arms. When grabbing materials on one side, the application adds weight to the other end to prevent the center of gravity above the support frame from shifting toward the direction of the first counterweight box or the second counterweight box, resulting in rollover. When grabbing materials on both sides, the weight increase can be cancelled, thereby avoiding too high a center of gravity, improving stability during use, and avoiding the occurrence of safety accidents.

Description

Technical Field

[0001] The invention belongs to the technical field of intelligent manufacturing equipment, and in particular relates to a symmetrical and retractable mechanical arm. Background Art

[0002] The robotic arm is a commonly used device in many industries, mostly used in production and manufacturing. The robotic arm can be divided into fixed and mobile types according to different usage scenarios. The mobile robotic arm can be moved to any position through the rollers at the bottom, and has high flexibility. The telescopic robotic arm is a mechanical device that can change its working radius and working height through telescopic movements without changing its basic structure. The telescopic robotic arm can adapt to a variety of different working environments and task requirements, and meet the operating requirements in different scenarios by adjusting the telescopic length.

[0003] The Chinese invention application with application number "CN104552335A" discloses a symmetrical retractable robotic arm. The use of two parallelogram mechanisms can keep the palm of the robotic arm always horizontal; the use of a symmetrical structure can achieve simultaneous operation on both sides, improving the stability and work efficiency of the device; the use of an electromagnetic arc groove clamp can achieve emergency braking of the support rod.

[0004] Although the symmetrical retractable robotic arm in the above application can improve the stability and working efficiency of the device, when the robotic arm on one side of the symmetrical retractable robotic arm grabs the goods and extends, the robotic arm on the other side does not grab the goods, resulting in uneven force on the robotic arms on both sides, which will cause the center of gravity above the supporting device to shift, causing one side of the bottom connection position to be subject to large force, which is prone to deformation over a long period of time, and in severe cases may cause the robotic arm to tip over, thereby causing a safety accident. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] A symmetrical telescopic mechanical arm, comprising a support frame, both sides of the top of the inner cavity of the support frame are fixedly connected to the telescopic mechanical arms, the output end of the telescopic mechanical arm is provided with a counterweight mechanism, the counterweight mechanism comprises a first counterweight box and a second counterweight box, the first counterweight box is fixedly connected to the output end of one of the telescopic mechanical arms, the second counterweight box is fixedly connected to the output end of the other telescopic mechanical arm, the top ends of the first counterweight box and the second counterweight box are fixedly connected to a pull rope, and the bottom end of the pull rope is fixedly connected to a piston assembly;

[0007] The inner cavity of the support frame is provided with a water storage mechanism, and the water storage mechanism includes a first water storage cylinder and a second water storage cylinder, the first water storage cylinder and the second water storage cylinder are both fixedly connected to the bottom of the inner cavity of the support frame, the top of the inner cavity of the first water storage cylinder and the second water storage cylinder are both fixedly connected with a return spring, the return spring is fixedly connected to the piston assembly, the top of the first water storage cylinder and the second water storage cylinder are both fixedly connected with a telescopic water pipe, the first counterweight box is connected to the top of the inner cavity of the second water storage cylinder through the telescopic water pipe, and the second counterweight box is connected to the top of the inner cavity of the first water storage cylinder through the telescopic water pipe.

[0008] As a preferred solution of the symmetrical telescopic mechanical arm provided by the present invention, the counterweight mechanism also includes support wheels, there are four support wheels in total, the four support wheels are all fixedly connected to the top of the support frame, and the support wheels are in contact with the pull rope.

[0009] As a preferred solution of the symmetrical retractable mechanical arm provided by the present invention, the piston assembly includes a round rod and a piston plate, the top of the round rod is fixedly connected to the pull rope, the top of the piston plate is fixedly connected to the bottom end of the return spring, and the piston plates are both in contact with the inner walls of the first water storage cylinder and the second water storage cylinder.

[0010] As a preferred solution of the present invention to provide a symmetrical telescopic robotic arm, the first counterweight box and the second counterweight box are fixedly connected to a robot on one side away from the telescopic robotic arm, and the bottom of the support frame is an electric turntable.

[0011] As a preferred solution of the present invention to provide a symmetrical telescopic mechanical arm, a drainage mechanism is provided at the bottom of the first counterweight box and the second counterweight box, and the drainage mechanism includes a blocking cylinder, which is fixedly connected to the bottom of the first counterweight box and the second counterweight box and is communicated with the inner cavity of the first counterweight box and the second counterweight box, a blocking spring is fixedly connected to the side of the inner cavity of the blocking cylinder close to the telescopic mechanical arm, a blocking block is fixedly connected to the side of the blocking spring away from the telescopic mechanical arm, a pull rod is fixedly connected to the center of the side of the blocking block close to the blocking spring, a limiting plate is fixedly connected to the top of the support frame close to the side of the blocking cylinder, and a disc is fixedly connected to the end of the pull rod away from the blocking block.

[0012] As a preferred solution of the symmetrical retractable mechanical arm provided by the present invention, the bottom end of the blocking cylinder is fixedly connected with a retractable drainage pipe, the left and right ends of the support frame are fixedly connected with support rings, and the retractable drainage pipe is fixedly sleeved in the inner cavity of the support ring.

[0013] As a preferred solution of the symmetrical telescopic mechanical arm provided by the present invention, a one-way valve is fixedly connected to the top of the piston plate, and the bottom of the telescopic drainage pipe is fixedly connected to the bottom of the first water storage cylinder and the bottom of the second water storage cylinder.

[0014] As a preferred solution of the symmetrical telescopic mechanical arm provided by the present invention, the pull rod is movably connected to the inner cavity of the limit plate, and the limit plate is located on the moving path of the disc.

[0015] As a preferred solution of the symmetrical retractable robotic arm provided by the present invention, the blocking block is located at the connection between the blocking cylinder and the second counterweight box and at the blocking cylinder. When the blocking spring contracts, the blocking block can move along the pull rod to the side of the inner cavity of the blocking cylinder close to the limit plate.

[0016] The beneficial effects of the present invention are as follows:

[0017] The present invention increases weight on the other end when grabbing materials on one side, thereby preventing the center of gravity above the support frame from shifting toward the first counterweight box or the second counterweight box and causing overturning, thereby improving stability during use and avoiding the occurrence of safety accidents. When grabbing materials on both sides, the weight increase can be cancelled, thereby avoiding the center of gravity from being too high, and further improving stability during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the overall connection structure of a symmetrical retractable mechanical arm is provided for the present invention;

[0019] Figure 2 The present invention provides a schematic diagram of the connection between a first counterweight box and a telescopic water pipe of a symmetrical telescopic mechanical arm;

[0020] Figure 3 An internal cross-sectional view of a support frame of a symmetrical telescopic mechanical arm is provided for the present invention;

[0021] Figure 4 For the present invention Figure 3 The connection diagram at A is enlarged;

[0022] Figure 5 For the present invention Figure 3 The connection diagram at B is enlarged;

[0023] Figure 6 The present invention provides a schematic diagram of the internal connection between a first water storage cylinder and a second water storage cylinder of a symmetrical telescopic mechanical arm.

[0024] In the figure: 1. support frame; 2. telescopic mechanical arm; 3. counterweight mechanism; 31. first counterweight box; 32. mechanical arm; 33. pull rope; 34. piston assembly; 341. round rod; 342. piston plate; 35. second counterweight box; 36. support wheel; 4. water storage mechanism; 41. first water storage cylinder; 42. second water storage cylinder; 43. reset spring; 44. telescopic water pipe; 5. drainage mechanism; 51. blocking cylinder; 52. pull rod; 53. blocking spring; 54. blocking block; 55. telescopic drainage pipe; 56. limit plate; 57. disc; 58. support ring; 59. one-way valve. DETAILED DESCRIPTION

[0025] 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. Example

[0026] like Figures 1 to 6 As shown, an embodiment of the present invention provides a symmetrical telescopic mechanical arm, including a support frame 1, both sides of the top of the inner cavity of the support frame 1 are fixedly connected with telescopic mechanical arms 2, the output end of the telescopic mechanical arm 2 is provided with a counterweight mechanism 3, the counterweight mechanism 3 includes a first counterweight box 31 and a second counterweight box 35, the first counterweight box 31 is fixedly connected to the output end of one of the telescopic mechanical arms 2, the second counterweight box 35 is fixedly connected to the output end of the other telescopic mechanical arm 2, the top ends of the first counterweight box 31 and the second counterweight box 35 are fixedly connected with a pull rope 33, and the bottom end of the pull rope 33 is fixedly connected with a piston assembly 34;

[0027] The inner cavity of the support frame 1 is provided with a water storage mechanism 4, which includes a first water storage cylinder 41 and a second water storage cylinder 42. The first water storage cylinder 41 and the second water storage cylinder 42 are both fixedly connected to the bottom of the inner cavity of the support frame 1, and the tops of the inner cavities of the first water storage cylinder 41 and the second water storage cylinder 42 are both fixedly connected with a return spring 43, and the return spring 43 is fixedly connected to the piston assembly 34. The tops of the first water storage cylinder 41 and the second water storage cylinder 42 are both fixedly connected with a telescopic water pipe 44, and the first counterweight box 31 is connected to the upper part of the inner cavity of the second water storage cylinder 42 through the telescopic water pipe 44, and the second counterweight box 35 is connected to the upper part of the inner cavity of the first water storage cylinder 41 through the telescopic water pipe 44;

[0028] The counterweight mechanism 3 further includes a support wheel 36, and there are four support wheels 36 in total. The four support wheels 36 are all fixedly connected to the top of the support frame 1, and the support wheels 36 are in contact with the pull rope 33;

[0029] The piston assembly 34 includes a round rod 341 and a piston plate 342. The top of the round rod 341 is fixedly connected to the pull rope 33, the top of the piston plate 342 is fixedly connected to the bottom of the return spring 43, and the piston plate 342 is in contact with the inner walls of the first water storage cylinder 41 and the second water storage cylinder 42.

[0030] The first counterweight box 31 and the second counterweight box 35 are both fixedly connected to the manipulator 32 on one side away from the telescopic manipulator arm 2, and the bottom of the support frame 1 is an electric turntable.

[0031] In this embodiment, when the material on one side of the first counterweight box 31 needs to be grabbed and transported, and the material on the side of the second counterweight box 35 does not need to be grabbed and transported, the telescopic mechanical arm 2 is started to drive the first counterweight box 31 to move, thereby driving the manipulator 32 (the manipulator 32 is a prior art and will not be described in detail here) fixedly connected to the first counterweight box 31 to grab the material, and the manipulator 32 on the side of the second counterweight box 35 remains stationary.

[0032] When the first counterweight box 31 moves, the end of the pull rope 33 and the first counterweight box 31 that is fixedly connected moves with the first counterweight box 31, so that the piston assembly 34 is pulled upward in the inner cavity of the first water storage cylinder 41 through the pull rope 33, and the water in the inner cavity of the first water storage cylinder 41 is squeezed upward to the inner cavity of the telescopic water pipe 44 through the piston assembly 34, and the water is transported to the inner cavity of the second counterweight box 35 along the telescopic water pipe 44, thereby increasing the weight of the second counterweight box 35, thereby preventing the telescopic mechanical arm 2 from driving the first counterweight box 31 and the manipulator 32 to move too long, resulting in a serious deviation of the center of gravity above the support frame 1 toward the direction of the first counterweight box 31, causing the support frame 1 to tip over, thereby improving the stability during use, and also preventing the support frame 1 and the movable plate below it from being subjected to excessive force at the connection position (when the two sides of the support frame 1 are subjected to uneven force, the connection position of the support frame 1 and the movable plate below it will be subjected to force), causing deformation over a long period of time;

[0033] When the material on one side of the second counterweight box 35 needs to be grabbed and transported, and the material on the one side of the first counterweight box 31 does not need to be grabbed and transported, similarly, the water in the inner cavity of the second water storage cylinder 42 enters the inner cavity of the first counterweight box 31 to increase the weight of the first counterweight box 31, so that the center of gravity of the support frame 1 is always balanced.

[0034] like Figures 1 to 6As shown, the embodiment of the present invention provides a symmetrical telescopic mechanical arm, the bottom of the first counterweight box 31 and the second counterweight box 35 are both provided with a drainage mechanism 5, the drainage mechanism 5 includes a blocking cylinder 51, the blocking cylinder 51 is fixedly connected to the bottom of the first counterweight box 31 and the second counterweight box 35 and is communicated with the inner cavity of the first counterweight box 31 and the second counterweight box 35, a blocking spring 53 is fixedly connected to the side of the inner cavity of the blocking cylinder 51 close to the telescopic mechanical arm 2, a blocking block 54 is fixedly connected to the side of the blocking spring 53 away from the telescopic mechanical arm 2, a pull rod 52 is fixedly connected to the center of the side of the blocking block 54 close to the blocking spring 53, a limiting plate 56 is fixedly connected to the side of the top of the support frame 1 close to the blocking cylinder 51, and a disc 57 is fixedly connected to the end of the pull rod 52 away from the blocking block 54;

[0035] The bottom end of the plugging cylinder 51 is fixedly connected with a telescopic drain pipe 55, and the left and right ends of the support frame 1 are fixedly connected with support rings 58, and the telescopic drain pipe 55 is fixedly sleeved in the inner cavity of the support ring 58;

[0036] A one-way valve 59 is fixedly connected to the top of the piston plate 342, and the bottom of the telescopic drain pipe 55 is fixedly connected to the bottom of the first water storage cylinder 41 and the bottom of the second water storage cylinder 42;

[0037] The pull rod 52 is movably connected to the inner cavity of the limit plate 56, and the limit plate 56 is located on the moving path of the disc 57;

[0038] The blocking block 54 is located at the connection between the blocking cylinder 51 and the second counterweight box 35 . When the blocking spring 53 contracts, the blocking block 54 can move along the pull rod 52 to the inner cavity of the blocking cylinder 51 close to the limit plate 56 .

[0039] In this embodiment, when the manipulators 32 of the first counterweight box 31 and the second counterweight box 35 need to grab materials at the same time, the telescopic mechanical arm 2 drives the first counterweight box 31 and the second counterweight box 35 to move, and the two manipulators 32 grab the materials at the same time. At this time, the first counterweight box 31 and the second counterweight box 35 drive the blocking cylinder 51 away from the limit plate 56. When the telescopic mechanical arm 2 drives the first counterweight box 31 and the second counterweight box 35 to move to the farthest distance from the support frame 1, the blocking spring 53 and the blocking block 54 are driven to move through the blocking cylinder 51, thereby driving the pull rod 52 to move, and then the pull rod 52 drives the disc 57 to contact the limit plate 56. When the telescopic mechanical arm 2 drives the first counterweight box 31 and the second counterweight box 35 to drive the blocking cylinder 51 When it moves to the farthest distance from the support frame 1, the limit plate 56 blocks the disc 57, making it impossible for the pull rod 52 to continue moving, so that the blocking block 54 fixedly connected to the pull rod 52 is pulled in the direction of 53 when the blocking cylinder 51 continues to move, so that the blocking block 54 leaves the connection between the telescopic drainage pipe 55 and the blocking cylinder 51, and then the water in the inner cavity of the first counterweight box 31 or the second counterweight box 35 enters the lower part of the inner cavity of the first water storage cylinder 41 or the second water storage cylinder 42 along the blocking cylinder 51 and the telescopic drainage pipe 55, avoiding the water in the inner cavity of the first counterweight box 31 and the second counterweight box 35 being filled with water at the same time, resulting in the upper part of the support frame 1 being too heavy, affecting the stability of the support frame 1, and avoiding the situation where the center of gravity is too high;

[0040] When the telescopic mechanical arm 2 drives the first counterweight box 31 and the second counterweight box 35 to reset, the first counterweight box 31 and the second counterweight box 35 are driven to move toward the center of the support frame 1, and the blocking cylinder 51 also moves toward the center of the support frame 1, so that the limit plate 56 and the disc 57 are separated, and the pull rod 52 loses its limit. At this time, the blocking block 54 is driven to reset to the connection between the telescopic drain pipe 55 and the blocking cylinder 51 by the thrust of the blocking spring 53, and the first counterweight box 31 or the second counterweight box 35 is blocked again, so that water cannot flow from the telescopic drain pipe 55 to the blocking cylinder 51.

[0041] When the first counterweight box 31 and the second counterweight box 35 are reset, the pull rope 33 loses the upward pulling force of the first counterweight box 31 or the second counterweight box 35. At this time, the elastic force of the reset spring 43 drives the piston assembly 34 to move downward in the inner cavity of the first water storage cylinder 41 or the second water storage cylinder 42, and squeezes the water located below the inner cavity of the first water storage cylinder 41 and the second water storage cylinder 42. Since the blocking block 54 blocks the blocking cylinder 51, the water can only return to the upper part of the inner cavity of the first water storage cylinder 41 or the second water storage cylinder 42 through the one-way valve 59. Since some water is retained in the interior of the telescopic drain pipe 55, the upper part of the inner cavity of the first water storage cylinder 41 and the second water storage cylinder 42 can also be filled with water.

[0042] Working principle and use process: When the material on one side of the first counterweight box 31 needs to be grabbed and transported, and the material on the side of the second counterweight box 35 does not need to be grabbed and transported, the telescopic mechanical arm 2 is started to drive the first counterweight box 31 to move and then drive the manipulator 32 to grab the material. When the telescopic mechanical arm 2 drives the first counterweight box 31 to move, the piston assembly 34 in the inner cavity of the first water storage cylinder 41 is pulled upward by the pull rope 33, and the water in the inner cavity of the first water storage cylinder 41 is squeezed into the inner cavity of the second counterweight box 35 along the telescopic water pipe 44, thereby increasing the weight of the second counterweight box 35, so that the center of gravity of the first counterweight box 31 and the second counterweight box 35 above the support frame 1 is balanced;

[0043] When the first counterweight box 31 and the second counterweight box 35 both need to grab materials, when the telescopic mechanical arm 2 drives the first counterweight box 31 and the second counterweight box 35 to move to the farthest distance from the support frame 1, the limit plate 56 contacts the disc 57, so that the pull rod 52 stops moving and pulls the blocking block 54. When the telescopic mechanical arm 2 drives the first counterweight box 31 and the second counterweight box 35 to move to the farthest distance from the support frame 1, the limit plate 56 blocks the disc 57 on the pull rod 52 so that the pull rod 52 cannot continue to move. The blocking block 54 is pulled by the pull rod 52 in the inner cavity of the blocking cylinder 51 and moves in the direction of the blocking spring 53 away from the connection between the blocking cylinder 51 and the telescopic drainage pipe 55, so that the water in the inner cavity of the first counterweight box 31 and the second counterweight box 35 loses the obstruction of the blocking block 54 and flows into the lower part of the inner cavity of the first water storage cylinder 41 and the second water storage cylinder 42 along the blocking cylinder 51 and the telescopic drainage pipe 55 through the height difference;

[0044] When the two telescopic mechanical arms 2 drive the first counterweight box 31 and the second counterweight box 35 to reset, the limit plate 56 separates from the disc 57, and the blocking spring 53 drives the blocking block 54 to reset and block the inner cavity of the blocking cylinder 51 again;

[0045] At the same time, due to the resetting of the first counterweight box 31 and the second counterweight box 35, the piston assembly 34 loses the pulling force of the pull rope 33. At this time, the piston plate 342 is pushed downward along the axial direction of the round rod 341 by the thrust of the reset spring 43. The water below the inner cavity of the first water storage cylinder 41 and the second water storage cylinder 42 and the telescopic drainage pipe 55 have been blocked by the blocking block 54, so that after the water is pressed by the piston plate 342, it can only return to the top of the inner cavity of the first water storage cylinder 41 and the second water storage cylinder 42 from the one-way valve 59.

[0046] 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.

[0047] 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 symmetrical telescopic mechanical arm, comprising a support frame (1), characterized in that: Both sides of the top of the inner cavity of the support frame (1) are fixedly connected to telescopic mechanical arms (2), and the output end of the telescopic mechanical arm (2) is provided with a counterweight mechanism (3), and the counterweight mechanism (3) comprises a first counterweight box (31) and a second counterweight box (35), the first counterweight box (31) is fixedly connected to the output end of one of the telescopic mechanical arms (2), and the second counterweight box (35) is fixedly connected to the output end of the other telescopic mechanical arm (2), and the top ends of the first counterweight box (31) and the second counterweight box (35) are fixedly connected to a pull rope (33), and the bottom ends of the pull ropes (33) are fixedly connected to a piston assembly (34); The inner cavity of the support frame (1) is provided with a water storage mechanism (4), and the water storage mechanism (4) comprises a first water storage cylinder (41) and a second water storage cylinder (42), the first water storage cylinder (41) and the second water storage cylinder (42) are both fixedly connected to the bottom of the inner cavity of the support frame (1), the top of the inner cavity of the first water storage cylinder (41) and the second water storage cylinder (42) are both fixedly connected to a return spring (43), the return spring (43) is fixedly connected to the piston assembly (34), the top of the first water storage cylinder (41) and the second water storage cylinder (42) are both fixedly connected to a telescopic water pipe (44), the first counterweight box (31) is connected to the upper part of the inner cavity of the second water storage cylinder (42) through the telescopic water pipe (44), and the second counterweight box (35) is connected to the upper part of the inner cavity of the first water storage cylinder (41) through the telescopic water pipe (44); One end of the pull rope (33) fixedly connected to the first counterweight box (31) moves with the first counterweight box (31), thereby pulling the piston assembly (34) upward in the inner cavity of the first water storage cylinder (41) through the pull rope (33); the piston assembly (34) comprises a round rod (341) and a piston plate (342); the top end of the round rod (341) is fixedly connected to the pull rope (33); the top end of the piston plate (342) is fixedly connected to the bottom end of the return spring (43); and the piston plate (342) is in contact with the inner walls of the first water storage cylinder (41) and the second water storage cylinder (42); A drainage mechanism (5) is provided at the bottom of each of the first counterweight box (31) and the second counterweight box (35). The drainage mechanism (5) comprises a blocking cylinder (51). The blocking cylinder (51) is fixedly connected to the bottom of each of the first counterweight box (31) and the second counterweight box (35) and is in communication with the inner cavities of the first counterweight box (31) and the second counterweight box (35). A blocking spring (53) is fixedly connected to the inner cavities of the blocking cylinder (51) on one side close to the telescopic mechanical arm (2). The blocking spring (53) is fixedly connected to the inner cavities of the blocking cylinder (51) on the other side away from the telescopic mechanical arm (2). A blocking block (54) is provided, and a pull rod (52) is fixedly connected to the center of one side of the blocking block (54) close to the blocking spring (53); a limiting plate (56) is fixedly connected to the top of the support frame (1) close to the blocking cylinder (51); and a disc (57) is fixedly connected to the end of the pull rod (52) away from the blocking block (54); a telescopic drainage pipe (55) is fixedly connected to the bottom of the first water storage cylinder (41) and the bottom of the second water storage cylinder (42).

2. A symmetrical retractable mechanical arm according to claim 1, characterized in that: The counterweight mechanism (3) further comprises a support wheel (36), there are four support wheels (36) in total, the four support wheels (36) are all fixedly connected to the top of the support frame (1), and the support wheels (36) are in contact with the pull rope (33).

3. A symmetrical retractable mechanical arm according to claim 2, characterized in that: The first counterweight box (31) and the second counterweight box (35) are both fixedly connected to a manipulator (32) on a side away from the telescopic manipulator arm (2), and the bottom of the support frame (1) is an electric turntable.

4. A symmetrical retractable mechanical arm according to claim 3, characterized in that: The left and right ends of the support frame (1) are both fixedly connected to support rings (58), and the telescopic drainage pipe (55) is fixedly sleeved in the inner cavity of the support ring (58).

5. A symmetrical retractable mechanical arm according to claim 4, characterized in that: A one-way valve (59) is fixedly connected to the top of the piston plate (342).

6. A symmetrical retractable mechanical arm according to claim 5, characterized in that: The pull rod (52) is movably connected to the inner cavity of the limit plate (56), and the limit plate (56) is located on the moving path of the disc (57).

7. A symmetrical retractable mechanical arm according to claim 6, characterized in that: The blocking block (54) is located at the connection between the blocking cylinder (51) and the second counterweight box (35), and when the blocking spring (53) contracts, the blocking block (54) can move along the pull rod (52) to the inner cavity of the blocking cylinder (51) near the limit plate (56).

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