Hydraulic double-legged robot leg device built in oil pipe

Abstract

The application provides a hydraulic double-legged robot leg device with an oil pipe, and relates to the technical field of hydraulic bionic robots.The device comprises a double-leg connecting plate and two bionic legs connected below the double-leg connecting plate.The bionic legs comprise, from top to bottom, a hip joint, a thigh structure, a knee joint, a lower leg structure, an ankle joint, a foot structure and an internal oil circuit system.The application adopts full hydraulic drive, has better dynamic response and stronger driving force compared with electric drive, adopts full internal oil circuit design, avoids oil pipe scratching, damage and leakage in complex working conditions, and can be adapted to high-risk and extreme working environments.On the other hand, the application adopts high-low pressure oil circuit independent design, and a rotary joint is matched with a rotary oil feeding mechanism to realize the use of a drilling processing method to process a hydraulic oil circuit to replace a traditional soft tube oil supply, solve the problems of easy oil mixing, leakage, damage and pipeline winding of the soft tube oil supply, and make the oil circuit operation more stable and the service life greatly increased.

Description

Technical Field

[0001] This invention relates to the field of hydraulic bionic robot technology, specifically to a hydraulic bipedal robot leg device with an internal oil pipe. Background Technology

[0002] Bipedal robots represent a cutting-edge, multidisciplinary technology with broad application prospects in specialized operations, complex terrain exploration, and heavy-duty transportation. The leg structures of bipedal robots typically mimic human or animal leg designs, with the core objectives of achieving stable walking, high dynamic response, and optimized energy efficiency. Mainstream designs employ a "human leg" configuration, including hip, knee, and ankle joints, to simulate human gait.

[0003] Hydraulic drives, with their core advantages of high power output, fast dynamic response, and strong load capacity, have become the mainstream drive solution for highly dynamic and heavy-duty bipedal robots. Compared with electric motor drives, hydraulic systems can output greater torque, making them more suitable for stable walking in complex terrains and high-intensity operations.

[0004] However, existing hydraulic bipedal robot leg devices still have technical shortcomings: Firstly, most hydraulic bipedal robots use external oil pipes. In complex terrain and high-risk extreme environments, the oil pipes are prone to scratches, damage, and oil leaks, which greatly reduces the reliability of the equipment and cannot meet the requirements of highly reliable professional operations. Secondly, the use of flexible hoses for oil connection at rotating joints can easily lead to problems such as hose entanglement, bending and damage, and cross-contamination of high and low pressure oil, making it difficult to guarantee the stability and sealing of the oil circuit.

[0005] The aforementioned shortcomings have limited the application and promotion of hydraulic bipedal robots under extreme working conditions. Therefore, there is an urgent need for a hydraulic bipedal robot leg device that takes into account biomimetic motion performance, environmental adaptability, and hydraulic circuit reliability. Summary of the Invention

[0006] To address the shortcomings of the prior art, the present invention aims to provide a hydraulic bipedal robot leg device with an internal oil pipe. It adopts an internal oil circuit design and is equipped with a rotary oil supply mechanism at the rotating joint, which avoids the problems of oil pipe scratching, damage, and leakage under complex working conditions. At the same time, it solves the problems of oil cross-contamination, leakage, and pipe entanglement, making the oil circuit operation more stable and adaptable to high-risk and extreme working environments.

[0007] Specifically, on one hand, the present invention provides a hydraulic bipedal robot leg device with an internal oil pipe, including a bipedal connecting plate and two bionic legs connected below the bipedal connecting plate, the bionic legs comprising, from top to bottom: Hip joint: Connected to the connecting plate of the two legs, the hip joint is equipped with a fourth hydraulic cylinder; Thigh structure: Rotatably connected to the hip joint, the piston rod of the fourth hydraulic cylinder is rotatably connected to the thigh mechanism to realize the pitching movement of the hip joint; Knee joint: including a third hydraulic cylinder mounted on the thigh structure; Lower leg structure: Rotatably connected to the thigh structure, the piston rod of its third hydraulic cylinder is rotatably connected to the lower leg structure to realize the flexion and extension movement of the knee joint; Ankle joint: includes a first hydraulic cylinder and a second hydraulic cylinder that are respectively rotatably connected to the lower leg structure; Foot structure: includes a bionic arch with an elastic truss structure. The bionic arch is rotatably connected to the lower leg structure via a cross shaft. The piston rods of the first hydraulic cylinder and the second hydraulic cylinder are rotatably connected to the left and right sides of the rear of the foot structure via fisheye bearings, which are used to drive the foot structure to tilt and swing forward, backward, left, and right. Built-in hydraulic system: including interconnected hydraulic pump station and hydraulic circuits. The hydraulic circuits are divided into independent high-pressure output circuits and low-pressure return circuits. The hydraulic pump station is installed above the double-leg connecting plate. The hydraulic circuits are all machined by drilling and are diverted into the bionic legs through the double-leg connecting plate to drive the movement of each hydraulic cylinder. The hydraulic circuits are connected to a rotary oil supply mechanism at the rotatable joints. The rotary oil supply mechanism uses the rotating shaft as the oil circuit channel. The shaft has high-pressure pipelines and low-pressure pipelines respectively connected to the high-pressure output circuit and the low-pressure return circuit to form a closed-loop oil circuit.

[0008] Furthermore, the bottom of the double-leg connecting plate is provided with two hinge seats, which are used to hinge the fifth hydraulic cylinder and the sixth hydraulic cylinder respectively. The opposite sides of the thigh structure of the two bionic legs are provided with hinge seats, which are used to hinge with the piston rods of the fifth hydraulic cylinder and the sixth hydraulic cylinder respectively, and the fifth hydraulic cylinder and the sixth hydraulic cylinder are arranged in a cross shape to realize the lateral swing movement of the hip joint.

[0009] Furthermore, a battery and control box are also installed above the connecting plate of the two legs. Both the battery and the control box are electrically connected to the hydraulic pump station. The control box can control the extension and retraction of each hydraulic cylinder.

[0010] Furthermore: the lower leg structure includes a rearwardly curved lower leg plate and a reinforcing rib. The top of the lower leg plate is rotatably connected to the thigh mechanism via a pivot, and the bottom is connected to the cross shaft. The top of the reinforcing rib is connected to the lower leg plate, and the bottom is connected to the cross shaft.

[0011] Furthermore: the hydraulic circuits in the lower leg mechanism are located within the reinforcing ribs.

[0012] Furthermore: the thigh mechanism includes two parallel thigh arc-shaped plates arranged on the left and right, the tops of the two thigh arc-shaped plates are rotatably connected to the hip joint, and the bottoms are rotatably connected to the calf structure; The piston rods of the third and fourth hydraulic cylinders are rotatably connected to the two thigh arc plates via pins connecting the two thigh arc plates.

[0013] Furthermore, the bionic arch is an upward-curving arc structure made of elastic alloy material to absorb impact vibrations.

[0014] Furthermore, the rotary oil supply device is provided with several oil inlets and several oil outlets, which are evenly arranged circumferentially and connected to the rotating shaft to realize the inflow and outflow of oil.

[0015] Furthermore, the piston rod of the third hydraulic cylinder is hinged to the extension node of the lower leg structure to convert the thrust of the third hydraulic cylinder into the rotational torque of the lower leg structure.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention adopts a fully hydraulic drive, which has better dynamic response and stronger driving force compared to electric drive. At the same time, it adopts a fully built-in oil circuit design, which avoids the problems of oil pipe scraping, damage, leakage, or the robot's movement being affected by oil pipe jamming under complex working conditions compared to the traditional external oil pipe solution. It can be adapted to high-risk and extreme working environments, improving the reliability and professionalism of equipment operation.

[0017] 2. The bipedal robot leg device proposed in this invention is designed with reference to the human leg mechanism in terms of the degree of freedom of each joint, motion parameters and hydraulic cylinder arrangement. The gait is natural and flexible. At the same time, the bionic arch, lower leg arc plate, thigh arc plate and other components form a multi-level elastic energy storage structure, which can cushion the landing and recover energy to improve the motion efficiency, while taking into account both lightweight and structural strength.

[0018] 3. This invention adopts an independent design for high and low pressure oil circuits, and a rotary joint is equipped with a rotary oil supply mechanism. It realizes the replacement of traditional hose oil supply with the method of drilling hydraulic pipelines, which solves the problems of easy cross-flow, leakage, damage and pipeline entanglement of hose oil supply. The oil circuit operation is more stable, the overall equipment is lighter, and the service life is greatly increased.

[0019] 4. In this invention, the foot structure is rotatably connected to the lower leg structure via a cross shaft. Pressure is applied to the foot structure by the synchronous extension or differential extension of the piston rods of the first and second hydraulic cylinders. When the first and second hydraulic cylinders extend synchronously, they drive the ankle joint to complete the pitching motion; when the first and second hydraulic cylinders extend differentially, they drive the ankle joint to complete the lateral swinging motion, thereby driving the foot structure to swing in the forward, backward, left, and right directions. Attached Figure Description

[0020] Figure 1 This is an overall schematic diagram of the hydraulic bipedal robot leg device with built-in oil pipes according to the present invention; Figure 2 This is a rear view of the hydraulic bipedal robot leg device of the present invention; Figure 3 This is a schematic diagram of the single-leg structure of the hydraulic bipedal robot of the present invention; Figure 4 This is the built-in high and low pressure oil route diagram of the present invention; Figure 5 This is a cross-sectional view of the hip joint rotational lubrication mechanism of the present invention; Figure 6 This is a perspective view of the knee joint rotation lubrication mechanism of the present invention.

[0021] Key reference numerals: 1. Thigh structure; 2. Lower leg structure; 3. Foot structure; 4. Ankle joint; 5. Knee joint; 6. Hip joint; 7. Leg connecting plate; 8. First hydraulic cylinder; 9. Second hydraulic cylinder; 10. Third hydraulic cylinder; 11. Fourth hydraulic cylinder; 12. Fifth hydraulic cylinder; 13. Sixth hydraulic cylinder; 14. Bionic arch; 15. Fisheye bearing; 16. Reinforcing rib; 17. Lower leg arc plate; 18. Thigh arc plate; 19. Rotary oil supply mechanism; 20. High-pressure oil circuit; 21. Low-pressure oil circuit; 22. Cross shaft. Detailed Implementation

[0022] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0023] Example 1 like Figures 1 to 3 As shown, this invention discloses a hydraulic bipedal robot leg device with built-in oil pipes, comprising a double-leg connecting plate 7 and two bionic legs disposed below the double-leg connecting plate 7. The double-leg connecting plate 7 supports the hydraulic pump station, control box, battery, and other devices above. The control box is electrically connected to each hydraulic cylinder and is used to control the extension and retraction of the hydraulic cylinders. Both the battery and the control box are electrically connected to the hydraulic pump station. In addition to connecting the two bionic legs, the double-leg connecting plate 7 also functions as a hydraulic valve block, with multiple hydraulic oil circuits inside and four oil pipe interfaces at the bottom, delivering hydraulic oil from the hydraulic pump station outlet to each hydraulic drive component through multiple pipelines. Since all hydraulic pipelines in this invention are machined using drilling methods and are all internally designed, common problems of traditional pipelines such as wear and leakage can be effectively avoided, making it suitable for various complex and harsh working environments.

[0024] Each bionic leg, from top to bottom, comprises a hip joint 6, a thigh structure 1, a knee joint 5, a calf structure 2, an ankle joint 4, and a foot structure 3, with its degrees of freedom and motion parameters designed based on the human leg's movement mechanism. Each hydraulic drive component uses a linear hydraulic cylinder as the power actuator, which is adapted and connected to each bionic joint structure to drive the joints to complete bionic movements, as detailed below: The hip joint 6 is a dual-degree-of-freedom structure for pitch and lateral movement. A fourth hydraulic cylinder 11 is hinged to the rear side of the hip joint 6. The piston rod of the fourth hydraulic cylinder 11 is rotatably connected to the thigh structure 1. When the fourth hydraulic cylinder 11 extends or retracts, the pitch movement of the hip joint 6 is realized. Hinges are provided on the left and right sides of the bottom of the double-leg connecting plate 7 to connect the fifth hydraulic cylinder 12 and the sixth hydraulic cylinder 13. A hinge is provided on the inner side of each of the two bionic leg thigh structures 1, which respectively hinges the piston rods of the fifth hydraulic cylinder 12 and the sixth hydraulic cylinder 13, so that the fifth hydraulic cylinder 12 and the sixth hydraulic cylinder 13 are arranged in a cross pattern, thereby controlling the lateral movement of the hip joint 6.

[0025] The thigh structure 1 is composed of two symmetrical and parallel thigh arc-shaped plates 18 spliced ​​together, which are rotatably connected to the piston rod of the fourth hydraulic cylinder 11 via a pin. The two thigh arc-shaped plates 18 are also rotatably connected to the third hydraulic cylinder 10 via a pin, achieving a lightweight design; the arc-shaped structure of the thigh arc-shaped plates 18 has both cushioning and shock absorption functions as well as elastic energy storage functions, adapting to complex terrain and multi-posture gait requirements.

[0026] The knee joint 5 is a single-degree-of-freedom pitch structure. The piston rod end of the third hydraulic cylinder 10 is hinged to the extension node of the lower leg structure 2. By optimizing the spatial position of the hinge point, the thrust of the third hydraulic cylinder 10 can be efficiently converted into the rotational torque of the lower leg structure 2. When the third hydraulic cylinder 10 extends, it drives the lower leg structure 2 to rotate backward around the knee joint 5; when the third hydraulic cylinder 10 retracts, it drives the lower leg structure 2 to return to the upright position, realizing the robot's action.

[0027] The lower leg structure 2 uses a lower leg arc plate 17 as the main body. The arc surface can realize the rapid storage and release of energy, enhancing the robot's jumping ability. The lower leg arc plate 17 has a reinforcing rib 16 welded in the middle, which greatly improves the structure's impact resistance and load capacity, and can withstand the explosive impact force and high load conditions during movement. The oil circuit in the lower leg structure 2 is embedded in the reinforcing rib 16, achieving the dual effect of oil circuit protection and structural reinforcement.

[0028] The ankle joint 4 is a dual-degree-of-freedom structure with pitch and lateral swing. It includes a first hydraulic cylinder 8 and a second hydraulic cylinder 9 that are rotatably connected to the lower leg structure 2. The first hydraulic cylinder 8 and the second hydraulic cylinder 9 are arranged left and right. The two piston rods at the bottom are rotatably connected to the left and right sides of the rear of the foot structure 3 through fisheye bearings 15 to realize small-amplitude lateral swing compensation and drive the foot structure 3 to tilt and swing forward, backward, left and right.

[0029] The foot structure 3 includes a bionic arch 14 with an elastic truss structure. The bionic arch 14 is rotatably connected to the lower leg structure 2 via a cross shaft 22. When landing, the bionic arch 14 can disperse the vertical impact force to multiple force points to achieve cushioning and shock absorption. When jumping, the bionic arch 14 compresses and stores energy, and releases energy after leaving the ground, which greatly improves the robot's dynamic motion performance. The truss structure effectively reduces the weight of the foot and achieves a lightweight design for the leg.

[0030] During actual movement, when the first linear hydraulic cylinder 8 and the second linear hydraulic cylinder 9 extend and retract synchronously, the rear of the foot structure 3 is subjected to a downward or upward force. According to the lever principle, the front of the foot structure 3 is subjected to a force in the opposite direction, thereby driving the ankle joint 4 to complete the pitching and rolling motion. The rotation angle replicates the range of motion of the human ankle joint. When the first hydraulic cylinder 8 and the second hydraulic lever 9 extend and retract differentially, the first hydraulic cylinder 8 and the second hydraulic lever 9 apply a downward pushing force and an upward pulling force to the left and right sides of the rear of the foot structure 3, respectively, driving the ankle joint 4 to complete the lateral swinging motion. The coaxial centerline layout can effectively eliminate radial sway during the movement of the hydraulic cylinder.

[0031] like Figure 4 The diagram shows the layout of the hydraulic lines within the leg assembly. Red represents high-pressure oil line 20, the output oil line; blue represents low-pressure oil line 21, the return oil line. High-pressure oil line 20 and low-pressure oil line 21 are independent and do not interfere with each other, independently supplying oil to the leg structure. Specifically, this includes oil lines for the double-leg connecting plate, thigh, lower leg, and hinge components. The double-leg connecting plate 7 serves as the main oil distribution hub, with pre-set oil channels inside to distribute the pressurized oil output from the top hydraulic pump station to the various hinge components and joint oil lines. High-pressure oil line 20 and low-pressure oil line 21 are independently arranged within the connecting plate, ultimately connecting with the pump station's inlet and outlet oil lines.

[0032] The thigh oil circuit delivers hydraulic oil supplied from the double leg connecting plate 7 to the support shaft of the third hydraulic cylinder 10, and guides it into the third hydraulic cylinder 10 through a rotary oil distribution method. The calf oil circuit is embedded inside the reinforcing rib 16 of the calf arc plate 17. After the oil supplied from the thigh is distributed by the rotary oil supply mechanism 19, the oil is diverted through the side pipe to the oil circuits on both sides of the ankle joint 4, realizing precise high and low pressure oil supply to the first hydraulic cylinder 8 and the second hydraulic cylinder 9 of the ankle joint 4. During oil return, the oil flows through the middle low-pressure oil circuit 21 and finally returns to the hydraulic pump station to form a closed loop.

[0033] like Figure 5 and Figure 6The figures shown are sectional and perspective views of the rotary oil supply mechanism. Since the hydraulic oil pipes in this invention are all made of metal, a rotary oil supply mechanism connecting pipes must be arranged at each joint. The rotary oil supply mechanism 19 uses a rotating shaft as the oil circuit carrier, with independent high-pressure and low-pressure pipes inside the shaft. The rotary oil supply mechanism 19 also has several inlet holes and several outlet holes, all evenly arranged circumferentially and connected to the rotating shaft. The circumferential openings allow oil to flow in and out, enabling the hydraulic oil circuit to circumferentially connect at the rotating joint.

[0034] Based on the existing mechanical structure and drive method of hydraulic bipedal robots, this invention designs and optimizes a multi-degree-of-freedom leg motion mechanism with the human leg as the biomimetic object. It is equipped with a joint hydraulic drive system and a fully built-in branched oil circuit to solve the problems of easy damage of external oil circuit, insufficient joint biomimeticity, poor buffer energy storage performance and weak oil circuit stability in the existing technology, so as to realize high dynamic, high reliability and high adaptability of robot legs.

[0035] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A hydraulic bipedal robot leg device with an internal oil pipe, comprising a bipedal connecting plate (7) and two bionic legs connected below the bipedal connecting plate (7), characterized in that: The bionic legs, from top to bottom, include: Hip joint (6): Connected to the double leg connecting plate (7), the hip joint (6) is equipped with a fourth hydraulic cylinder (11); Thigh structure (1): Rotatably connected to the hip joint (6), the piston rod of the fourth hydraulic cylinder (11) is rotatably connected to the thigh mechanism (1) to realize the pitching motion of the hip joint (6); Knee joint (5): including a third hydraulic cylinder (10) mounted on the thigh structure (1); Lower leg structure (2): Rotatably connected to thigh structure (1), the piston rod of its third hydraulic cylinder (10) is rotatably connected to lower leg structure (2) to realize the pitching movement of knee joint (5); Ankle joint (4): including a first hydraulic cylinder (8) and a second hydraulic cylinder (9) that are respectively rotatably connected to the lower leg structure (2); Foot structure (3): includes a bionic arch part (14) with an elastic truss structure. The bionic arch part (14) is rotatably connected to the lower leg structure (2) through a cross shaft (22). The piston rods of the first hydraulic cylinder (8) and the second hydraulic cylinder (9) are rotatably connected to the left and right sides of the rear of the foot structure (3) through a fish-eye bearing (15) to drive the foot structure (3) to tilt and swing forward, backward, left and right. Built-in oil circuit system: including interconnected hydraulic pump station and hydraulic oil circuit. The hydraulic oil circuit is divided into independent high pressure output oil circuit (20) and low pressure return oil circuit (21). The hydraulic pump station is installed above the double leg connecting plate (7). The hydraulic oil circuit is made by drilling and is diverted into the bionic leg through the double leg connecting plate (7) to drive the movement of each hydraulic cylinder. The hydraulic oil circuit is connected to a rotary oil supply mechanism (19) at the rotatable joint. The rotary oil supply mechanism (19) uses the rotating axis as the oil circuit channel. The high pressure pipeline and low pressure pipeline are opened in the axis respectively and connected to the high pressure output oil circuit (20) and low pressure return oil circuit (21) to form a closed loop oil circuit.

2. The hydraulic bipedal robot leg device with an internal oil pipe as described in claim 1, characterized in that: The bottom of the double-leg connecting plate (7) is provided with two hinge seats, which are used to hinge the fifth hydraulic cylinder (12) and the sixth hydraulic cylinder (13) respectively. The thigh structure (1) of the two bionic legs is provided with hinge seats on opposite sides, which are used to hinge with the piston rods of the fifth hydraulic cylinder (12) and the sixth hydraulic cylinder (13) respectively, and the fifth hydraulic cylinder (12) and the sixth hydraulic cylinder (13) are arranged in a cross shape to realize the lateral swing movement of the hip joint (6).

3. The hydraulic bipedal robot leg device with an internal oil pipe as described in claim 1, characterized in that: A battery and control box are also installed above the double-leg connecting plate (7). The battery and control box are electrically connected to the hydraulic pump station. The control box can control the extension and retraction of each hydraulic cylinder.

4. The hydraulic bipedal robot leg device with an internal oil pipe as described in claim 1, characterized in that: The lower leg structure (2) includes a lower leg arc plate (17) that bends backward and a reinforcing rib (16). The top of the lower leg arc plate (17) is rotatably connected to the thigh mechanism (1) via a pivot, and the bottom is connected to the cross shaft (22). The top of the reinforcing rib (16) is connected to the lower leg arc plate (17), and the bottom is connected to the cross shaft (22).

5. The hydraulic bipedal robot leg device with an internal oil pipe as described in claim 4, characterized in that: The hydraulic circuit in the lower leg mechanism (2) is located inside the reinforcing rib (16).

6. The hydraulic bipedal robot leg device with an internal oil pipe as described in claim 1, characterized in that: The thigh mechanism (1) includes two parallel thigh arc plates (18) arranged on the left and right. The tops of the two thigh arc plates (18) are rotatably connected to the hip joint (6), and the bottoms are rotatably connected to the calf structure (2). The piston rods of the third hydraulic cylinder (10) and the fourth hydraulic cylinder (11) are rotatably connected to the two thigh arc plates (18) through pins connecting the two thigh arc plates (18).

7. The hydraulic bipedal robot leg device with an internal oil pipe as described in claim 1, characterized in that: The bionic arch (14) is an upward-curving arc structure made of elastic alloy material to absorb impact vibration.

8. The hydraulic bipedal robot leg device with an internal oil pipe as described in claim 1, characterized in that: The rotary oil supply device (19) has several oil inlet holes and several oil outlet holes. The oil inlet holes and several oil outlet holes are evenly arranged in the circumference and are all connected to the rotating shaft to realize the inflow and outflow of oil.

9. The hydraulic bipedal robot leg device with an internal oil pipe as described in claim 1, characterized in that: The piston rod of the third hydraulic cylinder (10) is hinged to the extension node of the lower leg structure (2) to convert the thrust of the third hydraulic cylinder into the rotational torque of the lower leg structure (2).

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