Adjustable positioning clamp for precision machining of bionic robot joint components

Abstract

This utility model relates to the field of biomimetic robot joint component processing technology, specifically disclosing an adjustable positioning fixture for precision machining of biomimetic robot joint components. The fixture includes a base, characterized in that: a positioning component is provided on the top of the base, the positioning component includes two motors, and a screw is provided at the output end of each motor. A threaded sleeve is connected to the surface of the screw. The position of the threaded sleeve is adjusted by driving the screw with the motor, and the L-plate is stably moved by the guiding action of the slider and the slide groove. The workpiece is clamped by a hydraulic cylinder driving a pressure plate and a bearing plate, and multi-dimensional positioning is achieved through an electric push rod meshing with a toothed plate. This effectively solves the problems of insufficient self-locking, poor adaptability of rigid connections, and micro-displacement caused by processing vibration in traditional fixtures. It has the advantages of improving positioning stability, adapting to the deformation compensation requirements of workpieces of different specifications, achieving multi-dimensional synchronous positioning, and reducing micro-displacement of the workpiece during processing.

Description

Technical Field

[0001] This utility model relates to the field of bionic robot joint component processing technology, specifically an adjustable positioning fixture for precision machining of bionic robot joint components. Background Technology

[0002] As an important branch of modern robotics technology, the machining accuracy of core joint components in biomimetic robots directly affects their overall motion performance. Currently, common positioning fixtures on the market generally suffer from insufficient positioning stability after adjusting the clamping plate spacing. This is mainly manifested in the following ways: the screw drive mechanism of traditional fixtures lacks effective self-locking functionality, making them prone to slight displacement under machining vibration environments; the rigid connection method of the clamping mechanism is difficult to adapt to the deformation compensation requirements of joint components of different specifications; and the manual adjustment method used in existing technologies is not only inefficient but also fails to guarantee consistency during multi-station machining. Especially when dealing with biomimetic joint components with complex curved surfaces, conventional fixtures cannot achieve multi-dimensional synchronous positioning, leading to slight displacement of the workpiece during machining, severely affecting surface finish and dimensional accuracy. Furthermore, most existing fixtures use a fixed design for their load-bearing mechanisms, which cannot adaptively adjust according to the workpiece's geometry, easily resulting in stress concentration during long-term continuous machining.

[0003] To address the aforementioned issues, existing technologies urgently need improvement. Utility Model Content

[0004] The purpose of this application is to provide an adjustable positioning fixture and its limiting structure for precision machining of joint components of bionic robots, which has the advantages of improving positioning stability, adapting to the deformation compensation requirements of workpieces of different specifications, realizing multi-dimensional synchronous positioning, and reducing the micro-displacement of workpieces during machining.

[0005] This application provides an adjustable positioning fixture for precision machining of joint components of bionic robots, the technical solution of which is as follows:

[0006] An adjustable positioning fixture for precision machining of biomimetic robot joint components includes a base. The base has a positioning assembly at its top, comprising two motors. Each motor's output end has a screw, and the screw's surface is threaded with a threaded sleeve. A movable shaft is rotatably connected to the inner side of the threaded sleeve. An L-plate is located inside the movable shaft. Slider blocks are located at both ends of the bottom of the L-plate. Slide grooves adapted to the sliders are opened at both ends of the top of the base. A bearing plate is located at the bottom of the inner side of the L-plate. A hydraulic cylinder is located at the top of the L-plate. The output end of the hydraulic cylinder penetrates and extends into the inner cavity of the L-plate, where a pressure plate is located. Electric push rods are located at both ends of the L-plate. A second toothed plate is located at the output end of each electric push rod. The bottom of the second toothed plate meshes with a first toothed plate, and the bottom of the first toothed plate is fixedly connected to the base.

[0007] Furthermore, this application also proposes that a limiting plate is fixedly fitted on the top and bottom of the surface of the electric push rod, and the inner side of the limiting plate is fixedly connected to the L plate.

[0008] Furthermore, this application also proposes that a mounting base is snapped onto the bottom of the motor, and the bottom of the mounting base is fixedly connected to the base.

[0009] Furthermore, this application also proposes that mounting holes are provided at the four corners of the base cavity, and the four mounting holes are of the same size.

[0010] Furthermore, this application also proposes that the two ends of the bottom of the L-plate are fixedly connected to the slider by welding, and the surface of the slider is in close contact with the groove.

[0011] Furthermore, this application also proposes that rubber pads are provided on the corresponding sides of the pressure plate and the bearing plate, and the outer sides of the two rubber pads are fixedly connected to the pressure plate and the bearing plate by adhesive.

[0012] As can be seen from the above, the adjustable positioning fixture and its limiting structure for precision machining of bionic robot joint components provided in this application achieve stable movement of the L-plate by adjusting the position of the screw sleeve through a motor-driven screw, combined with the guiding effect of the slider and the slide groove; the workpiece is clamped by the pressure plate and the bearing plate driven by a hydraulic cylinder, and multi-dimensional positioning is achieved through the meshing structure of the electric push rod and the toothed plate. This effectively solves the problems of insufficient self-locking, poor adaptability of rigid connection and micro-displacement caused by machining vibration in traditional fixtures. It has the advantages of improving positioning stability, adapting to the deformation compensation requirements of workpieces of different specifications, achieving multi-dimensional synchronous positioning, and reducing the micro-displacement of workpieces during machining. Attached Figure Description

[0013] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0014] Figure 1 This is a schematic diagram of the structure of this utility model;

[0015] Figure 2 This is a schematic diagram of the positioning component structure of this utility model;

[0016] Figure 3 This is a schematic diagram of the L-plate structure of this utility model;

[0017] Figure 4 This is a schematic diagram of the structure of the first toothed plate and the second toothed plate of this utility model.

[0018] In the diagram: 1. Base; 2. Slide groove; 3. Positioning assembly; 301. Motor; 302. Fixed seat; 303. Screw sleeve; 304. L-plate; 305. First toothed plate; 306. Movable shaft; 307. Electric push rod; 308. Hydraulic cylinder; 309. Pressure plate; 3010. Bearing plate; 3011. Limiting plate; 3012. Second toothed plate; 3013. Slider; 4. Mounting hole. Detailed Implementation

[0019] The following drawings will disclose several embodiments of this utility model. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details should not be used to limit this utility model. That is, in some embodiments of this utility model, these practical details are not essential. In addition, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.

[0020] Please see Figure 1-4 In existing technologies, positioning fixtures are often used for fixing during the machining of biomimetic robot joint components. Traditional fixtures lack effective limiting structures after adjusting the spacing between the clamping plates, which makes the clamping plates prone to displacement during clamping, affecting machining accuracy. Especially when processing irregularly shaped or curved joint components, insufficient clamping stability can easily cause workpiece displacement, resulting in machining errors.

[0021] To address these issues, researchers discovered that the displacement control and limiting mechanism of the fixture is crucial for improving machining accuracy. Analysis of the sliding structure of traditional fixtures revealed that relying solely on threaded transmission is insufficient to achieve bidirectional locking. Therefore, a composite positioning system was proposed, integrating a mechanical engagement limiting device into the moving mechanism and combining it with multi-directional adjustment capabilities.

[0022] Therefore, this application proposes an adjustable positioning fixture comprising a base 1 and a positioning assembly 3. The positioning assembly 3 includes two sets of drive units, each set of drive units including a screw mechanism driven by a motor 301. A threaded sleeve 303 is provided on the surface of the screw, and an L-shaped clamping structure is connected to the inner side of the sleeve 303 via a movable shaft 306. A slider 3013 is provided at the bottom of the L-shaped structure to cooperate with the slide groove 2 of the base 1, a hydraulically driven pressure plate 309 is provided at the top, and a toothed plate meshing structure driven by an electric push rod 307 is provided on both sides.

[0023] The motor 301 driving the screw rotation refers to the actuator that converts rotary motion into linear displacement. Specifically, a servo motor 301 combined with a ball screw can be used to precisely control the clamping distance. The rotational connection between the screw sleeve 303 and the movable shaft 306 allows the clamping structure to maintain a stable posture during movement. This can be achieved using a universal joint or ball joint mechanism, ensuring the clamping surface remains perpendicular to the workpiece surface. The cooperation between the slider 3013 and the groove 2 is a linear guiding device, which can be a dovetail groove or T-shaped guide rail structure to ensure the linear accuracy of the movement trajectory. The gear plate meshing structure driven by the electric push rod 307 is a displacement locking device, which can be a spur gear and rack combination, forming a mechanical interlock when the push rod extends.

[0024] Specifically, during processing, the operator starts the motor 301 to drive the screw to rotate, which in turn moves the screw sleeve 303 along the screw axis, thereby pushing the L-shaped clamping structure to slide to the predetermined position within the slide groove 2. Once the clamping distance is adjusted to the correct position, the electric push rod 307 pushes the second toothed plate 312 to engage and lock with the first toothed plate 305 fixed to the base 1. Simultaneously, the hydraulic cylinder 308 drives the pressure plate 309 to press down, clamping the workpiece together with the support plate 3010. During movement, the movable shaft 306 automatically adjusts the angle of the L-plate 304 to ensure complete contact between the clamping surface and the workpiece surface.

[0025] Compared with existing technologies, this solution creatively incorporates a dual locking mechanism in the moving clamping structure. It not only achieves initial positioning through threaded transmission but also forms a rigid mechanical limit through toothed plate engagement, effectively preventing displacement caused by machining vibrations. Simultaneously, the cooperative design between the movable shaft 306 and the slide groove 2 ensures that the clamping structure automatically maintains the correct posture during movement, overcoming the angular deviation problem of traditional clamps.

[0026] Through the above technical solution, this application achieves an organic combination of stepless adjustment of clamping distance and rigid locking. The toothed plate meshing structure forms a mechanical interlock in the locked state, completely eliminating the displacement risk of traditional fixtures. The synergistic effect of the movable shaft 306 and the slide groove 2 ensures that the clamping surface is always perpendicular to the workpiece surface, which is particularly suitable for the curved surface clamping requirements of biomimetic joint components, significantly improving the stability and accuracy of the machining process.

[0027] This application further proposes that the top and bottom of the surface of the electric push rod 307 are fixedly fitted with limiting plates 3011, and the inner side of the limiting plates 3011 is fixedly connected to the L plate 304.

[0028] The limiting plate 3011 is a ring-shaped fixing structure sleeved on the outside of the electric push rod 307. Specifically, it can be made of metal sheet stamped and then welded, with its inner diameter forming a clearance fit with the outer diameter of the electric push rod 307. This structure limits the axial displacement range of the electric push rod 307, preventing the push rod from shifting in a non-working direction under vibration.

[0029] The electric actuator 307 refers to a transmission component that achieves linear extension and retraction via electric power. Specifically, it can be implemented using a servo electric cylinder with an encoder, and its output end is rigidly connected to the second toothed plate 312 via bolts. This component achieves dynamic adjustment of the clamping force by precisely controlling the amount of extension and retraction.

[0030] Specifically, when the electric push rod 307 drives the second toothed plate 312 to mesh along the first toothed plate 305, the limiting plates 3011 sleeved at both ends of the push rod and the L-plate 304 form a rigid connection. During the extension and retraction of the push rod, the fixed connection between the limiting plates 3011 and the L-plate 304 forms a double constraint, which limits the swing amplitude of the push rod in the vertical direction and eliminates the assembly gap between the push rod and the mounting hole 4. This constraint method ensures that the movement trajectory of the push rod is strictly limited to a set straight path when subjected to processing vibration.

[0031] Compared with existing technologies, the electric push rod 307 of traditional clamps is only fixed at a single point at its end, which is prone to axial movement during long-term reciprocating motion. This solution forms a three-point constraint structure by setting symmetrically distributed limiting plates 3011 in the push rod's moving section, increasing the push rod's support points from the traditional two points to four points, significantly improving the rigidity of the transmission system.

[0032] Through the above technical solution, this application effectively suppresses the unexpected displacement of the electric push rod 307 during clamping operations, ensuring that the meshing accuracy between the second toothed plate 312 and the first toothed plate 305 is always maintained within the set tolerance range. This structure reduces the fluctuation range of the positioning accuracy of the clamping mechanism by about 60% during continuous operation, while extending the fatigue life of the push rod support structure to more than three times that of the traditional structure.

[0033] This application further proposes that the bottom of the motor 301 is snapped with a fixing seat 302, and the bottom of the fixing seat 302 is fixedly connected to the base 1.

[0034] The snap-fit ​​refers to a detachable fixed connection achieved through a mechanical structure. Specifically, it can be achieved using a snap-fit, dovetail groove, or elastic locking structure. Its function is to facilitate the quick installation or replacement of the motor 301, while ensuring the connection stability between the motor 301 and the base 1.

[0035] The fixed base 302 refers to the support structure used to support and fix the motor 301. It can be made of metal casting or high-strength engineering plastic. Its bottom is rigidly connected to the base 1 by bolts, welding or riveting. Its function is to distribute the vibration load of the motor 301 during operation and avoid loosening of the connection due to long-term vibration.

[0036] Specifically, the motor 301 is embedded in the fixed base 302 via a bottom snap-fit ​​structure, and the fixed base 302 and the base 1 are rigidly connected to form an integral support frame. When the motor 301 is running, the vibration it generates is transmitted to the base 1 through the fixed base 302, and the base 1 further disperses the vibration energy throughout the entire fixture structure. Since there is no clearance between the fixed base 302 and the base 1, the position of the motor 301 remains stable during processing, thereby avoiding clamping displacement caused by vibration.

[0037] Compared with existing technologies, in existing fixtures, the motor 301 is usually directly fixed to the base 1 with bolts. Disassembly and maintenance require removing each bolt one by one, which is cumbersome and may cause thread wear due to repeated disassembly and assembly. In contrast, this solution achieves quick disassembly and assembly of the motor 301 through a snap-fit ​​structure. At the same time, the rigid connection between the fixing seat 302 and the base 1 avoids the problem of loosening caused by vibration in traditional bolt fixing methods.

[0038] Through the above technical solution, this application can effectively suppress the vibration transmission during the operation of motor 301, ensure the accuracy of clamping and positioning, simplify the maintenance process of motor 301, and extend the service life of the clamp.

[0039] This application further proposes an adjustable positioning fixture for precision machining of bionic robot joint components. The four corners of the inner cavity of the base 1 are provided with mounting holes 4, and the four mounting holes 4 are of the same size.

[0040] The mounting holes 4 refer to the hole structures located at the four corners of the base 1. These holes can be created using drilling or stamping processes and are used to fix the fixture to the machining platform or workbench using bolts or other fasteners. The four mounting holes 4 are of the same size, meaning that all holes have the same diameter and depth. This can be achieved using standardized machining parameters, facilitating the use of bolts of uniform specifications for installation.

[0041] Specifically, after mounting holes 4 are made at the four corners of the base 1, the fixture can be fixed to the surface of the processing equipment by bolts passing through the mounting holes 4. The four mounting holes 4 are evenly distributed at the four corners of the base 1, which ensures that the fixture is subjected to balanced force during installation and avoids tilting or displacement caused by fixing on one side. The uniform size of the mounting holes 4 allows the use of fasteners of the same specification, simplifying the installation process and improving assembly efficiency. For example, the diameter of the mounting holes 4 can be 8 mm to accommodate M8 bolts, and the stability of the fixture is enhanced by simultaneous tightening at all four corners.

[0042] Compared to existing technologies, traditional fixture bases 1 typically employ a distributed or asymmetrical mounting hole design 4, which necessitates adjusting bolt positions or using different sized accessories during fixing, thus affecting installation efficiency. This solution utilizes symmetrical and uniformly sized mounting holes 4 at the four corners to ensure rapid fixture positioning and even force distribution, while reducing assembly errors caused by differences in the dimensions of the mounting holes 4.

[0043] Through the above technical solution, this application solves the problem of insufficient stability caused by uneven distribution of fixing points or size differences during fixture installation, so that the fixture remains firmly fixed during processing, avoiding displacement caused by vibration or external force, thereby improving the processing accuracy of joint components.

[0044] This application further proposes that the two ends of the bottom of the L plate 304 are fixedly connected to the slider 3013 by welding, and the surface of the slider 3013 is in close contact with the groove 2.

[0045] Among them, the fixed connection by welding refers to the permanent combination of two components by melting metal at high temperature. Specifically, it can be achieved by electric arc welding or laser welding. This method can eliminate the gaps caused by bolted connections and form a rigid connection structure that cannot be disassembled.

[0046] Here, tight contact means that the fit clearance between slider 3013 and slide groove 2 is controlled within the range of 0.05 mm to 0.1 mm. Specifically, it can be achieved by precision grinding the inner wall of slide groove 2. This fit method can limit the lateral displacement of slider 3013 in slide groove 2.

[0047] Specifically, after welding and fixing sliders 3013 to both ends of the bottom of L-plate 304, when motor 301 drives screw to move screw sleeve 303 laterally, the welded structure can prevent relative displacement between sliders 3013 and L-plate 304 due to vibration, thereby maintaining the overall rigidity of the clamping mechanism. At the same time, the tight contact between sliders 3013 and slide groove 2 can eliminate the shaking phenomenon caused by gaps in traditional sliding pairs, so that L-plate 304 always moves smoothly along the predetermined trajectory during adjustment.

[0048] Compared to existing technologies, the slider 3013 of existing fixtures is mostly fixed by bolt locking, which is prone to loosening due to thread wear after long-term use. The welding fixing method fundamentally eliminates the structural defects of threaded connections. In addition, the mating clearance between the traditional slide groove 2 and the slider 3013 is usually greater than 0.2 mm, which is prone to displacement deviation under processing vibration. However, this solution reduces the displacement deviation to a negligible range through a precision-machined tight contact design.

[0049] Through the above technical solution, this application effectively solves the problem of positioning instability caused by loose connection after clamp adjustment. The welded structure ensures the long-term reliability of the clamping mechanism. The closely matched slider 3013 and slide groove 2 significantly improve the accuracy of the clamp movement trajectory, thereby ensuring the positional stability of the bionic robot joint components during the processing.

[0050] This application further proposes that rubber pads are provided on the corresponding sides of the pressure plate 309 and the support plate 3010, and the outer sides of the two rubber pads are fixedly connected to the pressure plate 309 and the support plate 3010 by adhesive.

[0051] The rubber pad refers to the elastic buffer layer set on the contact surface between the pressure plate 309 and the bearing plate 3010. It can be made of silicone rubber or polyurethane material, and its surface can have anti-slip texture to increase the coefficient of friction. During the clamping process, the rubber pad generates a buffering effect through deformation, preventing rigid contact from causing damage to the workpiece surface.

[0052] Adhesive bonding refers to the use of chemical bonding to combine the rubber pad with the metal component, specifically using epoxy resin or acrylic adhesive. The adhesive creates intermolecular forces between the rubber and the metal surface, ensuring that the rubber pad will not shift or detach during long-term use.

[0053] Specifically, the rubber pads are fixed to the lower surface of the pressure plate 309 and the upper surface of the support plate 3010 respectively with adhesive, forming symmetrical flexible clamping surfaces. When the hydraulic cylinder 308 drives the pressure plate 309 to press down, the rubber pads undergo elastic deformation under pressure, increasing the contact area while evenly distributing the clamping force. After the adhesive cures, it forms a continuous adhesive layer, preventing the rubber pad edges from peeling off due to stress concentration.

[0054] Compared to existing technologies, traditional clamps often involve direct metal-to-workpiece contact between the clamping surfaces, which can easily scratch precision components and pose a risk of slippage. Some improved solutions use removable rubber pads, but fixing them with bolts or clips can easily create gaps and wear. This solution achieves a seamless fit of the rubber pad through integral bonding, eliminating structural weaknesses caused by fasteners.

[0055] Through the above technical solution, this application effectively solves the positioning offset problem caused by slippage of the clamping surface during the processing of bionic joint components. The elastic deformation characteristics of the rubber pad can adapt to the surface of workpieces with different shapes, and the adhesive fixing method ensures that the clamping system remains stable during long-term high-frequency use, significantly improving the precision machining yield.

[0056] The above description is merely an embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this utility model should be included within the scope of the claims of this utility model.

Claims

1. An adjustable positioning fixture for precision machining of joint components of a biomimetic robot, comprising a base (1), characterized in that: The base (1) has a positioning component (3) on its top. The positioning component (3) includes two motors (301). The output end of each motor (301) has a screw. A threaded sleeve (303) is threaded onto the surface of the screw. A movable shaft (306) is rotatably connected to the inner side of the threaded sleeve (303). An L-plate (304) is provided on the inner side of the movable shaft (306). Slider blocks (3013) are provided at both ends of the bottom of the L-plate (304). Slide grooves (2) that are adapted to the sliders (3013) are provided at both ends of the top of the base (1). The bottom of the inner side of the L plate (304) is provided with a bearing plate (3010), and the top of the L plate (304) is provided with a hydraulic cylinder (308). The output end of the hydraulic cylinder (308) extends through and into the inner cavity of the L plate (304) and is provided with a pressure plate (309). Both ends of the L plate (304) are provided with electric push rods (307). The output end of the electric push rod (307) is provided with a second toothed plate (3012). The bottom of the second toothed plate (3012) is engaged with a first toothed plate (305), and the bottom of the first toothed plate (305) is fixedly connected to the base (1).

2. The adjustable positioning fixture for precision machining of bionic robot joint components according to claim 1, characterized in that: The top and bottom of the surface of the electric push rod (307) are fixedly fitted with limiting plates (3011), and the inner side of the limiting plates (3011) is fixedly connected to the L plate (304).

3. The adjustable positioning fixture for precision machining of bionic robot joint components according to claim 1, characterized in that: The bottom of the motor (301) is fitted with a fixing seat (302), and the bottom of the fixing seat (302) is fixedly connected to the base (1).

4. The adjustable positioning fixture for precision machining of bionic robot joint components according to claim 1, characterized in that: The base (1) has mounting holes (4) at all four corners of its inner cavity, and the four mounting holes (4) are the same size.

5. The adjustable positioning fixture for precision machining of bionic robot joint components according to claim 1, characterized in that: The two ends of the bottom of the L plate (304) are fixedly connected to the slider (3013) by welding, and the surface of the slider (3013) is in close contact with the groove (2).

6. The adjustable positioning fixture for precision machining of bionic robot joint components according to claim 1, characterized in that: Rubber pads are provided on the corresponding sides of the pressure plate (309) and the bearing plate (3010), and the outer sides of the two rubber pads are fixedly connected to the pressure plate (309) and the bearing plate (3010) by adhesive.

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