Self-adaptive clamping tool for plastic pipeline

Abstract

The invention discloses a self-adaptive clamping tool for a plastic pipeline. The self-adaptive clamping tool comprises a clamping base, double motors and a fixing flange. The first rotatable finger and the second rotatable finger are symmetrically installed on the two sides of the base, the tail ends of the first finger and the second finger are connected with the third finger and the fourth finger through detachable structures, and the triangular structures can be replaced to adapt to different pipe types. The driving gear is driven by a first motor and meshed with the driven gear to be in linkage with the supporting arm to control clamping opening and closing, and the elastic buffering structure is matched with multi-pipe-diameter clamping force. The second motor drives the base to rotate by 360 degrees, and the pressure sensor is embedded into the finger to feed back clamping force in real time and control the torque of the motor in a closed-loop mode. The non-slip mat can be heated to enhance the low-temperature friction performance. Self-adaptive lossless clamping, multi-angle precise positioning and intelligent force control of the pipeline are achieved, and the intelligent force control device is suitable for the automatic production scene of the PVC pipeline.

Description

Technical Field

[0001] The present invention relates to the field of plastic pipe processing equipment, and particularly relates to an adaptive clamping tooling for plastic pipes. Background Art

[0002] In the industrial production of PVC pipes, the production process generally includes the following core processes: raw material mixing → extrusion molding → cooling and shaping → cutting and sizing → surface inspection → stacking and packaging. Among them, from extrusion molding to subsequent processing links (such as cutting and inspection), the pipes need to be stably clamped and positioned. There are the following technical bottlenecks: 1. The freshly extruded PVC pipes are at a high temperature (160 - 180°C) and have a soft texture. Traditional rigid jigs are likely to cause surface indentations or deformations on the pipes, affecting roundness and dimensional accuracy; during the cooling process, the shrinkage rate of the pipes varies greatly (about 2 - 5%), and the fixed clamping structure cannot adapt to the shrinkage, resulting in local stress concentration and even cracking. 2. The PVC pipes need to be cut at high speed or laser engraved. After being clamped by traditional tooling, the pipes cannot be driven to rotate synchronously, and additional transmission equipment is required, resulting in complex processes; the cutting vibration is likely to cause sliding between the jig and the pipe, resulting in skewed cuts or burrs.

[0003] Traditional clamping tooling generally has the following problems: 1. Most clamping devices use fixed sizes or rigid structures, making it difficult to adapt to pipes of different diameters and shapes. Especially in mass production of multiple specifications, the jigs need to be frequently replaced, resulting in low efficiency. 2. The PVC material has a low hardness and a smooth surface. The rigid contact surfaces of traditional clamping tooling are likely to cause scratches or deformations on the pipe surface, affecting the quality of the finished product. 3. Lack of a real-time feedback mechanism. Excessive clamping force may crush the pipe, while too little force may cause sliding and falling off. Especially in an automated production line, it is difficult to accurately control. 4. Existing equipment usually only realizes the clamping function and cannot synchronously complete complex operations such as rotational positioning and adaptation to low-temperature environments. It relies on the cooperation of multiple devices, increasing costs and operation complexity. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide an adaptive clamping tooling for plastic pipes.

[0005] To solve the above technical problem, the present invention provides the following technical solutions: An adaptive clamping tooling for plastic pipes of the present invention includes a clamping base, a first motor, a second motor, and a fixed flange. The first finger and the second finger are symmetrically and rotatably installed on the right side of the clamping base. The right sides of the first finger and the second finger are respectively rotatably connected to the third finger and the fourth finger through a detachable connection structure. Anti-slip pads are provided on the inner sides of the third finger and the fourth finger, and the third finger and the fourth finger are replaceable triangular structures. An active gear and a driven gear are installed inside the clamping base. The active gear is drivingly connected to the first motor, and the active gear meshes with the driven gear. The first support arm and the second support arm are respectively hinged on the sides of the active gear and the driven gear. The end parts of the first support arm and the second support arm are respectively hinged to the vertices of the third finger and the fourth finger. The inner sides of the first support arm and the second support arm are elastically connected to the left sides of the first finger and the second finger through a tension spring. The tension spring has a predetermined stiffness coefficient to adapt to the clamping force of different pipe diameters. The second motor drives the clamping base to rotate 360° around its central axis through a bearing seat. The fixed flange is detachably connected to an external manipulator or an automated platform.

[0006] As a preferred technical solution of the present invention, the detachable connection structure is one of bolt fixation, snap locking, or a quick-release interface. The detachable connection structure is one of bolt fixation, snap locking, or a quick-release interface. And a fixed bearing is provided at the hinge position of the vertex of the triangular structure for adjusting the angle of the clamping contact surface.

[0007] As a preferred technical solution of the present invention, the contact surface of the anti-slip pad is provided with corrugated protrusions or granular textures, and the anti-slip pad is connected to the third finger and the fourth finger through magnetic adsorption or plug-in limit grooves.

[0008] As a preferred technical solution of the present invention, pressure sensors are provided on the inner surfaces of the third finger and the fourth finger. The pressure sensors are embedded in the contact surface of the anti-slip pad for real-time detection of the clamping force and feedback to the first motor to limit the clamping force from exceeding a preset threshold.

[0009] As a preferred technical solution of the present invention, the replaceable triangular structure includes at least one of the following types: the first type of triangular structure, whose bottom edge is a plane and is provided with hollow weight-reducing holes; the second type of triangular structure, whose bottom edge is an arc-shaped concave surface for adapting to circular or oval pipes; the third type of triangular structure, whose bottom edge is provided with a detachable flexible gasket for clamping pipes made of fragile materials.

[0010] As a preferred technical solution of the present invention, the control systems of the first motor and the second motor include: a signal acquisition module for receiving real-time clamping force signals of the outer diameter data of the pipeline or the pressure sensor; a control processor for dynamically adjusting the driving torque of the first motor and the rotation angle of the second motor according to the signals.

[0011] As a preferred technical solution of the present invention, a heating module is provided inside the triangular structure of the third finger and the fourth finger for locally heating the surface of the pipeline in a low-temperature environment to enhance the friction performance of the anti-slip pad.

[0012] As a preferred technical solution of the present invention, the clamping base, the first support arm and the second support arm are made of lightweight alloy or carbon fiber composite material, and an anti-corrosion coating is provided on the surface.

[0013] On the other hand, the present invention provides a clamping method for a clamping tooling, and the method includes the following steps: 1. Install the tooling to the end of the manipulator through a fixed flange; 2. Replace the corresponding triangular structure according to the shape of the target pipeline; 3. Start the first motor to drive the driving gear to rotate, and drive the third finger and the fourth finger to close to the surface of the pipeline through meshing transmission; 4. Control the first motor to stop driving or release the clamping force reversely according to the clamping force data fed back by the pressure sensor; 5. Start the second motor to drive the clamping base to rotate to the target angle. If it is detected that the surface temperature of the pipeline is lower than the preset threshold value in step 3, start the heating module inside the third finger and the fourth finger to heat the contact area of the anti-slip pad.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Adapt to multi-specification pipelines: The replaceable triangular clamping structures (plane, arc, flexible gasket) are adapted to pipelines of different shapes. Combined with the elastic pre-tightening force of the tension spring, adaptive clamping from small-diameter pipelines to large-diameter pipelines can be realized without frequent manual adjustment. The sliding adjustment groove design supports dynamic adjustment of the clamping angle to ensure that the contact surface fits tightly with the outer wall of the pipeline and avoid local stress concentration; 2. The corrugated / granular texture of the anti-slip pad is combined with the magnetic adsorption structure to increase the friction force while avoiding hard contact and protecting the integrity of the PVC surface; The embedded pressure sensor monitors the clamping force in real time, and the braking torque of the motor is controlled through closed-loop feedback to ensure that the clamping force is always within the safe threshold; 3. The dual-motor collaborative drive (clamping + rotation) supports 360° non-dead-angle rotation positioning after clamping, meeting the requirements of multiple processes such as cutting, welding, and detection; The heating module can improve the friction performance of the anti-slip pad for low-temperature environments (such as cold storage or winter operations) to avoid slipping caused by condensed water on the PVC surface. Description of the Drawings

[0015] The accompanying drawings are used to provide a further understanding of the present invention and form a part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation to the present invention. In the drawings: Figure 1 is a schematic diagram of the overall structure of the present invention; Figure 2 is the front view of the present invention; Figure 3 is the bottom view of the present invention; Figure 4 is the schematic cross-sectional structure of the present invention; In the figure: 1, clamping base; 2, first motor; 3, bearing seat; 4, second motor; 5, fixed flange; 6, anti-slip pad; 11, first finger; 12, second finger; 13, third finger; 14, fourth finger; 15, driving gear; 16, driven gear; 17, first support arm; 18, second support arm; 19, tension spring; 20, pressure sensor. Detailed embodiments

[0016] The following describes the preferred embodiments of the present invention with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to explain and illustrate the present invention and are not used to limit the present invention.

[0017] All the same reference numerals in the drawings refer to the same components.

[0018] As Figures 1-4 shown, the present invention provides an adaptive clamping tooling for plastic pipes, including 1. Main body frame and transmission system: Clamping base 1: A box structure cast from lightweight alloy, with a gear transmission cavity, a cable channel and a bearing installation position inside. Two shaft holes are symmetrically machined on the right side of the base for installing the first finger 11 and the second finger 12.

[0019] Driving gear 15: Fixedly connected to the output shaft of the first motor 2 through a flat key. The gear modulus matches the transmission requirements, and the tooth surface is hardened to improve wear resistance.

[0020] Driven gear 16: Installed inside the clamping base 1 through a deep groove ball bearing, meshing precisely with the driving gear 15. The meshing clearance is controlled within the range of 0.05 - 0.1 mm through an adjusting shim.

[0021] Second motor 4: Fixed to the bearing seat 3 at the bottom of the clamping base 1 through bolts. The output shaft is coaxially connected to the central axis of the clamping base 1 through a coupling to drive the overall rotation of the tooling.

[0022] Fixed flange 5: Bolted to the bottom of the clamping base 1, with standard bolt holes machined on the flange end face for rigid connection to the robotic arm or automation platform. Positioning pin holes are provided at the flange edge to ensure installation centering.

[0023] 2. Clamping actuator: The first finger 11 and the second finger 12: Are L-shaped forged steel parts, with the right end hinged to the rotating shaft hole of the clamping base 1 through a pin shaft, and two groups of mounting holes for the tension spring 19 are reserved on the left side.

[0024] Detachable connection structure: Fixed bearings are provided on both sides of the third finger 13 and the fourth finger 14, and are fixed to the right ends of the first finger 11 and the second finger 12 through M8 hexagon socket head cap screws.

[0025] Triangular finger structure: Planar type: The bottom edge is planar, with a mounting groove for the anti-slip pad 6 machined on the inner side, and weight-reducing holes are provided at the bottom to reduce inertia. Curved surface type: The bottom edge has an inner concave arc with a curvature radius matching common pipe diameters (e.g., R = 40mm for DN80 pipes), and the arc center line is aligned with the direction of the clamping force. Flexible gasket type: The bottom edge is grooved to install a detachable silicone gasket (Shore hardness 60A), fixed by a snap fastener, and the gasket thickness is 5mm to buffer local pressure.

[0026] Anti-slip pad 6: The surface is molded with corrugated protrusions (peak spacing 2mm, height 1mm), made of high-temperature resistant silicone (tolerant to -30°C to 200°C), and fixed to the inner sides of the third finger 13 and the fourth finger 14 by magnetic adsorption or dovetail groove insertion.

[0027] 3. Elastic buffer and force feedback system: Tension spring 19: Both ends are connected to the mounting holes on the inner side of the first support arm 17 and the left side of the first finger 11 through hooks. The spring stiffness coefficient is configured in grades according to the clamping pipe diameter range (e.g., 5N / mm for small pipe diameters and 10N / mm for large pipe diameters). Function: Provide elastic pre-tightening force during the clamping process, balance the rigid driving force of the gear transmission, and prevent the pipe from being crushed.

[0028] Pressure sensor 20: Embedded in the third finger 13 and the fourth finger 14, the detection surface is in vertical contact with the anti-slip pad 6 through a cemented carbide gasket, and the signal wire is led out through the internal wire groove of the finger and connected to the closed-loop control system of the first motor 2. Control logic: When the detected clamping force exceeds the preset threshold (e.g., 50N for PVC pipes), the system triggers the first motor 2 to reverse to release the clamping and records the over-limit alarm information.

[0029] 4. Drive and control system: The first motor 2: Adopts a servo motor, with an encoder resolution of 17 bits, drives the driving gear 15 through a speed reducer (speed ratio 10:1), the torque output range is 0.5 - 20 N·m, and the response time ≤ 50ms.

[0030] The second motor 4: adopts a stepper motor with a step angle of 1.8°, which drives the clamping base 1 to rotate through a planetary reducer (speed ratio 15:1). The rotation angle is fed back by an absolute encoder, and the positioning accuracy is ±0.5°.

[0031] Control system integration: Integrates signal acquisition module (receives data from pressure sensor 20 and external pipe diameter parameters) and control processor, and supports clamping force curve preset (such as linear increase, step clamping) and rotation angle programmed control through communication with the host computer.

[0032] 5. Auxiliary function module heating module Integrated inside the third finger 13 and the fourth finger 14, a thin film heater (power 50W / piece) is used to maintain the surface temperature of the anti-slip mat 6 at 40~60℃ through the PID temperature control module to prevent the surface of the PVC pipe from slipping in the low temperature environment in winter.

[0033] The use of the present invention is as follows: 1. Installation and initialization: Install the tooling to the end of the robot arm through the fixed flange 5, replace the arc-shaped third finger 13 and the fourth finger 14 according to the shape of the pipe, input the pipe diameter parameter (such as DN100) into the host computer, and the control system automatically matches the spring stiffness and the clamping force threshold; 2. Clamping and rotation: The first motor 2 drives the driving gear 15 to rotate, and pushes the third finger 13 and the fourth finger 14 to close through the support arms 17 and 18, and the tension spring 19 buffers the clamping impact.

[0034] The pressure sensor 20 provides real-time feedback of the clamping force. When the clamping force reaches the set value, the second motor 4 starts to drive the clamping base 1 to rotate 180° to complete the pipe cutting or welding. 3. Release and reset: The first motor 2 reverses to release the clamp, and the second motor 4 resets to the initial angle to prepare for the next operation cycle.

[0035] The present invention discloses an adaptive clamping tool for plastic pipes. The gear meshing clearance, spring stiffness, sensor sensitivity and other parameters are collaboratively designed to ensure a smooth and controllable clamping process. It supports fast mold change (changing fingers ≤ 2 minutes), automated force control and multi-angle operation, significantly improving the processing efficiency of plastic pipes such as PVC.

[0036] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A plastic pipe adaptive clamping tool, comprising a clamping base (1), a first motor (2), a second motor (4) and a fixing flange (5), characterized in that: The first finger (11) and the second finger (12) are symmetrically rotatably mounted on the right side of the clamping base (1); the right sides of the first finger (11) and the second finger (12) are rotatably connected to the third finger (13) and the fourth finger (14) via detachable connection structures; the inner sides of the third finger (13) and the fourth finger (14) are provided with anti-slip pads (6); and the third finger (13) and the fourth finger (14) are replaceable triangular structures; a driving gear (15) and a driven gear (16) are mounted inside the clamping base (1); the driving gear (15) is connected to the first motor (2) for driving, and the driving gear (15) is meshed with the driven gear (16); the driving gear (15) and the driven gear (16) are connected to the first motor (2) for driving; A first support arm (17) and a second support arm (18) are hinged on the side of the gear (16), and the ends of the first support arm (17) and the second support arm (18) are hinged to the vertices of the third finger (13) and the fourth finger (14), respectively; the inner sides of the first support arm (17) and the second support arm (18) are elastically connected to the left sides of the first finger (11) and the second finger (12) via a tension spring (19), and the tension spring (19) has a predetermined stiffness coefficient to adapt to the clamping force of different pipe diameters; the second motor (4) drives the clamping base (1) to rotate 360 ​​degrees around its central axis through the bearing seat (3); and the fixing flange (5) is detachably connected to an external manipulator or an automation platform.

2. The self-adaptive clamping tool for plastic pipes according to claim 1, characterized in that: The detachable connection structure is one of bolt fixing, snap locking or quick release interface, and a fixed bearing is provided at the vertex hinge position of the triangular structure for adjusting the angle of the clamping contact surface.

3. The self-adaptive clamping tool for plastic pipes according to claim 1, characterized in that: The contact surface of the anti-slip pad (6) is provided with corrugated protrusions or granular textures, and the anti-slip pad (6) is connected to the third finger (13) and the fourth finger (14) via magnetic adsorption or plug-in limiting grooves.

4. The self-adaptive clamping tool for plastic pipes according to claim 1, characterized in that: The third finger (13) and the fourth finger (14) are internally embedded with a pressure sensor (20), and the pressure sensor (20) is vertically connected to the contact surface of the anti-slip pad (6) and is used to detect the clamping force in real time and feed it back to the first motor (2) to limit the clamping force from exceeding a preset threshold.

5. The self-adaptive clamping tool for plastic pipes according to claim 1, characterized in that: The replaceable triangular structure includes at least one of the following types: a first type of triangular structure, whose bottom edge is a plane and is provided with a hollow weight-reducing hole; a second type of triangular structure, whose bottom edge is an arc-shaped concave surface, which is used to adapt to circular or elliptical pipes; a third type of triangular structure, whose bottom edge is provided with a removable flexible pad, which is used to clamp pipes made of fragile materials.

6. The self-adaptive clamping tool for plastic pipes according to claim 1, characterized in that: The control system of the first motor (2) and the second motor (4) comprises: a signal acquisition module for receiving pipeline outer diameter data or a real-time clamping force signal from a pressure sensor (20); and a control processor for dynamically adjusting the driving torque of the first motor (2) and the rotation angle of the second motor (4) according to the signal.

7. The self-adaptive clamping tool for plastic pipes according to claim 1, characterized in that: A heating module is provided inside the triangular structure of the third finger (13) and the fourth finger (14), which is used to locally heat the surface of the pipeline in a low-temperature environment, so as to enhance the friction performance of the anti-slip pad (6).

8. The self-adaptive clamping tool for plastic pipes according to claim 1, characterized in that: The clamping base (1), the first support arm (17) and the second support arm (18) are made of light alloy or carbon fiber composite material, and are provided with an anti-corrosion coating on their surfaces.

9. A method for using the clamping tool according to any one of claims 1 to 8, characterized in that: The following steps are involved:

1. Install the tooling to the end of the robot through the fixing flange (5); 2. Replace the corresponding triangular structure according to the target pipe shape; 3. Start the first motor (2) to drive the driving gear (15) to rotate, and drive the third finger (13) and the fourth finger (14) to close to the pipe surface through meshing transmission; 4. According to the clamping force data fed back by the pressure sensor (20), control the first motor (2) to stop driving or release the clamping force in the reverse direction; 5. Start the second motor (4) to drive the clamping base (1) to rotate to the target angle.

10. The method of use according to claim 9, characterized in that: If it is detected that the temperature of the pipe surface is lower than a preset threshold, the heating modules inside the third finger (13) and the fourth finger (14) are activated to heat the contact area of ​​the anti-slip pad (6).

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