A rotary pneumatic clamping tool suitable for an automated painting line

Abstract

The utility model relates to a rotary pneumatic clamping tool suitable for automatic coating line belongs to clamping tool technical field, including with the rotary station butt joint of automatic coating line and synchronous rotation rotary base assembly, drive the pneumatic clamping unit integrated on the rotary base assembly of clamping workpiece, the clamping jaw assembly of direct clamping workpiece is symmetrically set up in the both sides of pneumatic clamping unit, and the sealing protection assembly is set up between rotary base assembly and external fixed base and the outside of pneumatic clamping unit. The utility model degree of automation is high, adapts unmanned coating line, has the design of anti -interference simultaneously, can promote coating quality, and rotary precision is high, and coating uniformity is good.

Description

Technical Field

[0001] This utility model belongs to the field of clamping fixture technology, and in particular relates to a rotary pneumatic clamping fixture suitable for automated coating lines. Background Technology

[0002] In industrial coating processes (spray painting, powder coating, electrophoresis, etc.), tooling fixtures are core components that ensure precise workpiece positioning and stable clamping, and their performance directly affects coating efficiency and coating quality. However, existing coating fixtures still have the following shortcomings:

[0003] Firstly, they suffer from poor adaptability and low changeover efficiency. Traditional fixtures are mostly designed for specific purposes and are only suitable for a single workpiece size. When the workpiece model changes, a new special fixture needs to be designed and manufactured, which cannot meet the needs of flexible production with multiple varieties and small batches.

[0004] Secondly, the automation level is low and the reliance on manual labor is high. Most fixtures rely on manual locking, which is cumbersome and the consistency of manual operation is poor. Uneven clamping force and positioning deviation can easily lead to defects such as missed spraying and drips, making it difficult to integrate into the linkage control of automated painting lines.

[0005] Thirdly, coating interference and coating defects are prominent. Traditional clamping structures are mostly open and large-volume designs, which can easily obscure the coating surface of the workpiece, resulting in appearance defects such as clamping marks, missed spraying, and uneven coating. Some clamping mechanisms lack buffer protection, and the clamping surface can easily cause the workpiece surface to dent or the coating to peel off. After long-term use, the clamping parts of the rotary fixture are prone to wear, and the accuracy is further reduced.

[0006] Fourthly, insufficient rotational accuracy leads to poor coating uniformity. Automated coating lines mostly use rotary workstations, but the existing fixtures have low rotational positioning accuracy and poor coaxiality. The workpiece's posture is unstable during the spraying process, resulting in uneven coating thickness. In addition, the transmission components of the rotary mechanism (such as rubber bushings and belts) are wear parts, and slippage is likely to occur after wear, causing uneven surfaces on the workpiece.

[0007] Fifth, the sealing and protection are insufficient, and the maintainability is poor. The painting environment contains paint mist, dust, and corrosive solvents. Existing fixtures lack effective sealing and protection designs, making them prone to problems such as rust, jamming, and seal failure, resulting in high maintenance costs and short service life. Utility Model Content

[0008] To address the shortcomings of existing technologies, this utility model provides a rotary pneumatic clamping fixture suitable for automated coating lines, which solves the problems of poor adaptability, low automation, coating interference, insufficient rotational accuracy, and poor maintainability of traditional coating fixtures.

[0009] A rotary pneumatic clamping fixture suitable for automated coating lines includes a rotary base assembly that docks with and rotates synchronously with the rotary station of the automated coating line; a pneumatic clamping unit that drives and clamps the workpiece is integrated on the rotary base assembly; clamping claw assemblies that directly clamp the workpiece are symmetrically arranged on both sides of the pneumatic clamping unit; and a sealing and protective assembly is disposed between the rotary base assembly and an external fixed base and outside the pneumatic clamping unit.

[0010] The rotary base assembly is an integrated rotary structure, including a rotary mounting plate and a rotary support bearing. The rotary support bearing is installed between the rotary mounting plate and the external fixed base. The positioning stop is set on the lower end face of the rotary mounting plate, and the drive connection part is set on the lower end of the rotary mounting plate and integrally connected to the rotary mounting plate. The rotary mounting plate has an integrated air passage for supplying air to the pneumatic clamping unit, and the air passage is connected to an external air source.

[0011] The pneumatic clamping unit includes a double-acting pneumatic cylinder and a stroke limiting structure. The double-acting pneumatic cylinder is embedded in the center of the rotary base assembly. The stroke limiting structure includes a mechanical limiting block and a position detection element for detecting the clamping position.

[0012] The clamping jaw assembly includes an adjustable clamping jaw and a flexible buffer pressure head disposed inside the adjustable clamping jaw. The adjustable clamping jaw is provided with an oblong hole structure for adjusting the clamping position. The flexible buffer pressure head is made of elastic material and is detachably installed on the clamping surface of the adjustable clamping jaw.

[0013] The adjustable clamping jaw adopts a streamlined thin plate structure with an arc-shaped clamping surface; the clamping jaw assembly also includes a positioning limit block disposed inside the adjustable clamping jaw for axial positioning of the workpiece.

[0014] The sealing and protection assembly includes a rotary sealing ring and a cylinder sealing cover. The rotary sealing ring is installed between the rotary base assembly and the external fixed base. The cylinder sealing cover covers the outside of the pneumatic clamping unit and is made of transparent material.

[0015] It also includes an integrated pneumatic system, specifically including a pneumatic channel integrated inside the rotary base assembly, a quick-connect connector for connecting to an external air source, a pressure regulating valve for adjusting the clamping force, and a solenoid valve for linkage control with the automated painting line control system.

[0016] The slewing support bearing in the slewing base assembly is a high-precision crossed roller bearing.

[0017] The pneumatic clamping unit includes a double-acting pneumatic cylinder, and the clamping claw assembly is linked to the piston rod of the double-acting pneumatic cylinder. The clamping claw assembly opens and closes synchronously under the drive of the double-acting pneumatic cylinder.

[0018] The rotating base assembly, pneumatic clamping unit, and gripper assembly are arranged coaxially, forming a compact integrated structure around the rotation center axis.

[0019] By employing the above technical solution, this utility model application has at least the following beneficial effects:

[0020] 1. High degree of automation, suitable for unmanned painting lines: By integrating the pneumatic clamping unit into the center of the rotary base assembly and using a solenoid valve linked to the control system, automatic clamping and release of workpieces are achieved without manual intervention. Simultaneously, the rotary base assembly precisely connects to the rotary station of the painting line through positioning stops and drive connections. The overall structure is compatible with the linkage control of automated painting lines, providing a hardware foundation for unmanned painting production.

[0021] 2. Anti-interference design improves coating quality: The clamping claw assembly adopts a thin, streamlined structure with a small-area arc-shaped clamping surface, minimizing obstruction of the workpiece's coating surface; combined with a flexible buffer pressure head, it avoids workpiece surface damage and scratches. This structure effectively solves the defects of traditional fixtures caused by obstruction, such as missed spraying, clamping marks, and uneven coating, significantly improving the appearance quality of the coating.

[0022] 3. Flexible adaptability and high changeover efficiency: The adjustable gripper has radially extending adjustment holes at its root, which can be adjusted to the movable end of the pneumatic clamping unit via a connector, allowing for quick adjustment of the clamping position to adapt to different specifications and types of workpieces. Meanwhile, the flexible buffer pressure head is detachable and replaceable, further expanding the tooling's applicability and achieving "one tooling for multiple uses," significantly reducing fixture procurement costs and shortening changeover time to just a few minutes.

[0023] 4. High rotational accuracy and good coating uniformity: The rotating base assembly uses high-precision rolling bearings (such as crossed roller bearings), combined with the H7 precision mating surface of the positioning stop and the coaxial arrangement structure, ensuring that the tooling rotational accuracy can reach ±0.01mm. The workpiece maintains a stable posture during the spraying process, and the coating thickness is uniform, meeting the requirements of high-precision coating.

[0024] 5. Sealed protection and long service life: The sealing protection component includes a rotary sealing ring installed between the rotary mounting plate and the external fixed base, and a transparent cover covering the pneumatic clamping unit. This double-layer sealing design effectively isolates paint mist, dust and corrosive solvents in the painting environment, protects the rotary bearing and pneumatic components from corrosion, significantly reduces maintenance costs, extends the service life of tooling, and adapts to the harsh working conditions of the painting workshop.

[0025] 6. Integrated design for convenient installation and maintenance: The gas passage is integrated inside the rotary mounting plate, and gas components such as pressure regulating valves, reversing valves, and quick-connect fittings are all integrated into the tooling body, eliminating external piping entanglement or interference. The overall structure is compact, and the modular design facilitates quick disassembly and replacement of vulnerable parts, resulting in high maintenance efficiency. Attached Figure Description

[0026] Figure 1 A schematic diagram of a rotary pneumatic clamping fixture suitable for automated painting lines provided by this utility model. Figure 1 ;

[0027] Figure 2 A schematic diagram of a rotary pneumatic clamping fixture suitable for automated painting lines provided by this utility model. Figure 2 ;

[0028] Figure 3 This is a schematic diagram showing the installation positions of the pressure regulating valve and the solenoid valve in this utility model.

[0029] Figure 4 This is a schematic diagram of the internal structure of the present invention;

[0030] Figure 5 This is a schematic diagram of the installation of the double-acting pneumatic cylinder in this utility model;

[0031] Figure 6 This is a schematic diagram of the rotary mounting disc in this utility model;

[0032] Figure 7 This is a schematic diagram showing the installation position of the drive connection part in this utility model;

[0033] Figure 8 This is a schematic diagram of the drive connection part in this utility model;

[0034] Figure 9 This is a schematic diagram of the adjustable gripper in this utility model;

[0035] Figure 10 This is a schematic diagram of the flexible buffer head in this utility model;

[0036] Figure 11 This is a schematic diagram of a circular cap-like workpiece in an embodiment of this utility model;

[0037] In the picture:

[0038] 1-Slewing base assembly; 11-Slewing mounting plate; 12-Slewing support bearing; 13-Positioning stop; 14-Drive connection; 2-Pneumatic clamping unit; 21-Double-acting pneumatic cylinder; 22-Cylinder mounting seat; 3-Clamping claw assembly; 31-Adjustable clamping claw; 32-Flexible buffer pressure head; 33-Positioning limit block; 4-Sealing protection assembly; 41-Slewing sealing ring; 42-Magnetic switch; 43-Pneumatic sealing connector; 5-Integrated pneumatic system; 51-Pressure regulating valve; 52-Solenoid valve. Detailed Implementation

[0039] To better explain and facilitate understanding of this utility model, the technical solution and effects of this utility model will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] like Figures 1-11 As shown, this embodiment takes a circular cap-like workpiece with a spraying diameter of 80-120mm as an example to provide a rotary pneumatic clamping fixture suitable for automated painting lines. The rotary pneumatic clamping fixture is an integrated structure arranged coaxially. Specifically, it includes a rotary base assembly 1 located on the outermost side, which serves as the mounting foundation and core of the rotary transmission for the entire fixture. Specifically, the rotary base assembly 1 includes a rotary mounting plate 11 integrally machined from 304 stainless steel. The outer diameter of the rotary mounting plate 11 is 200mm, and its thickness is 20mm. The surface is passivated and treated for corrosion resistance to adapt to the corrosive environment of the painting workshop. A high-precision crossed roller bearing 12 is embedded below the center of the rotary mounting plate 11 as a rotary support bearing 12. In this embodiment, a CRBH20025 model is selected, with a rotational accuracy of ±0.01mm, ensuring the stability of the fixture during high-speed rotation. Furthermore, the bottom of the rotary mounting plate 11 is machined with a positioning stop 13 with a precision of Φ150H7, which is used to achieve rapid and accurate positioning docking with the rotary station of the automated painting line. At the same time, the lower end of the rotary mounting plate 11 is provided with a flange-type drive connection part 14, with four M8 bolt holes evenly distributed along the circumference. The connection is rigidly made with the rotary drive mechanism of the painting line through bolts, thereby transmitting the drive torque to the entire tooling.

[0041] Furthermore, a pneumatic clamping unit 2 is installed at the center of the rotary mounting plate 11. Specifically, the pneumatic clamping unit 2 includes a double-acting pneumatic cylinder 21. In this embodiment, an Airtac HFT20-20-S thin finger cylinder is selected, with a cylinder diameter of 20mm, a stroke of 20mm, and a maximum clamping force of 150N. The double-acting pneumatic cylinder 21 is fixed in the central countersunk hole of the rotary mounting plate 11 by an embedded cylinder mounting seat 22 and locked with four M6 bolts. This installation method ensures that the axis of the piston rod of the double-acting pneumatic cylinder 21 is strictly coincident with the rotation axis of the tooling. Furthermore, a magnetic switch 42 and a built-in mechanical limit block are installed on the cylinder body of the double-acting pneumatic cylinder 21; wherein, in this embodiment, the magnetic switch 42 is model CS1-J. Specifically, the mechanical limit block restricts the maximum extension and retraction position of the piston of the double-acting pneumatic cylinder 21 to prevent damage to the workpiece due to overpressure in the air circuit; the magnetic switch 42 is used to detect the position of the piston. When the gripper is closed or opened to the correct position, the magnetic switch 42 outputs an electrical signal and feeds it back to the PLC control system of the coating line.

[0042] The double-acting pneumatic cylinder 21 has two piston rods, each connected to an anti-interference gripping jaw assembly 3. Each gripping jaw assembly includes an adjustable gripping jaw 31, a flexible buffer pressure head 32, and a positioning limit block 33. The adjustable gripping jaw 31 uses a streamlined thin plate structure with a thickness of only 8mm, and the gripping surface is an R10 arc shape to minimize obstruction of the workpiece coating surface. Furthermore, the adjustable gripping jaw 31 has a waist-shaped hole at its root, which is connected to the piston rod of the double-acting pneumatic cylinder 21 by bolts; after loosening the bolts, the adjustable gripping jaw 31 can be adjusted radially by ±10mm to accommodate workpieces of different diameters. On the inner gripping surface of the adjustable gripping jaw 31, a flexible buffer pressure head 32 made of polyurethane material is detachably fixed by M4 bolts. The flexible buffer pressure head 32 has a thickness of 5mm. The flexible buffer head 32 has a certain degree of elasticity, which can avoid damage to the workpiece surface by rigid clamping and increase friction to ensure clamping stability. In addition, a stainless steel positioning limit block 33 is fixed to the inner root of each adjustable clamping claw 31. When the workpiece is clamped, the edge of the workpiece abuts against the two limit blocks, thereby achieving axial positioning and ensuring that the central axis of the workpiece coincides with the rotation axis of the tooling.

[0043] In addition, to protect the moving parts from paint mist, dust, and solvents in the painting environment, the tooling is equipped with a comprehensive sealing and protection assembly 4. Specifically, a rotary sealing ring 41 with a fluororubber double-lip seal structure, specifically model TC150×170×10, is installed between the rotary mounting plate 11 and the painting line fixing base. This rotary sealing ring 41 effectively prevents external contaminants from entering the rotary support bearing 12 and also prevents bearing grease leakage. Furthermore, the air passage connection points, i.e., the air passage sealing joints 43, all adopt quick-connect sealing joints, model Airtac PC8-02, to ensure no leakage.

[0044] The entire tooling's pneumatic control circuit is an integrated pneumatic system 5. The pneumatic passage uses an 8mm through hole and is directly machined and integrated inside the rotary mounting plate 11 (not shown in the figure), avoiding external hose entanglement or interference with the spraying operation. Compressed air enters the pressure regulating valve 51 (not shown in the figure) from an external air source via a quick-connect coupling (standard 8mm quick-connect). The pressure regulating valve 51 is installed in the control box below the rotary support bearing 12. The quick-connect coupling is a standard 8mm quick-connect, and the pressure regulating valve 51 is an Airtac AR2000 with an adjustment range of 0~0.8Mpa. The operator can rotate the pressure regulating valve to set the appropriate clamping force according to the workpiece material, such as sheet metal, plastic, or aluminum alloy. The pressure-regulated airflow enters the solenoid valve 52. This solenoid valve 52 is an Airtac 4V210-08 two-position five-way valve, powered by DC24V. The two working ports of this solenoid valve 52 are connected to the front and rear chambers of the double-acting pneumatic cylinder 21, respectively. Furthermore, the control terminal of the solenoid valve 52 is electrically connected to the PLC control system of the coating line, thereby realizing fully automatic control of clamping and releasing actions.

[0045] The workflow of the rotary pneumatic clamping fixture applicable to automated painting lines described above is as follows:

[0046] First, adjust and install the tooling. Loosen the oblong bolts on the two adjustable clamping jaws 31 according to the actual size of the workpiece to be painted, and move them radially to a suitable position so that the distance between the two flexible buffer pressure heads is slightly smaller than the diameter of the workpiece. Then, retighten the bolts. Quickly place the tooling onto the rotary station of the painting line through the positioning stop 13, and lock the drive connection 14 to the rotary drive mechanism with four M8 bolts. Then, connect the quick-connect fitting to the air circuit and make electrical connections to the solenoid valve 52 and the magnetic switch 42 on the cylinder body of the double-acting pneumatic cylinder 21.

[0047] Once the workpiece is conveyed to the top of the fixture and lowered to the predetermined position, the PLC control system of the coating line issues a command to energize the coil of solenoid valve 52, switching the air path. Compressed air enters the closed chamber of double-acting pneumatic cylinder 21 via pressure regulating valve 51 and solenoid valve 52, pushing the piston rod to drive the left and right adjustable clamping jaws 31 to close inward simultaneously. The flexible buffer pressure head 32 first contacts the workpiece surface, and then undergoes slight elastic deformation under continuous air pressure, thus firmly and without damage clamping the workpiece. When the workpiece is in place, the magnetic switch 42 on the double-acting pneumatic cylinder 21 detects the piston position and immediately sends a signal to the PLC control system of the coating line indicating that the clamping is in place.

[0048] After receiving the clamping signal, the PLC control system of the painting line starts the rotary drive mechanism. The driving force is transmitted to the rotary mounting plate 11 through the drive connection 14, and the entire fixture and workpiece rotate smoothly at the set speed. Thanks to the use of the rotary support bearing 12 with a rotation accuracy of ±0.01mm, the workpiece has no eccentric sway during rotation and its posture is stable. At this time, the spray gun begins the spraying operation. Because the adjustable clamping claw 31 adopts a thin-walled streamlined design and has a very small clamping surface, the workpiece surface is almost unobstructed, avoiding missed spraying or uneven coating thickness. At the same time, the rotary sealing ring 41 continuously isolates external paint mist, ensuring that the internal bearings and cylinders are not contaminated; the air passage integrated inside the rotary base assembly also avoids interference from external pipelines.

[0049] After the coating process is completed, the PLC control system of the coating line issues a command, the coil of solenoid valve 52 is de-energized and reversed; compressed air enters the opening chamber of double-acting pneumatic cylinder 21, and the piston rod drives the adjustable clamping claw 31 to open outwards synchronously. Once the magnetic switch 42 detects that the workpiece has been fully released, it sends feedback to the PLC control system of the coating line, and the conveyor then removes the coated workpiece. This completes one work cycle, and the fixture awaits the next workpiece.

[0050] In actual production, this tooling offers convenient adjustment and maintenance capabilities. When processing easily deformable plastic or thin-walled aluminum alloy workpieces, the operator only needs to rotate the pressure regulating valve 51 to reduce the output pressure, thereby reducing the clamping force and avoiding indentations. If the workpiece size changes beyond the adjustment range of the adjustable clamping jaws 31, the original adjustable clamping jaws 31 can be quickly removed and replaced with a set of adjustable clamping jaws 31 with different arc surfaces or different waist-shaped hole positions. After the flexible buffer pressure head 32 wears, it is not necessary to replace the entire clamping jaw assembly 3; it can be replaced individually simply by unscrewing the M4 bolts. Furthermore, all standard pneumatic components in this tooling, including quick-connect couplings, pressure regulating valves, and solenoid valves, are readily available for purchase and replacement on the market, resulting in low maintenance costs.

[0051] This utility model organically integrates the rotary base assembly, pneumatic clamping unit, anti-interference clamping claw assembly 3, sealing and protection assembly and integrated air circuit system 5 into one unit, realizing automatic clamping and releasing of workpieces, high-precision synchronous rotation and long-term reliable operation in harsh coating environments, significantly improving the production efficiency and coating quality of automated coating lines.

Claims

1. A rotary pneumatic clamping fixture suitable for automated coating lines, characterized in that: It includes a rotary base assembly that docks with and rotates synchronously with the rotary station of the automated coating line; a pneumatic clamping unit that drives and clamps the workpiece is integrated on the rotary base assembly; clamping claw assemblies that directly clamp the workpiece are symmetrically arranged on both sides of the pneumatic clamping unit; and a sealing and protection assembly is arranged between the rotary base assembly and the external fixed base and outside the pneumatic clamping unit.

2. The rotary pneumatic clamping fixture suitable for automated coating lines according to claim 1, characterized in that: The rotary base assembly is an integrated rotary structure, including a rotary mounting plate and a rotary support bearing. The rotary support bearing is installed between the rotary mounting plate and the external fixed base. The positioning stop is set on the lower end face of the rotary mounting plate, and the drive connection part is set on the lower end of the rotary mounting plate and integrally connected to the rotary mounting plate. The rotary mounting plate has an integrated air passage for supplying air to the pneumatic clamping unit, and the air passage is connected to an external air source.

3. A rotary pneumatic clamping fixture suitable for automated coating lines according to claim 1, characterized in that: The pneumatic clamping unit includes a double-acting pneumatic cylinder and a stroke limiting structure. The double-acting pneumatic cylinder is embedded in the center of the rotary base assembly. The stroke limiting structure includes a mechanical limiting block and a position detection element for detecting the clamping position.

4. A rotary pneumatic clamping fixture suitable for automated coating lines according to claim 1, characterized in that: The clamping jaw assembly includes an adjustable clamping jaw and a flexible buffer pressure head disposed inside the adjustable clamping jaw. The adjustable clamping jaw is provided with an oblong hole structure for adjusting the clamping position. The flexible buffer pressure head is made of elastic material and is detachably installed on the clamping surface of the adjustable clamping jaw.

5. A rotary pneumatic clamping fixture suitable for automated coating lines according to claim 4, characterized in that: The adjustable clamping jaw adopts a streamlined thin plate structure with an arc-shaped clamping surface; the clamping jaw assembly also includes a positioning limit block disposed inside the adjustable clamping jaw for axial positioning of the workpiece.

6. A rotary pneumatic clamping fixture suitable for automated coating lines according to claim 1, characterized in that: The sealing and protection assembly includes a rotary sealing ring and a cylinder sealing cover. The rotary sealing ring is installed between the rotary base assembly and the external fixed base. The cylinder sealing cover covers the outside of the pneumatic clamping unit and is made of transparent material.

7. A rotary pneumatic clamping fixture suitable for automated coating lines according to claim 1, characterized in that: It also includes an integrated pneumatic system, specifically including a pneumatic channel integrated inside the rotary base assembly, a quick-connect connector for connecting to an external air source, a pressure regulating valve for adjusting the clamping force, and a solenoid valve for linkage control with the automated painting line control system.

8. A rotary pneumatic clamping fixture suitable for automated coating lines according to claim 1, characterized in that: The slewing support bearing in the slewing base assembly is a high-precision crossed roller bearing.

9. A rotary pneumatic clamping fixture suitable for automated coating lines according to claim 1, characterized in that: The pneumatic clamping unit includes a double-acting pneumatic cylinder, and the clamping claw assembly is linked to the piston rod of the double-acting pneumatic cylinder. The clamping claw assembly opens and closes synchronously under the drive of the double-acting pneumatic cylinder.

10. A rotary pneumatic clamping fixture suitable for automated painting lines according to any one of claims 1 to 9, characterized in that: The rotating base assembly, pneumatic clamping unit, and gripper assembly are arranged coaxially, forming a compact integrated structure around the rotation center axis.

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