An automobile sheet metal clamp

Abstract

The present application belongs to the field of automobile manufacturing, and discloses a kind of automobile sheet metal clamp, including base, translation cylinder, pivot cylinder, clamping structure and sheet metal workpiece positioning mechanism, and synchronous motion control system for controlling the cooperative work of each cylinder;Clamping structure includes chuck and top block, chuck is used to clamp sheet metal workpiece, and top block is used to support and position sheet metal workpiece with chuck;Translation cylinder is installed on base and is used to drive clamping structure to move along horizontal direction, to realize the positioning adjustment of sheet metal workpiece;Pivot cylinder is connected with chuck, can drive chuck to rotate around horizontal pivot, to realize the oblique extension adjustment of sheet metal workpiece;Sheet metal workpiece positioning mechanism is set on base, to position the initial position of sheet metal workpiece before chuck clamps;Synchronous motion control system is used to control the cooperative action of translation cylinder and pivot cylinder;Compared with prior art, it can improve precision, is more convenient to maintain, and meets the production requirements of special-shaped workpiece.

Description

Technical Field

[0001] This invention relates to the field of automobile manufacturing, and in particular to a clamping device for forming tubular sheet metal parts. Background Technology

[0002] With the increasing demands for lightweight and high-strength automotive components, tubular sheet metal parts (such as door beams and support rods) are widely used in vehicle body structures. Existing sheet metal forming fixtures typically employ a single pneumatic or mechanical clamping method. The sheet metal workpiece is clamped by chucks fixed to a base, with initial positioning using locating pins and limit blocks, followed by forming by a single pressing device. However, these traditional technologies suffer from problems such as low positioning accuracy, poor forming synchronization, and poor adaptability to form changes.

[0003] Specifically, existing fixtures often rely on independent cylinders or mechanical structures for control during translational positioning, clamping, and pressing forming processes, lacking overall linkage and coordination. This results in sheet metal workpieces being prone to slight displacement during clamping or forming stages, failing to meet the forming requirements of high-precision trapezoidal and other irregular structures. Summary of the Invention

[0004] The purpose of this invention is to provide a compact automotive sheet metal fixture. By rationally configuring translation cylinders, rotating cylinders, and pressing cylinders, as well as multi-point top block support and sheet metal workpiece positioning mechanisms, it achieves high-precision positioning and synchronous linkage control of trapezoidal forming of tubular sheet metal parts, thereby meeting the forming requirements of high-precision trapezoidal and other irregular structures.

[0005] The present invention achieves the above objectives through the following technical solutions:

[0006] The automotive sheet metal fixture of the present invention includes a base, a translation cylinder, a rotating shaft cylinder, a pressing cylinder, a clamping structure and a sheet metal workpiece positioning mechanism, as well as a synchronous motion control system for controlling the coordinated operation of each cylinder.

[0007] The clamping structure includes a chuck and a top block. The chuck is used to clamp the sheet metal workpiece, and the top block is used to support and position the sheet metal workpiece in conjunction with the chuck.

[0008] The translation cylinder is mounted on the base and is used to drive the clamping structure to move horizontally in order to achieve the positioning and adjustment of the sheet metal workpiece;

[0009] The rotating cylinder is connected to the chuck and can drive the chuck to rotate around the horizontal rotating shaft, thereby realizing the tilting and extension adjustment of the sheet metal workpiece;

[0010] The sheet metal workpiece positioning mechanism is mounted on the base and is used to position the sheet metal workpiece in its initial position before the chuck clamps it.

[0011] The synchronous motion control system is used to control the coordinated movement of translation cylinders and rotary cylinders.

[0012] In a preferred embodiment, the structure consisting of chucks and rotary cylinders is divided into two groups, each group having two chucks and two rotary cylinders, symmetrically arranged on both sides of the sheet metal workpiece, all of which are hinged to the base via rotary shafts, and each chuck is driven by a rotary cylinder to clamp the sheet metal workpiece.

[0013] In a preferred embodiment, one end of the translation cylinder is fixed to the base, and the other end is connected to a sliding seat. A clamping structure is installed on the sliding seat. Driven by the translation cylinder, the sliding seat moves horizontally along the linear guide rail, thereby causing the clamping structure to move relative to the base to adjust the position of the sheet metal workpiece.

[0014] In a preferred embodiment, the pressure cylinder is positioned above the two clamps, with its piston rod connected to a pressure plate located directly above the sheet metal workpiece. When the pressure cylinder operates, the pressure plate presses down on the sheet metal workpiece to shape and fix it.

[0015] In a preferred embodiment, there are multiple top blocks distributed along the edge of the sheet metal workpiece to provide multi-point support to ensure its forming accuracy when the sheet metal workpiece is clamped and formed by the chuck.

[0016] In a preferred embodiment, the sheet metal workpiece positioning mechanism includes at least one positioning pin and at least one limiting block. The positioning pin is used to insert into a positioning hole on the sheet metal workpiece to define the planar position of the sheet metal workpiece, and the limiting block is used to abut against the edge of the sheet metal workpiece to define its placement direction, thereby achieving precise initial positioning of the sheet metal workpiece.

[0017] In a preferred embodiment, the synchronous motion control system is configured to sequentially drive the translation cylinder, the rotary cylinder, and the pressing cylinder to move. First, the translation cylinder moves the sheet metal workpiece to a predetermined positioning position. Then, the rotary cylinder drives the chuck to clamp the sheet metal workpiece. Finally, the pressing cylinder pushes the pressure plate to press the sheet metal workpiece down and form it, so as to achieve precise positioning and trapezoidal forming of the sheet metal workpiece.

[0018] The present invention has the following beneficial effects:

[0019] By using multi-cylinder synchronous linkage control, the positioning accuracy of sheet metal workpieces during clamping and forming processes is improved, effectively eliminating forming errors caused by minute displacements.

[0020] The structure is compact and reasonable, and the layout of the cylinder and clamp components is optimized, which saves space and facilitates maintenance.

[0021] Multiple top block supports ensure uniform force distribution and mold contact accuracy during the pressing and molding process;

[0022] Sheet metal workpiece positioning mechanism enables fast and reliable initial positioning, simplifies changeover and adjustment processes, and reduces manual operation costs;

[0023] This fixture is suitable for tubular sheet metal parts of various sizes and irregular shapes, including trapezoids, and has good expandability to meet the needs of multi-variety, small-batch production. Attached Figure Description

[0024] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0025] Figure 2 This is a top view of the structure of the present invention.

[0026] Figure 3 This is an exploded structural diagram of the base of the present invention.

[0027] Figure 4 This is a schematic diagram of the clamp structure of the present invention.

[0028] Figure 5 This is a schematic diagram of a sheet metal workpiece.

[0029] Figure 6 This is a schematic diagram of the top block structure of the present invention. Detailed Implementation

[0030] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0031] This automotive sheet metal fixture is used for positioning, clamping, and supporting thin sheet metal parts (such as door panel beams) to ensure positioning accuracy and forming quality during processing. The fixture structure provided in this embodiment is as follows: Figures 1 to 6 As shown, it includes a base 100, a translation cylinder 200, a chuck 510, a positioning component 300, a synchronous control system, and several connecting brackets and fasteners.

[0032] The base 100 is a rigid rectangular structure, comprising an upper mounting plate 105 and a base plate 101. The base plate 101 is preferably made of 20mm thick steel plate and machined to ensure flatness and verticality. Above the mounting plate 105 is a slide 107, which has multiple fixing structures, such as fixing holes 102 and side supports 106. A fixing bracket 103 is provided on the mounting plate 105 for mounting the power source of the translation cylinder 200 to form the sliding platform.

[0033] like Figure 3As shown, the mounting plate includes a linear guide rail 1051 and a slider 1052 assembly. This structure employs a parallel configuration of two guide rails, with one slider 1052 mounted on each rail. The two sliders 1052 are engaged with their respective guide rails 1051 via a rolling fit, allowing for smooth sliding along the guide rail 1051. Low-friction linear motion is achieved between the guide rails and sliders through internal rolling elements (such as steel balls).

[0034] like Figure 1 The cylinder body 200 of the translation cylinder is fixed to the rigid support of the slide table 107 via the front ball joint 202, so that the cylinder axis is parallel to the direction of the slide rail 1051. The ball joint at the piston rod end is hinged to the U-shaped lug 1071 of the slide table 107, and the ball joint 202 is embedded between the two walls of the lug 1071, thus forming a rotation space that is both rigid and capable of compensating for ±10° micro-angles in the vertical direction. When the cylinder extends or retracts, the pushing and pulling force is transmitted to the slide table through the ball joint 202 embedded in the lug 1071, driving it to move smoothly in a straight line along the double linear guide rail 1051. At the same time, the ball joint 202 absorbs the slight difference in the installation or posture of the guide rail to avoid lateral loads acting on the cylinder seals, which not only ensures the motion accuracy but also extends the service life of the mechanism. Moreover, disassembly and maintenance only require pulling out the pin to quickly separate the cylinder from the slide table 101.

[0035] Preferably, the dimensions of the base 100 are designed according to the size of the sheet metal workpiece 600, for example, approximately 1200mm x 800mm in length and width, and the height is set to an ergonomically suitable height for the sheet metal workpiece 600 to be processed on this fixture. Adjustable support feet 104 or positioning blocks are provided below the base 100. The positioning blocks 104 are mounted on the base plate 101 to ensure precise leveling when installed on a production line or workbench, and are fixed with anchor bolts to improve the stability and rigidity of the entire fixture.

[0036] Continue to refer to Figure 1 and Figure 2 Two sets of symmetrically arranged rotary cylinders 400 and chucks 510 are used to apply clamping force to the side of the sheet metal workpiece 600. Each set of rotary cylinders 400 is fixed to the side bracket 106 of the slide table 107 by its cylinder body mounting flange, and the end of the cylinder piston rod is connected to the chuck 510.

[0037] like Figure 4 As shown, the chuck 510 includes a clamping block 511 in the shape of jaws, the inner surface of which matches the contour of the sheet metal workpiece 600, and may be covered with a rubber pad or polyurethane pad to increase friction, prevent slippage, and protect the surface of the sheet metal workpiece from scratches. Each chuck 510 is hinged to the piston rod of the corresponding rotating cylinder 400 via a pin 512, so that the chuck 510 can adapt to the angular deviation of the surface of the sheet metal workpiece 600 within a certain range, ensuring that the clamping surface fully conforms to the sheet metal workpiece 600.

[0038] Preferably, the chuck 510 is made of high-strength alloy steel, and its surface is hardened and sandblasted, giving it wear-resistant and pressure-resistant properties. The replacement and adjustment of the chuck 510 are also relatively convenient.

[0039] Furthermore, when the chuck 510 is pushed by the rotating shaft cylinder, it rotates along the hinge shaft 513, causing the clamping block 511 to rotate clockwise to form a clamping action, or to rotate counterclockwise to achieve a releasing action.

[0040] Referring again to Figure 2, in this embodiment, four rotary cylinders 400 are provided, which are distributed in pairs on the left and right sides of the slide table 107 (e.g., Figure 2 The top-view layout shown clamps the opposite edges of the sheet metal workpiece 600. Two cylinders on each side are arranged along the length of the sheet metal workpiece 600, and the spacing can be adjusted according to the size of the workpiece 600 to ensure uniform clamping force distribution. For example, for long strip-shaped sheet metal parts such as door panel beams, a clamping mechanism can be set at each of the upper and lower ends of the door panel to achieve multi-point synchronous clamping. The translation cylinder 200 is a single-acting cylinder with a cylinder diameter of, for example, 50mm and a stroke of approximately 100mm. Each cylinder can generate approximately 1200N of thrust under an air pressure of 0.6MPa, used to reliably clamp the sheet metal workpiece slide. In actual design, cylinder specifications ranging from Φ50 to Φ80mm can be selected according to the size of the sheet metal workpiece 600 and the required clamping force. While ensuring clamping force, the cylinder volume is minimized to shorten the action response time and meet production cycle requirements.

[0041] Reference Figure 1 and Figure 6 As shown, a positioning assembly 300 is also installed on the slide table to accurately position the sheet metal workpiece 600 before clamping, thereby ensuring the accuracy of the sheet metal workpiece 600 forming and assembly. The positioning assembly 300 includes positioning pins 302 and positioning plates 304, etc. The positioning pins 302 are cylindrical pins or tapered pins, and are usually set at key reference positions of the slide table 107 (such as the hole position 601 or edge reference where the sheet metal workpiece 600 needs to be positioned).

[0042] When the sheet metal workpiece 600 is placed on the base, the positioning pin 302 is inserted into the positioning hole 601 on the sheet metal workpiece 600, and the positioning plate 304 abuts against the reference edge 602 of the sheet metal workpiece 600, thereby restricting the position of the sheet metal workpiece 600. The positioning plate 304 is a vertical plate fixed on the base, and its side serves as the reference surface of the sheet metal workpiece 600, used to support a certain plane or edge of the sheet metal workpiece 600.

[0043] The fixture is equipped with a cylinder synchronization control system. This system employs a combination of electrical and pneumatic control logic, including a programmable logic controller (PLC), solenoid valve assembly, throttle valves, and position sensors. The PLC issues clamping or releasing commands according to a preset program, controlling the solenoid valve assembly to simultaneously supply or exhaust air to the rotating cylinder 400. To ensure synchronized operation of each cylinder, an adjustable one-way throttle valve is installed on the intake branch of each rotating cylinder 400 to precisely control the airflow speed. By adjusting the throttle valves at the inlet and outlet of each cylinder to ensure identical charging and discharging rates, the piston movement speed of multiple cylinders can be made consistent, thus achieving synchronous drive. Furthermore, at the end of the cylinder piston rod stroke (approaching the clamping of the sheet metal workpiece), position sensors detect the position of each chuck 510. The PLC corrects for minute time differences through sensor feedback: if a chuck contacts the sheet metal workpiece prematurely, causing movement obstruction, the PLC can delay the movement of other cylinders until all chucks are in contact, and then synchronously apply the final locking pressure. This closed-loop control logic ensures that all chucks 510 contact and clamp the sheet metal workpiece 600 at approximately the same time, preventing one side of the chuck from contacting the sheet metal workpiece 600 first and causing it to be pushed away or causing positioning deviation.

[0044] Preferably, the synchronous control system also has a pressure equalization function. Through pressure sensors and pressure regulating valves installed in the air circuit, it monitors and equalizes the working pressure of each cylinder in real time, ensuring that the clamping force applied by each chuck is uniform. Even if the sheet metal workpiece 600 has uneven thickness in some areas, the output force of each cylinder can be automatically adjusted to a balanced state, thereby preventing the sheet metal workpiece 600 from deforming due to uneven force.

[0045] The usage process of this automotive sheet metal clamp is as follows:

[0046] Step 1: Place the sheet metal workpiece 600 to be processed on the base 100, press it against the positioning plate 304, and align the positioning holes / edges on the sheet metal workpiece 600 with the positions of the positioning pins 302 before positioning. The translation cylinder moves the stage a certain distance to pre-position the sheet metal workpiece 600.

[0047] Step 2: The PLC controls the operation of the clamp's chuck. Simultaneously, the solenoid valve assembly activates, and compressed air is diverted through the throttle valve into each rotating cylinder 400, pushing the piston rod to move the chuck 510 towards the sheet metal workpiece 600 and clamp it (e.g., ...). Figure 5(As indicated by the arrow). Under the coordination of the PLC synchronous control logic, the four chucks 510 contact the clamping side of the sheet metal workpiece 600 almost simultaneously. As the cylinder continues to apply pressure, the chucks 510 press the edge of the sheet metal workpiece 600 tightly against the positioning plate 304 or the chuck on the opposite side, achieving reliable clamping. During this process, simultaneous clamping at multiple points ensures that the sheet metal workpiece 600 is subjected to balanced forces; if a point contacts the sheet metal workpiece 600 first and applies force, the other chucks will immediately follow and apply the same clamping force, preventing the sheet metal workpiece 600 from shifting its posture. After clamping is completed, the system maintains air pressure supply to keep the sheet metal workpiece 600 fixed. The typical clamping pressure can be set according to the material of the sheet metal workpiece 600 and the requirements of subsequent processes. For example, when used for welding positioning, each chuck can apply a force of about 500N to meet the requirements, while when used for repair and straightening, the clamping force can be increased to 800-1000N to constrain the deformation of the sheet metal workpiece 600. By adjusting the air source pressure and the throttle valve, the clamping force and the speed of movement can be precisely controlled.

[0048] Step 3: After the sheet metal workpiece 600 is securely positioned by the fixture, subsequent processing operations can be performed. For example, if used for welding assemblies, a robot or worker can perform welding at predetermined positions on the sheet metal workpiece 600; if used for forming correction, external force can be applied to the free parts of the sheet metal workpiece 600 for finishing; or, when used for stamping and bending, the fixture can work with a press to press and form the unclamped parts. In these processes, the high-rigidity base 100 and positioning components 300 of the fixture provide stable support, preventing the sheet metal workpiece 600 from shifting when heated or stressed. Simultaneously, multi-point clamping can suppress local warping or twisting of the sheet metal workpiece 600, thereby ensuring processing accuracy. For example, during welding, because the fixture firmly fixes the sheet metal workpiece 600, the assembly gaps and relative positions of each weld point remain consistent, and the sheet metal workpiece 600 can still accurately maintain its designed shape after welding shrinkage; during the straightening and correction process, symmetrical clamping forces prevent over-correction or the generation of new deformations.

[0049] Step 4: After the process is completed, the PLC controls the switching of the solenoid valve group, and each chuck 510 synchronously retracts and resets to its initial open position. Once the chucks have completely released the sheet metal workpiece 600, the translation cylinder 200 moves the slide table, completely releasing the sheet metal workpiece's fixation. Subsequently, the operator or robot arm removes the processed sheet metal workpiece 600 from the fixture. The fixture then returns to standby mode, ready for the next cycle of sheet metal workpiece 600. To monitor the fixture's status, the system is equipped with sensors to detect the chuck position and the presence of the sheet metal workpiece 600. The next clamping action is only allowed when all chucks are in the open position and a new sheet metal workpiece 600 is placed in place, ensuring safe and reliable operation and seamless integration with the production line's cycle control system.

[0050] Through the above process, the automotive sheet metal fixture of the present invention can repeatedly and stably complete the high-precision positioning and clamping of sheet metal workpieces 600 in mass production. First, relying on high-precision positioning pins and positioning plates, the sheet metal workpiece 600 is accurately positioned before clamping, minimizing the initial positioning error. Second, the clamping process adopts multi-cylinder synchronous control and balanced force application, avoiding local deformation or positional displacement of the sheet metal workpiece 600 caused by single-point pressure, so that the sheet metal workpiece 600 strictly maintains the designed geometry after clamping. Third, each component of the fixture has sufficient rigidity and precision, the good flatness of the base 100 ensures that the sheet metal workpiece 600 is supported evenly, and the cylinder clamping force is appropriate and adjustable, preventing indentation or new deformation of the sheet metal workpiece 600.

[0051] The above embodiments are only used to illustrate the present invention and not to limit the present invention. Without departing from the concept of the present invention, those skilled in the art can make various modifications or equivalent substitutions to the details, and these should all be considered within the scope of protection of the present invention.

Claims

1. An automotive sheet metal clamp, characterized in that: It includes a base, translation cylinder, rotating cylinder, clamping structure and sheet metal workpiece positioning mechanism, as well as a synchronous motion control system for controlling the coordinated operation of each cylinder; The clamping structure includes a chuck and a top block. The chuck is used to clamp the sheet metal workpiece, and the top block is used to cooperate with the chuck to support and position the sheet metal workpiece. The translation cylinder is mounted on the base and is used to drive the clamping structure to move horizontally to achieve the positioning and adjustment of the sheet metal workpiece. The rotating shaft cylinder is connected to the chuck and can drive the chuck to rotate around the horizontal rotating shaft, thereby realizing the tilting and extension adjustment of the sheet metal workpiece. The sheet metal workpiece positioning mechanism is mounted on the base and is used to position the sheet metal workpiece at its initial position before the chuck clamps it. The synchronous motion control system is used to control the coordinated movement of the translation cylinder and the rotary cylinder.

2. The automotive sheet metal clamp according to claim 1, characterized in that: The structure consisting of the chucks and the rotating cylinders is divided into two groups, each group having two chucks and two rotating cylinders, symmetrically arranged on both sides of the sheet metal workpiece. They are all hinged to the base via rotating shafts, and each chuck is driven by one of the rotating cylinders to clamp the sheet metal workpiece.

3. The automotive sheet metal fixture according to claim 1, characterized in that: One end of the translation cylinder is fixed to the base, and the other end is connected to a sliding seat. The clamping structure is installed on the sliding seat. Driven by the translation cylinder, the sliding seat moves horizontally along the linear guide rail, thereby causing the clamping structure to move relative to the base to adjust the position of the sheet metal workpiece.

4. The automotive sheet metal fixture according to claim 1, characterized in that: The top blocks are multiple and distributed along the edge of the sheet metal workpiece to provide multi-point support to ensure its forming accuracy when the sheet metal workpiece is clamped and formed by the chuck.

5. The automotive sheet metal fixture according to claim 1, characterized in that: The sheet metal workpiece positioning mechanism includes at least one positioning pin and at least one limiting block. The positioning pin is used to insert into the positioning hole on the sheet metal workpiece to limit the planar position of the sheet metal workpiece, and the limiting block is used to abut against the edge of the sheet metal workpiece to limit its placement direction, thereby achieving precise initial positioning of the sheet metal workpiece.

6. The automotive sheet metal fixture according to claim 1, characterized in that: The synchronous motion control system is configured to sequentially drive the translation cylinder and the rotary cylinder to move. First, the translation cylinder moves the sheet metal workpiece to a predetermined positioning position, and then the rotary cylinder drives the chuck to clamp the sheet metal workpiece.

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