Flexible multi-point forming device for plates

Abstract

The invention relates to a flexible multi-point forming device for plates. The device comprises a hydraulic container with an opening, a flexible diaphragm mounted at the opening, a pressure regulating unit and multiple pressurizing units, wherein the flexible diaphragm seals the inside of the hydraulic container to form a hydraulic cavity, the pressure regulating unit is communicated with the hydraulic cavity, and the pressurizing units are arranged movably relatively to the flexible diaphragm. The pressurizing units move towards the direction of the flexible diaphragm, so that a to-be-formed plate arranged between the flexible diaphragm and the pressurizing units is deformed synchronously along with deformation of the flexible diaphragm towards to the inside of the hydraulic cavity until the to-be-deformed plate is formed in a preset shape. Since the flexible diaphragm can provide matched real-time adjustable and uniform normal acting force, effective normal constraint on the to-be-formed plate is formed, vacant regions in the forming process of cambered stamped parts are eliminated basically, and corrugation of the plate can be effectively inhibited. Formed workpieces are good in surface quality, uniform in thickness and free of defects such as pressing marks.

Description

technical field [0001] The invention relates to the field of curved plate forming, in particular to a plate flexible multi-point forming device. Background technique [0002] Flexible manufacturing is the development trend of the processing industry. Among them, multi-point forming technology is an advanced manufacturing technology for three-dimensional surface forming of plate parts. At present, research institutions at home and abroad have conducted in-depth research on it. [0003] CN2548792Y divides the forming surface of the forming die into a series of simple-shaped, discretely arranged, and height-adjustable indenters to form a dot-matrix die, and constructs the forming surface of the die to realize plate forming. The biggest advantage of this device is that it can construct different forming curved surfaces by arbitrarily adjusting the position of the indenter to realize the forming of the three-dimensional curved surface of the plate. However, when forming various ...

AI Technical Summary

Problems solved by technology

However, when forming various curved surfaces, especially parts with protruding parts such as spherical surfaces and conical surfaces, there will always be a considerable part of the plate in a suspended state at the initial stage of forming during the forming process. If it is not in contact with the suspended part of the plate, effective normal constraints cannot be imposed on it, resulting in wrinkles and other defects, which not only seriously affect the forming quality, precision and life of the mold, but also sometimes directly lead to the failure of the forming process.

[0004] CN1994611A adopts an elastic cushion, and proposes to sandwich the sheet in a certain elastic cushion for forming in multi-point forming, and rely on the deformation of the elastic cushion to impose normal constraints on the sheet, but in fact, wrinkling is more It appears in the initial stage of forming, and the elastic cushion layer only works when the upper and lower molds are basically pressed together or at the end of forming, and it cannot completely solve the problem of forming wrinkles

[0005] CN2460239Y proposes a device that does not adjust the position of the indenter in advance, but simultaneously adjusts the displacement and speed of all punches during forming to realize loading and deformation. However, the structure is complicated, the control is difficult, and the cost of the device is high: this device needs to install a set of specially manufactured hydraulic valves and hydraulic cylinders driven by stepping motors or servo motors on each indenter. The rotation speed of the motor is used to control the displacement of the hydraulic cylinder. Due to the need for simultaneous position detection and real-time speed and displacement control of hundreds or even hundreds of pressure heads, the control system can hardly achieve the designed function. Even if the manufacturing is successful, it is expensive. The cost and the instability of the system also make practical application almost impossible

[0006] CN1864884A proposes a combination of multi-point structure and viscous medium control on the upper half mold, and a forming device using viscous medium on the lower half mold. It also adopts the same method of not adjusting the pressure head in advance, but synchronously controlling the rotation of the stepping motor during the forming process. And control the flow and pressure of the viscous medium at the same time to realize the normal constraint on the sheet during the sheet forming process, but the disadvantages of complex structure, difficult control, and high device cost still exist: this device also needs to be installed on each indenter A set of high-power stepping motors is used to realize the deformation of the sheet when the rotating device drives the indenter down during the forming process. This also requires real-time detection of motion parameters (displacement, speed, etc.) of all indenters, and every Each stepper motor needs to be controlled in real time during the deformation process to achieve the final forming purpose. At the same time, multiple electro-hydraulic proportional relief valves are required to control the pressure of the viscous medium.

However, this device needs to process special hydraulic cylinders, and the manufacturing cost is high. It is also very difficult to ensure the installation and sealing of hundreds of densely arranged hydraulic cylinders. The size of the hydraulic cylinders limits the size of the basic body, which limits the density of the basic body. Forming accuracy is not easy to guarantee

At the same time, affected by the structure of the hydraulic cylinder, the maximum force acting on each basic body is also limited, thus restricting the ability to form complex thick plate surfaces

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