Showing papers on "Stamping published in 2012"

In situ non-contact measurements of surface roughness

Abstract: Surface roughness measurements are often required to validate a machining process. However, when using a 3D surface roughness measuring instruments it is usually necessary to remove the part from the machine tool between two operations, potentially introducing systematic errors. Furthermore, surface roughness measuring instruments are not suited for measuring heavy and large parts such as stamping dies. This paper presents a method to measure the surface topography of a part in situ, i.e. directly on the machine tool without removing the part. After introducing the sensor technology and the data acquisition chain, the effects of geometric imperfections of the machine tool and compensation for thermal effects on the measurement results are discussed. An application of the method is then presented to assess a finishing process on a five-axis machining centre including milling and polishing operations.

Stamping and wrinkling of elastic plates

Abstract: We study the peculiar wrinkling pattern of an elastic plate stamped into a spherical mold. We show that the wavelength of the wrinkles decreases with their amplitude, but reaches a minimum when the amplitude is of the order of the thickness of the plate. The force required for compressing the wrinkled plate presents a maximum independent of the thickness. A model is derived and verified experimentally for a simple one-dimensional case. This model is extended to the initial situation through an effective Young modulus representing the mechanical behavior of the wrinkled state. The theoretical predictions are shown to be in good agreement with the experiments. This approach provides a complement to the "tension field theory" developed for wrinkles with unconstrained amplitude.

Improvement of formability for fabricating thin continuously corrugated structures in sheet metal forming process

Abstract: A stamping process is widely used for fabricating various sheet metal parts for vehicles, airplanes, and electronic devices by the merit of low processing cost and high productivity. Recently, the use of thin sheets with a corrugated structure for sheet metal parts has rapidly increased for use in energy management devices, such as heat exchangers, separators in fuel cells, and many others. However, it is not easy to make thin corrugated structures directly using a single-step stamping process due to their geometrical complexity and very thin thickness. To solve this problem, a multi-step stamping (MSS) process that includes a heat treatment process to improve formability is proposed in this work: the sequential process is the initial stamping, heat treatment, and final shaping. By the proposed method, we achieved successful results in fabricating thin corrugated structures with an average thickness of 75 μm and increased formability of about 31% compared to the single-step stamping process. Such structures can be used in a plate-type heat exchanger requiring low weight and a compact shape.

Method for compensating rebounding error of automobile cover panel based on numerical simulation

Abstract: The invention discloses a method for compensating a rebounding error of an automobile cover panel based on numerical simulation. The method comprises the following steps of: constructing an ideal model of a stamping part in a computer, acquiring a finite element model of an original stamping die on the basis of the ideal model of the stamping part by a numerical simulation technology, and performing small-equidistance offsetting on the finite element model of the original stamping die to acquire the finite element model of a new die; stamping and forming the two dies and simulating the rebounding by the numerical simulation technology, and exporting grid data for rebounding analysis; and performing discrete Fourier transform on the grid data of the stamping part, which does not rebound, of the two dies, and the grid data of the stamping part, which rebounds, of the two dies respectively, and calculating a die molded surface which is subjected to compensation and correction by using a frequency domain transfer function concept of a linear system to acquire a computer-aided design (CAD) molded surface of the ideal die corresponding to an ideal stamping part. By performing numerical simulation of rebounding compensation on the die molded surface, a correction die size which can eliminate a geometric error caused by the rebounding of a workpiece can be obtained to ensure that the stamping part with high shape accuracy is obtained.

Lightweight steel door for vehicle and method for manufacturing the same

Abstract: A vehicle door assembly comprises an inner panel integrally formed by upper and lower horizontal beams interconnected by front and rear upright beams, and an outer panel bonded to the inner panel. The frame portion comprises opposite front and rear U-shaped side frame members non-detachably attached to each other by upper and lower intermediate frame members so as to form a continuous perimeter. The side frame members are made of a first steel material and the intermediate frame members made of a second steel material, which is different from the first steel material. A method for manufacturing the inner panel comprises the steps: providing U-shaped sheets of the first steel material, providing top and bottom sheets of the second steel material, non-detachably connecting the U-shaped sheets to the top and bottom sheets so as to form a blank, and stamping the blank into the frame portion.

Additive fabrication technologies for creating molds for die components

Abstract: A method comprising the use of additive manufacturing techniques for creating molds and pattern parts for subsequent use in the casting of die components and die shoes for use in die stamping processes.

Production equipment for coating and gold-stamping amboss of wallpaper

Abstract: The utility model discloses production equipment for a coating and gold-stamping amboss on wallpaper. The production equipment mainly comprises a material discharging unit, a material discharging traction unit, a coating unit, an oven unit, an amboss gold stamping unit, a cooling unit, a material collecting unit, wherein the wallpaper raw material which needs to be machined sequentially penetrates through the material discharging unit, the material discharging traction unit, the coating unit, the oven unit, the amboss gold stamping unit and the cooling unit, and finally enters the material collecting unit. The production equipment for a coating and gold-stamping amboss on wallpaper further comprises a control system controlling each structural unit, and the control system comprises control sensors arranged on the structural units and a controller transmitting a control instruction. After the production equipment is adopted, the coating, the gold stamping, the embossing and the separate coiling are combined on one production line, and the conventional method of segmenting can be changed. A polyvinyl chloride (PVC) coating semi-finished product is compounded with a gold film by the waste heat after the coating and the drying.

Method for manufacturing press-molded article and press molding equipment

Abstract: A method for press-molding a thin steel plate using a press molding mold and manufacturing a molded article, wherein the thin steel plate is heated to a temperature equal to or higher than the Ac1 transformation point, subsequently cooled to a temperature equal to or less than 600°C, and then molded using the mold. Molding is completed at a temperature equal to or higher than the martensite start temperature (Ms), whereupon the steel sheet is released from the mold and tempered, whereby a press-molded article is productively manufactured, the article having excellent formability to the extent of being suitable for deep drawing.

A Simple Discrete Method for the Simulation of the Preforming of Woven Fabric Reinforcement

Abstract: In this paper, a discrete approach for the simulation of the preforming of dry woven reinforcement is proposed. A “unit cell” is built using elastic isotropic shells and axial connectors instead of bars and beams used in previous studies. Shell elements are used to take into account the in-plane shear stiffness and to manage contact phenomenon with the punch and die. Connectors reinforce the structure in the yarn directions and naturally capture the specific behavior of the fabric. To identify the material parameters, uniaxial tensile tests and bias tests have been employed. A numerical algorithm, coupling Matlab and Abaqus/Explicit, is used to determine the shear parameters by an inverse method. The model has been implemented in Abaqus to simulate hemispherical stamping. Experimental results are compared to numerical simulations, good agreement between both results is shown.

Process for producing cigarette label by replacing large-area hot stamping with local dealuminization transfer

Abstract: The invention discloses a process for producing a cigarette label by replacing large-area hot stamping with local dealuminization transfer. Currently, the large-area hot stamping cigarette label producing process has the problems of large equipment investment, high requirement on elasticity of a hot stamping film adhesive layer, difficulty in realization and the like. The invention adopts the technical scheme that the process for producing the cigarette label by replacing large-area hot stamping with local dealuminization transfer comprises procedures of coating a base film, carrying out laser die pressing, aluminizing, neatening the base film, printing a protection coating, dealuminizing and drying, carrying out fixed-length compound, carrying out transfer stripping, carrying out position slitting and carrying out printing application processing sequentially. The process is used for replacing a large-area hot stamping process, so that the realization difficulty of a large-area bottomhot stamping printing product is avoided. The process has high quality. Even a dot laser pattern can be realized. Meanwhile, the combination firmness of the pattern on paper is improved and the gradeof the product is promoted. The investment level of equipment is reduced. The production cost is greatly reduced.

Method and device for hot stamping

Abstract: The invention relates to a method for hot stamping at least one part of at least one strip-shaped stamping foil (10, 20) on a strip-shaped substrate (30), and to a corresponding hot stamping device. The substrate (30) to be stamped is combined with a stamping foil (10, 20) of the at least one stamping foil (10, 20). The substrate (30) and the stamping foil (10, 20) located thereon are guided along the circumference of a first heated stamping roll, wherein a first stamping layer is stamped on the substrate (30) during a first stamping operation. After being stamped once, the substrate (30) is guided away from the first stamping roll and, in the running direction (33) of the substrate (30), is recombined downstream of the first stamping roll with the same stamping foil or with an additional stamping foil (10, 20) of the at least one stamping foil (10, 20). After being imprinted once, the substrate (30) and the stamping foil (10, 20) located thereon are guided along the circumference of a second heated stamping roll, wherein a second stamping layer is stamped on the substrate (30) during a second stamping operation. Finally, after being imprinted twice, the substrate (30) is guided away from the second stamping roll.

Power semiconductor device packaging

Abstract: Embodiments of the present invention relate to the use of stamping to form features on a lead frame of a semiconductor device package. In one embodiment, portions of the lead frame such as pins are moved out of the horizontal plane of a diepad by stamping. In certain embodiments, indentations or a complex cross-sectional profile, such as chamfered, may be imparted to portions of the pins and/or diepad by stamping. The complexity offered by such a stamped cross-sectional profile serves to enhance mechanical interlocking of the lead frame within the plastic molding of the package body. Other techniques such as selective electroplating and/or formation of a brown oxide guard band to limit spreading of adhesive material during die attach, may be employed alone or in combination to facilitate fabrication of a package having such stamped features.

Automatic file stamping device

Abstract: The utility model relates to an automatic file stamping device comprising a stamping mechanism and a paper delivery mechanism, wherein the stamping mechanism consists of a bracket, a shell, a main motor, two cams, a stamp fixture and a supporting seat; a speed reducer which is driven by the motor and the supporting seat are installed in the shell; the cams are installed on a transmission shaft; the transmission shaft is installed on the supporting seat and is driven by the speed reducer; a pushing rod is installed below the cams; the pushing rod is connected with the stamp fixture and is sleeved on a shaft sleeve which is connected with a rack; the rack is driven by a gear motor; the shell is installed on the bracket; the bracket is provided with a stamp-pad ink platform; the positions of the two cams respectively correspond to the positions of stamping and dipping stamp-pad ink; the paper delivery mechanism consists of a paper storage box, a paper-rubbing roller and a stamping platen; the stamping platen is placed in the paper storage box; the paper-rubbing roller is placed on the paper storage box and is driven by a paper-rubbing motor; the paper storage box is installed on the bracket; and all the motors are controlled by a PLC (Programmable Logic Controller). The automatic file stamping device is compact in structure, coordinating in action and high in accuracy, the functions of stamping, dipping the stamp-pad ink, drying and delivering paper are automatically completed, and the efficiency of making a stamping file is improved.

Universal electronic stamping system implementation method based on PKI

Abstract: This invention relates to a universal electronic stamping system based on PKI, which is used in information security technology field, wherein, the invention uses digital certificate to issue electric stamp certificate for user held opposite private key, which can be stored and transferred in network safely with even little data damage can be detected by system. By introducing the trustful third party, any two entities without confidence with each other can take electric trade and exchange e-document safely and rapidly. Based on the electronic stamping system of the invention as a universal system without having relation with other business, the invention has high security with simple structure to integrate with other system easily, and has great value for development of EC and EGA.