Papers by Keyword: Caulking

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Authors: Yasunori Harada
Abstract: The cold joining of dissimilar metal sheets using a shot peening process was investigated. In shot peening the substrate undergoes large plastic deformation near the surface due to the hit with shots. Consequently, plastic flow areas formed by cold working may form the surface layer. The dissimilar sheets with the concavo-convex edge are connected, and then the contact area is shot-peened. In this joining, the convex edges of the sheet are laid on the other sheet. Namely, in the joining area, the two sheets are superimposed. In the experiment, the shot peening treatment was performed by using an air-type peening machine. The shots used were made of high carbon cast steel. Air pressure was 0.6MPa and peening time was in the range of 30-150s. The peening conditions were controlled in the experiment. The sheets were commercial low-carbon steel, stainless steel, pure aluminum, pure titanium, pure copper, and magnesium alloy. The effects of processing conditions on the joinability were mainly examined. The joint strength increased with the kinetic energy of shots. It was found that the present method was effective for cold joining of dissimilar metal sheets.
Authors: Johannes von Lindenfels, Andreas Heyder, Stefan Funk, Stefan Pigler, Jörg Franke
Abstract: Electromagnetic actors (solenoids) are used in automotive and automation technology as valve actors for pneumatics and hydraulics or as actuating and pressure solenoids. During assembly there are often press-in and caulking processes used. A central quality aspect of the final control elements is the adherence to defined actuating force ranges in order to ensure the switching process and at the same time to keep wear within limits. These defined force ranges can currently only be maintained by additional heat treatment of the parts. The hysteresis of the assembled unit can be influenced by the caulking. The objective of this paper is to propose the potential reduction of annealing processes by revealing the interdependencies between the magnetic interactions of the individual components and the assembly process parameters. In addition, errors in the caulking process are detected and prevented at an early stage. A magnetic characterization of the soft magnetic components and assemblies before and during their assembly is proposed. Furthermore, the integration of the measurement data into a process control system is intended. The precondition is the development and construction of measuring equipment and systems that can be used to assess the magnetic properties at an early stage of assembly. The assembly can then be adjusted in order to compensate batch fluctuations. As a consequence new materials can be used to eliminate complex annealing processes prior to assembly.
Authors: Yoon Kim, Dong Woo Kang, Tae Wan Ku, Jeong Kim, Beom Soo Kang
Abstract: This study is dedicated to three-dimensional finite element analysis of seaming process, which consists of bending, curling and caulking process, of a large tubular mechanical bonded structure. The seaming process is often used to improve a high bonding strength as avoiding any kind of defect. Finite element simulations of the seaming process were preformed for two different initial conditions with pre-analyzed results and without those from bending process. The mechanical bonding strength of the seamed area in the large tubular structure was estimated and compared through finite element analysis among several different analysis conditions of the bending and the caulking. Tensile test for the specimen extracted from the large tubular mechanical bonded structure was also executed and compared with the results of finite element analysis, in order to verify which initial condition in finite element analysis was suitable for this kind of multi stage seaming process. As a result, the effect on an accuracy of finite element analysis for the multi stage seaming process was evaluated in this study. Finally, it is noted that the pre-analyzed results from bending process should be considered in order to obtain the accurate results from finite element analysis.
Authors: Yasunori Harada, Kenzo Fukaura
Abstract: In this study, plastic flow joining using a shot peening process was investigated. Surface treatment is necessary to improve the surface properties. Shot peening is one of the surface treatments. Since the surface of substrate is hit repeatedly with a large number of shots, the substrate undergoes a large plastic deformation near its surface. Therefore, plastic flow characterized by a shear droop occurs at the edge of the substrate due to shot peening. If an implant made of a dissimilar material is set in a hollow space on the surface of the substrate and then shot-peened, it can be joined to the substrate due to the peening droop generated by the large plastic deformation during shot peening. In this method, the availability of the plastic flow, i.e., the peening droop makes the joining of the implant possible. In the experiment, a compressed-air-type shot peening machine was employed. To examine experimentally the influence of working temperature on bondability, equipment with a heating furnace was produced. The influence of processing conditions on the joining of the implant and the substrate was examined. The joint strength increased with the kinetic energy of shots and processing temperature. The improved implant with a step was effective in improving in bondability. The dissimilar material was also successfully joined to a thin sheet by using of the interaction of peening droops. It was found that the present method using the peening droop was effective for joining the dissimilar materials.
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