Fixture Planning of Valve-Body Part Based on Machining Capability of NC Machining Center

To solve the problem that fixture planning of the batch valve-body part of car, the NC machining process of the batch valve-body parts based on the normal vector is analyzed in this paper. The different fixture planning of the valve-body part based on the capabilities of three-axis and four-axis and five-axis NC machining center (MC) is discussed. According to the questions that the feature of different machined position holes and faces of valve-body part on three-axis NC machining center, the multi-piece fixture planning and multi-position rotational fixture planning are designed. The results indicate that the proposed fixture planning can improve the machining productivity, which based on cabapility of three-axis NC machining center (MC).

A Computer-Based Design System for Lightweight Grippers in the Automotive Industry

This paper presents the development as well as the architecture of a computer-aided dedicated fixture design system intended to support the design of lightweight (carbon fiber composite) grippers for a major truck company. Lightweight grippers were required due to the increasing production rates in the automotive industry. The current robotic equipment was facing diverse problems during transportation and aligning of the parts, problems related to mass inertia, accuracy and stability. Moreover, the increased demands for truck customization and fast release of new product versions required a computer-based support for the design of the appropriate fixtures. This application is believed to be of interest for fixture research because the design of such complex fixtures is likely to appear more and more often. Specifically, such fixtures are subject to specific requirements that necessitate a systematic requirement elicitation method; they also require extensive conceptual design work as well as careful analysis activity planning. The main steps requisite for the development of the design system are reported: setup planning, fixture planning, conceptual design of the gripper. The architecture, the process and the constituent elements of the design system are also described and illustrated.

Workpiece Fixture Planning Method for Continuous Multi-Axis Machining with Consideration of Motion on Translational Axis

This study deals with a new method to plan fixture conditions of a workpiece on a trunnion table in a continuous multi-axis-controlled machine tool. The motion of the translational axes on the machine tool is usually greatly affected by machine tool structure, tool posture change, and the fixture conditions of the workpiece. However, in a conventional CAM scheme, the fixture conditions are designed to be determined separately. Furthermore, a method of planning these conditions to reduce total machining time has not been proposed. Therefore, this paper proposes a new planning method for workpiece position and posture on a trunnion table. The proposed method consists of two different steps. In the first step, a large number of fixture condition candidates are assumed automatically. In the second step, geometric calculations are executed to estimate the distribution of features in terms of motion on the translation axes. The second step is equivalent to the repetition of coordinate transformations in the conventional post process software. In the developed prototype system, parallel processing technology known as GPGPU is introduced to drastically reduce calculation time. The developed system can visualize differences in total travel distance, maximum velocity, and total machining time for each candidate. These results can assist a CAM operator in selecting the optimal fixture conditions in a short time.