机械外文翻译---基于注塑模具钢研磨和抛光工序的自动化表面处理-模具设计(编辑修改稿)

机械外文翻译---基于注塑模具钢研磨和抛光工序的自动化表面处理-模具设计(编辑修改稿)内容摘要：

r than that of the original surface. Consequently, the spherical grinding process is an example of a smallerthebetter type problem. The S/N ratio, η, is defined by the following equation: η =−10 log10(mean square quality characteristic) =−10 log10  ni iyn 121 where: yi : observations of the quality characteristic under different noise conditions n: number of experiment After the S/N ratio from the experimental data of each L18 orthogonal array is calculated, the main effect of each factor was determined by using an analysis of variance (ANOVA) technique and an Fratio test. The optimization strategy of the smallerthe better problem is to maximize η, as defined by Eq. 1. Levels that maximize η will be selected for the factors that have a significant effect on η. The optimal conditions for spherical grinding can then be determined. 4 Experimental work and results The material used in this study was PDS5 tool steel (equivalent to AISI P20), which is monly used for the molds of large plastic injection products in the field of automobile ponents and domestic appliances. The hardness of this material is about HRC33 (HS46). One specific advantage of this material is that after machining, the mold can be directly used for further finishing processes without heat treatment due to its special pretreatment. The specimens were designed and manufactured so that they could be mounted on a dynamometer to measure the reaction force. The PDS5 specimen was roughly machined and then mounted on the dynamometer to carry out the fine milling on a threeaxis machining center made by YangIron Company (type MV3A), equipped with a FUNUC Company NCcontroller (type 0M). The premachined surface roughness was measured, using Hommelwerke T4000 equipment, to be about μm. Figure 6 shows the experimental setup of the spherical grinding process. A MP10 touchtrigger probe made by the Renishaw Company was also integrated with the machining center tool magazine to measure and determine the coordinated origin of the specimen to be ground. The NC codes needed for the ballburnishing path were generated by PowerMILL CAM software. These codes can be transmitted to the CNC controller of the machining center via RS232 serial interface. . Experimental setup to determine the optimal spherical grinding parameters Table 2 summarizes the measured ground surface roughness alue Ra and the calculated S/N ratio of each L18 orthogonal array sing Eq. 1, after having executed the 18 matrix experiments. The average S/N ratio for each level of the four actors is shown graphically in Fig. 7. Table2. Ground surface roughness of PDS5 specimen Exp. Inner array (control factors) Measured surface roughness value (Ra) Response no A B C D  my1  my2  my3 S/N(η(dB)) Mean  my_ 1 1 1 1 1 2 1 2 2 2 3 1 3 3 3 4 2 1 2 3 5 2 2 3 1 6 2 3 1 2 7 3 1 3 2 8 3 2 1 3 9 3 3 2 1 10 1 1 2 2 11 1 2 3 3 12 1 3 1 1 13 2 1 1 3 14 2 2 2 1 15 2 3 3 2 16 3 1 3 1 17 3 2 1 2 18 3 3 2 3 . Plots of control factor effects The goal in the spherical grinding process is to minimize the surface roughness value of the ground specimen by determining the optimal level of each factor. Since −log is a monotone decreasing function, we should maximize the S/N ratio. Consequently, we can determine the optimal level for each factor as being the level that has the highest value of η. Therefore, based on the matrix experiment, the optimal abrasive material was pink aluminum oxide。 the optimal feed was 50 mm/min。 the optimal depth of grinding was 20 μm。 and the optimal revolution was 18 000 rpm, as shown in Table 3. The optimal parameters for surface spherical grinding obtained from the Taguchi’s matrix experiments were applied to the surface finish of the freeform surface mold insert to evaluate the surface roughness improvement. A perfume bottle was selected as th。