【正文】 此合格。XSZY250注射機(jī)為液壓—機(jī)械式合模機(jī)構(gòu)的注射機(jī)，其最大開模行程系由肘桿機(jī)構(gòu)或合模液壓缸沖程所決定，而不受模具厚度影響，按注射機(jī)最大開模行程大于模具所需的開模距離進(jìn)行校核。因此對(duì)于單分型面開模行程的校核公式為Smax≥H1+H2+(5～10)。然而這種校核方法是針對(duì)如圖14所示不帶側(cè)向抽芯機(jī)構(gòu)的模具。 圖14此次設(shè)計(jì)的模具，其側(cè)向抽芯動(dòng)作是通過斜導(dǎo)柱帶動(dòng)滑塊實(shí)現(xiàn)的，這時(shí)，需根據(jù)側(cè)向抽芯的抽拔距離來決定開模行程Smax。對(duì)注射機(jī)的校核還有安裝部分的尺寸校核，因?yàn)樵谀＞呓Y(jié)構(gòu)設(shè)計(jì)時(shí)，就根據(jù)注射機(jī)的模具安裝要求設(shè)計(jì)的，所以此校核可以省略。在模架設(shè)計(jì)上盡量選擇標(biāo)準(zhǔn)模架，雖然模具生產(chǎn)是單件小批量生產(chǎn)，但模具標(biāo)準(zhǔn)化對(duì)于提高模具設(shè)計(jì)和制造水平、提高模具質(zhì)量、縮短制模周期、降低成本、節(jié)約材料和采用高新技術(shù)，都具有十分重要的意義。參考文獻(xiàn)[1] :機(jī)械工業(yè)出版社,1997.[2] :高等教育出版社,2005.[3] :機(jī)械工業(yè)出版社,1992.[4] :化學(xué)工業(yè)出版社,2006.[5] . 北京:機(jī)械工業(yè)出版社,2001.[6] 唐志玉,:國防工業(yè)出版社,1993.[7] 于 華. :機(jī)械工業(yè)出版社,1998．[8] :國防工業(yè)出版社,2006．[9] :機(jī)械工業(yè)出版社,2000．[10] :機(jī)械工業(yè)出版社,2003．[11] 章飛,:化學(xué)工業(yè)出版社,2003．[12] 李德群， :江西科學(xué)技術(shù)出版社,2003．[13] :機(jī)械工業(yè)出版社,2004．[14] :化學(xué)工業(yè)出版社,2005．[15] :機(jī)械工業(yè)出版社,2006．附錄1：英文資料MetalCasting ProcessesAbstractFollowing a description of the fundamentals of solidification of metals in the preceding chapter and the roles of fluid flow and heat transfer in molds, we now describe in detail:l Characteristics of expendablemold and permanentmold processes.Applications advantages, and limitations of mon casting processes.l Casting of single crystals. l Inspection techniques for castings.l Brief review of foundries and their automation.Typical products made by casting: engine blocks, crankshafts, hubcaps, power tools, turbine blades, plumbing, zipper teeth, dies and molds, gears, railroad wheels, propellers, office equipment, statues, and housings.Alternative processes: forging, powder metallurgy, machining, and fabrication. IntroductionThe first metal castings were made during the period from 4000 to 3000 ., using stone and metal molds for casting copper. Various casting processes have been developed over time, each with its own characteristics and applications (see also Fig. ), to meet specific engineering and service requirements (Table ). A large variety of parts and ponents are made by casting, such as engine blocks, crankshafts, automotive ponents and power trains (Fig. ), agricultural and railroad equipment, pipes and plumbing fixtures, power tools, gun barrels, frying pans, office equipment, and very large ponents for hydraulic turbines.Two trends have had a major impact on the casting industry .The first is the mechanization and automation of the casting process, which has led to significant changes in the use of equipment and labor. Advanced machinery and automated processcontrol systems have replaced traditional methods of casting. The second major trend has been the increasing demand for highquality castings with close dimensional tolerances.This chapter is organized around the major classifications of casting practices (see Fig.Ⅱ.2 in the Introduction to Part Ⅱ). These classifications are related to mold materials, molding processes, and methods of feeding the mold with molten metal.The major categories are as follows:1. Expendable molds, which typically are made of sand, plaster, ceramics, and similar materials and generally are mixed with various binders (bonding agents) for improved properties. A typical sand mold consists of 90% sand, 7% clay, and 3% water. As described in Chapter 8, these materials are refractories (that is, they are capable of withstanding the high temperatures of molten metals). After the casting has solidified, the mold is broken up to remove the casting.2. Permanent molds, which are made of metals that maintain their strength at high temperatures. As the name implies, they are used repeatedly and are designed in such a way that the casting can be removed easily and the mold used for the next casting. Metal molds are better heat conductors than expendable nonmetallic molds (see Table )。 although, as expected, sand castings generally have rough, grainy surfaces. Dimensional tolerances generally are not as good as those in machining and other netshape processes. However, intricate shapes can be made by casting, such as castiron engine blocks and very large propellers for ocean liners.Because of their unique characteristics and applications, particularly in manufacturing microelectronic devices (PartⅤ), basic crystalgrowing techniques also are described in this chapter, which concludes with a brief overview of modern foundries. ExpendableMold Casting ProcessesThe major categories of expendablemold casting are sand, shell mold, plaster mold, ceramic mold, evaporative pattern, and investment casting. Sand castingThe traditional method of casting metals is in sand molds and has been used for millennia. Sand casting is still the most prevalent form of casting。 they are stronger than greensand molds and impart better dimensional accuracy and surface finish to the casting. However, this method has the following drawbacks: (a) distortion of the mold is greater, (b) the castings are more susceptible to hot tearing because of the lower collapsibility of the mold, and (c) the production rate is lower because of the considerable drying time required.1. The flask, which supports the mold itself. Twopiece molds consist of a cope on top and a drag on the bottom。 they generally are made of wood and are inexpensive. Split patterns are twopiece patterns, made such that each part forms a portion of the cavity for the casting。 hence, cores are made of sand aggregates. The core is anchored by core prints, which are recesses added to the pattern to support the core and to provide vents for the escape for the escape of gages (). A mon problem with cores is that (for some casting requirements, as in the case where a recess is required) they may lack sufficient structural support in the cavity. To keep the core from shifting, metal supports (chaplets) may be used to anchor the core in place ().Cores generally are made in a manner similar to that used in mold making。 they are used to fill large flasks and are operated typically by machine. An impeller in the machine throws sand from its blades (or cups) at such high speeds that the machin