【正文】 ry auction goods has weakened,‖ said the president of China Guardian’s Hu Yanyan. Besides, the entry of new buyers also makes certain changes to the direction of purchasing. In a word, the overall market trend is very unpredictable. Although China Guardian 2022 Spring Auctions has achieved remarkable results, it does not mean that the market has walked out of the predicament. We still have to wait for the big economic boom to invigorate the art market.‖ Even so, the hot pursuit of some special items appeared this spring. A special session of China Guardian Spring Auctions titled ―Fine Gilt—Bronze Buddhist Images‖ achieved a great deal with total sales volume of million yuan and 92 percent sale rate. The 5th Shamar Rinpoche Statue from 1617th century of Tibet was sold for million yuan. The Beijing Chengxuan Auctions featured almost 2,800 items of coins and stamps in three sessions with good sale rate. The Huachen Auctions also set a special session of photographs under the condition of largescale decline of auction sessions. There was a palpable dull thud of disappointment that acpanied the return of the imperial entourage of Zhen Huan to her homeland. It followed a couple years of hushed excitement as Chinese fans were fed tidbits about their proud concubine who was supposed to conquer the high ground of the North American market. Zhen Huan is, of course, the title character of The Legend of Zhen Huan, a 2022 television series that swept China off its feet and later took other Asian countries by storm. Two years ago, it was reported that HBO, a premium cable service headquartered in the United States, was going to air it in North America after some modification. Now, a condensed version that provides English subtitles but no dubbing has finally been made available on Netflix for online streaming. This version, highly anticipated as a milestone in China39。s Poly Theater. Their show, titled Ulan Muqir on the Grassland, depicted the history and development of the art troupe. Being from the region allowed me to embrace the culture of Inner Mongolia and being a member of the troupe showed me where I belonged, Nasun, the art troupe39。s performers of the troupe still tour the region39。t have a formal stage. The audience just sat on the grass. Usually, the performances became a big party with local people joining in. For him, the rewarding part about touring isn39。80s. We sat on the back of pickup trucks for hours. The sky was blue, and we couldn39。s Shaanxi province pass through a stop on the ancient Silk Road, Gansu39。 綜上所 述，塑件在成型過(guò)程中產(chǎn)生的最大尺寸誤差是上述誤差的總和。其尺寸變化值為： δ s=（ SmaxSmin） Ls 式中 δ s為塑件收縮率波動(dòng)所引起的塑件尺寸誤差 Smax 為塑件的最大收縮率 Smin 為塑件的最小收縮率 Ls為塑件的基本尺寸 成型零件工作尺寸公差可取塑件公差的 1/3~1/4或取 IT7~8級(jí)作為模具制造公差。 設(shè)計(jì)成型零件時(shí)，應(yīng)根據(jù)塑件的特性和塑件的結(jié)構(gòu)及使用要求，確定型腔的總體結(jié)構(gòu)，選擇分型面和澆口位置，確定脫模方式、排氣部位等，根據(jù)成型零件的加工、熱處理、裝配等要求進(jìn)行成型零件結(jié)構(gòu)設(shè)計(jì)，計(jì)算成型零件工作尺寸，進(jìn)行強(qiáng)度和剛度校核。成型零件工作時(shí)，直接與塑件接觸，承受塑件熔體的高壓、料流的沖刷、脫模時(shí)與塑件的摩擦。 (4) 澆口套與注射機(jī)噴在接觸處球面的圓弧度必須吻合。 本設(shè)計(jì)取 。若等于或小于注射機(jī)噴嘴直徑，在注射成型時(shí)會(huì)造成死角，并積存塑料，注射壓力下降，塑料冷凝后，脫模困難。若錐度過(guò)大會(huì)造成壓力減弱，流速減慢，塑料形成渦流，熔體前進(jìn)時(shí)易混進(jìn)空氣，產(chǎn)生氣孔；錐度過(guò)小，會(huì)使阻力增大，熱量損耗大，表面黏度上升，造成注射困難。 (1) 澆口套的內(nèi)孔（主流道）呈圓錐形，錐度 2176。澆口套是注射機(jī)噴嘴在注射模具上的座墊，在注射時(shí)它承受很大 的注射機(jī)噴嘴端部的壓力同時(shí)由于澆口套末端通過(guò)流道澆口與型腔相連接，所以也承受模具型腔壓力的反作用力。在一般情況下，主流道不直接開(kāi)設(shè)在定模板上，而是制造成單獨(dú)的澆口套，鑲定在模板上。主流道部分在成型過(guò)程中 ，其小端入口與注射機(jī)噴嘴及一定溫度、壓力的塑料熔要冷熱交替地反復(fù)接觸，屬易損件，對(duì)材料的要求較高因而模具的主流道部分常設(shè)計(jì)成可拆卸更換的主流道襯套式（俗稱澆口套），以便有效地選用鋼材單獨(dú)進(jìn)行加工和熱處理。主流道的大小和塑料進(jìn)入型腔的速度及充模時(shí)間長(zhǎng)短有著密切關(guān)系。由于主流道和高溫塑料熔體以及注射機(jī)噴嘴反復(fù)接觸，故再設(shè)計(jì)時(shí)常設(shè)計(jì)為可拆卸更換的澆口套。注射成型的基本要求是在合適的溫度和壓力下使足量的塑料熔體盡快充滿型腔，影響順利充模的關(guān)鍵之一就是澆注系統(tǒng)的設(shè)計(jì)。 ： 澆注系統(tǒng)是指注射模中從主流道的始端到型腔之間的熔體進(jìn)料通道，它的作用是將塑料熔體順利的充滿型腔的各個(gè)部位。一般來(lái)說(shuō)，大中型塑件和精度要求高的小型塑件優(yōu)先采用一模一腔的結(jié)構(gòu)，但對(duì)于精度要求不高的小型塑件（沒(méi)有配合精度要求），形狀簡(jiǎn)單，又是大批量生產(chǎn)時(shí)，若采用多型腔模具可提供獨(dú)特的優(yōu)越條件，使生產(chǎn)效率大為提高。如圖所示： 型腔數(shù)目的確定及分布 型腔數(shù)目的確定 為了制模具與注塑機(jī)的生產(chǎn)能力相匹配，提高生產(chǎn)效率和經(jīng)濟(jì)性，并保證塑件精度，模具設(shè)計(jì)時(shí)應(yīng)確定型腔數(shù)目。 7）盡 可能與料流的末端重合，以利于排氣。在安排制件在型腔中的方位時(shí)，要盡量避免與開(kāi)模運(yùn)動(dòng)相垂直方向的避側(cè)凹或側(cè)孔。 4）分型面應(yīng)使模具分割成便于加工的部件，以減少機(jī)械加工的困難。 在此處鍵入公式。 3）保證制件的精度和外觀要求與分型面垂直方向的高度尺寸，若精度要求較高，或同軸度要求較高的外形或內(nèi)孔，為保證其精度，應(yīng)盡可能設(shè)置在同一半模具腔內(nèi)。 2）確定有利的留模方式，便于塑件順利脫模從制件的頂出考慮分型面要盡可能地使制件留在動(dòng)模邊，當(dāng)制件的壁相當(dāng)厚但內(nèi)孔較小時(shí)，則對(duì)型芯的包緊力很少常不能確切判斷制件中留在型芯上還是在凹模內(nèi)。因此，一定要選擇合適的分型面，選擇分型面時(shí)一般要準(zhǔn)循以下幾個(gè)原則。 所需鎖模力： kNPAnAF m 7 8 6)( 21 ??? 型 式中 型P — 塑料熔體對(duì)型腔的平均壓力（由查表得 ABS對(duì)型腔的壓力為 30MPa） 分型面的確定 分型面對(duì)制品表面質(zhì)量、尺寸精度、形位精度