【正文】 tions were repealed, such as a deduction available to twoine married couples that had been used to avoid the marriage penalty (a greater tax liability incurred when two persons filed their ine tax return as a married couple rather than as individuals). Although the personal exemption exclusion was increased, an exemption for elderly and blind persons who itemize deductions was repealed. In addition, a special capital gains rate was repealed, as was an investment tax 玩具汽車外殼的模具設(shè)計(jì) 32 credit that had been introduced in 1962 by President john f. kennedy. The Omnibus Budget Reconciliation Act of 1993, the first budget and tax act enacted during the Clinton administration, was vigorously debated, and passed with only the minimum number of necessary votes. This law provided for ine tax rates of 15, 28, 31, 36, and percent on varying levels of ine and for the taxation of social security ine if the taxpayer receives other ine over a certain level. In 2022 Congress enacted a major ine tax cut at the urging of President gee w. bush. Over the course of 11 years the law reduces marginal ine tax rates across all levels of ine. The 36 percent rate will be lowered to 33 percent, the 31 percent rate to 28 percent, the 28 percent rate 。 the explanation of the tax reform act of 1986 was more than thirteen hundred pages long (Pub. L. 99514, Oct. 22, 1986, 100 Stat. 2085). Commerce Clearing House, a publisher of tax information, released a version of the Internal Revenue Code in the early 1990s that was four times thicker than its version in 1953. Changes to the tax laws often reflect the times. The flat tax of 1913 was later replaced with a graduated tax. After the United States entered world war i, the War Revenue Act of 1917 imposed a maximum tax rate for individuals of 67 percent, pared with a rate of 13 percent in 1916. In 1924 Secretary of the Treasury Andrew W. Mellon, speaking to Congress about the high level of taxation, stated, The present system is a failure. It was an emergency measure, adopted under the pressure of war necessity and not to be counted upon as a permanent part of our revenue structure…. The high rates put pressure on taxpayers to reduce their taxable ine, tend to destroy individual initiative and enterprise, and seriously impede the development of productive business…. Ways will always be found to avoid taxes so destructive in their nature, and the only way to save the situation is to put the taxes on a reasonable basis that will permit business to go on and 玩具汽車外殼的模具設(shè)計(jì) 31 industry to develop. Consequently, the Revenue Act of 1924 reduced the maximum individual tax rate to 43 percent (Revenue Acts, June 2, 1924, ch. 234, 43 Stat. 253). In 1926 the rate was further reduced to 25 percent. The Revenue Act of 1932 was the first tax law passed during the Great Depression (Revenue Acts, June 6, 1932, ch. 209, 47 Stat. 169). It increased the individual maximum rate from 25 to 63 percent, and reduced personal exemptions from $1,500 to $1,000 for single persons, and from $3,500 to $2,500 for married couples. The national industrial recovery act of 1933 (NIRA), part of President franklin d. roosevelt39。 玩具汽車外殼的模具設(shè)計(jì) 28 參考文獻(xiàn) [1] 曹宏深 ， 趙仲治 .塑料成型工藝及模具設(shè)計(jì) [M].北京 ： 機(jī)械工業(yè)出版社 ， 1993． [2] 黃虹 .塑料成型加工與模具 [M].化學(xué)工業(yè)出版社 ， 2022. [3] 黃銳主編 .塑料工程 手冊(cè) [M]下冊(cè) .機(jī)械工業(yè)出版社 ， 1988． [4] 宋卓頤 ， 史勤芳 ， 房雙寬 等 .塑料原料與助劑 [J].科學(xué)技術(shù)文獻(xiàn)出版社 ， 2022. [5] 黃銳主 .塑料成型工藝學(xué) [M].中國(guó)輕工業(yè)出版社 ， 1997. [6] 塑料模設(shè)計(jì)手冊(cè)（軟件版） [M].機(jī)械工業(yè)出版社 ， 2022. [7] 王文廣 ,田寶善 ,田雁晨 .塑料注射模具設(shè)計(jì)技巧與實(shí)例 [M].化學(xué)工業(yè)出版社 ， 2022. [8] 田春年 .塑料注射成型模具結(jié)構(gòu)設(shè)計(jì)圖冊(cè) [M].北京 :輕工業(yè)出版社 ， 1998. [9] 單巖 .模具分析技術(shù)基礎(chǔ) [M].清華大學(xué)出版社 ， 1993． [10] 單巖 .模具分析技術(shù)基礎(chǔ) [M].清華大學(xué)出版社 ， 2022. [11] 陸寧 .實(shí)用注塑模具設(shè)計(jì) [J].中國(guó)輕工業(yè)出版社 ， 1999. [12] 李德群 .塑料成型工藝及模具設(shè)計(jì) [J].機(jī)械工業(yè)出版社 ， 1999. [13] 屈華昌 .塑料成型工藝與模具設(shè)計(jì) [J].高等教育出版社 ， 2022. [14] Donggang Yao, Scaling Issues in Miniaturizaton of Injection Molded Parts Journal of Manufacturing Science and Engineering[J]. November 2022, [15] The Thickness Profile of UltraHigh Molecular Weight Polythene Films During Sequential Biaxial Drawing[J].Polymer Engineering and Science ,January 2022. [22] Jayaram S， Xu X Y， Cross J D． Highdividerratio Fastresponse Capacitive Dividers for Highvoltage Pulse Measurements [J]． IEEE Trans on Industry Applications， 2022， 36（ 3）：920922． 玩具汽車外殼的模具設(shè)計(jì) 29 附 錄 模具總裝圖 圖 裝配圖 玩具汽車外殼的模具設(shè)計(jì) 30 請(qǐng)刪除以下內(nèi)容， O(∩ _∩ )O 謝謝！！！ The origin of taxation in the United States can be traced to the time when the colonists were heavily taxed by Great Britain on everything from tea to legal and business documents that were required by the Stamp Tax. The colonists39。 玩具汽車外殼的模具設(shè)計(jì) 27 致 謝 在本次畢業(yè)設(shè)計(jì)中，特別感謝指導(dǎo)老師王鑫的指導(dǎo)和幫助，給予了我充分的信心和把握，讓我按時(shí)完成了本次設(shè)計(jì)。并且，通過(guò)這次設(shè)計(jì)，我了解了注射模設(shè)計(jì)概況，熟悉了注射設(shè)備，基本掌握了注射成型的一般原理。 圖 配合 對(duì)于固定在模板內(nèi)部分如上圖，與模板內(nèi)安裝孔采取 H7/m6 的過(guò)度配合，斜導(dǎo)柱直徑計(jì)算：可以利用查表法，首先，求得抽芯力 F 和已經(jīng)選定的斜導(dǎo)柱傾斜角 ? ，在 文獻(xiàn) [15]表 中查到最大彎 曲力為 11kN。 3176。 玩具汽車外殼的模具設(shè)計(jì) 24 圖 側(cè)向抽芯 采用的是側(cè)型芯滑塊抽芯方向與開(kāi)合模方向垂直的方式。抽芯距的確 定：側(cè)向抽芯距一般比塑件上的側(cè)凹，側(cè)孔的深度或者凸臺(tái)的高度大23mm。 圖 塑件結(jié)構(gòu)圖 那么塑件就不能直接有推桿推出脫模。則，選取水孔直徑為 8mm。 (1) 冷卻管路的位置與尺寸 塑件壁厚應(yīng)該盡可能維持均勻。在脫模時(shí)，必須要使模玩具汽車外殼的模具設(shè)計(jì) 22 具降溫，則為此模具設(shè)計(jì)冷卻系統(tǒng)，選用最普遍的循環(huán)式水冷方式，如下圖。推桿與推桿孔配合選為8/8 fH 。推桿的直徑大于5mm。其是由一塊與凸模按照一定配合精度想配合的模板和推桿組成，在推出機(jī)構(gòu)開(kāi)始工作后，推桿推動(dòng)推件板，推件板從塑件端面將其從型芯中推出，這種推出機(jī)構(gòu)結(jié)構(gòu)緊湊，連貫性強(qiáng)。 （ 3） 塑件的外觀質(zhì)量要有 保證。所以，當(dāng)塑件表面沒(méi)有留下焦痕時(shí)，可以認(rèn)為型腔內(nèi)的排氣是充分的。成型零部件直接與塑料接觸，成型塑件的某些部分，承受著塑料熔體壓力，決定著塑件形狀與精度，因此成型零部件的設(shè)計(jì)是注射模具的重要部分。它的意思就是： AB板的尺寸為250X450mm。其導(dǎo)套的固定配合采用 H7/n6 或者較松的過(guò)盈配合。 動(dòng)模板和定模扳必須要有足夠強(qiáng)度和剛度，一般，小型的模具要求兩個(gè)模板厚度大于 13mm。 冷料穴一般開(kāi)設(shè)在主流道對(duì)面的動(dòng)模板上，其標(biāo)稱直徑與主流道直徑相同或略大一些，這里取為 mm7 ，目的是為了保證冷料體積小于冷料穴體積。（ 根據(jù)塑件壁厚的 3231? ），寬度 b 取。 根據(jù)澆口選用原則和為保證塑件表面質(zhì)量及美觀效果，由于澆口界面小，去除澆口比較容易，不留明顯痕跡，故采用側(cè)澆口。要做到這一點(diǎn)必須使 (1)流程 (包括分支流程 )為最短； (2)每一股分流都能大致同時(shí)到達(dá)其最遠(yuǎn)端； (3)應(yīng)先從壁厚較厚的部位進(jìn)料； (4)考慮各股分流的轉(zhuǎn)向越小越好。如圖所示。 圖 定位圈零件圖 （ 4） 主流道襯套的固定 主流道襯套的固定，直接采用 2 個(gè) M5X20 的螺絲直接鎖附固定。本次設(shè)計(jì)取直徑 5mm。澆口套采用碳素工具鋼材料熱處理，熱處理硬度 53— 57HRC。 為了使主流道