柴油機(jī)手動(dòng)三位四通換向閥的工藝結(jié)構(gòu)設(shè)計(jì)-[機(jī)械畢業(yè)設(shè)計(jì)論文A1016]
柴油機(jī)手動(dòng)三位四通換向閥的工藝結(jié)構(gòu)設(shè)計(jì)-[機(jī)械畢業(yè)設(shè)計(jì)論文A1016],機(jī)械畢業(yè)設(shè)計(jì)論文A1016,柴油機(jī),手動(dòng),三位,四通,換向,工藝,結(jié)構(gòu)設(shè)計(jì),機(jī)械,畢業(yè)設(shè)計(jì),論文,a1016
附表一 ：
分類號(hào) 密級(jí)
無錫職業(yè)技術(shù)學(xué)院
畢業(yè)設(shè)計(jì)說明書
題 目 柴油機(jī)專用換向閥工藝結(jié)構(gòu)設(shè)計(jì)
學(xué)生姓名: 陳 超
專 業(yè): 數(shù)控機(jī)床加工技術(shù)
指導(dǎo)教師: 陳胡興
職 稱 : 助 教
畢業(yè)設(shè)計(jì)說明書提交日期 2007.04.15 地址：
畢業(yè)設(shè)計(jì)任務(wù)書
2007年2月27日
畢業(yè)設(shè)計(jì)題目
柴油機(jī)專用換向閥工藝結(jié)構(gòu)設(shè)計(jì)
指導(dǎo)老師
陳胡興
職稱
講師
專業(yè)名稱
數(shù)控機(jī)床加工技術(shù)及應(yīng)用
班級(jí)
數(shù)機(jī)50431
學(xué)生名稱
陳超
學(xué)號(hào)
3
設(shè)計(jì)要求
1．布置課題，收集相關(guān)資料；
2．繪制零件圖或毛坯—零件綜合圖
3. 工藝規(guī)程設(shè)計(jì)
4．工裝設(shè)計(jì)
5．編寫說明書，專外翻譯
6. 整理畢業(yè)設(shè)計(jì)資料，完成答辯。
完成畢業(yè)課題的計(jì)劃安排
序號(hào)
內(nèi)容
時(shí)間安排
1
布置課題，收集相關(guān)資料；
2月27日—3月3日
2
繪制零件圖或毛坯—零件綜合圖；
3月3日—3月25日
3
工藝規(guī)程設(shè)計(jì)
3月25日—4月1日
4
工裝設(shè)計(jì)
4月1日—4月7日
5
編寫說明書，專外翻譯
4月7日—14日
6
整理畢業(yè)設(shè)計(jì)資料，完成答辯。
4月15日—20日
答辯提交資料
畢業(yè)設(shè)計(jì)論文
計(jì)劃答辯時(shí)間
2007年4月23日
機(jī)械工程學(xué)院
2007年2月28日
無 錫 職 業(yè) 技 術(shù) 學(xué) 院 畢 業(yè) 設(shè) 計(jì) 說 明 書 論 文 I 摘 要 換向閥在液壓回路控制中起著更改油液線路的重要作用 在現(xiàn)代工業(yè)中 液壓傳動(dòng)的 應(yīng)用所以能得到的迅速的發(fā)展 是由于它存在著工作平穩(wěn) 動(dòng)作靈敏 不少的優(yōu)點(diǎn) 本課題的設(shè)計(jì)任務(wù)是手動(dòng)三位四通換向閥的設(shè)計(jì) 研究背景中介紹了課題的來源 研 究的目的和期望達(dá)到的結(jié)果 通過查閱相關(guān)的各種資料 據(jù)此熟習(xí)了設(shè)計(jì)的內(nèi)容 合 理的安排設(shè)計(jì)任務(wù)的進(jìn)度 關(guān)鍵詞 換向閥 工作腔 閥心 閥體 三位四通 無 錫 職 業(yè) 技 術(shù) 學(xué) 院 畢 業(yè) 設(shè) 計(jì) 說 明 書 論 文 II 目錄 1 引言 3 1 1 課題來源及意義 3 1 2 對(duì)換 向閥注意的幾個(gè)問題 3 2 換向閥和零件的結(jié)構(gòu)工藝性分析 8 2 1 換向閥設(shè)計(jì)的基本要求 8 2 2 換向閥設(shè)計(jì)的構(gòu)造與工作原理 8 2 3 換向閥的滑閥機(jī)能 圖 2 3 12 2 4 作用在滑閥閥芯上的力 14 3 總體方案設(shè)計(jì)及選擇 24 4 換向閥的設(shè)計(jì)和校核 29 4 1 確定進(jìn) 出油孔直徑 29 4 2 閥芯外徑閥桿直徑和中心直徑 29 4 3 密封與潤(rùn)滑 31 4 4 主要設(shè)計(jì)計(jì)算 31 小結(jié) 32 致謝 33 參考文獻(xiàn) 34 無 錫 職 業(yè) 技 術(shù) 學(xué) 院 畢 業(yè) 設(shè) 計(jì) 說 明 書 論 文 3
無論是手工編程還是自動(dòng)編程，在編程前都要對(duì)所加工的零件進(jìn)行工藝分析，擬訂工藝方案，選擇合適的刀具，確定切削用量。在編程中，對(duì)一些工藝問題（如對(duì)刀點(diǎn)，加工路線等）也需要做一些處理。因此，數(shù)控編程的工藝處理是一項(xiàng)十分重要的工作。 一．?dāng)?shù)控加工的基本特點(diǎn)：
１．?dāng)?shù)控加工的工序內(nèi)容比普通機(jī)加工的工序內(nèi)容復(fù)雜。
２．?dāng)?shù)控機(jī)床加工程序的編制比普通機(jī)床工藝規(guī)程的編制復(fù)雜。這是因?yàn)樵谄胀C(jī)床的加工工藝中不必考慮的問題，如工序內(nèi)工步的安排、對(duì)刀點(diǎn)、換刀點(diǎn)及走刀路線的確定等問題，在編制數(shù)控加工工藝時(shí)卻要認(rèn)真考慮。二．?dāng)?shù)控加工工藝的主要內(nèi)容
１．選擇適合在數(shù)控上加工的零件，確定工序內(nèi)容。
２．分析加工零件的圖紙，明確加工內(nèi)容及技術(shù)要求，確定加工方案，制定數(shù)控加工路線，如工序的劃分、加工順序的安排、非數(shù)控加工工序的銜接等。設(shè)計(jì)數(shù)控加工工序，如工序的劃分、刀具的選擇、夾具的定位與安裝、切削用量的確定、走刀路線的確定等等。
３．調(diào)整數(shù)控加工工序的程序。如對(duì)刀點(diǎn)、換刀點(diǎn)的選擇、刀具的補(bǔ)償。
４．分配數(shù)控加工中的容差。
５．處理數(shù)控機(jī)床上部分工藝指令。三．常用數(shù)控加工方法
１．平面孔系零件
常用點(diǎn)位、直線控制數(shù)控機(jī)床（如數(shù)控鉆床）來加工，選擇工藝路線時(shí)，主要考慮加工精度和加工效率兩個(gè)原則。
若考慮效率，則上述零件采用圖１的路線比圖２好，因?yàn)榻?jīng)過計(jì)算前者刀具空行程路線短。若考慮精度，則采用圖3的路線比圖4差，因?yàn)楹笳呦朔聪蜷g隙。
２．旋轉(zhuǎn)體類零件
常用數(shù)控車床或磨床加工。
（１）考慮加工效率：在車床上加工時(shí)，通常加工余量大，必須合理安排粗加工路線，以提高加工效率。實(shí)際編程時(shí)，一般不宜采用循環(huán)指令（否則，以工進(jìn)速度的空刀太大）。比較好的方法是用粗車盡快去除材料，再精車。
（２）考慮刀尖強(qiáng)度：數(shù)控車床上經(jīng)常用到低強(qiáng)度刀具加工細(xì)小凹槽。圖５的b采用斜向進(jìn)刀，不宜崩刃，a則易崩刃。
３．平面輪廓零件
常用數(shù)控銑床加工。應(yīng)注意：
（１）切入與切出方向控制：圖６左圖的徑向切入，工件表面留有凹坑；右圖切向切入、切出，工件表面光滑。
（２）一次逼近方法選擇：只具有直線和圓弧插補(bǔ)功能的數(shù)控機(jī)床在加工不規(guī)則曲線輪廓時(shí)，需要用微小直線段或圓弧段去逼近被加工輪廓（其誤差稱為一次逼近誤差），逼近時(shí)，應(yīng)該使工件誤差在合格范圍同時(shí)程序段的數(shù)量少為佳。
４．立體輪廓零件
（１）考慮工件強(qiáng)度及表面質(zhì)量：圖７b，該形狀的工件受力后，強(qiáng)度較a差，c的表面質(zhì)量最好。
（２）考慮機(jī)床的插補(bǔ)功能：加工飛機(jī)大梁直紋扭曲面時(shí)，若加工機(jī)床三軸聯(lián)動(dòng)，只好用效率較低的球頭銑刀；若機(jī)床為四軸聯(lián)動(dòng)，則可以選用效率較高的圓柱銑刀銑削（圖８）。
less of is the manual programming or programs automatically, all must to the components which processes carry on the craft analysis before the programming, drafts the craft plan, chooses the appropriate cutting tool, the determination cutting specifications.In the programming, to some craft question (for example to knife spot, processes route and so on) also to need to make some processing.Therefore, numerical control programming craft processing is an extremely important work. One. Numerical control processing essential feature:
1. numerical control processing working procedure content is more complex than the ordinary machining working procedure content.
2. numerical control engine bed processing procedure establishment is more complex than the ordinary engine bed technological process establishment.This is because does not need to consider in the ordinary engine bed processing craft the question, like in the working procedure a labor step arrangement, to knife, trades knife and feeds the route indeed to grade the question, when establishment numerical control processing craft must consider earnestly actually.Two. Numerical control processing craft primary coverage
1. choices suits the components which processes in the numerical control, definite working procedure content.
2. analysis processing components blueprint, is clear about the processing content and the specification, the determination processing plan, the formulation numerical control processing route, like working procedure division, processing order arrangement, non-numerical control processing working procedure engagement and so on.The design numerical control processing working procedures, like the working procedure division, the cutting tool choice, the jig localization and the installment, the cutting specifications determination, feeds route determination and so on.
3. adjustment numerical control processing working procedure procedure.If to knife, trades a knife choice, the cutting tool compensation.
In 4. assignment numerical control processing tolerance.
On 5. processing numerical control engine bed partial craft instruction.Three. The commonly used numerical control processing method
1. even faces are the components
commonly used spot position, the linear control numerical control engine bed (for example numerical control drilling machine) process, when choice craft route, mainly considers the processing precision and the processing efficiency two principles.
If consideration efficiency, then above components use Figure 1 route compared to Figure 2 well, because the process calculates the former cutting tool spatial traveling schedule route to be short.If consideration precision, then uses Figure 3 routes compared to Figure 4 the difference, because the latter eliminated the reverse gap.
2. solid of revolution class components
commonly used numerical control lathe or grinder processing.
(1) consideration processing efficiency: Processes when the lathe, usually processes the remainder to be big, must arrange the rough machining route reasonably, enhances the processing efficiency.When actual programming, (otherwise not suitably uses the circulation instruction generally, enters speed by labor run-out too to be big).Is removes the material as soon as possible compared with the good method with the roughing, again lathe finishing.
(2) consideration knife point intensity: On the numerical control lathe uses the low intensity cutting tool to process the tiny scoop channel frequently.Figure 5 b uses the diagonal feed, not suitable breaking, a then easy breaking.
3. plane outline components
commonly used numerical control milling machine processing.Should pay attention:
(1) cuts into with cuts the directional control: Figure 6 left chart radial directions cut into, the work piece surface leaves leeway the pit; The figure to the right tangential cuts into, cuts, the work piece surface is smooth.
(2) (2) one time approaches the method choice: Only has the straight line and the circular arc interpolation function numerical control engine bed when the processing irregular curve outline, needs to use the small tangential path or the round segmental arc approaches is processed the outline (its error to be called a time approximate error), when approaches, should cause the work piece error segment quantity to be short good for while the qualified scope.
(3) 4. three-dimensional outline components
(4) (1) consideration work piece intensity and surface quality: Chart 7b, after this shape work piece stress, the intensity compares a difference, the c surface quality is best.
(5) (2) considers the engine bed the interpolation function: When processing airplane summer beam straight burr distortion surface, if the processing engine bed three axle linkage, has to use an efficiency low ball milling cutter; If the engine bed is four axis linkages, then may select the efficiency high column milling cutter milling (Figure 8).
一.數(shù)控機(jī)床編程的方法
數(shù)控機(jī)床程序編制的方法有三種：即手工編程、自動(dòng)編程和CAD/CAM 。
1．手工編程
由人工完成零件圖樣分析、工藝處理、數(shù)值計(jì)算、書寫程序清單直到程序的輸入和檢驗(yàn)。適用于點(diǎn)位加工或幾何形狀不太復(fù)雜的零件，但是，非常費(fèi)時(shí)，且編制復(fù)雜零件時(shí)，容易出錯(cuò)。
2．自動(dòng)編程
使用計(jì)算機(jī)或程編機(jī)，完成零件程序的編制的過程，對(duì)于復(fù)雜的零件很方便。
3．CAD/CAM
利用CAD/CAM軟件，實(shí)現(xiàn)造型及圖象自動(dòng)編程。最為典型的軟件是Master CAM，其可以完成銑削二坐標(biāo)、三坐標(biāo)、四坐標(biāo)和五坐標(biāo)、車削、線切割的編程，此類軟件雖然功能單一，但簡(jiǎn)單易學(xué)，價(jià)格較低，仍是目前中小企業(yè)的選擇。
二.數(shù)控機(jī)床程序編制的內(nèi)容和步驟
1.數(shù)控機(jī)床編程的主要內(nèi)容
分析零件圖樣、確定加工工藝過程、進(jìn)行數(shù)學(xué)處理、編寫程序清單、制作控制介質(zhì)、進(jìn)行程序檢查、輸入程序以及工件試切。
2.數(shù)控機(jī)床的步驟
?。治隽慵D樣和工藝處理
根據(jù)圖樣對(duì)零件的幾何形狀尺寸，技術(shù)要求進(jìn)行分析，明確加工的內(nèi)容及要求，決定加工方案、確定加工順序、設(shè)計(jì)夾具、選擇刀具、確定合理的走刀路線及選擇合理的切削用量等。
同時(shí)還應(yīng)發(fā)揮數(shù)控系統(tǒng)的功能和數(shù)控機(jī)床本身的能力，正確選擇對(duì)刀點(diǎn)，切入方式，盡量減少諸如換刀、轉(zhuǎn)位等輔助時(shí)間。
?。?dāng)?shù)學(xué)處理
編程前，根據(jù)零件的幾何特征，先建立一個(gè)工件坐標(biāo)系，根據(jù)零件圖紙的要求，制定加工路，在建立的工件坐標(biāo)系上，首先計(jì)算出刀具的運(yùn)動(dòng)軌跡。對(duì)于形狀比較簡(jiǎn)單的零件（如直線和圓弧組成的零件），只需計(jì)算出幾何元素的起點(diǎn)、終點(diǎn)、圓弧的圓心、兩幾何元素的交點(diǎn)或切點(diǎn)的坐標(biāo)值。
?。帉懥慵绦蚯鍐?
加工路線和工藝參數(shù)確定以后，根據(jù)數(shù)控系統(tǒng)規(guī)定的指定代碼及程序段格式，編寫零件程序清單。
?。绦蜉斎?
．程序校驗(yàn)與首件試切
三.數(shù)控加工程序的結(jié)構(gòu)
１．程序的構(gòu)成：由多個(gè)程序段組成。
O0001；Ｏ（FANUC-O,AB8400-P,SINUMERIK8M-%）機(jī)能指定程序號(hào)，每個(gè)程序號(hào)對(duì)應(yīng)一個(gè)加工零件。
N010 G92 X0 Y0；分號(hào)表示程序段結(jié)束
N020 G90 G00 X50 Y60；
...；可以調(diào)用子程序。
N150 M05；
N160 M02；
２．程序段格式：
（１）字地址格式：如N020 G90 G00 X50 Y60；
最常用的格式，現(xiàn)代數(shù)控機(jī)床都采用它。地址Ｎ為程序段號(hào)，地址Ｇ和數(shù)字９０構(gòu)成字地址為準(zhǔn)備功能，...。
（２）可變程序段格式：如B2000 B3000 B B6000；
使用分割符Ｂ各開各個(gè)字，若沒有數(shù)據(jù)，分割符不能省去。常見于數(shù)控線切割機(jī)床，另外，還有３Ｂ編程等格式。
（３）固定順序程序段格式：如00701+02500-13400153002；
比較少見。
其中的數(shù)據(jù)嚴(yán)格按照順序和長(zhǎng)度排列，不得有誤，上面程序段的意思是：N007 G01 X+02500 Y-13400 F15 S30 M02；
One. The numerical control engine bed programs the method
numerical control engine bed programming method has three kinds: Namely manual programming, automatic programming and CAD/CAM.
1. manual programming
by completes the components pattern analysis, craft processing, the value computation, the written procedure detailed list artificially until the procedure input and the examination.Is suitable in the position processing or the geometry shape not too complex components, but, extremely time-consuming, when also establishment complex components, easy to make a mistake.
2. automatic programming
use computer or Cheng Bianji, completes the components procedure the establishment process, is very convenient regarding the complex components.
3.CAD/CAM
uses the CAD/CAM software, the realization modelling and the image automatic programming.The most typical software is Master CAM, its may complete the milling two coordinates, three coordinates, four coordinates and five coordinates, the turning, the line cutting programming, although this kind of software the function is unitary, but simple easy to study, the price is low, was still the present small and medium-sized enterprise choice
Two. The numerical control engine bed programming content and
the step 1. numerical control engine bed programs the primary coverage
analysis components pattern, the determination processing technological process, carries on mathematics processing, the compilation procedure detailed list, the manufacture control medium, carries on the program check, the input routine as well as the work piece tries to cut.
2. numerical control engine bed step
. The analysis components pattern and the craft processing
basis pattern to the components geometry shape size, the specification carries on the analysis, is clear about the processing the content and the request, decided the processing plan, the determination processing order, designs the jig, chooses the cutting tool, the determination reasonable feeds the route and the choice reasonable cutting specifications and so on.
Simultaneously also should display the numerical control system the function and the numerical control engine bed itself ability, the correct choice to the knife spot, cuts into the way, reduces as far as possible such as trades the knife, indexing and so on the non-cutting time.
. Before mathematics
processing programming, according to the components geometry characteristic, establishes a work piece coordinate system first, according to the components blueprint request, the formulation processing road, in the establishment work piece coordinate system, first calculates the cutting tool the path.Regarding the shape quite simple components (for example straight line and circular arc composition components), only must calculate the geometry element the beginning, the end point, the circular arc center of circle, two geometry element point of intersection or the tangential point coordinate figure.
. Compilation components procedure detailed list
processing route and after craft parameter determination, stipulates according to the numerical control system assigns the code and the segment form, the compilation components procedure detailed list.
. Procedure input
. The program check tries with first to cut
Three. Numerical control processing procedure structure
1. procedure constitutions: Is composed by many segments.
O0001; O(FANUC-O, AB8400-P, SINUMERIK8M-%) function assigns the procedure number, each procedure number corresponds processing components.
N010 G92 X0 Y0; The semicolon expressed the segment finished
N020 G90 G00 X50 Y60;
…; May transfer the subroutine.
N150 M05;
N160 M02;
2. segment forms:
(1) word address format: If N020 G90 G00 X50 Y60;
The most commonly used form, the modern numerical control engine bed all uses it.Address N is the segment number, address G and the digital 90 constitution character address is the preparation function,….
(2) invariable segment form: If B2000 B3000 B B6000;
Use minute tally B opens each character respectively, if does not have the data, divides the tally not to be able to omit.Common in numerical control line cutting engine bed, moreover, but also has forms and so on 3B programming.
(3) fixed smooth segment form: If 00701+02500-13400153002;
Quite rare.
Data strictly according to the order and the length arrangement, acts without fail, above segment meaning is: N007 G01 X+02500 Y-13400 F15 S30 M02;
盡管對(duì)高速加工的研究已有多年，但現(xiàn)在對(duì)高速加工還缺少一個(gè)明確簡(jiǎn)潔的定義和解釋。高速加工的基本出發(fā)點(diǎn)是高速低負(fù)荷狀態(tài)下的切削可較低速高負(fù)荷狀態(tài)下切削更快地切除材料。低負(fù)荷切削意味著可減輕切削力，從而減少切削過程中的振動(dòng)和變形。使用合適的刀具，在高速狀態(tài)下可切削高硬質(zhì)的材料。同時(shí)，高速切削可使大部分的切削熱通過切屑帶走，從而減少零件的熱變形。
上述這些優(yōu)點(diǎn)僅在合適的加工策略的情況下才能實(shí)現(xiàn)。如果使用了不適當(dāng)?shù)募庸げ呗裕p則會(huì)導(dǎo)致刀具壽命的降低，重則可能導(dǎo)致更加可怕的結(jié)果。有一點(diǎn)必須記住，這就是高速加工并不是簡(jiǎn)單地使用現(xiàn)有刀具路徑，通過提高主軸轉(zhuǎn)速和進(jìn)給率實(shí)現(xiàn)。
高速加工刀具路徑
高速銑削刀具路徑有多種限制，當(dāng)將這些限制逐一列出后，則之所以需要這些限制的原因就一目了然。
1. 刀具不能和零件產(chǎn)生碰撞
2. 切削負(fù)荷必須在刀具的極限負(fù)荷之內(nèi)
3. 殘留材料不能大于指定極限
4. 應(yīng)避免材料切除率的突然變化
5. 切削速度和加速度必須在機(jī)床能力范圍內(nèi)
6. 切削方向（順銑/逆銑）應(yīng)保持恒定
7. 應(yīng)避免切削方向的突然變化
8. 盡量減少空程移動(dòng)
9. 切削時(shí)間應(yīng)減少到最短
然而，在實(shí)際零件的刀具路徑編制過程中，很難全部滿足上述要求。事實(shí)上，在加工復(fù)雜形狀的零件時(shí)，也根本無法全部滿足上述要求。在這種情況下，應(yīng)盡可能地滿足這些要求，同時(shí)，在必要的情況下可忽視一個(gè)或多個(gè)限制。在上述限制中，有些限制相對(duì)其它限制來說顯然更加重要，應(yīng)首先滿足這些限制。上述的這些限制是大致按其重要性而順序列出。
精加工為高速加工提出了一個(gè)特殊的問題，即刀痕問題。由于零件形狀的限制，對(duì)切削條件的妥協(xié)常常會(huì)在加工后的零件表面上留下可見刀痕。當(dāng)然，可通過拋光的方法來消除這些刀痕，但這樣就違背了我們使用高速加工的初衷。可很容易地對(duì)粗加工和半精加工進(jìn)行優(yōu)化處理，因?yàn)樵谶M(jìn)行過這些操作后，CAM操作者有多種選擇來修改零件的形狀，刀痕可通過隨后的精加工來消除。
編程能力
好的高速加工程序在機(jī)床上執(zhí)行得非?？欤漠a(chǎn)生卻需花費(fèi)很長(zhǎng)的時(shí)間和大量的精力。在如模具制造這樣的單件加工領(lǐng)域，因等待加工程序而導(dǎo)致機(jī)床停機(jī)的現(xiàn)象非常普遍。如果簡(jiǎn)單地將這種壓力強(qiáng)加給CAM操作者，讓他們更快地產(chǎn)生刀具路徑，常常會(huì)迫使他們走捷徑。其結(jié)果是所編制的程序并不經(jīng)濟(jì)、有效。盡管機(jī)床在繼續(xù)運(yùn)轉(zhuǎn)，但加工速度卻大打折扣。
顯然，使用這種策略進(jìn)行高速加工是不明智的。要得到最好的高速加工結(jié)果，必須提供足夠強(qiáng)大的CAM能力，以能得到高質(zhì)量的加工程序，保證機(jī)床能全負(fù)荷地進(jìn)行工作。為此需：
? 使用具備自動(dòng)高速加工功能的CAM軟件。這樣可減少操作者優(yōu)化程序的工作量。
? 使用能快速計(jì)算出無過切刀具路徑的CAM軟件。批處理功能可將復(fù)雜程序的計(jì)算留在夜間進(jìn)行。
? 使用高性能的計(jì)算機(jī)并經(jīng)常更新配置。確保計(jì)算機(jī)具有足夠內(nèi)存，以提高其運(yùn)行效能。
? 確保每臺(tái)機(jī)床都配備有足夠多的CAM編程人員。培訓(xùn)機(jī)床操作者，使他們能直接在車間進(jìn)行加工編程，這樣可最大限度地發(fā)揮他們的加工技能。
? 確保對(duì)操作者進(jìn)行了適當(dāng)?shù)母咚偌庸ぞ幊膛嘤?xùn)。
安排加工順序
除最簡(jiǎn)單的零件外，高速加工總是牽扯到多個(gè)加工步驟。在高速加工編程中，最重要的是選取正確的加工順序。Delcam所遇到的用戶問題，有很大一部分都是策略的使用順序問題，而不是策略本身的使用問題。盡管CAM軟件如PowerMILL的自動(dòng)化水平日益提高和增強(qiáng)，但它最終代替不了用戶自己對(duì)加工零件和加工策略的理解和經(jīng)驗(yàn)。
在這里我們無法詳細(xì)討論如何安排加工順序，在此，僅給出幾條安排加工順序的基本原則：
? 永遠(yuǎn)同時(shí)考慮欲切除的材料，而不是僅僅考慮要加工成形的幾何形狀。
? 盡可能地將加工步驟減少到最少。
? 盡可能地使用連續(xù)策略，例如，偏置路徑通常比平行路徑好。
? 在可能情況下應(yīng)盡量避免垂直下刀，盡量從材料外部切入材料。
? 在零件的一些臨界區(qū)域應(yīng)盡量保證不同步驟的精加工路徑不重疊。這些區(qū)域如果出現(xiàn)路徑重疊，勢(shì)必會(huì)出現(xiàn)刀痕。
? 盡量不換刀，使用單個(gè)刀具精加工臨界區(qū)域。刀具設(shè)置錯(cuò)誤常常導(dǎo)致精加工后加工表面出現(xiàn)刀痕。
? 盡可能使用短刀具。長(zhǎng)刀具更容易磨損。如有可能，應(yīng)考慮重新定位零件方向，使用短刀具來加工不容易加工的區(qū)域。
結(jié)論：
高速加工對(duì)加工工程中的每個(gè)環(huán)節(jié)的要求都很苛刻。使用正確的物理設(shè)備是進(jìn)行高速加工的基本要求，可精確指定這些物理設(shè)備的參數(shù)。很難具體指定高速加工中需要什么樣的CAD和CAM功能，而CAD和CAM對(duì)高速加工的質(zhì)量和穩(wěn)定性具有顯著影響。
供高速加工使用的CAD模型必須能精確地表達(dá)要加工出的模型形狀，這意味著兩點(diǎn)，其一，模型精度必須大于加工公差；其二，在可能的情況下，應(yīng)將不需要進(jìn)行銑削加工的模型特征從模型中刪除或遮蓋。
昂貴的高速加工設(shè)備必須配備以足夠的CAM編程人員，以保證機(jī)床使用的是最好的程序。讓機(jī)床加工人員在車間編制加工程序是提高編程質(zhì)量的一個(gè)途徑。
確保CAM操作者和機(jī)床操作人員進(jìn)行過良好的高速加工技術(shù)培訓(xùn)。
仔細(xì)安排加工順序至關(guān)重要。適當(dāng)使用CAM系統(tǒng)所提供的加工策略是獲得良好高速加工結(jié)果的最有效途徑。
Although had many years to the high speed processing research, but also lacks an explicit succinct definition and the explanation now to the high speed processing.The high speed processing basic starting point is under the high speed low load condition cutting may compare under the low speed high load condition to cut excises the material quickly.The low load cutting meant may reduce the cutting force, thus in reduced cutting process vibration and distortion.Uses the appropriate cutting tool, may cut the high flinty material under the high-speed run.At the same time, the high-speed cutting may cause the majority of cuttings to carry off hotly through the scrap, thus reduced components thermal deformation.
The above these merits only can realize in the appropriate processing strategy situation.If has used not the suitable processing strategy, light can cause the cutting tool life depression, the heavy piece possibly causes a more fearful result.Some point must remember that, this is the high speed processing uses the existing cutting tool way simply, through enhances the main axle rotational speed and to feed rate realization.
High speed processing cutting tool way
The high speed milling cutting tool way has many kinds of limits, after lists one by one these limits, then the reason that needs these limits the reason to be clear.
1. The cutting tool cannot produce with the components collides
2. The cutting load must within the cutting tool limit load
3. The residual material cannot be bigger than assigns limit
4. Should avoid the material excision rate changing 5
suddenly. The cutting speed and the acceleration must in the engine bed area of competence
6. The direction of cut (down milling/up milling) should maintain constant
7. Should avoid the direction of cut changing
8 suddenly. Reduces the spatial regulation to move
9as far as possible. The cutting time should reduce short to
However, in the actual components cutting tool way establishment process, very difficult to satisfy the above request completely.In fact, when processing complex shape components, also is unable to satisfy the above request completely radically.In this case, should satisfy these requests as far as possible, simultaneously, may neglect or many limits in the essential situation.In the above limit, some limit relative other limits are obviously more important, should first satisfy these limits.But the above these limits are press its importance the order to list approximately.
The precision work asked a special question for the high speed processing, namely slash question.As a result of the components shape limit, to cuts the condition the compromise to be able to leave behind the obvious slash frequently on the processing components surface.Certainly, may eliminate these slashes through the polishing method, but has like this violated the original intention which we use process high speed.May very easily carries on optimized processing to the rough machining and the semi-finishing, because after has carried on these operations, the CAM operator has the multiple options to revise the components the shape, the slash may eliminate through afterwards precision work.
The programming ability
good high speed processing procedure carries out extremely quickly on the engine bed, but its production must spend the very long time and the massive energy actually.Makes such single unit processing domain in like the mold, causes the engine bed engine off because of the waiting processing procedure the phenomenon to be extremely common.If imposes simply this pressure on the CAM operator, lets them have the cutting tool way quickly, can force them frequently to walk the shortcut.Its result is the procedure which establishes is uneconomical, is effective.Although the engine bed is continuing to revolve, but the processing speed greatly sells at a discount actually.
Obviously, uses this kind of strategy to carry on the high speed processing is wise.Must obtain the best high speed processing result, must provide the enough formidable CAM ability, by can obtain the high grade processing procedure, guaranteed the engine bed can the capacity load carry on the work.Needs for this:
Forever simultaneously considered wants to excise the material, but is not considered merely must process formed the geometry shape.
? Processes the step to reduce few as far as possible to.
? Uses the continual strategy as far as possible, for example, the bias way is usually better than the parallel way.
? To be supposed to avoid the vertical under knife as far as possible in the possible situation, as far as possible cuts into the material from the material.
? In components some critical regions should guarantee as far as possible the different step the precision work way does not overlap.If these regions appear the way to overlap, will be able to appear the slash inevitably.
? Does not trade the knife as far as possible, the use single cutting tool precision work critical region.The cutting tool establishment wrong causes the precision work postprocessing surface to appear the slash frequently.
? Uses the short cutting tool as far as possible.The long cutting tool is easier to wear.If has the possibility, should consider locates the components direction, uses region which the short cutting tool processes not not easily to process.
Conclusion:
The high speed processing to processes in the project each link request very to be all harsh.Uses the correct physical equipment is carries on the high speed processing the basic request, but assigns these physical equipment precisely the parameter.Very difficult to assign in the high speed processing to need any type specifically CAD and the CAM function, but CAD and CAM have the remarkable influence to the high speed processing quality and the stabi
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