0011-智能機器人傳菜員總體方案設計及液壓端盤機械手的設計與制作【全套18張CAD圖+文獻翻譯+說明書】
0011-智能機器人傳菜員總體方案設計及液壓端盤機械手的設計與制作【全套18張CAD圖+文獻翻譯+說明書】,全套18張CAD圖+文獻翻譯+說明書,智能,機器人,傳菜員,總體,整體,方案設計,液壓,機械手,設計,制作,全套,18,cad,文獻,翻譯,說明書,仿單
英文原文
Influence factors on the quality of the workplace surface
Processing process on the surface quality of the influence
The vibration of the process system of the influence on the quality of the surface
In mechanical processing process technology system sometimes occur vibration, that is, in the cutting edge tool and workplace is cutting surface except on the name between cutting motion, but also can appear a cyclical relative motion.
Vibration that process system by forming movement of the interference and damage, make processing surface appear chatter marks, increases the surface roughness value, worsening processing surface quality.
Cutter geometrical parameters, materials and cutting quality to the surface quality of the influence
The cutting tool geometric parameters on the surface roughness of the biggest influence is vice PianJiao, the main point PianJiao, arc radius. Under certain conditions, reduce PianJiao, Lord, vice PianJiao point arc radius can reduce surface roughness. Under the same conditions, carbide cutting tools process of surface roughness value less than high speed steel paper cutting knife, and diamond and CBN) tools and better than hard alloy, but because the diamond and iron family affinity materials, it should not be used for processing iron family materials. In addition, the cutting tool before and after the face, cutting knife blade itself directly influence the roughness of the processing the roughness of the surface, therefore, improve the quality of cutting tool, cutting tool and face, cutting knife blade roughness value should be lower than the roughness of the 1 ~ 2 levels.
Cutting fluid to the influence on the quality of the surface
Cutting fluid cooling and lubrication effect can reduce the cutting process of interface friction, reduce the temperature of cutting zone, the cutting metal surface layer of plastic deformation degree down, restrain the develop the thorn and scales produced in the production of different materials for reasonable choice of cutting fluids can reduce the surface roughness.
The workplace material on the surface quality of the influence
The workplace material nature; Processing plastic materials, the cutting tools for metal extrusion produced plastic deformation, and the cutting tool and workplace forced separation of the torn scraps effect, make the surface roughness value increase. The workplace material tenacity the better, metal, plastic deformation, the bigger the processing surface is the more the rough. Processing brittle material in the chip broken granular, due to the collapse in broken and endows the machined surface left many pitted surface roughness.
General toughness large plastic materials, processing after large surface roughness, and toughness of smaller plastic materials, processing to get smaller after the surface roughness. For the same kind of material, the greater the grain size of the organization, the larger the surface roughness. Therefore, in order to reduce the surface roughness, often in cutting processing of material before quenching and tempering or is the fire of treatment to obtain homogeneous fine grain organization and high hardness.
Cutting condition the influence on the quality of the surface
And cutting condition of the relevant process factors, including cutting dosages, cooling lubrication. In low speed processing plastic materials,, easy to produce the develop and scales thorn, so, improve the cutting speed, can reduce the develop and scales thorn, decreasing part already the surface roughness value; For brittle material, general won't form the develop and scales thorn, so, cutting speed on the surface roughness basically no influence. The increase speed, plastic deformation also increases, the surface roughness increases, so, reduce the speed can reduce the surface roughness value, however, feeding reduced to certain value, roughness won't obviously decreased. Normal cutting conditions, cutting depth on the surface roughness the impact is not big, therefore, mechanical process cannot select the too small cutting depth.
Cutting speed on the surface roughness influence
General at the early choose low speed cutting and finishing choose high speed cutting can reduce the surface roughness. In the medium speed cutting plastic materials, due to easy to produce the develop, and plastic deformation is bigger, so after processing parts surface roughness is bigger. Usually by low or high speed cutting plastic material, can effectively avoid the develop of generation, this to reduce table and roughness have positive role.
On the surface quality of the grinding effects
The influence of the grinding wheel grinding wheel granularity the thinner, per unit area grain number grinding, the more of the grinding surface in fine scratches the surface roughness is small; But if too fine granularity, processing to jam wheel it will increase the surface roughness, also easy to produce the ripple and cause burns. The hardness of the grinding wheel should be the right size, its half the longer the better passivation period; The hardness of the grinding wheel is too high, grinding mill is not easy to fall off when grain, make processing surface is of friction, extrusion action intensifies, thus increasing the plastic deformation, making the surface roughness increases, also easy cause burns; But the grinding wheel is too soft, grits too easy to fall off, can make grinding action is reduced, leading to the surface roughness increases, so to select the right grinding wheel hardness. Grinding wheel dressing the higher the quality, the surface of the grinding wheel cutting the blade, cutting the number of all the more the better of the blade contour sex, grinding surface roughness and smaller.
The influence of the grinding wheel speed increase dosage, unit time through the processing of grinding surface grain number increase, each star grits is ground to reduce thickness of the metal, the surface area of the residual reduced; And at the same time, improve the grinding wheel speed can also reduce the workplace material of plastic deformation, these can make processing surface roughness value reduced. Reduce the speed, unit time through the processing of grinding surface grain number increase, the surface roughness decreased; But the low speed, workplace and grinding wheel contact time long, to the quantity of heat of the increasing, opposite will increase the roughness, may also increase surface burn. Increase grinding depth and longitudinal feeding, the plastic deformation increase, will lead to the surface roughness value increase. Radial feeding increase, the grinding process grinding force and grinding temperature will increase, grinding surface plastic deformation degree increase, which will increase the surface roughness. To guarantee the machining quality in the premise of grinding efficiency increase, will require a higher surface the coarse grinding and fine grinding separately, coarse grinding is used when the big radial direction feeding, fine grinding the radial feeding the smaller when, finally without into to grinding, to get the surface roughness of surface is very small.
The workplace material the workplace material of hardness, plastic and thermal conductivity on the surface roughness of big effect. Large plastic soft material easy jam grinding wheel, thermal conductivity poor heat resistant alloy easy for the abrasive early caving, will lead to increased grinding surface roughness.
In addition, because grinding to the high temperature, reasonable use cutting fluids can reduce the grinding of temperature, reduce burns, can also rushed to fall off the grits and scraps, avoid scratch workplace, so as to reduce the surface roughness.
Affect the surface of physical and mechanical properties of factors
Surface layer cold hardening. The cutting edges obtuse radius increased, and the surface of metal the extrusion of enhanced, plastic deformation intensifies, cold hard to strengthen. After cutting tool knife surface wear increases, the knife surface and after processed surface friction intensified, plastic deformation increase, cold hard to strengthen. Cutting speed increase, cutting tool and workplace role time is shortened, make plastic deformation expand the depth decreases, and cold hard layer depth decreases. After cutting speed increase, heat cutting in the surface layer effect time also shortened, will make cold hard degree increase. Feeding increases, cutting force also increased, and the surface of the metal plastic deformation intensifies, cold hard effect is strengthening. The workplace material of plastic is larger and the cold hard phenomenon the serious.
Surface layer material metallographic composition change. When cutting the heat was processing surface temperature of phase change after more than temperature, the surface of the metal microstructure will change. Grinding burns when a surface temperature of phase change to millers temperature above, metal surface microstructure occurred change, make the surface of the metal strength and hardness of the lower, and with residual stress produce appear even microscopic cracks, this phenomenon is called grinding burns. Improve grinding burns grinding heat caused by grinding way is the root of the burn, so improving grinding burns by two ways: one is as far as possible to reduce the generation of grinding heat; 2 it is improved cooling condition, make as far as possible the quantity of heat to produce less workplace. The correct choice grinding wheel reasonable choice of cutting dosages improved cooling conditions.
Surface layer residual stress. Produce residual stress of reason: cutting in processing the metal layer and the surface when there were plastic deformation occurs, the surface of the metal to hematocrit increase; Cutting processing, cutting area will have a lot of heat cutting produce; Different analysis of metallographic organization has different density, also have different olume is necessarily affected by the change of connected the matrix of the metal bar, hence residual stress produce. The main work surface eventually process to the choice of methods. Choose the main parts work surface eventually process method, we must consider the main parts of the specific work surface working conditions and the possible damage to the form. In alternating load, the machine parts on the surface of the local micro cracks, because of tensile stress of action to make primary crack expanding, resulting in parts fracture. Improve parts from the view point of fatigue damage resistance, the final process should choose the surface in the surface produces residual stress processing method. In the machining process, tools on the squash and friction make metal materials happen plastic deformation, cause the original residue area of distortion or groove lines deepened, increases the surface roughness. When the medium or medium low cutting speed cutting plastic material, the surface before the sword in easy to form a high hardness of the devolop, it can take the place of the cutting tool, but state very unstable, the develop generation, grow up and fall off will seriously affect the machined surface roughness value. In addition, in cutting process due to the strong scraps and former knife friction role and tear phenomenon, but also in processing on the surface may produce scale thorn, make processing surface roughness increases.
Grinding surface layer analysis of metallographic organization changes and grinding burns
Mechanical processing produces in the process of heat cutting processing surface of workplace will make the rise of temperature of the violently, when the temperature more than the workplace material metallographic organization changes of the critical temperature, metallographic organization change will occur. In grinding processing, because most grits before cutting Angle is negative, grinding temperature is high, the quantity of heat of generation is much higher than cutting calories at, and grinding heat have 60 to 80% to the workplace, so very prone to the change of metallographic organization, makes the metal surface hardness and strength of decline, produce residual stress and even cause microcracks, this phenomenon is called grinding burns. Produce grinding burns, processing surface often appear yellow, brown, purple, green and burn color, this is grinding surface oxidation of high temperature in instantaneous film under color. Different burns color, shows that the surface of different levels by burns.
Grinding hardened steel, workplace surface layer due to the role of the instantaneous heat, it may produce the following three metallographic organization changes:
If grinding surface layer temperature not over phase transition temperature, but more than martensite transition temperature, then martensite will change to become low hardness of tempering methods, and meanwhile body or body, this call tempering burns.
If grinding surface layer temperature more than phase transition temperatures, the martensite transformation for austenitic, at this time without cutting fluids, the grinding surface hardness fell sharply, surface was annealing, this phenomenon is called annealing burns. When dry grinding is easy to produce this kind of phenomenon.
If grinding surface layer temperature more than phase transition temperature, but have the full cutting fluid on the cooling, the grinding surface layer will be urgent cold forming secondary hardened martensitic, hardness than tempering martensite high, but the surface layer is very thin, and only a few microns thick, under which the low hardness for tempering saxhlet body and saxhlet body, make the surface layer general hardness still reduce, called quenching burns.
Grinding burns improvement measure
Influence factors of grinding burns is grinding dosage, grinding wheel, the workpiece material and cooling conditions. Because grinding heat caused by grinding burns is the root cause of, because this wants to avoid grinding burns, should as far as possible to reduce the heat generated when grinding and decrease as far as possible to the quantity of heat of workplace. Specific can adopt the following measures:
Choosing grinding reasonable dosage cannot use the too big grinding depth, because when grinding depth increases, the plastic deformation is increased, the surface layer and the temperature will increase, burns will also increase; The speed increase, a surface temperature will increase grinding zone, but due to the hot action time reduced, so can reduce the burn.
The workplace material the workplace material grinding zone of the influence of the temperature of depends primarily on its hardness and strength, toughness and thermal conductivity. The workplace material hardness, the higher the strength, toughness, the bigger the grinding work when the more consumption, the quantity of heat that produced the more, the easy generation burns; Thermal conductivity of poor material, also easy to appear in the grinding burns.
The choice of high hardness of the grinding wheel grinding wheel, passivated grits is not easy to fall off, easy to produce burns, so with soft grinding wheel is better; Choose coarse granularity grinding wheel grinding, not easily by grinding wheel grinding jams, can reduce burned; Combine agent of grinding burns also has a great influence, resin combination agent than ceramic combination agent easy to produce burns, rubber binder than resin binder are more likely to have burned.
Cooling conditions for reduction in grinding of temperature, widely used in this cutting liquid cooling. In order to make cutting fluids can injection to the surface, usually the cutting fluid flow increase.
中文譯文
影響工件表面質量的因素
加工過程對表面質量的影響
工藝系統(tǒng)的振動對工件表面質量的影響
在機械加工過程中工藝系統(tǒng)有時會發(fā)生振動,即在刀具的切削刃與工件上正在切削的表面之間除了名義上的切削運動之外,還會出現(xiàn)一種周期性的相對運動。
振動使工藝系統(tǒng)的各種成形運動受到干擾和破壞,使加工表面出現(xiàn)振紋,增大表面粗糙度值,惡化加工表面質量。
刀具幾何參數(shù)、材料和刃磨質量對表面質量的影響
刀具的幾何參數(shù)中對表面粗糙度影響最大主要是副偏角、主偏角、刀尖圓弧半徑。在一定的條件下,減小副偏角、主偏角、刀尖圓弧半徑都可以降低表面粗糙度。在同樣條件下,硬質合金刀具加工的表面粗糙度值低于高速鋼刀具,而金剛石、立方氮化硼刀具又優(yōu)于硬質合金,但由于金剛石與鐵族材料親和力大,故不宜用來加工鐵族材料。另外,刀具的前、后刀面、切削刃本身的粗糙度直接影響加工表面的粗糙度,因此,提高刀具的刃磨質量,使刀具前后刀面、切削刃的粗糙度值應低于工件的粗糙度值的1~2級。?
切削液對表面質量的影響
切削液的冷卻和潤滑作用能減小切削過程中的界面摩擦,降低切削區(qū)溫度,使切削層金屬表面的塑性變形程度下降,抑制積屑瘤和鱗刺的產(chǎn)生,在生產(chǎn)中對于不同材料合理選用切削液可大大減小工件表面粗糙度。
工件材料對表面質量的影響
工件材料的性質;加工塑性材料時,由刀具對金屬的擠壓產(chǎn)生了塑性變形,加之刀具迫使切屑與工件分離的撕裂作用,使表面粗糙度值加大。工件材料韌性越好,金屬的塑性變形越大,加工表面就愈越粗糙。加工脆性材料時其切屑呈碎粒狀,由于切屑的崩碎而在加工表面留下許多麻點使表面粗糙。
一般韌性較大的塑性材料,加工后表面粗糙度較大,而韌性較小的塑性材料,加工后易得到較小的表面粗糙度。對于同種材料,其晶粒組織越大,加工表面粗糙度越大。因此,為了減小加工表面粗糙度,常在切削加工前對材料進行調質或正火處理,以獲得均勻細密的晶粒組織和較高的硬度。?
切削條件對工件表面質量的影響
與切削條件有關的工藝因素,包括切削用量、冷卻潤滑情況。中、低速加工塑性材料時,容易產(chǎn)生積屑瘤和鱗刺,所以,提高切削速度,可以減少積屑瘤和鱗刺,減小零件已加工表面粗糙度值;對于脆性材料,一般不會形成積屑瘤和鱗刺,所以,切削速度對表面粗糙度基本上無影響。進給速度增大,塑性變形也增大,表面粗糙度值增大,所以,減小進給速度可以減小表面粗糙度值,但是,進給量減小到一定值時,粗糙度值不會明顯下降。正常切削條件下,切削深度對表面粗糙度影響不大,因此,機械加工時不能選用過小的切削深度。
切削速度對表面粗糙度的影響
一般在粗加工選用低速車削,精加工選用高速車削可以減小表面粗糙度。在中速切削塑性材料時,由于容易產(chǎn)生積屑瘤,且塑性變形較大,因此加工后零件表面粗糙度較大。通常采用低速或高速切削塑性材料,可有效地避免積屑瘤的產(chǎn)生,這對減小表而粗糙度有積極作用。?
磨削加工對表面質量的影響
砂輪的影響 砂輪的粒度越細,單位面積上的磨粒數(shù)越多,在磨削表面的刻痕越細,表面粗糙度越小;但若粒度太細,加工時砂輪易被堵塞反而會使表面粗糙度增大,還容易產(chǎn)生波紋和引起燒傷。砂輪的硬度應大小合適,其半鈍化期愈長愈好;砂輪的硬度太高,磨削時磨粒不易脫落,使加工表面受到的摩擦、擠壓作用加劇,從而增加了塑性變形,使得表面粗糙度增大,還易引起燒傷;但砂輪太軟,磨粒太易脫落,會使磨削作用減弱,導致表面粗糙度增加,所以要選擇合適的砂輪硬度。砂輪的修整質量越高,砂輪表面的切削微刃數(shù)越多、各切削微刃的等高性越好,磨削表面的粗糙度越小。
磨削用量的影響 增大砂輪速度,單位時間內(nèi)通過加工表面的磨粒數(shù)增多,每顆磨粒磨去的金屬厚度減少,工件表面的殘留面積減少;同時提高砂輪速度還能減少工件材料的塑性變形,這些都可使加工表面的表面粗糙度值降低。降低工件速度,單位時間內(nèi)通過加工表面的磨粒數(shù)增多,表面粗糙度值減??;但工件速度太低,工件與砂輪的接觸時間長,傳到工件上的熱量增多,反面會增大粗糙度,還可能增加表面燒傷。增大磨削深度和縱向進給量,工件的塑性變形增大,會導致表面粗糙度值增大。徑向進給量增加,磨削過程中磨削力和磨削溫度都會增加,磨削表面塑性變形程度增大,從而會增大表面粗糙度值。為在保證加工質量的前提下提高磨削效率,可將要求較高的表面的粗磨和精磨分開進行,粗磨時采用較大的徑向進給量,精磨時采用較小的徑向進給量,最后進行無進給磨削,以獲得表面粗糙度值很小的表面。
工件材料 工件材料的硬度、塑性、導熱性等對表面粗糙度的影響較大。塑性大的軟材料容易堵塞砂輪,導熱性差的耐熱合金容易使磨料早期崩落,都會導致磨削表面粗糙度增大。
另外,由于磨削溫度高,合理使用切削液既可以降低磨削區(qū)的溫度,減少燒傷,還可以沖去脫落的磨粒和切屑,避免劃傷工件,從而降低表面粗糙度值。
影響工件表面物理機械性能的因素
表面層冷作硬化。切削刃鈍圓半徑增大,對表層金屬的擠壓作用增強,塑性變形加劇,導致冷硬增強。刀具后刀面磨損增大,后刀面與被加工表面的摩擦加劇,塑性變形增大,導致冷硬增強。切削速度增大,刀具與工件的作用時間縮短,使塑性變形擴展深度減小,冷硬層深度減小。切削速度增大后,切削熱在工件表面層上的作用時間也縮短了,將使冷硬程度增加。進給量增大,切削力也增大,表層金屬的塑性變形加劇,冷硬作用加強。工件材料的塑性愈大,冷硬現(xiàn)象就愈嚴重。
表面層材料金相組織變化。當切削熱使被加工表面的溫度超過相變溫度后,表層金屬的金相組織將會發(fā)生變化。磨削燒傷當被磨工件表面層溫度達到相變溫度以上時,表層金屬發(fā)生金相組織的變化,使表層金屬強度和硬度降低,并伴有殘余應力產(chǎn)生甚至出現(xiàn)微觀裂紋,這種現(xiàn)象稱為磨削燒傷。改善磨削燒傷的途徑磨削熱是造成磨削燒傷的根源,故改善磨削燒傷由兩個途徑:一是盡可能地減少磨削熱的產(chǎn)生;二是改善冷卻條件,盡量使產(chǎn)生的熱量少傳入工件。正確選擇砂輪合理選擇切削用量改善冷卻條件。
表面層殘余應力。產(chǎn)生殘余應力的原因:切削時在加工表面金屬層內(nèi)有塑性變形發(fā)生,使表面金屬的比容加大;切削加工中,切削區(qū)會有大量的切削熱產(chǎn)生;不同金相組織具有不同的密度,亦具有不同的比容的變化必然要受到與相連的基體金屬的阻礙,因而就有殘余應力產(chǎn)生。工件主要工作表面最終工序加工方法的選擇。選擇零件主要工作表面最終工序加工方法,須考慮該零件主要工作表面的具體工作條件和可能的損壞形式。在交變載荷作用下,機器零件表面上的局部微觀裂紋,會因拉應力的作用使原生裂紋擴大,最后導致零件斷裂。從提高零件抵抗疲勞破壞的角度考慮,該表面最終工序應選擇能在該表面產(chǎn)生殘余壓應力的加工方法。在切削加工過程中,刀具對工件的擠壓和摩擦使金屬材料發(fā)生塑性變形,引起原有的殘留面積扭曲或溝紋加深,增大表面粗糙度。當采用中等或中等偏低的切削速度切削塑性材料時,在前刀面上容易形成硬度很高的積屑瘤,它可以代替刀具進行切削,但狀態(tài)極不穩(wěn)定,積屑瘤生成、長大和脫落將嚴重影響加工表面的表面粗糙度值。另外,在切削過程中由于切屑和前刀面的強烈摩擦作用以及撕裂現(xiàn)象,還可能在加工表面上產(chǎn)生鱗刺,使加工表面的粗糙度增加。
磨削表面層金相組織變化與磨削燒傷
機械加工過程中產(chǎn)生的切削熱會使得工件的加工表面產(chǎn)生劇烈的溫升,當溫度超過工件材料金相組織變化的臨界溫度時,將發(fā)生金相組織轉變。在磨削加工中,由于多數(shù)磨粒為負前角切削,磨削溫度很高,產(chǎn)生的熱量遠遠高于切削時的熱量,而且磨削熱有60~80%傳給工件,所以極容易出現(xiàn)金相組織的轉變,使得表面層金屬的硬度和強度下降,產(chǎn)生殘余應力甚至引起顯微裂紋,這種現(xiàn)象稱為磨削燒傷。產(chǎn)生磨削燒傷時,加工表面常會出現(xiàn)黃、褐、紫、青等燒傷色,這是磨削表面在瞬時高溫下的氧化下膜顏色。不同的燒傷色,表明工件表面受到的燒傷程度不同。
磨削淬火鋼時,工件表面層由于受到瞬時高溫的作用,將可能產(chǎn)生以下三種金相組織變化:
如果磨削表面層溫度未超過相變溫度,但超過了馬氏體的轉變溫度,這時馬氏體將轉變成為硬度較低的回火索氏體或索氏體,這叫回火燒傷。
如果磨削表面層溫度超過相變溫度,則馬氏體轉變?yōu)閵W氏體,這時若無切削液,則磨削表面硬度急劇下降,表層被退火,這種現(xiàn)象稱為退火燒傷。干磨時很容易產(chǎn)生這種現(xiàn)象。
如果磨削表面層溫度超過相變溫度,但有充分的切削液對其進行冷卻,則磨削表面層將急冷形成二次淬火馬氏體,硬度比回火馬氏體高,不過該表面層很薄,只有幾微米厚,其下為硬度較低的回火索氏體和索氏體,使表面層總的硬度仍然降低,稱為淬火燒傷。
磨削燒傷的改善措施
影響磨削燒傷的因素主要是磨削用量、砂輪、工件材料和冷卻條件。由于磨削熱是造成磨削燒傷的根本原因,因此要避免磨削燒傷,就應盡可能減少磨削時產(chǎn)生的熱量及盡量減少傳入工件的熱量。具體可采用下列措施:
合理選擇磨削用量 不能采用太大的磨削深度,因為當磨削深度增加時,工件的塑性變形會隨之增加,工件表面及里層的溫度都將升高,燒傷亦會增加;工件速度增加,磨削區(qū)表面溫度會增高,但由于熱作用時間減少,因而可減輕燒傷。
工件材料 工件材料對磨削區(qū)溫度的影響主要取決于它的硬度、強度、韌性和熱導率。工件材料硬度、強度越高,韌性越大,磨削時耗功越多,產(chǎn)生的熱量越多,越易產(chǎn)生燒傷;導熱性較差的材料,在磨削時也容易出現(xiàn)燒傷。
砂輪的選擇 硬度太高的砂輪,鈍化后的磨粒不易脫落,容易產(chǎn)生燒傷,因此用軟砂輪較好;選用粗粒度砂輪磨削,砂輪不易被磨削堵塞,可減少燒傷;結合劑對磨削燒傷也有很大影響,樹脂結合劑比陶瓷結合劑容易產(chǎn)生燒傷,橡膠結合劑比樹脂結合劑更易產(chǎn)生燒傷。
冷卻條件為降低磨削區(qū)的溫度,在磨削時廣泛采用切削液冷卻。為了使切削液能噴注到工件表面上,通常增加切削液的流量和壓力并采用特殊噴嘴,并在砂輪上安裝帶有空氣擋板的切削液噴嘴,這樣既可加強冷卻作用,又能減輕高速旋轉砂輪表面的高壓附著作用,使切削液順利地噴注到磨削區(qū)。此外,還可采用多孔砂
收藏