蝸輪箱-NC小型蝸輪減速器箱體的鉆8XM8孔夾具設(shè)計及加工工藝裝備-工裝及數(shù)控編程含5張CAD圖
蝸輪箱-NC小型蝸輪減速器箱體的鉆8XM8孔夾具設(shè)計及加工工藝裝備-工裝及數(shù)控編程含5張CAD圖,蝸輪,NC,小型,減速器,箱體,XM8,夾具,設(shè)計,加工,工藝,裝備,工裝,數(shù)控,編程,CAD
減速器工藝規(guī)程
減速機是一種動力傳達機構(gòu),利用齒輪的速度轉(zhuǎn)換器,將電機(馬達)的回轉(zhuǎn)數(shù)減速到所要的回轉(zhuǎn)數(shù),并得到較大轉(zhuǎn)矩的機構(gòu)。在目前用于傳遞動力與運動的機構(gòu)中,減速機的應用范圍相當廣泛。幾乎在各式機械的傳動系統(tǒng)中都可以見到它的蹤跡,從交通工具的船舶、汽車、機車、建筑用的重型機具,機械工業(yè)所用的加工機具及自動化生產(chǎn)設(shè)備,到日常生活中常見的家電,鐘表等等其應用從大動力的傳輸工作,到小負荷,精確的角度傳輸都可以見到減速機的應用,且在工業(yè)應用上,減速機具有減速及增加轉(zhuǎn)矩功能。因此廣泛應用在速度與扭矩的轉(zhuǎn)換設(shè)備。
減速器的作用主要有:
1)降速同時提高輸出扭矩,扭矩輸出比例按電機輸出乘減速比,但要注意不能超出減速機額定扭矩。
2)減速同時降低了負載的慣量,慣量的減少為減速比的平方。大家可以看-下一般電機都有一個慣量數(shù)值。
減速機的工作原理減速機一般用于低轉(zhuǎn)速大扭矩的傳動設(shè)備,把電動機內(nèi)燃機或其它高速運轉(zhuǎn)的動力通過減速機的輸入軸上的齒數(shù)少的齒輪嚙合輸出軸上的大齒輪來達到減速的目的,普通的減速機也會有幾對相同原理齒輪達到理想的減速效果,大小齒輪的法數(shù)之比,就是傳動比。
減速機的種類
減速機是一種相對精密的機械,使用它的目的是降低轉(zhuǎn)速,增加轉(zhuǎn)矩。它的種類繁多,型號各異,不同種類有不同的用途。減速器的種類繁多,按照傳動類型可分為齒輪減速器、蝸桿減速器和行星齒輪減速器,按照傳動級數(shù)不同可分為單級和多級減速器按照齒輪形狀可分為圓柱齒輪減速器、圓錐齒輪減速器和圓錐一圓柱齒輪減速器按照傳動的布置形式又可分為展開式、分流式和同軸式減遮器。以下是常用的減速機分類: (1)擺線針輪減速機
(2)硬齒面圓柱齒輪減速器
(3)行星齒輪減速機
(4)軟齒面減速機
(5)三環(huán)減速機
(6)起重機減速機
(7)蝸桿減速機
(8)軸裝式硬齒面減速機
(9)無級變速器
工藝路線是制造單位按照規(guī)定的作業(yè)流程完成生產(chǎn)任務的途徑,主要用來進行工序排產(chǎn)和車間成本統(tǒng)計。其包含了定位基準的選擇,主要表面的加工,加工階段的劃分與工序的合理組合等內(nèi)容。通過查閱了楊淑子主編《機械加工工藝師手冊》現(xiàn)就文中有關(guān)內(nèi)容論述如下:
定位基準的選擇
在制定工藝過程時,選擇定位基準的主要目的是為了保證加工表面的位置精度,因此選擇定位基準的總原則應該是從有較高位置精度要求的表面中進行選擇。
定位基準的選擇包括粗基準和精基準的選擇
在制訂零件機械加工工藝路線時,總是首先考慮選擇怎樣的精基準把各個主要表面加工出來,然后再考慮選擇怎么的粗基準把作為精基準的表面先加工出來。
機械加工工藝路線的制定中粗基準和精基準的選擇很關(guān)鍵,選擇是否合理直接關(guān)系到加工工藝路線制訂的全局。
(1)粗基準的選擇
選擇粗基準時,考慮的重點是如何保證各加工表面有足夠的余量,使不加工表面與加工表面間的尺寸、位子符合圖紙要求。
粗基準的選擇原則是:
1)選擇應加工表面為粗基準。目的是為了保證加工面與不加工面的相互位置關(guān)系精度。如果工件上表面有好幾個不需加工的表面,則應選擇其中與加工表面的相互位置精度要求較高的表面作為粗基準。以求壁厚均勻、外形對稱、少裝夾等。
2)選擇加工余量要求均勻的重要表面作為粗基準。例如機床床身導軌面是其余量要求均勻的重要表面。因而在加工時選擇導軌面作為粗基準,加工床身的底面,再以底面作為精基準加工導軌面。這樣就能保證均勻地去掉較少余量,使表層保留而細致的組織,以增加耐磨性。
3)應選擇加工余量最小的表面作為粗基準。這樣可以保證該面有足夠的
加工余量。
4)應盡可能選擇平整、光潔、面積足夠大的表面作為粗基準,以保證定位準確夾緊可靠。有澆口、冒口、飛邊、毛刺的表面不宜選作粗基準,必要時需經(jīng)初加工。
5)粗基準應避免重復使用,因為粗基準的表面大多數(shù)是粗糙不規(guī)則的,多次使用難以保證表面間的位置精度。
箱體粗基準選擇要求在保證各加工表面均有加工余量的前提下,使主要孔加工余量均勻;裝入箱體內(nèi)的旋轉(zhuǎn)零件應與箱體內(nèi)壁有足夠問隙;此外還應保證定位、夾緊可靠。為了滿足上述要求,一般選箱體的主要孔的毛坯孔作為粗基準。
減速箱體加工的第一個面是蓋或底座的結(jié)合面,由于分離式箱體軸承孔的毛坯孔分布在蓋和底座兩個不同的部分上很不規(guī)則,因而在加工蓋和底座的結(jié)合面時無法用主要孔的毛坯作粗基準。而是用頂面與底面作為粗基準。這樣可以保證結(jié)合面加工后凸緣的厚度叫均勻。
(2)精基準的選擇
選擇精基準的原則時,考慮的重點是有利于保證工件的加工精度并使裝夾準確、牢固、方便。
精基準選擇原則是
基準重合原則。即盡可能選擇設(shè)計基準作為定位基準。這樣可以避免定位基準與設(shè)計基準不重合而引起的基準不重合誤差。
基準統(tǒng)一原則。應盡可能選用統(tǒng)一的定位基準?；鶞实慕y(tǒng)一有利于保證個表面間的位置精度,避免基準轉(zhuǎn)換所帶來的誤差,并且各工序所采用的夾具比較統(tǒng)一,從而可減少夾具設(shè)計和制造工作。例如軸類零件常用頂針孔作為定位基準。車削、磨削都是頂針孔定位,這樣不但在一次裝夾中能加工大多數(shù)表面, 而且保證了各外圓表面的同軸度及端面與軸心線的垂直度。
互為基準的原則。選擇精基準時,有時兩個被加工面,可以互為基準反復加工。例如對淬火后的齒輪磨齒,是以齒面為基準磨內(nèi)孔,再以孔為基準磨齒面,這樣能保證齒面余量均勻。
自為基準原則。有些精加工或光整加工工序要求余量小而均勻,可以選擇加工表面本身為基準。例如:磨削機床導軌面時,是以導軌面找正定位的。
此外,像拉孔在無心磨床上磨外圓等,都是自為基準的例子。
此外,還應選擇工件上精度高,尺寸較大的表面為精基準,以保證定位穩(wěn)固可靠。并考慮工件裝夾和加工方便、夾具設(shè)計簡單等。
箱體上孔與孔、孔與平面、平面與平面之間都有較高的位置精度要求,這些要求的保證與精基準的選擇有很大的關(guān)系。為此,通常優(yōu)先考慮“基準統(tǒng)一”原則。使具有相互位置精度要求的大部分工序,盡可能用同一組基準定位。以避免因基準轉(zhuǎn)換過多而帶來的積累誤差,并且由于采用同一基準,使所用夾具具有相似的結(jié)構(gòu)形式,可減少夾具設(shè)計與制造工作量、降低成本。
2、主要表面的加工
(1)箱體的平面加工
箱體平面的粗加工和半精加工常選擇刨削和銑削加工。
創(chuàng)削箱體平面的主要特點是:刀具結(jié)構(gòu)簡單;機床調(diào)整方便:在龍門創(chuàng)床上可以用幾個刀架,在一次安裝工件中,同時加工幾個表面,于是,經(jīng)濟地保證了這些表面的位置精度。
箱體平面銑削加工的生產(chǎn)率比刨削高。在成批生產(chǎn)中,常采用銑削加工。
當批量較大時,常在多軸龍門銑床上用幾把銑刀同時加工幾個平面,即保證了平面間的位置精度,又提高了生產(chǎn)率。
孔系加工
減速器箱體的孔系,是有位置精度要求的各軸承孔的總和,其中有平行孔系和同軸孔系兩類。
平行孔系主要技術(shù)要求是各平行孔
中心線之間以及中心線與基準面之間的尺寸精度和平行精度根據(jù)生產(chǎn)類型的不同,可以在普通鏜床上或?qū)Ｓ苗M床上加工。
單件小批生產(chǎn)箱體時,為保證孔距精度主要采用劃線法。為了提高劃線找正的精度,可采用試切法,雖然精度有所提高,但由于劃線、試切、測量都要消耗較多的時間,所以生產(chǎn)率仍很低。坐標法加工孔系,許多工廠在單件小批量生產(chǎn)中也廣泛采用,特別是在普通鏈床上加裝較精密的測量裝置(如數(shù)顯等)后,可以較大地提高其坐標位移精度。必須指出,采用坐標發(fā)加工孔系時,原始孔和加工順序的選定是很重要的。因為,各排孔的孔距是靠坐標尺寸保證的。坐標尺寸的積累誤差會影響孔距精度。如果原始孔和孔的假定順序選擇的合理,就可以減少積累誤差。成批或大量生產(chǎn)箱體時,加工孔系都采用鏜模?？拙嗑戎饕Q與鏜模的精度和安裝質(zhì)量。雖然鋒模制造比較復雜,造價較高,但可利用精度不高的機床加工出精度較高的工件。因此,在某些情況下,小批生產(chǎn)也可考慮使用鏜模加工平行孔系。同軸孔系的主要技術(shù)要求是各孔的同軸度精度。
成批生產(chǎn)時,箱體的同軸孔的同軸度大部分是用鏡模保證,單件小批量生產(chǎn)中,在普通鏜床上用以下兩種方法進行加工:
1)從箱體一端進行加工
加工同軸孔系時,出現(xiàn)同軸度誤差的主要原因是當主軸進給時,鏜桿在重力作用下,使主軸產(chǎn)生撓度而引起孔的同軸度誤差當工作臺進給時,導軌的直線度誤差會影響各孔的同軸度精度。對于箱壁較近的同軸孔,可采用導向套加工同軸孔。對于大型箱體,可利用鏜床后立柱導套支撐鏜桿。
2)從箱體兩端進行罐孔
一般是采用“調(diào)頭鏜”使工件在一次安裝下,鏜完一端的孔后,將鏜床工作臺回轉(zhuǎn)180,在錯另一端的孔。
具體辦法是加工好一端孔后,將工件退出主軸,使工作臺回轉(zhuǎn)1800 ,用百(千)分表找正已加工孔壁與主軸同軸,即可加工另一孔?！罢{(diào)頭鏜”不用夾具和長刀桿,鏜桿懸伸長度短,剛性好。但調(diào)整比較麻煩和費時,適合與箱體壁相距較遠的同軸孔。
3、加工階段的劃分與工序的合理組合
零件上的全部加工表面應安排在一個合理的加工順序中加工,這對保證零件質(zhì)量,提高生產(chǎn)率,降低加工成本都至關(guān)重要。參考文獻[1]中的第1篇械加工工藝基礎(chǔ)第4章機械加工工藝規(guī)程制訂有:
(1)加工階段的劃分按加工性質(zhì)和目的的不同,工藝過程一般可劃分成粗加工、半精加工、精加工和光整加工幾個階段。劃分加工階段的作用是能減少或消除內(nèi)應力、切削力和切削熱對精加工的影響;及早發(fā)現(xiàn)毛坯缺陷;便于安排熱處理、可合理使用機床;
避免或減少損傷已精加工過的表面。
(2)工序的組合
組合工序有兩種不同的原則,即工序集中原則和工序分散原則。
工序集中的特點零件各個表面的加工集中在少數(shù)幾個工序中完成,每個工序所安排的加工內(nèi)容多;有利于保證各加工面間的相互位置精度要求;有利于采用高效機床和工藝裝備;生產(chǎn)面積和操作工人數(shù)量減少;生產(chǎn)計劃和生產(chǎn)組織得到簡化;工件裝夾次數(shù)減少。
工序分散的特點;工序多,工藝過程長,每個工序所包含的加工內(nèi)容少:所使用的工藝設(shè)備和裝備比較簡單、易于調(diào)整和掌握生產(chǎn)技術(shù)準備工作較容易,易于變換產(chǎn)品。
Process regulation of reducer
Reducer is a kind of power transmission mechanism, which uses the speed converter of gear to reduce the number of revolutions of motor (motor) to the required number of revolutions and obtain a larger torque. At present, among the mechanisms used to transmit power and motion, reducers are widely used. It can be seen in the transmission system of almost all kinds of machinery, From vehicles, ships, automobiles, locomotives, heavy machinery and tools for construction, The application of reducers can be seen in the processing machines and automatic production equipment used in the mechanical industry, as well as the common household appliances, clocks and watches in daily life, from the transmission of large power to the transmission of small load and accurate angle. In industrial application, reducers have the functions of decelerating and increasing torque. Therefore, it is widely used in speed and torque conversion equipment.
The main functions of reducer are:
1) Increase the output torque at the same time of speed reduction. The torque output ratio shall be multiplied by the motor output ratio, but care shall be taken not to exceed the rated torque of the reducer.
2) Deceleration also reduces the inertia of the load, and the reduction of inertia is the square of the reduction ratio. You can watch it-General motors have an inertia value.
Working Principle of Reducer Reducer is generally used for transmission equipment with low speed and large torque, The motor, internal combustion engine or other power running at high speed can achieve the purpose of deceleration by meshing the gear with a small number of teeth on the input shaft of the reducer with the large gear on the output shaft. Ordinary reducers also have several pairs of gears with the same principle to achieve the ideal deceleration effect. The ratio of the normal number of large and small gears is the transmission ratio.
Types of reducers
Reducer is a relatively precise machine, which is used to reduce the speed and increase the torque. There are many kinds and models of it, and different kinds have different uses. There are many kinds of reducers, According to the transmission type, it can be divided into gear reducer, worm reducer and planetary gear reducer. According to the different transmission stages, it can be divided into single-stage and multi-stage reducers. According to the gear shape, it can be divided into cylindrical gear reducers. Bevel gear reducers and conical-cylindrical gear reducers can be divided into expanded, split-flow and coaxial type reducers according to the transmission arrangement. The following are commonly used reducer classifications:
(1) Cycloidal pinwheel reducer
(2) Cylindrical gear reducer with hard tooth surface
(3) Planetary gear reducer
(4) Soft tooth surface reducer
(5) Three-ring reducer
(6) Crane reducer
(7) Worm reducer
(8) Shaft-mounted hard tooth surface reducer
(9) Continuously variable transmission
Process route is the way for manufacturing units to complete production tasks according to the specified operation process, which is mainly used for process scheduling and workshop cost statistics. It includes the selection of positioning datum, the machining of main surfaces, the division of machining stages and the reasonable combination of working procedures. Through consulting the Handbook of Machining Technologists edited by Yang Shuzi.
The relevant contents in this article are discussed as follows:
Selection of positioning datum
When formulating the technological process, the main purpose of selecting the positioning datum is to ensure the position accuracy of the machined surface, so the general principle of selecting the positioning datum should be to select from the surface with higher position accuracy requirements.
The selection of positioning datum includes the selection of coarse datum and fine datum.
When working out the machining process route of parts, we always consider what kind of fine datum to choose to process each main surface first, and then consider what kind of coarse datum to choose to process the surface as fine datum first.
The selection of rough datum and fine datum is very important in the formulation of machining process route, and whether the selection is reasonable or not is directly related to the overall situation of machining process route formulation.
(1) Selection of rough datum
When selecting coarse datum, the key point to consider is how to ensure that each machined surface has enough allowance, so that the size and position between the unmachined surface and the machined surface meet the drawing requirements.
The selection principle of rough benchmark is:
1) Select the surface to be machined as the rough datum. The purpose is to ensure the accuracy of the position relationship between the machined surface and the non-machined surface. If there are several surfaces on the upper surface of the workpiece that do not need to be machined, the surface with higher mutual position accuracy with the machined surface should be selected as the rough reference. In order to achieve uniform wall thickness, symmetrical shape, less clamping, etc.
2) Select the important surface with uniform machining allowance as the rough reference. For example, the guide rail surface of the machine tool bed is an important surface that requires uniform rest. Therefore, when machining, the guide rail surface is selected as the rough reference, the bottom surface of the lathe bed is machined, and then the bottom surface is used as the fine reference to machine the guide rail surface. In this way, less allowance can be removed evenly, so that the surface layer retains fine structure and increases wear resistance.
3) The surface with the smallest machining allowance shall be selected as the rough reference. This ensures that the face has enough Machining allowance.
4) Smooth, smooth and large enough surface shall be selected as coarse reference as far as possible to ensure accurate positioning and reliable clamping. The surface with gate, riser, flash and burr should not be selected as coarse reference, and should be preliminarily processed when necessary.
5) Repeated use of coarse datum should be avoided, because the surface of coarse datum is mostly rough and irregular, and it is difficult to ensure the position accuracy between surfaces after repeated use.
The selection of rough datum of box body requires that the machining allowance of main holes should be uniform on the premise of ensuring that all machining surfaces have machining allowance; The rotating parts installed in the box should have enough clearance with the inner wall of the box; In addition, reliable positioning and clamping should be ensured. In order to meet the above requirements, the blank hole of the main hole of the box body is generally selected as the rough reference.
The first surface processed by the reduction box body is the joint surface of the cover or the base. As the blank holes of the bearing holes of the separated box body are irregularly distributed on the two different parts of the cover and the base, the blank of the main hole cannot be used as a rough reference when processing the joint surface of the cover and the base. Instead, the top and bottom surfaces are used as rough references. This can ensure that the thickness of the flange after machining the joint surface is called uniform.
(2) Selection of fine datum
When selecting the principle of fine datum, the key point to consider is to ensure the machining accuracy of workpiece and make clamping accurate, firm and convenient.
The fine benchmark selection principle is Benchmark coincidence principle. That is, the design benchmark is selected as the positioning benchmark as much as possible. In this way, the datum misalignment error caused by the misalignment between the positioning datum and the design datum can be avoided.
Principle of harmonization of benchmarks. Unified positioning datum should be selected as much as possible. The unification of datum is beneficial to ensure the position accuracy between surfaces and avoid the error caused by datum conversion, and the fixtures used in each process are relatively unified, thus reducing the design and manufacture of fixtures. For example, the top pinhole is often used as the positioning reference for shaft parts. Turning and grinding are all pinhole positioning, which not only can process most surfaces in one clamping, but also ensures the coaxiality of each cylindrical surface and the verticality between the end face and the axis line.
The principle of mutual benchmarking. When selecting fine datum, sometimes two machined surfaces can be machined repeatedly as datum for each other. For example, for quenched gears, the inner hole is ground based on the tooth surface, and then the tooth surface is ground based on the hole, so as to ensure uniform tooth surface allowance.
Self-benchmark principle. Some finishing or finishing processes require small and uniform margins, and the machined surface itself can be selected as the benchmark. For example, when grinding the guide rail surface of a machine tool, the guide rail surface is aligned and positioned.
In addition, examples such as drawing holes to grind cylinders on centerless grinders are self-reference examples.
In addition, the surface with high precision and large size on the workpiece should be selected as the fine reference to ensure stable and reliable positioning. It also considers the convenience of workpiece clamping and processing, and the simple design of fixture.
There are high position accuracy requirements between holes, holes and planes, planes and planes on the box body, and the guarantee of these requirements has a great relationship with the selection of fine datum. For this reason, priority is usually given to the principle of "harmonization of benchmarks". So that most processes with mutual position accuracy requirements can be positioned with the same set of datum as much as possible. In order to avoid the accumulated error caused by excessive reference conversion, and because the same reference is adopted, the used fixtures have similar structural forms, which can reduce the workload of fixture design and manufacture and reduce the cost.
2. Processing of main surfaces
(1) Plane machining of box body
Planing and milling are often selected for rough machining and semi-finishing of box plane.
The main characteristics of cutting box plane are: simple tool structure; The adjustment of the machine tool is convenient: several tool holders can be used on the gantry machine, and several surfaces can be processed at the same time in one installation of the workpiece, thus economically ensuring the position accuracy of these surfaces.
The productivity of box plane milling is higher than that of planing. Milling is often used in batch production.
When the batch is large, several planes are often processed with several milling cutters on the multi-axis gantry milling machine at the same time, which not only ensures the position accuracy between planes, but also improves the productivity.
Hole system machining
The hole system of reducer box is the sum of bearing holes with position accuracy requirements, including parallel hole system and coaxial hole system.
The main technical requirements of the parallel hole system are that each parallel hole
The dimensional accuracy and parallel accuracy between the centerlines and between the centerlines and the datum plane can be machined on ordinary boring machines or special boring machines according to different production types.
In order to ensure the accuracy of hole spacing, the marking method is mainly adopted when producing boxes in single piece and small batch. In order to improve the accuracy of marking alignment, trial cutting method can be adopted. Although the accuracy has been improved, the productivity is still very low because marking, trial cutting and measurement all consume more time. Coordinate method is widely used in single-piece and small-batch production in many factories, especially after installing more precise measuring devices (such as digital display, etc.) on ordinary chain bed, its coordinate displacement accuracy can be greatly improved. It must be pointed out that it is very important to select the original hole and machining sequence when using coordinate development hole system. Because, the hole spacing of each row of holes is guaranteed by coordinate size. The accumulated error of coordinate size will affect the accuracy of hole spacing. If the original holes and the assumed order of holes are selected reasonably, the accumulated errors can be reduced. When producing boxes in batches or in large quantities, boring dies are used for machining holes. The accuracy of hole spacing mainly depends on the accuracy and installation quality of boring die. Although the manufacturing of front die is complicated and the cost is high, the workpiece with high precision can be processed by machine tools with low precision. Therefore, in some cases, small batch production can also consider using boring dies to machine parallel hole systems. The main technical requirement of coaxial hole system is the coaxiality accuracy of each hole.
In batch production, the coaxiality of the coaxial hole of the box body is mostly guaranteed by a mirror mold. In single-piece small batch production, the following two methods are used for processing on a common boring machine:
1) proces from one end of that box body
When machining coaxial hole system, the main reason for the coaxiality error is that when the spindle feeds, the boring bar is deflected under the action of gravity, which causes the coaxiality error of the hole. When the worktable feeds, the straightness error of the guide rail will affect the coaxiality accuracy of each hole. For coaxial holes near the box wall, guide sleeves can be used to process coaxial holes. For large boxes, the boring bar can be supported by the guide sleeve of the rear column of the boring machine.
2) carry out tank holes from both end of that box body
Generally, "U-turn boring" is used to make the workpiece rotate 180 after boring the hole at one end and wrong the hole at the other end.
The specific method is to withdraw the workpiece from the spindle after processing the hole at one end, rotate the worktable 1800, and align the wall of the machined hole with a hundred (thousand) sub-meter to be coaxial with the spindle, so that the other hole can be processed. "U-turn boring" does not need clamps and long cutter bars, and the boring bar has short overhang length and good rigidity. However, the adjustment is troublesome and time-consuming, and is suitable for coaxial holes far away from the box wall.
3. Division of processing stages and reasonable combination of working procedures
All machined surfaces on parts should be machined in a reasonable machining sequence, which is very important to ensure the quality of parts, improve productivity and reduce machining costs. The first part of reference [1] is the basis of machining technology. Chapter 4 is the formulation of machining technology regulations:
(1) The division of processing stages According to the different processing properties and purposes, the technological process can generally be divided into rough machining, semi-finishing, finishing and finishing stages. The function of dividing machining stages is to reduce or eliminate the influence of internal stress, cutting force and cutting heat on finishing; Early detection of blank defects; Easy to arrange heat treatment and reasonable use of machine tools;Avoid or reduce damage to finished surfaces.
(2) Combination of operations
There are two different principles for
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