常州亿创钣金加工厂专业从事精密钣金加工、激光切割加工为主的钣金加工型厂家

常州亿创钣金加工厂

示例图片三
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钣金加工注意事项与加工流程介绍

2018-05-05 14:54:10 常州亿创钣金加工厂 阅读

金属板材加工就叫钣金加工。具体譬如利用板材制作烟囱、铁桶、油箱油壶、通风管道、弯头大小头、天园地方、漏斗形等,主要工序是剪切、折弯扣边、弯曲成型、焊接、铆接等,需要一定几何知识。钣金件就是薄板五金件,也就是可以通过冲压,弯曲,拉伸等手段来加工的零件,一个大体的定义就是在加工过程中厚度不变的零件. 相对应的是铸造件,锻压件,机械加工零件等;

钣金加工材料的选用

钣金加一般用到的材料有冷轧板(SPCC)、热轧板(SHCC)、镀锌板(SECC、SGCC),铜(CU)黄铜、紫铜、铍铜,铝板(6061、6063、硬铝等),铝型材,不锈钢(镜面、拉丝面、雾面),根据产品作用不同,选用材料不同,一般需从产品其用途及成本上来考虑。 

1.冷轧板SPCC,主要用电镀和烤漆件,成本低,易成型,材料厚度≤3.2mm。

2.热轧板SHCC,材料T≥3.0mm ,也是用电镀,烤漆件,成本低,但难成型,主要用平板件。

3.镀锌板SECC、SGCC。SECC电解板分N料、P料,N料主要不作表面处理,成本高,P料用于喷涂件。

4.铜:主要用导电作用料件,其表面处理是镀镍、镀铬,或不作处理,成本高。

5.铝板:一般用表面铬酸盐(J11-A),氧化(导电氧化,化学氧化),成本高,有镀银,镀镍。

6.铝型材:截面结构复杂的料件,大量用于各种插箱中。表面处理同铝板。

7.不锈钢:主要用不作任何表面处理,成本高。

钣金展开注意事项

展开图是依据零件图(3D)展开的平面图(2D) 

1.展开方式要合,要便利节省材料及加工性

2.合理选择问隙及包边方式,T=2.0以下问隙0.2,T=2-3问隙0.5,包边方式采用长边包短边(门板类)

3.合理考虑公差外形尺寸:负差走到底,正差走一半;孔形尺寸:正差走到底,负差走一半。

4.毛刺方向

5.抽牙、压铆、撕裂、冲凸点(包),等位置方向,画出剖视图

6.核对材质,板厚,以板厚公差

7.特殊角度,折弯角内半径(一般R=0.5)要试折而定展开 

8.有易出错(相似不对称)的地方应重点提示 

9.尺寸较多的地方要加放大图

10. 需喷涂保护地方须表示

板金加工的工艺流程

根据钣金件结构的差异,工艺流程可各不相同,但总的不超过以下几点。

1、下料:下料方式有各种,主要有以下几种方式

①. 剪床:是利用剪床剪切条料简单料件,它主要是为模具落料成形准备加工,成本低,精度低于0.2,但只能加工无孔无切角的条料或块料。

②. 冲床:是利用冲床分一步或多步在板材上将零件展开后的平板件冲裁成形各种形状料件,其优点是耗费工时短,效率高,精度高,成本低,适用大批量生产,但要设计模具。

③. NC数控下料,NC下料时首先要编写数控加工程式,利用编程软件,将绘制的展开图编写成NC数拉加工机床可识别的程式,让其根据这些程式一步一刀在平板上冲裁各构形状平板件,但其结构 受刀具结构所至,成本低,精度于0.15。

④. 镭射下料,是利用激光切割方式,在大平板上将其平板的结构形状切割出来,同NC下料一样需编写镭射程式,它可下各种复杂形状的平板件,成本高,精度于0.1.

⑤. 锯床:主要用下铝型材、方管、图管、圆棒料之类,成本低,精度低。

1. 钳工:沉孔、攻丝、扩孔、钻孔 沉孔角度一般120℃,用于拉铆钉,90℃用于沉头螺钉,攻丝英制底孔。

2. 翻边:又叫抽孔、翻孔,就是在一个较小的基孔上抽成一个稍大的孔,再攻丝,主要用板厚比较薄的钣金加工,增加其强度和螺纹圈数,避免滑牙,一般用于板厚比较薄,其孔周正常的浅翻边,厚度基本没有变化,允许有厚度的变薄30-40%时,可得到比正常翻边高度大高40-60%的高度,用挤薄50%时,可得最大的翻边高度,当板厚较大时,如2.0、2.5等以上的板厚,便可直接攻丝。

3. 冲床:是利用模具成形的加工工序,一般冲床加工的有冲孔、切角、落料、冲凸包(凸点),冲撕裂、抽孔、成形等加工方式,其加工需要有相应的模具来完成操作,如冲孔落料模、凸包模、撕裂模、抽孔模、成型模等,操作主要注意位置,方向性。

4. 压铆:压铆就本公司而言,主要有压铆螺母、螺钉、松不脱等,其是通过液压压铆机或冲床来完成操作,将其铆接到钣金件上,还有涨铆方式,需注意方向性。

5. 折弯;折弯就是将2D的平板件,折成功D的零件。其加工需要有折床及相应折弯模具完成,它也有一定折弯顺序,其原则是对下一刀不产生干涉的先折,会产生干涉的后折。

l 折弯条数是T=3.0mm以下6倍板厚计算槽宽,如:T=1.0、V=6 .0 F=1.8、T=1.2、V=8、F=2.2、T=1.5、V=10、F=2.7、T=2.0、V=12、F=4.0

l 折床模具分类,直刀、弯刀(80℃、30℃)

l 铝板折弯时,有裂纹,可增加下模槽宽式增加上模R(退火可避免裂纹)

l 折弯时注意事项:Ⅰ图面,要求板材厚度,数量; Ⅱ折弯方向 Ⅲ折弯角度;Ⅳ折弯尺寸;Ⅵ外观、电镀铬化料件不许有折痕。

折弯与压铆工序关系,一般情况下先压铆后折弯,但有料件压铆后会干涉就要先折后压,又有些需折弯—压铆—再折弯等工序。

6. 焊接:焊接定义:被焊材料原子与分子距京达晶格距离形成一体

①分类:a 熔化焊:氩弧焊、CO2焊、气体焊、手工焊

b 压力焊:点焊、对焊、撞焊

c 钎焊:电铬焊、铜丝

② 焊接方式:a CO2气体保护焊

b 氩弧焊

c 点焊接等

d 机器人焊

焊接方式的选用是根据实际要求和材质而定,一般来说CO2气体保护焊用于铁板类焊搠;氩弧焊用于不锈钢、铝板类焊接上,机器人焊接,可节省工时,提高工作效率和焊接质量,减轻工作强度。

③ 焊接符号:Δ 角焊, Д、I型焊, V型焊接, 单边V型焊接(V) 带钝边V型焊接(V), 点焊(O), 塞焊或槽焊(∏),卷边焊(χ), 带钝边单边V型焊(V), 带钝之U型焊, 带钝的J型焊,封底焊, 逢焊 

④ 箭头线和接头

⑤ 焊接缺失及其预防措失

点焊:强度不够可打凸点,强加焊接面积

CO2焊:生产率高,能源消耗少,成本低,抗锈能力强

氩弧焊:溶深浅,溶接速度慢,效率低,生产成本高,具有夹钨缺陷,但具有焊接质量较好的优点,可焊接有色金属,如铝、铜、镁等。 

⑥ 焊接变形原因:焊接前准备不足,需增加夹具

焊接治具不良改善工艺

焊接顺序不好

⑦ 焊接变形效正法:火焰效正法

振动法 

锤击法

人工时效法

Sheet metal processing is called sheet metal processing. For example, making use of plate to make chimneys, iron buckets, oil tank oil pot, ventilation pipe, big head of elbow, Tianyuan place, funnel shape and so on. The main working procedure is cutting, bending and buckle edge, bending forming, welding, riveting and so on. It needs certain geometric knowledge. Sheet metal parts are sheet metal parts, that is, parts that can be processed by means of stamping, bending and stretching. A general definition is the parts with constant thickness during the process of processing. The corresponding parts are casting parts, forging parts, machined parts, etc.

Selection of sheet metal processing materials

The materials used for sheet metal are cold rolled plate (SPCC), hot rolled plate (SHCC), galvanized sheet (SECC, SGCC), copper (CU) brass, copper, beryllium copper, aluminum sheet (6061, 6063, hard aluminum, etc.), aluminum profiles, stainless steel (mirror, drawing surface, fog surface), according to the different products, the selection of materials is usually different. The use and cost of the product are considered.

1. cold rolled plate SPCC, mainly used in electroplating and baking parts, low cost, easy to shape, material thickness less than 3.2mm.

2. hot-rolled sheet SHCC, material T or more 3.0mm, is also used electroplating, baking paint parts, low cost, but difficult to shape, mainly using flat parts.

3. galvanized sheet SECC, SGCC. SECC electrolysis plate is divided into N material and P material. N material is mainly used for surface treatment and high cost. P material is used for spraying parts.

4. copper: mainly used as conductive material, the surface treatment is nickel plated, chrome plated, or not processed, and the cost is high.

5. aluminum plate: commonly used surface chromate (J11-A), oxidation (conductive oxidation, chemical oxidation), high cost, silver plated, nickel plated.

6. aluminum profile: material with complex section structure, used in various inserts. The surface is treated with the same aluminum plate.

7. stainless steel: it is mainly used without any surface treatment, and the cost is high.

Notices of sheet metal expansion

The expansion diagram is a plan (2D) based on part diagram (3D).

1., the way of expansion should be combined, so as to save materials and workability.

2. reasonable choice of gap and wrapping method, T=2.0 below the gap 0.2, T=2-3 ask gap 0.5, the way of wrapping long edge package short edge (door type)

3. reasonably consider the tolerance dimension: the negative difference goes to the end, the positive error goes half; the hole size: the positive error goes to the end, the negative difference walks half.

4. burr direction

5. draw teeth, press riveting, tearing, bump bump (package), etc. position direction, draw sectional view.

6. check material, plate thickness, plate thickness tolerance

7. special angle, the radius of the bending angle (general R=0.5) should be measured and expanded.

8. where there is error prone (similar asymmetry), we should give priority to hints.

9. places with more size should be added to the big picture

10. the need for spraying protection must be expressed

Process flow of plate gold processing

According to the difference of sheet metal structure, the process flow can be different, but the total does not exceed the following points.

1. Blanking: there are various ways of cutting materials, mainly in the following ways.

Scissors: it is a simple material for cutting the strip by cutting the cutting bed. It is mainly prepared for the molding of die blanking. The cost is low and the precision is less than 0.2.

(2). Punching machine: it is a kind of shape material that can be blanked out by one or more steps on the plate. The advantage is that it takes short time, high efficiency, high precision and low cost, and it is suitable for mass production, but it is necessary to design a mold.

(3).NC numerical control blanking, NC is the first to write the numerical control process program, using the programming software, the drawing of the expansion map is written into the NC number drawing machine tool can be identified, so that the program according to these programs one step on the plate blanking the flat plate, but its structure is subject to the tool structure, low cost, precision 0.15.

(4). Laser cutting is used to cut the structure of the flat plate on a large plate by laser cutting. It needs to write a laser program like the NC material. It can lower the complex shape of the flat plate, and the cost is high and the precision is in the 0.1..

Sawing machine: mainly use lower aluminum profile, square tube, picture tube, round bar material and so on, with low cost and low precision.

1. fitter: deep hole, tapping, reaming, drill hole sinking angle generally 120 degrees, for pulling rivet, 90 degrees for countersunk screw, tapping the British bottom hole.

2. flanging: also called hole and hole, that is to draw a slightly larger hole on a smaller base hole, and then tapping, mainly using sheet metal processing with thin plate thickness, increasing its strength and number of threads to avoid sliding teeth, generally used for thin plate thickness, the shallow flanging of the hole Zhou Zhengchang, the thickness is basically unchanged, allowed to have the thickness. When the thickness is thinner 30-40%, the height of 40-60% higher than the normal flanging height can be obtained. The maximum flanging height can be obtained when the thickness is 50%. When the thickness of the plate is larger, the thickness of the plate, such as 2, 2.5 and so on, can be tapped directly.

3. punching machine: using die forming process, the general punching machine has punching, cutting angle, blanking, punching bulge (Bump), punching and tearing, drawing holes, forming and other processing methods, its processing needs corresponding die to complete the operation, such as punching and falling die, punch die, tearing die, drawing die, molding mould, etc. The operation mainly pays attention to the position and direction.

4. pressure rivet: pressure riveting on the company, the main pressure riveting nuts, screws, loose and so on, it is through the hydraulic pressure riveting machine or punch to complete the operation, it is riveted to sheet metal parts, there is also rising riveting way, need to pay attention to the direction.

5. bending; bending is to fold the 2D flat parts into D parts. Its processing needs to have a folding bed and the corresponding bending die to finish. It also has a certain bending sequence.



标签:   钣金加工