欧美人妻精品一区二区三区99,中文字幕日韩精品内射,精品国产综合成人亚洲区,久久香蕉国产线熟妇人妻

Which is best for precision boring inner holes? Carbide or HSS? We opt for low-speed cutting using a carbide offset boring tool. Carbide tools were chosen for its excellent heat and wear resistance, which compensates for the shortcomings of HSS tools. At low cutting speeds, the carbide tool maintains durability and sharpness, preventing vibration, deflection, and built-up edge formation. This avoids taper and wavy surfaces in the inner hole, ensuring dimensional and surface roughness precision, and achieving good form accuracy.

What problem may HSS tools be across in precission boring inner holes?

the resultant holes that machined by HSS tools at low speed gennerally have a lower surface roughness. Additionally, the small cuttings happens and results in longer machining times and lower efficiency, making HSS tools generally suitable only for finishing operations. To eliminate taper in the inner hole, switching to medium-speed cutting can be attempted, but this often leads to built-up edge formation on the tool’s rake face, increasing surface roughness and failing to meet the required surface finish. If a HSS tool is used at high speeds for precision boring, the poor heat and wear resistance of HSS causes rapid tool wear and insufficient tool strength, leading to tool deflection and difficulty in controlling dimensions. On the other hand, using a carbide tool at high speeds can result in poor tool rigidity and significant vibration, leading to a wavy surface on the inner hole, thereby affecting precision.

boring tool

 

How to address and tackle these technical issues in precision boring of inner holes?

Tool Design

To achieve good precision in inner hole machining, it’s essential to reasonably select the type and grade of carbide tool, appropriate geometry, and suitable cutting parameters.

1.Selection of Carbide Type and Grade

Choose a tungsten-cobalt carbide boring tool, grade YG8 (equivalent to ISO grade K20-K30). This tool features high strength, good impact and vibration resistance, and is suitable for low-speed turning, making it ideal for precision boring.

2.Tool Geometry Selection

Positive rake angle (λs) for sharpness;
Main cutting edge angle (Kr) between 93-96 degrees to reduce radial force;
Rake angle (γ0) and relief angle (α0) both at 6 degrees to improve sharpness and reduce cutting deformation;
Secondary cutting edge angle (Kr) at 6 degrees to minimize surface roughness.

How to Address Various Issues and Tackle Them in Precision Boring Tool for Inner Holes? 2

3.Basis and Analysis for Boring Tool Geometry Selection

Rake angle is the angle between the main cutting edge and the base plane. A positive rake angle makes the boring tool sharp, reducing cutting resistance due to the small machining allowance during finishing.
The main cutting edge angle is the angle between the main cutting edge’s projection on the base plane and the feed direction. It directly affects the radial force. A smaller angle increases tool tip strength, while a larger angle reduces radial force. Hence, an angle of 93-96 degrees is chosen to reduce radial force and facilitate cutting of stepped surfaces in the inner hole.
The rake angle, typically 5-20 degrees, improves boring tool sharpness and reduces cutting force. However, increasing the rake angle decreases cutting edge strength. During finishing, a larger rake angle is chosen to ensure sharpness. The relief angle, between 3-12 degrees, reduces friction between the tool’s relief face and the workpiece.
The secondary cutting edge angle, 6-8 degrees (6 degrees in this case), reduces surface roughness by minimizing the angle between the secondary cutting edge’s projection and the feed direction.

4.Cutting Parameters Selection

Based on the tool characteristics, tests have determined that the cutting speedv for precision boring a carbon steel inner hole of
Φ45 is about 25m/min (workpiece speed around 180r/min), with a cutting depth a of 0.05-0.10mm and a feed rate f of 0.2mm/r.

 

Features of Using This Tool

Using a chip-breaking tool for inner hole precision boring ensures that the small finishing allowance doesn’t affect the surface roughness;

The larger main cutting edge angle reduces radial cutting force and vibration;

A larger boring tool holder diameter ensures sufficient rigidity, avoiding vibrations and surface waviness caused by inadequate tool rigidity.

How to Address Various Issues and Tackle Them in Precision Boring Tool for Inner Holes? 3

Precautions When Using Carbide Offset Boring Tools for Precision Boring

Before precision boring, ensure a machining allowance of 0.08-0.12mm and a surface roughness around Ra3-2. If the allowance is too small, finishing won’t remove rough machining marks; if too large, cutting resistance increases, reducing hole precision.
The tool is only suitable for finishing, not roughing.
During machining, avoid tool impact on stepped surfaces. Although carbide is hard and wear-resistant, it is brittle and not impact-resistant. Thus, operate carefully, switching to manual feed 2-3mm before the desired hole depth to achieve the required depth accurately.

Bir cevap yaz?n

E-posta hesab?n?z yay?mlanmayacak. Gerekli alanlar * ile i?aretlenmi?lerdir

日本韩国国产精品一区| 国产精品三级一区二区| 妺妺坐在我腿上下面好湿| 国产精品高潮久久久久a| 亚洲欧美一区二区三区在| 日韩美女一区二区三区香蕉视频| 久久久久久亚洲精品首页| 日本欧美人一区二区三区| 色婷婷五月综合久久| 日本亚欧乱色视频69室| 大黑屌后入骚妇屁股| 亚洲男性天堂一区二区三区| 黑丝美女被操到高潮| 中日韩国内精品视频| 欧美日本大白屁股大黑逼操逼视频| 女教师色色天天免费播放| 嗯啊好大好想要视频| 福利国产第一视频| 2021国产一区二区岛国| 午夜精品在线视频| 免费国产香蕉视频在线观看| 男人插女人视频软件| 人妻含泪让粗大挺进| 加勒比五月综合久久伊人| 老熟妇高潮一区二区高清视频| 操纯欲女生小穴视频| 国产精品高潮久久久久a| 黄色日女人逼视频| 999精品免费视频| 五月天国产成人免费视频| 久久婷婷综合五月一区二区| 鸡巴插骚逼真舒服| 熟妇人妻无乱码中文字幕| av黄色资源在线观看| 国产成人无码AV一区二区三区| 国产精品毛片无遮挡高清| 妓女综合网在线观看| 欧美 日本 亚洲 国产| 日本中文字幕无人区一区二区| 成年女人永久看片视频 | 亚洲Av无码专区一区二区三区|