国产少妇影视乱伦-国产少又黄又爽的A片-国产社区视频在线永久免费观看-国产呻吟久久久久久久92-国产深夜福利-国产深夜福利电影

1

Detailed explanation of the technical scheme for grinding force and grinding heat by the Engineering Technology Center of the External Grinding Machine

Time:2019-10-12 Visits:967
CNC cylindrical grinding is a systematic engineering process. If it's just a grinding wheel and a grinding machine, and you can grind the workpiece with electricity, it's really not difficult. If you want to solve the grinding problem thoroughly, you need to participate in the entire grinding system and decompose it in order to solve it.

1、 Grinding force.

① The source and decomposition of grinding force.

During grinding, there are forces of equal magnitude and opposite directions acting on the grinding wheel and workpiece, and this force generated during the grinding process is called grinding force (cutting force).

The grinding force mainly consists of two parts: the abrasive particles need to cause significant plastic deformation of the metal being cut during cutting, resulting in cutting force; The grinding force generated between the abrasive particles and the surface of the workpiece during cutting.

② The influence of grinding force on machining.

When grinding, the abrasive particles cut at a negative rake angle, and the radius R of the edge corner is often larger than the back feed, so the radial extrusion force of the abrasive particles on the workpiece is very large, usually Fp=(2-3) FC. Due to the large radial force, the process system composed of the machine tool, workpiece, and grinding wheel undergoes significant elastic deformation, thereby affecting the grinding accuracy.

If the workpiece undergoes deformation due to radial and tangential forces, and its axis moves relative to e, it will cause a diameter error in the workpiece.

The deformation of the process system caused by radial force often results in a difference between the actual back cutting amount and the tree value shown on the feed scale of the grinding wheel. Therefore, a reasonable grinding cycle is to stop for a while after the feed to eliminate deformation caused by radial forces. This type of non feed grinding is called smooth grinding or spark free grinding. When grinding a slender shaft, the workpiece is ground into a drum shape by radial force.

The characteristics of the grinding wheel, the grinding width of the grinding wheel, the material of the workpiece, and the grinding amount (ap, f) have a significant impact on the radial force.

2、 Grinding heat.

1. Grinding heat and its conduction.

During grinding, the intense friction between the grinding wheel and the surface of the workpiece causes the instantaneous temperature in the local area of grinding to reach over 1000 ℃.

Grinding sparks refer to the phenomenon of grinding debris oxidizing and burning in the air. The friction between the abrasive particles and the workpiece, as well as the plastic deformation energy of the metal layer, are all converted into thermal energy. Therefore, the grinding heat and its conduction can be expressed as follows:

Q=Q Friction+Q Deformation=Q workpiece+Q debris+Q grinding wheel+Q medium

2. The impact of grinding heat on machining.

① Causing surface burns on the workpiece: The surface of the workpiece may be burned under instantaneous high temperature.

The so-called burn generally refers to the uneven annealing of the metal material on the surface of the quenched workpiece under the action of grinding heat. As a result, the surface hardness of the workpiece decreases, which affects the performance and lifespan of the parts.

The surface of severely burned workpieces can be seen with the naked eye, presenting a layer of burnt yellow or burnt black oxide film.

The surface of the workpiece with minor burns appears light yellow. Grinding materials with poor thermal conductivity, such as bearing steel, heat-resistant alloy steel, etc., is most likely to cause burns.

② Residual stress and cracks on the surface of the workpiece: When the temperature in the grinding zone reaches a level that causes a change in the metallographic structure of the metal material (referred to as phase transformation), it causes a change in the metallographic structure of the metal surface and generates stress. When the local stress exceeds the strength limit of the workpiece material, cracks appear on the surface of the workpiece.

③ Affects the workpiece
主站蜘蛛池模板: 老师解我胸罩让我去他办公室| 欧美乱大交xxxxx| 风韵丰满熟妇啪啪区老老熟女百度| 国产性夜夜性夜夜爽91| 在线看片免费观看| 国产精品久久影院| 中国亚州女人69内射少妇| 国产玖玖在线观看| 中文字幕乱码 电影在线观看| 日本精品在线播放| 免费看成人www的网站软件| 亚洲天堂黄| 久久精品视频在这里16| 国产精品久人妻精品| 成人福利网| 肉蒲团从国内封禁到日本成经典| 涩狠狠狠狠色| 日日摸夜夜添夜夜添A片图片| 日韩精品无码久久一区二区三| 欧美日韩在线视频观看 | 日韩一级特黄毛片在线看| 欧美性综合| 粗大挺进尤物人妻中文字幕| 亚洲一级成人| 国产三级日本三级在线播放| 伦理片天堂eeuss影院2o12| 有坂深雪初尝黑人在线观看| 5月丁香婷婷| 99热这里只就有精品22| 国产福利一区二区三区在线观看| 欧美wwwwxxxx| 水蜜桃免费视频看爱如潮水| 免费韩国伦理2017最新| xxxww免费看| 久久久这里只有免费精品2024| 日本精品不卡| 999伊人| 肉蒲团从国内封禁到日本成经典| 一个人看的视频在线观看高清| 91免费福利精品国产| 色偷拍自怕亚洲在线|