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

The surface roughness of a part is a technical requirement that measures the surface processing quality of the part. It significantly impacts the part’s fit, wear resistance, corrosion resistance, and sealing performance. The factors that affect surface roughness mainly include the workpiece material, cutting parameters, machine tool performance, and tool material and geometry parameters.

During the actual machining process, the cutting depth, feed rate, and spindle speed are predetermined and kept constant throughout the cutting process. Therefore, it is essential to optimize the combination of factors affecting surface roughness to obtain the optimal surface quality value. This article begins with the calculation formula of surface roughness and its relationship with chip thickness. It further explores the relationship between surface roughness, cutting depth, and feed rate. Additionally, it examines the impact of various factors on surface roughness through experimentation.

How To Calculate the Surface Roughness in Ball-end Milling 2

Mechanism of Surface Roughness Generation

Mechanism of Residual Height Generation

In curved surface machining, the residual height is mainly formed by the tool moving along the tool path and leaving material on the surface of the workpiece unremoved. As shown in Figure 1, the following parameters are defined: P as the tool contact point, R as the radius of the curved surface, θ as the angle between two radius lines, and n as the normal vector at point P. The stepover distance is represented by d, and it is closely related to the residual height h. Based on Figure 2(a), we can derive the following relationship:

How To Calculate the Surface Roughness in Ball-end Milling 3

In the equation: r represents the tool radius, and kh represents the normal curvature of the machining surface along the cutting feed direction.

 

 

How To Calculate the Surface Roughness in Ball-end Milling 4

When using the sectional plane method to generate tool paths, calculating the normal curvature (kh) can be challenging. In practical machining, an approximation is often used, where a plane approximates the surface between two adjacent tool paths, as shown in Figure 2(b). The stepover distance is considered the normal distance between the sectional planes. In this case, the residual height (h) can be described by the following equation:

How To Calculate the Surface Roughness in Ball-end Milling 5

1.2Calculation of Surface Roughness

Due to the presence of residual height, the surface of the part after mechanical machining will have many uneven peaks and valleys. This microscopic geometric shape is known as surface roughness, as shown in Figure 3. The parameter Ra is defined as the surface roughness, which is given by:

How To Calculate the Surface Roughness in Ball-end Milling 6

In the equation, L represents the sampling length.

How To Calculate the Surface Roughness in Ball-end Milling 7

Zooming in on Figure 3, we obtain Figure 4. When h’ is less than Y et, we can deduce:

How To Calculate the Surface Roughness in Ball-end Milling 86

 

How To Calculate the Surface Roughness in Ball-end Milling 9

When h” is greater than Y et, we can deduce:

How To Calculate the Surface Roughness in Ball-end Milling 10

In the equation, E represents the area of the region. Since y_a needs to ensure that the area above and below the central line is equal, i.e.,

How To Calculate the Surface Roughness in Ball-end Milling 11

In equation (6), p’ and p” are weighting factors. p is closely related to the chip thickness h. After a series of derivations, we can obtain

How To Calculate the Surface Roughness in Ball-end Milling 12

the expression of the sampling area is as follows

How To Calculate the Surface Roughness in Ball-end Milling 13

In the expression:

How To Calculate the Surface Roughness in Ball-end Milling 14

Substituting equations (4) and (5) into equation (8), we obtain:

How To Calculate the Surface Roughness in Ball-end Milling 15

After substituting equation (7) into equation (9) and simplifying through calculations, the relationship between the sampling area of surface roughness and the chip thickness is obtained as follows:

How To Calculate the Surface Roughness in Ball-end Milling 16

According to the above equation, it can be seen that there is a very simple relationship between surface roughness and chip thickness. When milling with a ball-end cutter, the feed per tooth is constant, while the chip thickness varies continuously based on the cutting depth and feed rate.

 

Experimental Data and Analysis

Experimental Conditions

Under steady-state cutting conditions, by varying the cutting depth and feed rate, the surface roughness values are measured for different parameter combinations. The micro-topography of the machined surfaces is observed using a three-dimensional profilometer, and the influence of cutting parameters on surface roughness is analyzed.

The experiment is conducted on the edge part shown in Figure 5, using a FANUC precision machining center machine. The workpiece material is 45# steel, and a high-speed steel milling cutter with a diameter of 12.5mm is selected as the cutting tool. The spindle speed is set at 800 r/min, and the cutting depth varies from 1mm to 6mm. Different feed rates are used for cutting at depths of 1mm, 2mm, 4mm, and 6mm, as illustrated in Figure 6.

 

Data Measurement

After completing the machining of the part, measurement points are selected on the curved section of the part shown in Figure 5. For each set of experimental conditions, data at these measurement points are measured twice, and the average value is taken as the experimental value. The experimental data are presented in Table 1

How To Calculate the Surface Roughness in Ball-end Milling 17

 

How To Calculate the Surface Roughness in Ball-end Milling 18

 

ボールエンドミル加工における表面粗さの計(jì)算方法 19

 

Data Analysis

From the experimental data, it can be observed that when machining the part using a ball-end cutter and keeping the feed rate constant, the surface roughness increases with an increase in cutting depth (see Figure 7). At lower cutting depths, the surface roughness values are smaller, but excessively small cutting depths result in longer cutting times and lower processing efficiency.

Although there is a certain difference between the experimental values and theoretical values in this study, they are relatively close. Hence, the provided calculation formula in this study can be adopted. For the selected workpiece in this study, the optimum surface roughness is achieved when the cutting depth is 2mm, and the feed rate is 700mm/min.

 

 

roughness

 

3conclusion

The study investigated the influence of various machining parameters on surface roughness during the milling process of the workpiece. The theoretical impact of surface roughness on the surface quality of the workpiece was explored, and a theoretical calculation formula for surface roughness was derived based on its generation mechanism.

Using the trial machining method and different combinations of parameter data, the surface roughness of the machined parts was measured using a three-dimensional profilometer. The calculated theoretical values from the formula were then compared with the experimental values.

The research demonstrated that both the calculation formula and the machining method are feasible and effective in predicting and controlling surface roughness during the milling process.

コメントを殘す

メールアドレスが公開されることはありません。 が付いている欄は必須項(xiàng)目です

男人摸女人下面视频| 操老女人大逼视频| 精品国产自在久国产应用| 大香蕉尹人97超级视频| 国产亚洲一区二区手机在线观看| 美女嫩逼插进大屌| 日本高清一区二区三区不卡| 国产亚洲一区白丝在线观看| 影音先锋亚洲中文综合网| 亚洲精品国产综合一线久久| 日本熟妇一区二区三区四区| 啊啊啊啊大鸡巴操我视频| 美国女人抠插bbb| 中文字幕一高清免费视频| 国产午夜爽爽爽男女免费动漫AV| 久久国产亚洲高清| 涩涩屋操美女视频| 女同舔我下面直流水| 少妇勾搭外卖员在线观看| 久久久久九九九国产精品| 骚逼被狂插视频教程| 手机成人三级a在线观看| 亚洲欧美日韩中文v在线| 大鸡巴日大鸡巴在线观看| 亚洲一区二区三区日本在线| 欧美大鸡巴操穴日韩| 精品日韩欧美精品日韩| 国产欧美一二区不卡视频| 男人和女人干污污| 日韩 欧美 一区 二区三区| 国产美女裸体视频全免费| 午夜国产精品午夜福利网| 国产精品视频美熟女一区二区| 加勒比五月综合久久伊人| 久久99热人妻偷产精品| 欧美一区二区高清视频在线观看| 男人操女人下面国产剧情| 男人摸女人下面视频| 日韩久久奶茶视频| 久久国产精品二卡| 成人久久久久久蜜桃免费|