Extruded Parts
挤出件
No limitation on length. Minimum solid cross-section is limited to 0.028 in. extrusions. Wall thickness of hollow extrusions varies with material but 0.020 in. can be achieved with most materials (S6308, 1215, 1273).
长度无限制。最小实心截面限制在0.028英寸。中空挤出件的壁厚随材料不同而变化，但是大多数材料（S6308、1215、1273）都能达到0.020英寸。
8. General Tolerances
8. 一般公差
Table 4 provides general tolerances for conductive elastomer gaskets. It is important to note that all flat die-cut, molded, and extruded gaskets are subject to free-state variation in the unrestrained condition. The use of inspection fixtures to verify conformance of finished parts is common and recommended where appropriate.
表4给出了导电橡胶垫片的一般公差。应注意到的很重要一点是，所有平模切、模制及挤出垫片在无约束的条件下都有自由状态变化。使用检验器具来确认完工零件是否合格是一种通常做法并在适用时推荐其使用。
Also note that “Overall Dimensions” for flat die-cut gaskets and molded gaskets includes any feature-to-feature dimensions (e.g., edge-to-edge, edge-to-hole, hole-to-hole).
还应注意，平模切垫片和模制垫片的“总体尺寸”还包括任意特征到特征尺寸（如，边到边、边到孔、孔到孔）。
9. Gasket Cross Section Based on Junction Gaps
9. 结合间隙基础上的垫片截面
Gasket geometry is largely determined by the largest gap allowed to exist in the junction. Sheet metal enclosures will have larger variations than machined or die castings. The ultimate choice in allowable gap tolerance is a compromise between cost, performance and the reliability required during the life of the device. When a value analysis is conducted, it should be made of the entire junction, including the machining required, special handling, treatment of the surfaces and other factors required to make the junction functional. Often, the gasket is the least expensive item, and contributes to cost-effectiveness by allowing loosely-toleranced flanges to be made EMI-tight.
垫片几何形状很大程度上取决于结合面处允许存在的最大间隙。板金机箱相对于机加工或模铸机箱其变动更大。间隙许可公差的最终选择是成本、性能和设备寿命期间所需可靠性之间的折中。当进行数据分析时，数据应来自整个结合面，包括所需机加工、特殊处理、表面处理及使结合面正常工作的其它因素。通常，垫片是最便宜的零件，但通过使宽松公差凸缘成为电磁干扰密闭结合，贡献其成本效益。
华译网上海翻译公司曾经翻译过大量有关电气性能资料文件，Beijing Chinese Subtitling Translation Service Agency has translated many technical documents about Electrical performance.
The maximum gap allowed to exist in a junction is generally determined by the minimum electrical performance expected of the seal. A secondary consideration must be given to the barrier as a pressure seal if gas pressures of significant magnitude are expected. The gasket will blow out if the pressure is too high for the gap.
结合面允许存在的最大间隙通常由此处密封的预计最小电气特性来确定。第二要考虑的应当是如果存在较高气压时用作压力密封的隔离物。如果压力对于间隙来说过高，垫片就会爆开。
The minimum gap allowed in the junction is determined by the allowable squeeze that can be tolerated by the gasket material. Deflection of conductive elastomer gaskets is given in Figure 11. Flat gaskets may be deflected as much as 6-10 percent (nominal), depending on initial thickness and applied force. O-shaped and D-shaped gaskets are normally deflected 10 to 25 percent; however, greater deflections can be achieved by manipulating cross section configuration.
结合面允许的最小间隙取决于垫片材料可以承受的许可挤压力。导电橡胶垫片的变形在图11中给出。平垫片的变形取决于初始厚度和所施加力，可能达到（公称值的）百分之6-10。O形或D 形垫片一般变形为百分之10至25；并且，通过利用截面配置，可获得更大变形。
Determination of the exact gasket thickness is a complex problem involving electrical performance, flange characteristics, fastener spacing and the properties of the gasket material. However, an initial estimate of the necessary thickness of a noncontained gasket can be determined by multiplying the difference in the expected minimum and maximum flange gaps by a factor of 4, as illustrated in Figure 12.
确定垫片的精确厚度是一个复杂问题，涉及到电气性能、凸缘特性、紧固件间距和垫片材料性质。然而，垫片所需无约束状态厚度的初始估计可以通过预计凸缘最小和最大间隙之差乘以系数4来确定，如图12所示。
A more detailed discussion, and a more accurate determination of gasket performance under loaded flange conditions, can be found in the Fastener Requirements section.
更详细的讨论，以及在已加载凸缘条件下垫片性能的更精确确定，参见紧固件要求部分。
Figure 12. Gasket Deflection Along a Flange
图12 沿凸缘的垫片变形
Table 4. General Tolerances
表4 一般公差
FLAT DIE-CUT GASKETS
模切平垫片
inch (mm) 英寸 (mm) Tolerance 公差
Overall Dimensions 总尺寸
≤10 (254) ±0.010 (0.25)
>10 to ≤15 (254 to 381) ±0.020 (0.51)
>15 (>381) ±0.20% Nom. Dim.
±0.20% 公称尺寸
Thickness 厚度
0.020 (0.51) ±0.004 (0.10)
0.032 (0.81) ±0.005 (0.13)
0.045 (1.14) ±0.006 (0.15)
0.062 (1.57) ±0.007 (0.18)
0.093 (2.36) ±0.010 (0.25)
0.125 (3.18) ±0.010 (0.25)
>0.125 (>3.18) Contact a XXXX Applications or Sales Engineer
联系XXXX 应用工程师或销售工程师
Hole Diameters 孔直径
>0.060 (1.52) dia. if sheet thickness is...
>0.060 (1.52) 直径，如果薄片厚度为…
≤0.062 (1.57) ±0.005 (0.13)
>0.062 (1.57) ±0.008 (0.20)
Location of Hole Center ±0.007 (0.18)
孔中心位置 ±0.007 (0.18)
MOLDED GASKETS 模制垫片
inch (mm) 英寸 (mm) Tolerance 公差
Overall Dimensions 总尺寸
0.100 to 1.500 (2.54 to 38.10) 0.100 至 1.500 (2.54 至 38.10) ±0.010 (0.25)
1.501 to 2.500 (38.13 to 63.50)
1.501 至 2.500 (38.13 至 63.50) ±0.015 (0.38)
2.501 to 4.500 (63.53 to 114.30) 2.501 至 4.500 (63.53 至 114.30) ±0.020 (0.51)
4.501 to 7.000 (114.33 to 177.80)
4.501 至 7.000 (114.33 至 177.80) ±0.025 (0.64)
>7.000 (>177.80) ±0.35% Nom. Dim.
±0.35% 公称尺寸
Cross Section 横截面
0.040 to 0.069 (1.02 to 1.75)
0.040 至 0.069 (1.02 至 1.75) ±0.003 (0.08)
0.070 to 0.100 (1.78 to 2.54)
0.070 至 0.100 (1.78 至 2.54) ±0.004 (0.11)
0.101 to 0.200 (2.57 to 5.08)
0.101 至 0.200 (2.57 至 5.08) ±0.005 (0.13)
0.201 to 0.350 (5.11 to 8.89)
0.201 至 0.350 (5.11 至 8.89) ±0.008 (0.20)
EXTRUDED STRIP GASKETS
挤制衬垫条
inch (mm) 英寸 (mm) Tolerance 公差
Cut Length 切割长度
<1.000 (25.40) ±0.020 (0.51)
1.0 to 30.000 (25.40 to 762)
1.0 至 30.000 (25.40 至 762) ±0.062 (1.58)
> 30.000 (762) ±0.20% Nom. Dim.
±0.20% 公称尺寸
Cross Section 横截面
< 0.200 (5.08) ±0.005 (0.13)
0.200-0.349 (5.08-8.86) ±0.008 (0.20)
0.350-0.500 (8.89-12.70) ±0.010 (0.25)
>0.500 (12.70) ±3% Nom. Dim.
±3% 公称尺寸
Gasket Mounting Choices
垫片安装选择
Our various EMI gasket mounting techniques offer designers cost-effective choices in both materials and assembly. These options offer aesthetic choices and accommodate packaging requirements such as tight spaces, weight limits, housing materials and assembly costs. Most XXXX gaskets attach using easily repairable systems. Our Applications Engineering Department or your local XXXX representative can provide full details on EMI gasket mounting. The most common systems are shown here with the available shielding products.
我们的各种抗电磁干扰垫片安装技术在材料和部件两方面为设计者提供了高成本效益的选择。这些选项提供了美学选择，并适应诸如密闭空间、重量极限、外壳材料和部件成本等包装要求。大多数 XXXX 垫片安装使用容易维修的系统。我们的应用工程部或您当地的 XXXX 代表可以为抗电磁干扰垫片安装提供完全详细的资料。此处表示了最常用系统及可用屏蔽产品。 |
