本研究主題一使用硬度 Shore A 20°、40°、60°、80°之防水圈,透過自行設計可調整壓縮量測漏治具,將不同硬度及壓縮量防水圈投入 IP67 浸水治具測試,研究顯示當壓縮量≥10%即已達 IP67 防護功能。
第二個主題為利用水的表面張力與漏孔斷面壓力平衡就不會從很小漏孔中洩漏的關係方程式,計算出水下 1m 時水無法通過的最小孔徑為 0.0288 mm,再換算空氣通過該孔的流率而得到在水無洩漏下的空氣允許洩漏值為75.2 Pa。接著利用氣密測試機與浸水治具,驗證不同金屬線徑壓附在防水圈上所造成的空氣漏率,在水下 1m 發生滲漏進水的關係。研究結果顯示氣密洩漏值 61.8 KPa 即發生滲水,並與理論計算結果有 13.4 Pa 異。;The purpose of this thesis includes two main themes. The first purpose aims to study the effect of sealing O-rings used on automotive cameras with different hardness and compression levels on the protection functionality of IP67. The second theme focuses on calculating the permissible air leakage for automotive camera modules that the ingress of water won’t occur when submerged 1 meter underwater and verifying the relationship between different air leakage and ingress of water at 1 meter underwater using an air leakage testing machine and a water tank jig.
This first theme utilized waterproof seals with Shore A hardness of 20°, 40°, 60°, and 80°. Via a self-designed adjustable compression and air leakage testing jig, waterproof seals of different hardness and compression levels were tested by IP67 water tank jig. The research results indicate that when the compression level is ≥10%, it already achieves IP67 protection functionality.
The second theme utilizes of the equation that water won’t leak from very small pinholes while the surface tension of water and the pressure on the cross-section of the leak hole are balanced. The experimental results revealed that the minimum hole diameter through which water cannot pass at 1 meter underwater is 0.0288 mm. Calculating the airflow through the hole enabled us to obtain the air leakage rate without water intrusion 75.2Pa. Next, an air leakage testing machine and a water tank jig were applied to verify the relationship between the air leakage rate and the ingress of water at 1 meter underwater by placing metal wires of different diameters onto the waterproof seals. The research results show that water infiltration occurs when the air leakage rate reaches 61.8 kPa, which differs by 13.4 Pa from the theoretical calculation result.