M352395 八、新型說明： 【新型所屬之技術領域】 本新型是有關於一種螺旋槳，特別是指一種用於產生 推進力的模型飛機專用螺旋槳。 【先前技術】M352395 VIII. New description: [New technical field] The present invention relates to a propeller, in particular to a propeller for a model aircraft for generating propulsion. [Prior Art]
Λ >閱圖1以般的模型飛機1的螺旋槳2為例，主要 包含一中心部21，及由該中心部21朝相反方向相對延伸的 二紫葉22。該等柴葉22分別具有鄰接該中心部21的一柴 根221、反向於該槳根221的一槳失222，及形成在二面且 曲率不同的一前槳面223與一後漿面224。 田5玄等槳葉22旋轉時，氣流會因為該前槳面223與該 後槳面224的曲率不一樣，對曲率大的前槳^ 223形成較 小的壓力’對曲率小的的後槳面224形成較大的壓力，此 一壓力差’會產生向前拉動該等槳葉22的空氣動力，成為 牵拉飛機1向前飛行的動力之一。 a式N辕~ ργ(Ν紫·螺旋槳的有效功率，p :螺旋 禁的拉力’V:飛行速度）可知，螺旋槳2的有效功率盘拉 力成正比，再由公式T=ct p n2D4(ci :拉力係數，Cp:功率 係數’ p .空氣密度’ n :螺旋槳轉速，D ••螺旋槳直經）可 知，螺旋槳2的拉力又與轉速2成正比，也就是說，螺旋紫 2的轉速愈快，拉力就愈大。 惟，由於該等樂f 22是作圓週運動，因此，該樂尖 ⑵的轉速遠大於該紫根221的轉速，所以，愈靠近該心 222的部位，會産生愈大的拉力，造成該槳葉u彎曲，使 5 M352395 整個紫葉22的前槳面223形成了前傾的錐形，而於該槳尖 222部位出現波阻’導致旋轉效率急劇下降。 【新型内容】 因此’本新型之目的，即在提供一種能提高旋轉效率 的模型飛機專用螺旋槳。 於疋本新型模型飛機專用.螺旋槳，包含一中心部， 及至少二槳葉。該等槳葉是分別由該中心部朝相反方向相 對延伸，並具有形成在一端且鄰接該中心部的一槳根，及 形成在另一端且朝迎向氣流方向上揚的一槳尖。 本新型的功效是能以該上揚的槳尖縮小迎角，減緩與 該紫根受氣流影響的拉力差，維持螺旋槳旋動時的穩定性 及旋轉效率。 【實施方式】 有關本新型之前述及其他技術内容、特點與功效，在Λ > Referring to Figure 1 , the propeller 2 of the model aircraft 1 is exemplified, and mainly includes a center portion 21 and two purple leaves 22 extending in opposite directions from the center portion 21. The firewood blades 22 respectively have a wood root 221 adjacent to the central portion 21, a paddle 222 opposite to the blade root 221, and a front paddle surface 223 and a rear slurry surface formed on two sides and having different curvatures. 224. When the blade 22 of the field 5 is rotated, the airflow is different because the curvature of the front paddle surface 223 and the rear paddle surface 224 is different, and the front paddle 223 having a large curvature forms a small pressure. The face 224 creates a relatively large pressure which creates an aerodynamic force that pulls the blades 22 forward, becoming one of the driving forces for the aircraft 1 to fly forward. a formula N辕~ ργ (Ν紫·propeller effective power, p: spiral prohibited pull force 'V: flight speed) It can be seen that the effective power of the propeller 2 is proportional to the pulling force, and then by the formula T=ct p n2D4 (ci : Pulling force coefficient, Cp: power coefficient 'p. Air density 'n: propeller speed, D••propeller straight through) It can be seen that the pulling force of the propeller 2 is proportional to the rotational speed 2, that is, the faster the spiral purple 2 rotates, The greater the pull. However, since the music f 22 is a circular motion, the rotational speed of the music tip (2) is much larger than the rotational speed of the purple root 221, so that the closer to the portion of the core 222, the greater the pulling force is generated, resulting in the blade. u is bent so that the front paddle surface 223 of the entire Mickey blade 22 of 5 M352395 forms a forwardly inclined cone, and the occurrence of a wave resistance at the tip of the blade tip 222 causes a sharp drop in the rotational efficiency. [New content] Therefore, the purpose of the present invention is to provide a propeller for a model aircraft capable of improving the rotational efficiency. The propeller of the new model aircraft of the present invention includes a center portion and at least two blades. The blades extend from the center portion in opposite directions, respectively, and have a paddle formed at one end and adjacent to the center portion, and a paddle tip formed at the other end and rising toward the direction of the airflow. The utility model has the advantages that the angle of attack can be narrowed by the rising tip, the tension difference with the purple root affected by the airflow is reduced, and the stability and the rotation efficiency of the propeller are maintained. [Embodiment] The foregoing and other technical contents, features and effects of the present invention are
以下配合參考圖式之一較佳實施例的詳細說明中，將可清 楚的呈現。 圖2圖3，及圖4，本新型模型飛機專用螺孩 的一較佳貫施例包含一中心部3，及二槳葉4。 該中心部3具有環繞一轴線的一外周面3丄。 该等槳葉4是分別由該中心部3外周面3 1朝相反方 相對延伸’並具有形成在-端且鄰接該中心部3的-槳 41、形成在另一端且朝迎向氣流方向上揚的一槳尖π、 成在一面且迎向氣流的—前槳面43,及形成在另一面且 向於該則紫面4 3的-健將JEL Λ Λ u* ,- 97後槳面44。該槳尖42與依循該後 M352395 面44延伸的一水平線X形成有不大於15度的一夹角0J， 使該槳尖42因為上揚的夹角Θ1而縮小迎向氣流的一迎角 Θ2，並具有朝向該中心部3的一低點421，及與該中心部 3相反方向的-高點422。該低點421到該高點422的距離 L1是與該槳葉4的長度L2呈正比。In the following detailed description of a preferred embodiment of the drawings, reference will be made. 2, and 4, a preferred embodiment of the present model aircraft special screw child includes a center portion 3 and two blades 4. The center portion 3 has an outer peripheral surface 3丄 around an axis. The blades 4 are respectively extended from the outer peripheral surface 31 of the center portion 3 toward the opposite side and have a paddle 41 formed at the end and adjacent to the center portion 3, formed at the other end and rising toward the direction of the airflow. A paddle tip π, a front paddle surface 43 that is on one side and converges toward the airflow, and a JEL Λ Λ u*, - 97 rear paddle surface 44 formed on the other side and toward the purple face 43. The blade tip 42 forms an angle 0J of not more than 15 degrees with a horizontal line X extending along the rear face M352395, so that the tip 42 is narrowed toward an angle of attack 迎2 toward the airflow due to the angle Θ1 of the rising. And has a low point 421 toward the center portion 3, and a - high point 422 opposite to the center portion 3. The distance L1 from the low point 421 to the high point 422 is proportional to the length L2 of the paddle 4.
就實務而言，設計螺旋槳時，爲了保證旋轉拉力面的 平衡，一般都會增大槳根41的迎角和面積，而獲得較大的 拉力較J的阻力矩，也就是效率較高。惟，擴增該紫根 41的迎角和面積’就會加大該等紫葉4，因此，本新型是 在不影響該槳根41迎角及面積原設計的情形下，使該槳尖 42形成有上揚的夾角01，而縮小該槳尖42的迎角θ2,藉 此，減緩該樂尖42與該槳根41受氣流影響的拉力差 免δ亥專槳葉4有彎曲的情形。 據上所述可知，本新型之模型飛機專用螺旋槳具有下 列優點及功效： -本新型是藉由該上揚的㈣42縮小迎角02,減緩與 該木，41 $氣流影響的拉力差，不但能維持螺㈣旋動時 的穩定性，且能降低波阻，提昇旋轉效率。 &准Χ上所述者，僅為本新型之較佳實施例而已，當不 能以此限定本新型實施之範圍，即大凡依本新型中請:利 I:圍及新型說明内容所作之簡單的等效變化與修飾，皆仍 屬本新型專利涵蓋之範圍内。 7 M352395 【圖式簡單說明】 圖1是一立體圖，說明一般模型飛機； 圖2是一立體圖，說明本新型一模型飛機專用螺旋槳 的一較佳實施例； 圖3是該較佳實施例的一側視圖；及 圖4是該較佳實施例的一剖視圖。 M352395 【主要元件符號說明】 3 ·· 31· 4 ·· 41 · 42· 421 中心部 422 ··.. 问點 外周面 43…… …·韵槳面 槳葉 44…… •…後槳面 槳根 Θ 1 ··· •…夾角 槳尖 Θ 2 ··· •…迎角 低點As far as practice is concerned, when designing the propeller, in order to ensure the balance of the rotating tension surface, the angle of attack and the area of the blade root 41 are generally increased, and a larger pulling force is obtained than the resistance torque of J, that is, the efficiency is high. However, amplifying the angle of attack and the area of the purple root 41 will increase the purple leaves 4, and therefore, the present invention makes the tip 42 without affecting the original design of the angle of attack and the area of the blade root 41. An angle 01 with an upward angle is formed, and an angle of attack θ2 of the tip 42 is reduced, whereby the difference in tension between the tip 42 and the blade root 41 by the airflow is reduced to avoid bending of the blade 4. According to the above description, the propeller of the model airplane of the present invention has the following advantages and effects: - The novel is to reduce the angle of attack 02 by the upward (four) 42 to slow down the tension difference with the wood, 41 $ airflow, not only can maintain Spiral (four) stability when rotating, and can reduce the wave resistance and improve the rotation efficiency. The above description is only the preferred embodiment of the present invention, and it is not possible to limit the scope of the novel implementation, that is, the simpleness of the present invention: the benefit of the I: and the new description The equivalent changes and modifications are still within the scope of this new patent. 7 M352395 [Simplified illustration of the drawings] Fig. 1 is a perspective view showing a general model airplane; Fig. 2 is a perspective view showing a preferred embodiment of a propeller for a model aircraft of the present invention; Fig. 3 is a view of the preferred embodiment of the present invention; Side view; and Figure 4 is a cross-sectional view of the preferred embodiment. M352395 [Explanation of main component symbols] 3 ·· 31· 4 ·· 41 · 42· 421 Center part 422 ··.. Ask the outer peripheral surface 43... ...· rhyme paddle blade 44... •... rear paddle paddle Root Θ 1 ··· •... angled tip Θ 2 ··· •... low angle of attack