离心调节器是怎样改变点火提前角的？
参考答案：
离心式点火提前装置是根据发动机转速的变化自动调节点火提前角的，由一端固定在分电器小轴上的两个离心块和两根粗细不等的弹簧等组成，其基本原理是通过离心力的变化自动调节点火提前角，具体的工作原理如下：
当发动机的转速升高时，分电器的转速随之升高，两重块在离心力作用下，克服弹簧外力向外甩开，同时带动拨板和凸轮沿凸轮旋转的方向相对于分电器轴转动一个角度，点火提前角增大。转速越高，离心块离心力越大，点火提前角越大。
当转速降低时，弹簧将重块拉回，凸轮逆旋转方向回转，点火提前角减小。
为了使点火提前角的变化基本适应发动机的要求，离心调节器中的两个弹簧的弹力是不同的，低速时，只有弹力小的弹簧起作用，提前角的增加幅度较大；高速时，两个弹簧共同起作用，提前角增加的幅度较小。当转速达到一定值时，点火提前角不再增加。
Evelyn Glennie was the first lady of solo percussion in Scotland. In an interview, she talked about how she became a percussion soloist（打击乐器独奏演员）in spite of deafness. “Early on I decided not to allow the 1 of others to stop me from becoming a musician. I grew up on a farm in northeast Scotland and began 2 piano lessons when I was eight. The older I got, the more my passion（酷爱）for music grew. But I also began to lose my 3 . Doctors told me that the nerve damage(神经损伤) was the 4 and by age twelve, I was completely deaf. But my love for music never left me.” “My 5 was to become a percussion soloist, even though there were none at that time. To perform, I learned to ‘hear’ music differently from others. I play in my stocking feet and can 6 the pitch of a note（音调高低）by the vibrations（振动）I feel through my body and through my imagination. My sound world exists by making use of almost every 7 that I have.” “I decided to be a musician even though I was deaf, and applied to the famous Royal Academy of Music in London. No other deaf student had 8 this before and some teachers disagreed with me. Because of my performance, I finally entered the academy and went on to 9 with the academy’s highest honors a few years later.” “I’ve been a soloist for more than ten years. 10 the doctor thought I was totally deaf, it didn’t mean that my passion couldn’t be realized. I would encourage people not to allow themselves to be limited by others. Follow your passion; follow your heart. They will lead you to the place you want to go.”
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