步履式長螺(luo)旋(xuan)鉆機(ji)適用(yong)于灌(guan)注(zhu)樁(zhuang)、擠擴(kuo)樁(zhuang)、軟(ruan)地基(ji)處理(li)等各種基(ji)礎(chu)工(gong)程，廣泛(fan)應用(yong)于城建、能源等中(zhong)高(gao)(gao)層及橋梁基(ji)礎(chu)設施方面，隨著(zhu)目(mu)(mu)前工(gong)業、民用(yong)建筑施工(gong)建設中(zhong)要求工(gong)期短(duan)(duan)、成孔(kong)效(xiao)(xiao)率高(gao)(gao)，特別是(shi)當(dang)下效(xiao)(xiao)率快(kuai)節(jie)奏(zou)背景下，原有(you)的(de)長螺(luo)旋(xuan)鉆機(ji)短(duan)(duan)板凸顯一覽(lan)無余：動力頭(tou)輸出扭矩小；樁(zhuang)的(de)深度(du)不夠；目(mu)(mu)前施工(gong)中(zhong)要求樁(zhuang)的(de)深度(du)超過30米，成孔(kong)直徑(jing)達到800mm。

長螺旋動力頭電氣系統起動方式采用自耦變壓器降壓起動，控制方式為傳統的接觸器-繼電器控制形式，這種起動方式的特點是結構簡單、維護方便，電氣造價低。缺點是起動時電動機軸輸出的扭矩小，切換方式采用時間繼電器控制，切換瞬間沖擊電流達到額定電流的3-4倍，對電網沖擊大，導致系統電壓下降，造成工地上其他施工機器無法正常運轉，嚴重時會燒毀現場電源變壓器。氣動架柱式鉆機

原理(li)簡(jian)述：動(dong)(dong)力頭(tou)正(zheng)轉(zhuan)(zhuan)(zhuan)用接(jie)觸(chu)(chu)(chu)器(qi)(qi)(qi)KM10控制，反轉(zhuan)(zhuan)(zhuan)用KM11控制，三位旋鈕選擇正(zheng)轉(zhuan)(zhuan)(zhuan)或反轉(zhuan)(zhuan)(zhuan)情況下，KM10或KM11線(xian)圈(quan)吸合，自耦變壓(ya)器(qi)(qi)(qi)“星點”接(jie)觸(chu)(chu)(chu)器(qi)(qi)(qi)KM3可靠動(dong)(dong)作后，自耦變壓(ya)器(qi)(qi)(qi)電(dian)壓(ya)輸入端接(jie)觸(chu)(chu)(chu)器(qi)(qi)(qi)KM2動(dong)(dong)作，同(tong)時起動(dong)(dong)延時繼電(dian)器(qi)(qi)(qi)，當電(dian)機轉(zhuan)(zhuan)(zhuan)速達(da)到一定值(zhi)時，延時繼電(dian)器(qi)(qi)(qi)動(dong)(dong)作，延時觸(chu)(chu)(chu)點起動(dong)(dong)中間繼電(dian)器(qi)(qi)(qi)KA，中間繼電(dian)器(qi)(qi)(qi)KA動(dong)(dong)作并自保(bao)持，同(tong)時切(qie)斷(duan)自耦變壓(ya)器(qi)(qi)(qi)起動(dong)(dong)回路，起動(dong)(dong)旁路接(jie)觸(chu)(chu)(chu)器(qi)(qi)(qi)KM3，完成了(le)一次起動(dong)(dong)過程(cheng)。電(dian)氣主回路圖及控制原理(li)圖。

為防止運行過(guo)程中出現過(guo)載，采用熱繼電(dian)(dian)(dian)器KH作過(guo)載保(bao)護(hu)，熱繼電(dian)(dian)(dian)器的整(zheng)(zheng)定(ding)值根(gen)據(ju)電(dian)(dian)(dian)流互(hu)感器的變比及動力頭電(dian)(dian)(dian)機額定(ding)電(dian)(dian)(dian)流來計算整(zheng)(zheng)定(ding)值，時間繼電(dian)(dian)(dian)器整(zheng)(zheng)定(ding)值按自耦變壓器要求進(jin)行整(zheng)(zheng)定(ding)。僅供參考。