交流變頻調(diào)壓調(diào)速乘客電梯設(shè)計(jì)
交流變頻調(diào)壓調(diào)速乘客電梯設(shè)計(jì),交流變頻調(diào)壓調(diào)速乘客電梯設(shè)計(jì),交流,交換,變頻,調(diào)壓,調(diào)速,乘客電梯,設(shè)計(jì)
鑒定文件之十
TKJ2000/1.0-JXW(VVVF)
交流變頻調(diào)壓調(diào)速乘客電梯
產(chǎn)品設(shè)計(jì)計(jì)算書(shū)
南海市奧特電梯有限公司
二00三年六月
17
目 錄
1、 計(jì)算說(shuō)明
2、 主要技術(shù)性能參數(shù)
3、 傳動(dòng)系統(tǒng)計(jì)算
3.1參數(shù)
3.2電動(dòng)機(jī)功率計(jì)算及選用曳引機(jī)
3.3驗(yàn)算電梯額定運(yùn)行速度
3.4曳引條件計(jì)算
3.5繩槽比壓驗(yàn)算
3.6鋼絲繩安全系數(shù)驗(yàn)算
4、 結(jié)構(gòu)計(jì)算
4.1轎廂架計(jì)算
4.1.1參數(shù)及材料幾何特性
4.1.2轎廂架上梁計(jì)算
4.1.3下梁計(jì)算
4.1.4立梁計(jì)算
4.1.5轎廂架聯(lián)接螺栓強(qiáng)度校核
4.2承重梁計(jì)算
4.2.1承重梁支反力計(jì)算
4.2.2承重梁應(yīng)力計(jì)算
4.2.3承重梁撓度計(jì)算
4.3導(dǎo)軌彎曲應(yīng)力計(jì)算
5、 安全部件驗(yàn)算
5.1限速器驗(yàn)算
5.1.1動(dòng)作速度校核
5.1.2限速器繩的張緊力驗(yàn)算
5.2安全鉗驗(yàn)算
5.3緩沖器驗(yàn)算
6、 電氣計(jì)算說(shuō)明
6.1調(diào)速系統(tǒng)計(jì)算
6.2控制系統(tǒng)計(jì)算
7、 參考資料
產(chǎn)品設(shè)計(jì)計(jì)算書(shū)
1、 計(jì)算說(shuō)明
TKJ1000/1.6-JXW(VVVF)型交流變頻調(diào)壓調(diào)速乘客電梯設(shè)計(jì)依據(jù)為GB7588-1995《電梯制造與安裝安全規(guī)范》和GB/T10058-1997《電梯技術(shù)條件》。根據(jù)GB/T7025.1-1997電梯主參數(shù)及轎廂、井道、機(jī)房的形式與尺寸進(jìn)行規(guī)范設(shè)計(jì)。
2、 主要技術(shù)性能參數(shù)
額定載荷：Q=2000kg
額定速度：V=1.0m/s
平衡系數(shù)：取0.45
提升高度：H=70m(20層)
轎廂總質(zhì)量:G=1800kg
對(duì)重總質(zhì)量:W3=2700kg
平衡鏈質(zhì)量:W1=220kg(3kg/m)
電纜重量:W2=80kg
鋼絲繩規(guī)格:GB8903-88 8×19S+NF Φ13×5(根)
3、 傳動(dòng)系統(tǒng)驗(yàn)算
3.1參數(shù)
電梯起動(dòng)加速度和制動(dòng)減速度:a≤0.9 m/s2
曳引傳動(dòng)總效率:η=0.55
鋼絲繩與繩輪間摩擦系數(shù):μ=0.09
鋼絲繩許用安全系數(shù):[S]=12
鋼絲繩總重量:W4=230kg
3.2電動(dòng)機(jī)功率計(jì)算及選用曳引機(jī)
(1-φ).Q.V (1-0.45)×2000×1.0
P= = =19.6KW
102.η 102×0.55
選用佛山南洋電梯機(jī)械廠生產(chǎn)型號(hào)為YJVF10型VVVF電梯曳引機(jī),有關(guān)技術(shù)參數(shù)如下:
電動(dòng)機(jī)功率:P=22kW
電動(dòng)機(jī)轉(zhuǎn)速:ne=1450r/min
曳引機(jī)傳動(dòng)比:i=49:2
曳引輪節(jié)圓直徑:D=660mm
導(dǎo)向輪直徑:DR=520mm
曳引比：m= 2：1
曳引包角:a=180°(按機(jī)房實(shí)際計(jì)算)
曳引輪槽型為切口槽:角度β=95°
曳引鋼絲繩根數(shù):n=5
曳引鋼絲繩直徑:d=13mm
3.3驗(yàn)算電梯額定運(yùn)行速度V.
nπD 1450×π×0.66×2
V= = =1.02m/s
60im 60×49×2
1.02-1.0
×100%=102%
1.0
根據(jù)GB10058-1997《電梯技術(shù)條件》第3.3.1條款運(yùn)行速度不得大于額定速度的105%且不得小于額定速度的92%，結(jié)論:滿(mǎn)足要求.
3.4曳引條件計(jì)算
曳引系統(tǒng)簡(jiǎn)圖如(圖一),曳引條件應(yīng)滿(mǎn)足下列條件:
(1)
式中-在載有125%額定載荷的轎廂位于最低站時(shí)及空載轎廂位于最高層站的情況下,曳引輪兩邊曳引繩中的較大靜拉力與較小靜拉力之比。
(2)
按GB7588標(biāo)準(zhǔn)中C1的最小允許值(V為額定速度):
1. 00m/s40
代入:D/d=660/13=50.8>40
符合標(biāo)準(zhǔn)要求。
3.6.2 曳引鋼絲繩選型
根據(jù)曳引輪的要求應(yīng)配5×φ13鋼絲繩 按GB8903-88鋼絲繩國(guó)標(biāo)的要求選用型號(hào)為: 8×19S+NF-13-1500(雙)右交-GB8903-88
按GB8903-88查表可知: 單根鋼絲繩最小破斷拉力:SK=74.3KN
3.6.3 鋼絲繩安全系數(shù)驗(yàn)算
按GB7588中9.2.2要求懸掛繩的安全系數(shù)在三根以上鋼絲繩的曳引驅(qū)動(dòng)電梯為[S]=12
即:
式中:T—鋼絲繩最大靜拉力T=(G+Q+W4)/2= (18+20+2.3)/2=20.2kN
n—鋼絲繩根數(shù).n=5
SK—鋼絲繩最小破斷拉力
∴ (結(jié)論:安全)
按GB7588規(guī)定、鋼絲繩其端接裝置的接合處至少應(yīng)能承受鋼絲繩最小破斷負(fù)荷的80%，（即59.44kN）查型式試驗(yàn)報(bào)告該繩頭組合承受的拉力為84.5kN,符合要求。
4、結(jié)構(gòu)計(jì)算
4.1轎廂架計(jì)算
4.1.1參數(shù)及材料幾何特性
額定載重量:Q=2000kg
轎廂質(zhì)量:G=1800kg
電纜重量+平衡鏈重量:Q1=80+220=300kg
P=（Q+G+Q1）/2=（2000+1800+300）÷2=2050 kg=20.5 kN
轎廂寬度:B=2000
上、下梁跨度：L0=2100
立梁自由彎S曲長(zhǎng)度：L=3050
上、下導(dǎo)靴間的垂直距離：H=3700
材料彈性模量：E=2.00×1011Pa=2.00×105 N/mm2
許用應(yīng)力:[σ]=94MPa
許用撓度:[f]=
上梁慣性矩: Ix =2×9.35×10-6=1.87×10-5m4
下梁慣性矩:Ix=0.575×10-5m4
立梁慣性矩:Iy=8.39×10-7m4(單根)
上梁抗彎模量:Wx=2×1.17×10-4=2.34×10-4m3
下梁抗彎模量:Wx=0.81×10-4m3
立梁抗彎模量:Wy=1.57×10-5m3
立梁載面面積:A0=1.97×10-3m2
4.1.2轎廂架上梁計(jì)算
各梁幾何尺寸如(圖二),有關(guān)參數(shù)如下:
上梁受力簡(jiǎn)圖如(圖三),
a.上梁最大彎矩
b.上梁最大應(yīng)力:(結(jié)論:安全)
c.上梁最大撓度:
Ymax=
=
=0.96mm ＜[Y]=2.19mm （結(jié)論：安全）
4.1.3下梁計(jì)算
下梁受力簡(jiǎn)圖如(圖四)
a. 下梁計(jì)算:
(均布作用下梁,Q1為集中載荷作用于下梁中部)
最大彎矩:
b. 最大應(yīng)力:(結(jié)論:安全)
c. 最大撓度:
結(jié)論:安全
4.1.4立梁計(jì)算
強(qiáng)度校核
結(jié)論:安全
4.1.5轎廂架聯(lián)接螺栓強(qiáng)度校核
螺栓規(guī)格M16×35 GB5783-86查手冊(cè)M16的公稱(chēng)應(yīng)力面積F=157mm2，性能等級(jí)為8.8級(jí)。材料:σs=640Mpa。
n1—安全系數(shù),查GB3811-83表14,nl=1.5
∴[σ]= 640 =426.7MPa
1.5
按安全鉗制停和轎廂急停工況校核上梁與立梁、下梁與立梁聯(lián)接螺栓，制動(dòng)力F制取2P。
式中:Qp — 螺栓預(yù)緊力
K — 動(dòng)載系數(shù)，K=1.2
m — 螺栓個(gè)數(shù)，m=16
μ— 摩擦系數(shù)，μ=0.3
∴
螺栓最大應(yīng)力計(jì)算：
σmax = 1.3 Qρ = 1.3 ×13500
F 157
=111.8MPa＜[σ]=426.7MPa
結(jié)論：安全
4.2承重梁計(jì)算
承重梁結(jié)構(gòu)簡(jiǎn)圖如(圖五)
4.2.1承重梁支反力計(jì)算
式中:Q—載重量：Q=1000kg
G—轎廂重：G=1400kg
W1—平衡鏈重量：W1=220kg
W2—電纜重：W2=80kg
G1—曳引機(jī)和承重梁自重
G1=1850kg
W4—鋼絲繩重量：W4=230kg
∴
式中：W3—平衡重重量
W3=18.5kN
∴P2=18.5+1/3×18.5+2. 3=26.96
∑Y=0 得
P1+P2=R1+R2
得 R1=P1+P2-R2=41.63+26.96-R2=68.59-R2
∑MA=0 得
R2×2.5=P1×1.288+P2×1.746
R1=68.59-40.28=28.31kN
4.2.2承重梁應(yīng)力校核:
a. I22a抗彎模量:
WX=309cm3
b. Mmax=R1×a
最大應(yīng)力 (結(jié)論:安全)
4.2.3承重梁撓度計(jì)算
承重梁采用兩根I22a工字鋼支承、工字鋼撓度應(yīng)滿(mǎn)足下式:
其中:a=1.288m、b=0.458m、C=0.754m、=2.5m、P1=41.63kN、P2=26.96kN
IX—承重梁慣性矩I22a=3.4×10-5m4
E—彈性模量：E=2.1×105MPa
當(dāng)Z=a時(shí)
=0.001402m=1.402mm<[f]=2.6mm(結(jié)論:安全)
4.3導(dǎo)軌彎曲應(yīng)力計(jì)算
根據(jù)GB7588《電梯制造與安裝安全規(guī)范》要求，安全鉗裝置動(dòng)作時(shí)、導(dǎo)軌彎曲應(yīng)力σk可按下列公式近似計(jì)算。
對(duì)漸進(jìn)式安全鉗裝置：
式中：σk —對(duì)抗拉強(qiáng)度為370MPa的導(dǎo)軌鋼材取σk ≤140MPa。
P—空載轎廂的質(zhì)量和補(bǔ)償鏈、電纜等的總和，P=1400+300=1700kg。
Q—額定載重量，Q=1000kg。
A—導(dǎo)軌載面積、導(dǎo)軌選用T89/B軌時(shí)，A=1570mm2
ω—彎曲系數(shù)，查GB7588表4，ω=1.92
λ—細(xì)長(zhǎng)比，λ=
Lk—導(dǎo)軌支架的最大距離，Lk=2000mm。
ｉ—導(dǎo)軌回轉(zhuǎn)半徑，T89/B軌，ｉ=19.8mm。
∴ （結(jié)論：安全）
5、安全部件選型驗(yàn)算
5.1限速器
根據(jù)GB7588-1995的要求選用適合本公司產(chǎn)品TKJ1000/1.6-JXW(VVVF)乘客電梯的限速器。
寧波歐達(dá)電梯配件廠生產(chǎn)的型號(hào)PB73.3限速器及張緊裝置經(jīng)檢測(cè)中心檢測(cè),具有鉛封調(diào)整。其性能是：
a. 限速器動(dòng)作速度：2.0m/s。
b. 限速器鉗口夾緊時(shí)鋼絲繩在繩輪中的最大附著力1303N，安全鉗提拉力不大于651N。
c. 限速器裝有符合（GB7588中14.1.2）“在安全鉗裝置動(dòng)作前使電動(dòng)機(jī)停轉(zhuǎn)的電氣安全裝置?！?
5.1.1動(dòng)作速度校核
根據(jù)GB7588第9.9.1條要求,限速器的動(dòng)作應(yīng)發(fā)生在速度至少等于額定速度的115%但應(yīng)小于;現(xiàn)在選用的限速器動(dòng)作速度為2.0m/s。是額定速度的125%而又小于2.16m/s，因此該限速器的動(dòng)作速度符合標(biāo)準(zhǔn)規(guī)范要求。
5.1.2限速器繩的張緊力驗(yàn)算
限速器動(dòng)作時(shí)限速器繩的張緊力不得小于300N和安全鉗裝置起作用所需力的兩倍（GB7588中9.9.4）?，F(xiàn)在選用的限速器最大附著力為1303N,所以該限速器張緊力符合標(biāo)準(zhǔn)規(guī)范要求。
綜合以上校核該限速器符合GB7588《電梯制造與安裝安全規(guī)范》的要求。
結(jié)論：寧波歐達(dá)電梯配件廠生產(chǎn)型號(hào)為PB73.3的額定速度為1.6m/s的限速器可用為本公司乘客電梯的配套部件。
5.2安全鉗驗(yàn)算
本梯選用廣東南海華輝電梯設(shè)備廠生產(chǎn)的QJ102型的漸進(jìn)式安全鉗,其性能是:
(1) 適用于電梯的額定速度:1.6m/s;
(2) 配限速器的最大動(dòng)作速度:2.16m/S;
(3) 適用電梯的額定載重量:1000kg;
(4) 適用電梯的最大總質(zhì)量:P+Q=2500kg
本梯的額定速度是1.6m/s,根據(jù)GB7588第9.8.4條,選用漸進(jìn)式安全鉗是合適的。而本梯的總質(zhì)量P+Q=2400kg，小于該安全鉗的最大總質(zhì)量：P+Q=2500kg。
該安全鉗的減速度也符合GB7588第9.8.4條漸進(jìn)式安全鉗制動(dòng)時(shí)的平均減速度的要求.所以選用該廠生產(chǎn)的安全鉗是適合本公司TKJ1000/1.6-JXW(VVVF)乘客電梯的配套部件。
（技術(shù)參數(shù)來(lái)源于型式試驗(yàn)報(bào)告）
5.3緩沖器驗(yàn)算
本電梯選用廣東省南海市通力電梯配件廠生產(chǎn)的JKZ07型緩沖器其性能是:最大總質(zhì)量:P+Q=2500kg;最小總質(zhì)量780kg;
緩沖行程:175mm;
緩沖制停平均減速度:a≤1gn; a大于2.5gn的減速時(shí)間≤0.04s;
額定速度:1.6m/s
根據(jù)GB7588第10.4.3.1緩沖器總行程應(yīng)至小相應(yīng)于115%額定速度的制停距離:0.067V2=172mm<175mm(符合要求)。
允許質(zhì)量校核：
本電梯的轎廂總質(zhì)量為：P+Q=2400kg對(duì)重質(zhì)量為1850kg，而該緩沖器允許的最大總質(zhì)量范圍：780～2500kg，可見(jiàn)本電梯轎廂和對(duì)重端各用一個(gè)緩沖器是適合的。結(jié)論:廣東南海市通力電梯配件廠生產(chǎn)的液壓緩沖器可作為本公司TKJ1000/1.6-JXW(VVVF)乘客電梯的配套部件。
（參數(shù)資料來(lái)源于型式試驗(yàn)報(bào)告）
6、電氣系統(tǒng)計(jì)算分析
6.1調(diào)速系統(tǒng)計(jì)算:
6.1.1選用日本安川VS616G5型變頻調(diào)速器。主要性能和參數(shù)如下：
(1)輸入:三相交流電壓380V±10% 50HZ±5%
輸出:26KVA 34A 適用電機(jī)最大功率15KW。
(2)靜態(tài)特性：調(diào)速控制比 1:3600轉(zhuǎn)速精度±0.02%。
轉(zhuǎn)矩限幅50～200%電機(jī)額定扭矩,轉(zhuǎn)矩精度: ±5%。
零速最大轉(zhuǎn)矩200%電機(jī)額定轉(zhuǎn)矩。
頻率控制范圍0～375 HZ，頻率指令分辨率1/32 HZ。
(3)動(dòng)態(tài)性能：加速、減速0.05～3000 HZ/S。
起動(dòng)，零速最大轉(zhuǎn)矩200%電機(jī)額定轉(zhuǎn)矩
(4)控制方式：正弦波數(shù)字方式矢量控制內(nèi)置電梯曲線控制軟件。
(5)調(diào)速器保護(hù)功能:包括過(guò)電流、過(guò)電壓、欠電壓、過(guò)熱保護(hù)及故障顯示和報(bào)警。
(6)測(cè)速編碼器：48～2500每轉(zhuǎn)脈沖數(shù)，變頻器內(nèi)有PG-B2矢量控制方式專(zhuān)用卡及電源CD 12V供PG用。
6.1.2速度驗(yàn)算:
電機(jī)額定功率:P=15kW電機(jī)額定轉(zhuǎn)速:n=1450轉(zhuǎn)/每分鐘
電機(jī)額定電壓:V=380V
調(diào)速器輸出線電壓從0到380V連續(xù)變化,對(duì)應(yīng)電動(dòng)機(jī)轉(zhuǎn)速為0～1420轉(zhuǎn)/每分鐘,當(dāng)轉(zhuǎn)速n=1420時(shí),電梯運(yùn)行速度為1.54～1.6m/s。
6.1.3加減速度驗(yàn)算:
a. 起動(dòng)加速度:加速時(shí)間t=1.5s
初始速度V1=0 m/s,額定速度V2=1.6 m/s
加速度
初始頻率f1=0 額定頻率f2=50
b. 制動(dòng)減速度:減速時(shí)間t=1.8s
初始速度V1=1.6 m/s,V2=0 m/s
減速度
(結(jié)論:速度和加、減速度符合要求,在0.05～3000HZ/S之內(nèi)。)
6.2控制系統(tǒng)計(jì)算
6.2.1 PC機(jī)計(jì)算:
a. 選用三菱FX2N系列PC機(jī),其參數(shù)如下:
電源電壓:100～240V AC 50/60HZ
電力消耗:70VA(FX2N-80MR)
輸入繼電器:DC24V,7mA,光電隔離;點(diǎn)數(shù):128(帶擴(kuò)展)
輸出繼電器:250V AC,2A,點(diǎn)數(shù):128(帶擴(kuò)展)
輔助斷電器:500點(diǎn)
定時(shí)器:0.1～3276.7秒,200點(diǎn)
計(jì)數(shù)器:120點(diǎn),計(jì)數(shù)范圍1～32767
程序容量:2kW步RAM(標(biāo)準(zhǔn)配置)
指令數(shù):基本邏輯指令20條,步進(jìn)指令2條,功能指令85條。
b. 驗(yàn)算:
以20層站電梯為例,要求輸入點(diǎn)數(shù)為84點(diǎn),輸出點(diǎn)數(shù)為75點(diǎn),程序步數(shù)為2K步以下。
結(jié)論：該型PC機(jī)控制20層站以下電梯是合適的。
6.2.2接觸器計(jì)算:
a. 選用接觸器型號(hào)為:S-K50/220,其參數(shù)為
線圈電壓:220V 50HZ
主觸點(diǎn)額定電流:50A
額定電壓:220V,380V,660V,對(duì)應(yīng)的控制電機(jī)功率15KW、22KW、33KW。
主觸點(diǎn)數(shù)量:3對(duì)
輔助觸點(diǎn)數(shù)量:2常開(kāi)，2常閉。
b. 驗(yàn)算：
線路額定電壓Vex=380V，可控制22KW電動(dòng)機(jī)>15KW
公式:
Ve:電動(dòng)機(jī)額定線電壓（V）；
Iec:被選定的接觸器額定電流；
Pe:被控電動(dòng)機(jī)功率（kW）
Ic:接觸器主觸點(diǎn)電流
K：經(jīng)驗(yàn)常數(shù)，一般取1～1.4,現(xiàn)取1，代入公式：
Iec=50A>Ic (結(jié)論:可靠)
6.2.3繼電器計(jì)算:
中間繼電器觸點(diǎn)的最大負(fù)載情況為控制交流接觸器線圈的吸合和斷開(kāi)。
接觸器S-K50/220（CJX2-129）的起動(dòng)功率Srd=230（70）VA，吸持功率Sxc=32（10）VA，則接觸器觸點(diǎn)電流，在接觸器吸持情況下，
6.2.4開(kāi)、關(guān)門(mén)接觸器計(jì)算:
開(kāi)關(guān)門(mén)電機(jī)最大功率P1=123W,電阻消耗最大功率P2=200W
開(kāi)關(guān)門(mén)電流
選用接觸器型號(hào):CJX2-129
線圈電壓:AC220V
電流:12A
(結(jié)論:根據(jù)以上條件選用進(jìn)口三菱交流接觸器可滿(mǎn)足15KW的曳引電動(dòng)機(jī)的要求)
6.2.5變壓器計(jì)算:
變壓器所需容量(VA):Sb
控制電路最大負(fù)載所需功率(VA):∑Sxc
變壓器容量的儲(chǔ)備系數(shù):KB=1.1～1.25。
中間繼電器在起動(dòng)時(shí)所需總功率(VA): ∑Sjq,
同時(shí)吸合的中間繼電器數(shù)量:3個(gè),
吸持功率:12VA,
起動(dòng)功率:75VA,
門(mén)系統(tǒng)功率:323VA
制動(dòng)器消耗功率:120VA
PC機(jī)功率(包括一個(gè)擴(kuò)展):140VA
信號(hào)顯示功率:50VA
∑Sxc=12×3+323+120+140+50+32+2×10=721(VA)
∑Sjq=75×3+323+120+140+50+230+2×70=1228(VA)
公式(1):Sb1= KB∑Sxc=1.25×721=901.25(VA)
公式(2):Sb2=0.6∑Sxc+0.25∑Sjq+110
=0.6×721+0.25×1228+110
=849.6(VA)
≈850(VA)
所選用的電源變壓器型號(hào)為:TBK-1KVA
容量:1000VA
(結(jié)論:可靠)
6.2.6斷路器計(jì)算:公式:負(fù)載電流
a. QF4：接觸器功率230VA，和PLC140VA，V=220，
選用額定電流：3A
b. QF1、QF2:變壓器功率1kVA,變壓器1000VA/380V≈3A
選用額定電流:10A
c. QF3:排風(fēng)扇繼電器
選用額定電流:3A
d. QF5:顯示器指示燈
選用額定電流:3A
e. QF6:110V DC電源交流側(cè)
120+2×75+12+323=605（VA）
（A）
選用額定電流6A
f. QF10:低壓照明燈
選用額定電流:6A
g. QF7:門(mén)機(jī)直流電源側(cè)
選用額定電流:3A
h. QF8:交流接觸器230VA
選用額定電流3A
i. QF9:PLC輸入端每點(diǎn)7mA，如選用80點(diǎn)電流0.56A，選用額定電流1A。
QF1～QF10選用DZ47-63高分?jǐn)嘈⌒蛿嗦菲?
(結(jié)論:可靠)
6.2.7熱繼電器計(jì)算:
電機(jī)額定電流Ied1=32(A);
根據(jù)熱繼電器整定電流I1=32(A);
選用45A熱件其電流調(diào)節(jié)范圍28～45A;
JR16B-60/3型熱繼電器額定電流60A
(結(jié)論:可靠)
6.2.8導(dǎo)線截面積驗(yàn)算:
根據(jù)GB4706.1:電器額定電流≤6A,導(dǎo)線標(biāo)稱(chēng)截面積為0.75mm2;電器額定電流為38～52A時(shí),導(dǎo)線標(biāo)稱(chēng)截面積10mm2。
由以上計(jì)算可知:主回路額定電流I≈35A,
控制回路額定電流I≤6A。
選用主回路導(dǎo)線截面積:10mm2
選用控制回路導(dǎo)線截面積:1mm2
注:本節(jié)的導(dǎo)線均指長(zhǎng)度在50m以?xún)?nèi),長(zhǎng)度超過(guò)50m時(shí),導(dǎo)線截面積須乘以長(zhǎng)度系數(shù),其值為:實(shí)際長(zhǎng)度(m)/50。
6.2.9主電源開(kāi)關(guān)計(jì)算：
根據(jù)變頻的輸入電流為34A,起動(dòng)為軟起動(dòng),選用DZ20J-100(40A)型,自動(dòng)斷路器,選40A脫扣器電流符合變頻率器對(duì)外設(shè)斷路器的要求。
(結(jié)論:可靠)
6.2.10信號(hào)顯示說(shuō)明:
指令應(yīng)答燈、召喚應(yīng)答燈,方向指示燈均為24V,3W,層站顯示為七段數(shù)碼管顯示,經(jīng)檢驗(yàn)證明:信號(hào)顯示清晰、明亮。符合要求。
7、參考資料
7.1 GB7588《電梯制造與安裝安全規(guī)范》
7.2 GB/T10058《電梯技術(shù)條件》
7.3 GB/T7025《電梯主參數(shù)及轎廂、井道、機(jī)房的型式與尺寸》
7.4 GB10060《電梯安裝驗(yàn)收規(guī)范》
7.5 GB/T13435《電梯曳引機(jī)》
7.6 JG/T5072.1-1996《電梯T型導(dǎo)軌》
7.7 電梯機(jī)械設(shè)計(jì)原理與概念《中國(guó)建筑科學(xué)研究院機(jī)械化研究所》
7.8 機(jī)械工程手冊(cè)(第4篇)工程力學(xué)
7.9 交流調(diào)速電梯原理、設(shè)計(jì)及安裝維修《機(jī)械工業(yè)出版社》
7.10 機(jī)床電氣自動(dòng)控制《重慶大學(xué)出版社》
7.11 GB8903～8904《電梯用鋼絲繩》
7.12 GB2455《低壓接觸器》（電梯用部分）
7.13 GB3811-83《起重機(jī)設(shè)計(jì)規(guī)范》
南海市奧特電梯有限公司
2002年11月
黃河科技學(xué)院畢業(yè)設(shè)計(jì) 第 23 頁(yè)
畢業(yè)設(shè)計(jì)(論文)
文獻(xiàn)翻譯
院（系）名稱(chēng)
工學(xué)院機(jī)械系
專(zhuān)業(yè)名稱(chēng)
機(jī)械設(shè)計(jì)制造及其自動(dòng)化
學(xué)生姓名
赫栓柱
指導(dǎo)教師
李安生
2012年 03 月 10 日
ELEVATOR SAFETY: GIVE THE MINER A BRAKE
ABSTRACT
Over a five-year period, there were at least 18 documented cases of ascending elevators striking the overhead. In some cases, the accidents resulted in serious injuries or fatalities. These accidents occurred on counter weighted elevators as a result of electrical, mechanical, and structural failures. Elevator cars are fitted with safeties that grip the guide rails and stop a falling car; however, these devices do not provide protection in the upward direction.
Rules and regulations applying to elevator safety have come under review in response to these accidents. Some governing authorities have already revised their regulations to require ascending car over speed protection. This paper will discuss basic elevator design, hazards, regulations, and emergency braking systems designed to provide ascending car over speed protection. In addition, a case-study report on a pneumatic rope brake system installed and tested on a mine elevator will be discussed.
I NTRODUCT I ON
Elevators incorporate several safety features to prevent the car from crashing into the bottom of the shaft. Safeties installed on the car can prevent this type of accident from occurring when the machine brake fails or the wire ropes suspending the car break. However, the inherent design of the safeties render them inoperative in the ascending direction.
In the upward direction, the machine brake is required to stop the cage Rive an emergency condition occurs. Under normal operation, the machine brake serves only as a parking braked to hold the cage at rest. However, when an emergency condition is detected, modern elevator control system designs rely solely on the machine brake to stop the car.
In the United States mining industry, the accident history has proven that this is not the best control strategy [2], [3]. These accidents occurred when the retarding effort of the drive motor was defeated when the mechanical brakes were inoperative. This allowed the counterweight to fall to the bottom of the shaft, causing the car to over speed and strike the head frame. The high-speed elevator crashes into the overhead structure caused extensive mechanical damage and potentially fatal injuries.
ELEVATOR DES I GN
A basic understanding of elevator operation is required in order to assess the safety hazards present and determine the accident prevent methods available. Figure 1 shows a complete view of a mine elevator.
Fig.1 Mico Elevator
SUSPENSION riCPCS
In a typical elevator, the ear is raised and leered by six to eight motor–driven wire ropes that are attached to the top of the car at one end, travel around a pair of sheaves, and are again attached to a counterweight at the other end.
The counterweight adds accelerating force when the elevator car is ascending and provides a retarding effort when the car is descending so that less motor horsepower is required. The counterweight is a collection of metal weights that is equal to the weight of the car containing about 45% of its rated load. A set of chains are looped from the bottom of the counterweight to the underside of the car to help maintain balance by offsetting the weight of the suspension ropes
Guide rails that run the length of the shaft keep the car and counterweight from swaying or twisting during their travel. Rollers are attached to the car and the counterweight to provide smooth travel along the guide rails.
The traction to raise and lower the car comes from the friction of the wire ropes against the grooved sheaves. The main sheave is driven by an electric motor.
Motor-generator (M-G) sets typically pro-vide to dc power for the drive motor. Newer systems use a static drive control. The elevator controls vary the motor' s speed based on a set of feedback signals that indicate the car' s position in the shaft way. As the car approaches its destination, a switch near the landing signals the controls to stop the car at floor level. Additional shaft way limit switches are installed to monitor over travel conditions.
The worst fear of 'litany passengers is that the elevator will go out of control and fall through space until it smashes into the bottom of the shaft. There are several safety features in modern elevators to prevent this from occurring. The first is the high-strength wire ropes themselves. Each 0. 625-in-diameter extra-high-strength wire rope can support 32, 000 lb, or about twice the average weight of a mine elevator filled with 20 passengers. For safety' s sake and to reduce wear, each car has six to eight of these cables. In addition, elevators have buffers installed at the shaft bottom that can stop the car without killing its passengers if they are struck at the normal speed of the elevator
As previously discussed, modern elevators have several speed control features. If they do not work, the controls will disconnect the motor and apply the machine brake. Finally, the elevator itself is equipped with safeties mounted underneath the car. If the car surpasses the rated speed by 15 to 25%, the governor will trip, and the safeties will grip the guide rails and stop the car. This was the invention that made elevator transportation acceptable for the general public.
SAFETY HAZARDS
A historical perspective of elevator development can account for today' s problems with elevator safety rules and regulations [4]. In the beginning of modern elevator history, it was realized that although there were several factors of safety in the suspension rope design, the quality of construction and periodic inspection could not be assured. Therefore, the elevator car was equipped with reliable stand by 'safeties" that would stop the car safely if the suspension ropes failed. In 1853, Elisha. Otis, a New York mechanic, designed and demonstrated an instantaneous safety capable of safely stopping a free– falling car. This addressed the hazard shown in figure 2.
Later on, it was realized that passengers may be injured when the car over speeds in the down direction with suspension ropes intact, as shown in figure 3. To prevent this hazard, an over speed governor with gradually applied safeties was developed. It detected the over peeling condition and activated the safeties.
Furthermore, it was noticed that frequent application of safeties
caused mechanical stress on the elevator structure and safety system. Therefore, a governor over speed switch was installed that would try to stop the car by machine brake before the safeties activated. The switch was a useful idea because it could also initiate stopping in the case of over speeding in the up direction as well.
The problem started in the 1920's when the American Elevator Safety Code was developed. The writers most likely looked at the technology that was available at that time and subsequently required it on all elevators covered by the Code.
The writers were so concentrated on describing the design of the required devices that they forgot to acknowledge the hazards that the
devices are guarding against and the elevator components that may fail
and cause the hazards. They did not consider the fact that for 90% of the elevator trips, the elevator is partially loaded (i. e. less than 45% of rated load) [5]. Therefore, if a brake failure occurs, the elevator will over speed and crash in the up direction as shown in figure 4
.
Fig.4 Car over speed UP
Until recently, elevator safety systems have not differed significantly from the early 1900' s designs. The problem arises because rule rnakeing committees and regulatory authorities are reluctant to require new safeguards when the technology has not been fully developed. Conversely, the elevator manufacturing industry cannot justify the product development expense for a new safety device with little marketability. This problem will be addressed in the following sections
RULES AND REGULATIONS
Several rulemaking committees and government safety authorities have addressed the deficiencies in the existing elevator regulations and have proposed revisions to the elevator safety codes.
The report from the American Society of Mechanical Engineers A17 Mechanical Design Committee on "Cars ascending into the building overhead, "-dated September 1987, contained the types of failures that could result in elevators accelerating into overhead structure and an analysis of the possible solutions. In addition, a proposal to the A17. 1 Committee for a new code Rule 205. 6 was introduced as follows:
Rule 205. 6 ("Prevention of over speeding car from striking the overhead structure') : All traction elevators shall be provided with a means to prevent an ascending car from striking the overhead structure. This rneans shall conform to the following requirements:
1.Prior to the time when the counterweight strikes its buffer, it shall reduce the speed of the car to the speed for which the counterweight buffer is designed.
2.It shall not develop an average retardation of the car in excess of 32.2 ft /s2 (9.81 m/s2) during the stopping phase.
3.1t shall be a mechanical means independent of the driving machine brake.
4.1t shall prevent over speeding of the elevator system through the control of one or more of the following
a. counterweight
b. car
c. suspension or compensating rope system.
This proposed rule is currently under committee review, and consideration has been given to requiring protection to prevent the car from leaving the landing with the doors opened or unlocked.
Pennsylvania Bureau of Deep Mine Safety
An ascending elevator car accident occurred at a western Pennsylvania coal mine on February 4, 1987 and caused extensive structural damage and disabled the elevator for two months. Following this accident, the Pennsylvania. Bureau of Deep Mine Safety established an advisory committee to determine these devices that are available to provide ascending car over speed protection for new and existing mine elevator installations.
The following four protective methods were determined to be feasible based on engineering principles or extensive mine testing.
1.Weight balancing (counterweight equals the empty car weight)
2.Counterweight safeties
3.Dynamic braking
4.Rope brake
The Pennsylvania Bureau of Deep Mine Safety has approved these four methods and has made ascending car over speed protection mandatory on all existing counterweighted mine elevators.
Dynamic Braking
A second solution used in the United States mining industry is the application of passive dynamic braking to the elevator drive motor [6]. As mentioned earlier, most elevators use direct current drive motors that can perform as generators when lowering an overhauling load. Dynamic braking simply connects a resistive load across the motor armature to dissipate the electrical energy generated by the falling counterweight. The dynamic braking control can he designed to function when the main power is interrupted. Dynamic braking does not stop the elevator but limits the runaway speed in either direction; therefore, the buffers can safely stop the conveyance.
Rope Brake
A pneumatic rope brake that grips the suspension ropes and stops the elevator during emergency conditions has been developed by Bode Aufzugel [7]. This rope brake has been used in the Netherlands since August 12, 1957.
Case Study: Rope Brake Testing and Evaluatio
The first pneumatic rope brake was installed in the United States at a western Pennsylvania coal mine on September 8, 1989. The largest capacity Bode rope brake (model 580) was installed on this coal mine elevator. This rope brake installation was tested extensively by Mine Safety and Health Administration engineers from the Pittsburgh Safety and Health Technology Center. A summary of the findings will be presented in this study.
Function
The rope brake is a safety device to guard against over speed in the upward and downward directions and to provide protection for uncontrolled elevator car movements
The rope brake is activated when the normal running speed is exceeded by 15%as a result of a mechanical drive, motor control system, or machine brake failure. The rope brake does not guard against free fall as a result of a break in the suspension ropes.
Standstill of the elevator car is also monitored by the rope brake system. If the elevator car moves more than 2 to 8 inches in either direction when the doors are open or not locked, the rope brake is activated and the control circuit interrupted. The rope brake control must be manually reset to restore normal operation.
The rope brake also provides jammed conveyance protection for elevators and friction driven hoists. If the elevator car does not move when the drive sheave is turning, the rope brake will set, and the elevator control circuit will be interrupted.
The rope brake control contains self-monitoring features. The rope brake is activated if a signal is not received from the pulse tachometer when the drive is running
The rope brake requires electrical power and air pressure to function properly. The rope brake sets if the control power is interrupted. When the power is restored, the rope brake will automatically release.
Typically, elevator braking systems are spring applied and electrically release. Therefore, no external energy source is needed to set the brake. The rope brake requires stored pressurized air to set the brake and stop the elevator. Therefore, monitoring of the air pressure is essential. If the working air pressure falls below a preset minimum, the motor armature current is interrupted, and the machine brake is set. When the air pressure is restored, the fault string is reset.
Pneumatic Design
The rope brake system is shown in figure 5. Starting from the air compressor tank, the pressurized air passes through a water separator and manual shut off valve to a check valve. The check valve was required to ensure the rope brake remains set even if an air leak develops in the compressed air supply. A pressure switch monitors for low air pressure at this point and will set the machine brake as mentioned earlier. The air supply is split after the check valve and goes to two independent magnetic two-way valves. The air supply is shut off (port A), while the magnetic valve coil is energized. When the magnetic valve coil is reenergized, the air supply is directed to the B port, which is open to the rope brake cylinder. The air pushes the piston inside the rope brake cylinder and forces a movable brake pad toward a stationary brake pad. The suspension ropes are clamped between the two brake pads. The rope brake is released by energizing the magnetic valve, which vents the pressurized rope brake cylinder to the atmosphere through a blowout silencer on port S.
The force exerted on the suspension ropes equals the air pressure multiplied by the surface area of the piston. The rope brake model number 580 designates the diameters of the brake cylinder in millimeters. This translates into 409. :36 in of surface area.. The working air pressure varies from 90 to 120 lbf/in2. The corresponding range of force applied to the suspension ropes is 36, 842 to 49, 123 lb. The force experienced by the ropes as they pass over the drive sheave under fully loaded conditions is about 34, 775 lb. Therefore, the ropes experience a 6 to 41% greater force during emergency conditions than normally encountered during full load operation.
Mechanical Modifications
Prior to testing, several mechanical modifications were required to protect the rope brake system from environmental and mechanical damage. The modifications also reduced the possibility and the undesirable effect of an air leak in the pneumatic system. The following modifications were included in the rope brake design:
1.The 200 lbf/in2 rated plastic air hose was replaced with 2, 000 lbflin2 rated metal braided hose with integral couplings.
2.The air hose compression fittings were replaced by stainless
steel threaded connectors.
3.All the electrical components were installed in protective
enclosures, and the wiring was installed in conduit.
4. A check valve was installed in the compressed air supply line to hold the rope in the applied position once it was set even if air pressure was lost in the air compressor tank.
5. The added check valve required an additional pressure switch to monitor the supply air pressure. The original pressure switch would not detect a. pressure loss in the air compressor tank when the check valve was installed. The contacts of the two pressure switches were installed in series.
Mechanical Testing
Tests were conducted to determine if the rope brake would operate reliably in the mining environment to provide ascending car over speed protection.
First, accelerated mechanical testing was performed to determine if the braking system could withstand repeated operation without experiencing significant wear or failure. These tests were performed while the suspension ropes were stationary. This testing was conducted at both the mine site installation and in the laboratory.
Mine site testing was conducted every 4 hr. Mechanical counters were installed on both the machine brake and the rope brake to record the total number of operations for each brake. Every 4 hr, the number of times the machine brake had set during the previous 4 hr period was noted, and then, the rope brake was operated an equal number of times.
The mechanical testing concluded after 30 days of around the clock testing. The total number of rope brake operations was 3430. The temperature range varied from 25 to 83.
One of the rope brake components subjected to wear was the piston ring gasket. This gasket provides the air seal between the moving piston, which presses against the traveling brake pad, and the stationary cylinder. An overload test was conducted to determine the
integrity of this seal.
For the test, 8750 lb (125% of rated load) was loaded onto the car at the bottom of the shaft. Then, the rope brake was set, and the machine brake was disengaged. The air pressure was released from the air compressor tank, and the air pressure inside the rope brake cylinder was monitored. The load was successfully held stationary for 1 hr. The initial air pressure was 114 lbflin2, and after 1 hr, the pressure was 102 lbflin2. The pressured reduction may be attributed to an air leak through the check valve or past the piston ring gasket as a result of wear.
Laboratory mechanical tests were also performed on the rope brake in the Mine Electrical Systems Division laboratories located at. The Pittsburgh Safety and Health Technology Center. The testing was performed on the smaller Bode rope brake model 200. The rope brake system was positioned outside the laboratory building under an awning that allowed the brake system to be exposed to the outside air temperature and humidity but was protected from direct contact with the rain and snow. The rope brake was activated remotely by computer control. The computer was programmed to apply and then release the rope brake every 38 s and log the number of operations. The outside air temperature, relative humidity, and barometric pressure were also continuously recorded.
After 2 mo of testing and 146, 836 operations, the rope brake was disassembled and inspected for wear. The pneumatic. piston ring gasket exhibited minimal wear. Superficial rust was evident where the compressed air entered the rope brake and displaced the lubricant.
Over the 70 days of testing, the temperature ranged from 5 to 82, and the relative humidity varied from 25 to 100%. At times, thick accumulations of frost build up on the air line between the magnetic valve and the rope
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