液壓與氣壓傳動 作業(yè)講解課堂

1、液壓與氣壓傳動,Hydraulic and Fluid Transmission,1,作業(yè)講解,題,2.6,如圖,2.31,所示，有一直,徑為,d,重量為,G,的活塞浸在液,體中，并在力,F,的作用下處于靜,止?fàn)顟B(tài)。若液體的密度為,活,塞浸入深度為,h,試確定液體在,測壓管內(nèi)的上升高度,x,d,F,G,h,x,液壓與氣壓傳動,Hydraulic and Fluid Transmission,2,作業(yè)講解,d,F,G,h,x,液壓與氣壓傳動,Hydraulic and Fluid Transmission,3,作業(yè)講解,O,2,2,2,1,1,1,H,A,2,A,1,題,2.9,如圖,2.34,

2、所示，已知水,深,H,10m,截面,A,1,0.02m,2,截,面,A,2,0.04m,2,求孔口的出流流,量以及點,2,處的表壓力,取,1,A,1000kg/m,3,不計損失,液壓與氣壓傳動,Hydraulic and Fluid Transmission,4,作業(yè)講解,O,2,2,2,1,1,1,H,A,2,A,1,液壓與氣壓傳動,Hydraulic and Fluid Transmission,5,作業(yè)講解,O,2,2,2,1,1,1,H,A,2,A,1,液壓與氣壓傳動,Hydraulic and Fluid Transmission,6,作業(yè)講解,題,2.12,液體在管中的流速,u,4

3、m/s,管道內(nèi)徑,d,60mm,油液的運(yùn)動粘度,v,30,10,6,m,2,s,試確定流,態(tài)，若要保證其為層流，其流速應(yīng)為多少,液壓與氣壓傳動,Hydraulic and Fluid Transmission,7,作業(yè)講解,題,2.13,運(yùn)動粘度,v,40,10,6,m,2,s,的油液通過水平管道,油液密度,900kg/m,3,管道內(nèi)徑為,d,10mm,l,5m,進(jìn)口壓力,p,1,4.0MPa,問流速為,3m/s,時，出口壓力,p,2,為,多少,液壓與氣壓傳動,Hydraulic and Fluid Transmission,8,作業(yè)講解,液壓與氣壓傳動,Hydraulic and Fluid

4、 Transmission,9,作業(yè)講解,題,5.10,圖,5.60,所示系統(tǒng)，若不計管路壓力損失時，液,壓泵的出口壓力為多少,3MPa,p,p,c,4MPa,a,2MPa,2MPa,4MPa,3MPa,p,p,p,p,2MPa,d,3MPa,4MPa,b,7MPa,至系統(tǒng),p,p,6MPa,0.5MPa,4MPa,至系統(tǒng),至系統(tǒng),至系統(tǒng),液壓與氣壓傳動,Hydraulic and Fluid Transmission,10,作業(yè)講解,a,這是一個先導(dǎo)型,溢流閥進(jìn)行遠(yuǎn)程調(diào)壓的,回路，遠(yuǎn)程調(diào)壓閥起作,用的條件是必須比本體,上的先導(dǎo)閥調(diào)節(jié)的壓力,要低，因此，根據(jù)此條,件，系統(tǒng)的壓力最終由,2MPa

5、,的遠(yuǎn)程調(diào)壓閥確,定，即泵出口壓力為,2MPa,p,p,a,2MPa,2MPa,4MPa,3MPa,p,p,至,至系統(tǒng),至系統(tǒng),液壓與氣壓傳動,Hydraulic and Fluid Transmission,11,作業(yè)講解,b,根據(jù)回路圖所示狀,態(tài)，遠(yuǎn)程調(diào)壓閥被切斷,因此不起作用。兩個溢流,閥串聯(lián)，后一個溢流閥是,前一個溢流閥的出口背壓,而溢流閥進(jìn)口壓力實際上,是相當(dāng)于把出口大氣壓看,成零的進(jìn)出口壓差，當(dāng)出,口壓力不為零時，需要加,上出口壓力，即泵出口壓,力為,13MPa,當(dāng)電磁閥通,電后，第一個閥接入了遠(yuǎn),程調(diào)壓閥，其壓力為,0.5MPa,因此，泵出口,壓力為,7.5MPa,p,p,4MP

6、a,a,2MPa,2MPa,4MPa,3MPa,p,p,p,p,2MPa,3MPa,4MPa,b,7MPa,至系統(tǒng),p,p,6MPa,0.5MPa,4MPa,至系統(tǒng),至系統(tǒng),至系統(tǒng),液壓與氣壓傳動,Hydraulic and Fluid Transmission,12,作業(yè)講解,3MPa,p,p,c,4MPa,a,2MPa,2MPa,4MPa,至,至系統(tǒng),p,p,c,4MPa,a,2MPa,2MPa,4MPa,3MPa,p,p,p,p,2MPa,d,3MPa,4MPa,b,7MPa,至系統(tǒng),p,p,6MPa,0.5MPa,4MPa,至系統(tǒng),至系統(tǒng),至系統(tǒng),c,這是三個溢流閥并聯(lián)，顯然,打開壓力

7、小的溢流閥，因此,泵出口壓力為,2MPa,d,這是三個溢流閥串聯(lián)，同,上述,b,的情況，泵出口壓力為,9MPa,液壓與氣壓傳動,Hydraulic and Fluid Transmission,13,作業(yè)講解,題,5.12,如圖,5.62,所示的回路，知液壓缸無桿腔有效,面積均為,100cm,2,有桿腔的有效面積均為,50cm,2,當(dāng)最大負(fù)載均為,F,1,14,10,3,N,F,2,4250N,背壓,p,1.5,10,5,Pa,減壓閥,3,調(diào)定壓力為,12,10,5,Pa,節(jié),流閥,2,的壓差,p,2,10,5,Pa,時，試問,1,A,B,C,各點的壓力（忽略管路損失,2,泵和閥,1,2,3,

8、最小應(yīng)選多大的額定壓力,3,若兩缸進(jìn)給速度為,1,3.5cm/s,2,4cm/s,泵,和各閥的額定流量應(yīng)選多大,1,A,3,B,2,C,F,2,2,p,F,1,1,液壓與氣壓傳動,Hydraulic and Fluid Transmission,14,作業(yè)講解,1,A,3,B,2,C,F,2,2,p,F,1,1,液壓與氣壓傳動,Hydraulic and Fluid Transmission,15,作業(yè)講解,1,A,3,B,2,C,F,2,2,p,F,1,1,液壓與氣壓傳動,Hydraulic and Fluid Transmission,16,作業(yè)講解,液壓與氣壓傳動,Hydraulic a

9、nd Fluid Transmission,17,作業(yè)講解,題,5.14,圖示系統(tǒng)中溢流閥的調(diào),整壓力分別為,p,A,3MPa,p,B,1.4MPa,p,C,2MPa,試求,系統(tǒng)的外負(fù)載趨于無窮大時,泵輸出的壓力為多少,如將溢流閥,B,的遠(yuǎn)程控制口,堵住，泵輸出的壓力為多少,至,系,統(tǒng),p,p,B,C,A,解,如圖，方框中用結(jié)構(gòu)簡圖表示的是,B,閥，用圖形符,號表示的閥是,C,閥，看遙控口,k,堵死和不堵死,B,和,C,內(nèi)部,油路的不同連接的情況,液壓與氣壓傳動,Hydraulic and Fluid Transmission,18,作業(yè)講解,C,閥,1,當(dāng)遙控口,k,不堵死,時,B,閥,方框

10、中,的,先導(dǎo)閥腔和彈簧泄,油腔通過遙控口,k,連,通（圖中藍(lán)線,先導(dǎo)閥受液壓和彈,簧力作用始終壓在,閥座上，不可能開,啟，通過阻尼孔的,壓力油只能打開,C,閥（圖形符號表示,的閥），由,C,閥調(diào),定，即通過,B,C,兩,閥的壓力就是,p,c,的,壓力，即為,2MPa,液壓與氣壓傳動,Hydraulic and Fluid Transmission,19,作業(yè)講解,2,當(dāng)紅線即遙控口,k,堵死時,B,閥打開的條件必須是其先導(dǎo),閥要打開，而此時先導(dǎo)閥的彈,簧腔不僅作用了彈簧力，還作,用有壓力,p,c,必須在,C,閥也打開,的情況下,B,閥才能打開，此時,B,C,兩閥通路的壓力就為,p,c,p,B,

11、1.4,2,3.4MPa,圖中閥,A,閥,B,C,為并聯(lián)，當(dāng)負(fù)載無,限大時，泵的出口壓力由兩者,中小的決定，而,B,C,串聯(lián),后,p,c,p,B,3.4MPa,p,A,3MPa,因此為,3Mpa,遙控口,k,不堵死時：泵輸出壓力為,2MPa,遙控口,k,堵死時：泵輸出壓力為,3Mpa,液壓與氣壓傳動,Hydraulic and Fluid Transmission,20,作業(yè)講解,題,5.15,圖示溢流閥的調(diào)定壓力為,4MPa,若閥芯阻尼小孔造成的損,失不計，試判斷下列情況下壓力,表讀數(shù)各為多少,1,YV,斷電，且負(fù)載無窮大時,2,YV,斷電，且負(fù)載壓力為,2MPa,時,3,YV,得電，且負(fù)載

12、壓力為,2MPa,時,p,p,A,YV,液壓與氣壓傳動,Hydraulic and Fluid Transmission,21,作業(yè)講解,液壓與氣壓傳動,Hydraulic and Fluid Transmission,22,作業(yè)講解,題,5.16,圖示回路，負(fù)載壓力,p,L,減壓,閥調(diào)整壓力,p,J,溢流閥的調(diào)整壓力,p,Y,且,p,Y,p,J,試分析泵的工作壓力由什么值,來確定,p,p,p,L,p,J,p,Y,液壓與氣壓傳動,Hydraulic and Fluid Transmission,23,作業(yè)講解,題,5.17,圖示回路，溢流閥的調(diào)整壓,力為,5MPa,減壓閥的調(diào)整壓力為,1.5M

13、Pa,活塞運(yùn)動時負(fù)載壓力為,1MPa,其它損失不計，試求,1,活塞在運(yùn)動期間和碰到死擋鐵,后管道中,A,B,處的壓力值,2,如果減壓閥的外泄油口在安裝,時未接油箱，當(dāng)活塞碰到死擋鐵,后,A,B,處的壓力值,B,p,L,A,液壓與氣壓傳動,Hydraulic and Fluid Transmission,24,作業(yè)講解,B,p,L,A,液壓與氣壓傳動,Hydraulic and Fluid Transmission,25,作業(yè)講解,B,p,L,A,液壓與氣壓傳動,Hydraulic and Fluid Transmission,26,作業(yè)講解,圖,5.18,圖示回路，順序閥的調(diào)整,壓力,p,X,

14、3MPa,溢流閥的調(diào)整壓,力,p,Y,5MPa,問在下列情況下,A,B,點的壓力等于多少,1,液壓缸運(yùn)動時，負(fù)載壓力,p,L,4MPa,2,如負(fù)載壓力,p,L,變?yōu)?1MPa,3,如活塞運(yùn)動到右端時,B,A,p,Y,p,X,p,L,液壓與氣壓傳動,Hydraulic and Fluid Transmission,27,作業(yè)講解,液壓與氣壓傳動,Hydraulic and Fluid Transmission,28,作業(yè)講解,題,5.19,順序閥和溢流閥串聯(lián)，它們的,調(diào)整壓力分別為,p,X,和,p,Y,當(dāng)系統(tǒng)的外負(fù),載無限大時，泵出口的壓力是多少？若,把兩只閥的位置互換一下，泵出口處的,壓力是多

15、少,B,p,Y,p,X,液壓與氣壓傳動,Hydraulic and Fluid Transmission,29,作業(yè)講解,題,7.6,在圖,7.44,回路中，如,p,Y1,2MPa,p,Y2,4MPa,卸荷時的各種壓力損失均可,忽略不計，試列表表示,A,B,兩點處在電磁閥不同調(diào)度工,況下的壓力值,p,1YV,p,Y1,3,A,1,B,Y2,4,2YV,2,液壓與氣壓傳動,Hydraulic and Fluid Transmission,30,作業(yè)講解,題,7.7,在圖,7.45,回路中，已知活塞,運(yùn)動時的負(fù)載,F,1200N,活塞面積,A,15cm,2,溢流閥調(diào)整值為,p,Y,4.5MPa,兩

16、個減壓閥的調(diào)整值分別,為,p,J1,3.5MPa,p,J2,2MPa,如果油,液流過減壓閥及管路時的損失略去不,計，試確定活塞在運(yùn)動時和停在右端,終點位置處時,A,B,C,三點的壓力,C,B,Y,p,A,J 2,p,p,J 1,F,解,運(yùn)動時,p,A,p,B,p,C,0.8MPa,停止時,p,A,4.5MPa,p,B,3.5MPa,p,C,2MPa,液壓與氣壓傳動,Hydraulic and Fluid Transmission,31,作業(yè)講解,題,7.8,圖,7.46a,和圖,7.46b,所示回路均為實現(xiàn),快進(jìn),工,進(jìn),1,工進(jìn),2,快退,停止,動作的回路,工進(jìn),1,速,度比工進(jìn),2,快,試

17、問這些電磁閥應(yīng)如何調(diào)度,a,3YV,4YV,1YV,2YV,退,進(jìn),b,3YV,1YV,2YV,4YV,退,進(jìn),液壓與氣壓傳動,Hydraulic and Fluid Transmission,32,作業(yè)講解,a,3YV,4YV,1YV,2YV,退,進(jìn),b,3YV,1YV,2YV,4YV,退,進(jìn),液壓與氣壓傳動,Hydraulic and Fluid Transmission,33,作業(yè)講解,題,7.9,圖,7.47,所示回路中,已知兩活塞向右運(yùn)動時,缸,I,的,負(fù)載壓力為,2.5MPa,缸,的,負(fù)載壓力為,0.5MPa,負(fù)載為,阻力負(fù)載。如順序閥、減壓,閥和溢流閥的調(diào)整壓力分別,為,p,x,

18、3.5Mpa,p,J,2Mpa,p,y,4.5Mpa,三種壓力閥全開,時的壓力損失均為,0.2 Mpa,其它損失不計。說明圖示狀,態(tài)下兩液壓缸的順序動作,并求,A,B,C,和,D,四點處的壓,力變化情況,C,A,B,p,Y,p,X,1YV,D,p,J,2YV,液壓與氣壓傳動,Hydraulic and Fluid Transmission,34,作業(yè)講解,C,A,B,p,Y,p,X,1YV,D,p,J,2YV,缸,I,負(fù)載壓力,2.5MPa,缸,負(fù)載壓力,0.5MPa,p,x,3.5Mpa,p,J,2Mpa,p,y,4.5Mpa,三壓力閥全開時,壓力損失,0.2 Mpa,液壓與氣壓傳動,Hyd

19、raulic and Fluid Transmission,35,作業(yè)講解,題,7.10,圖,7.48,所示回路中，已知,兩液壓缸的活塞面積相同，且為,A,20cm,2,但負(fù)載分別為,F,1,8000N,F,2,4000N,如溢流閥,的調(diào)整壓力為,p,Y,4.5MPa,試分,析減壓閥壓力調(diào)整值分別為,1MPa,2MPa,4MPa,時，兩液壓缸的動,作情況,p,p,Y,B,J,A,p,C,1,F,1,p,2,F,2,解,p,J,1Mpa,時,缸,I,移動,缸,不動,p,J,2MPa,時,缸,I,缸,同時動作,p,J,4MPa,時,缸,移動，停止后,缸,I,再移動,液壓與氣壓傳動,Hydrauli

20、c and Fluid Transmission,36,作業(yè)講解,題,8.5,圖,8.11,所示的,液壓系統(tǒng)是,怎樣工作的,按其動作循,環(huán)表,表,8.5,中提示進(jìn)行,閱讀，將表,填寫完整,作出系統(tǒng)的,工作原理說,明，并寫出,油液流動情,況,定,位,拔,銷,松,開,快進(jìn),YJ,快退,快進(jìn),工進(jìn),快退,2YV,高,p,3,p,2,p,1,12YV,21YV,11YV,p,3,p,1,p,2,1YV,22YV,工進(jìn),低,夾,緊,液壓與氣壓傳動,Hydraulic and Fluid Transmission,37,定,位,拔,銷,松,開,快,進(jìn),Y,J,快,退,快,進(jìn),工,進(jìn),快,退,2,Y,V,高

21、,p,3,p,2,p,1,1,2,Y,V,2,1,Y,V,1,1,Y,V,p,3,p,1,p,2,1,Y,V,工,進(jìn),低,夾,緊,2,2,Y,V,液壓與氣壓傳動,Hydraulic and Fluid Transmission,38,定,位,拔,銷,松,開,快,進(jìn),Y,J,快,退,快,進(jìn),工,進(jìn),快,退,2,Y,V,高,p,3,p,2,p,1,1,2,Y,V,2,1,Y,V,1,1,Y,V,p,3,p,1,p,2,1,Y,V,工,進(jìn),低,夾,緊,2,2,Y,V,液壓與氣壓傳動,Hydraulic and Fluid Transmission,39,定,位,拔,銷,松,開,快,進(jìn),Y,J,快,退,快,進(jìn),工,進(jìn),快,退,2,Y,V,高,p,3,p,2,p,1,1,2,Y,V,2,1,Y,V,1,1,Y,V,p,3,p,1,p,2,1,Y,V,工,進(jìn),低,夾,緊,2,2,Y,V,液壓與氣壓傳動,Hydraulic and Fluid Transmission,40,定,位,拔,銷,松,開,快,進(jìn),Y,J,快,退,快,進(jìn),工,進(jìn),快,退,2,Y,V,高,p,3,p,2,p,1,1,2,Y,V,2,1,Y,V,1,1,Y,V,p,3,p,1,p,2,1,Y,V,工,進(jìn),低,夾,緊,2,2,Y,V,液壓與氣壓傳動