Design of system of hydraulic pressure of rolling mill lifting platform and computation

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Summary: The article discussed the design of system of hydraulic pressure of rolling mill lifting platform, rise to its and drop the parameter such as the discharge when operating mode and pressure had analysis and consideration. Keyword: Crock of lifting platform balance rises fall lifting platform of crock of 1 introductive and large rolling mill, use a convention more at present " hang down hammer balance, drive of brace linkage mechanism " structural type. This kind of lifting platform weighs hammer because of its inertial big, corresponding mechanical drive, fixing device is damaged easily, die device malfunction much, upkeep costs workload of tall, management is big, year machine down time is long. The structural type that studies new-style hydraulic pressure lifting platform replaces a tradition already made trend of a kind of development. System of hydraulic pressure of 2 lifting platform and its job principle pursue 1 for sketch map of job of hydraulic pressure lifting platform, the FG in the graph is lifting platform and billet gravity, fs falls to rise thrust of crock force plunger, fp is thrust of balance crock force plunger. Graph sketch map of job of lifting platform of hydraulic pressure of 1 rolling mill pursues 2 pursue for principle of system of lifting platform hydraulic pressure, this system by oily source, balance loop, litre fall loop and composition of loop of discharge carry on one's shoulder. When lifting platform is in horizontal position, fixed bearing bears the weight of of lifting platform and billet self-prossessed, when the system enters preliminary work state, electric machinery of starting oil pump, oil pump the pressure oily classics of 15 output is one-way a powerful person 5 enter balance accumulator 8, when its pressure achieves Pp1=xcFG/xp, electric contact pressure expresses 12 hair dispatch, IDT gets report, awl a powerful person 1 open, a powerful person of awl of hydraulic pressure oily classics 1 enter litre fall crock 7, litre fall the pressure of the crock rises ceaselessly, litre fall crock and balance crock drive lifting platform to rise together, in lifting platform ascendant process, the pressure Pp that balances loop by arrive greatly little change, and litre fall the pressure Ps of loop criterion by small to big change (3) seeing a picture, when lifting platform rises to set position, by rotate coder detects intercurrent dispatch makes 3DT gets report, awl a powerful person 3 open, pump is right accumulator 9 fill fluid, achieve Ps2+0 when pressure.

After 3MPa, express 13 hair dispatch by electric contact pressure, make IDT breaks phone, awl a powerful person 1 shut, make 4DT gets report then, awl a powerful person 4 open, pump discharge carries on his shoulder or back, accumulator 9 carry out fall to rising the filling oil function of loop, prevent lifting platform to fall because of rising the leak of loop and drop, maintain in position of top dead centre. Balance accumulator 8 also offer indispensible priority valve to control oily source, the dependability that works in order to assure a system and successional. When lifting platform drops, 3DT breaks phone, awl a powerful person 3 shut, then 2DT gets report, awl a powerful person 2 open, litre fall a powerful person of awl of oily fluid classics of the crock 2 control throttle J oil sump tank with fluid, lifting platform is mixed in XcFG of self-prossessed moment of force balance crock, litre fall of the crock on drop below the joint action that holds pitching moment XpAppp and XsAsps in the palm, in drop in the process, the pressure Pp that balances loop by small greaten (the oily fluid that balances a crock is pressed into balance accumulator right now 8 in) , litre fall the pressure Ps of loop criterion by big decrescent, turn into finally 0. When lifting platform drops to issue dead centre, by rotate coder sends message, make 2DT breaks phone, awl a powerful person 2 shut, a job ends circularly. Graph graph of principle of system of hydraulic pressure of lifting platform of 2 rolling mill pursues this system installed 3 　 to reserve pump and reserve group of a powerful person (a) was not drawn in the graph, in order to assure the dependability that the system works. The computation of 3 concerned parameter and the basic data that choose lifting platform are as follows: Length of lifting platform theory: L=12.

75m; The academic height that lifting platform rises: H=0.

9m; Lifting platform is the biggest corner: φ =4.

038 ° ; Lifting platform is self-prossessed: FG=1.

274 × 106N; Position of lifting platform centroid: Xc=5.

34m; Litre fall crock position: Xs=3.

75m; Balance crock position: Xp=6.

75m; Lifting platform rises or decay time: T=2.

4s. (The consideration that 1) balances loop to concern parameter and accumulator of balance of choice 　 ① the low end of 8 pressure Pp1 　 is reached when lifting platform at horizontal position, the gravitational quadrature that balances crock of thrust quadrature of 6 and lifting platform and billet is balanced, namely 　 of Pp1=xcFG/(xpAp) of ∴ of XpAppp1=xcFG 　 　 (in 1) type: Ap -- balance crock of force plunger area of 6 (M2) , ap= π Dp2/4, dp is balance crock the force plunger diameter of 6, dp=0.

25m. ② balances accumulator the 　 of high-end pressure Pp2 of 8 go up because of lifting platform or or decay time T=2.

4s is very short, can regard its as isothermal process, reason has 　 of Pp2=V6-1pp1/V6-2 of ∴ of 　 of 　 V6-1pp1=V6-2pp2 　 (in 2) type: V6-1 -- the azotic gas of 8 accumulates accumulator of the balance when pressure is Pp1, v6-1=0.

18m3; V6-2 -- the azotic gas of 8 accumulates accumulator of the balance when pressure is Pp2, v6-2=0.

20335m3. ③ balances 　 of crock of discharge Qp 　 of 6 Qp=ApHp/t 　 (in 3) type: Hp -- balance crock of journey of 6, hp=0.

4757m. (2) rises fall the computation of loop concerned parameter and choice 　 ① rise fall crock of low end of 7 pressure Ps1 　 is in horizontal position to secure bearing to bear the weight of from time to tome because of lifting platform of lifting platform and billet self-prossessed, and when should be in preliminary ascendant condition, balance quadrature of crock of force plunger thrust of 8 and lifting platform and billet gravity quadrature, so, rise right now fall crock pressure is 0, namely ② of Ps1=0 　 　 rises fall 　 becomes crock of high-end pressure Ps2 of 7 when lifting platform is in high-end position, litre fall the sum of quadrature of force plunger thrust of 8 and lifting platform and billet gravity quadrature balance quadrature of crock of force plunger thrust of 7 and balance crock, namely ／ of Ps2=(xcFG-xpApV6-1pp1/V6-2) of ∴ of 　 of 　 XsAsps2+xpAppp2=xcFG 　 (XsAs)=(xcFGV6-2-xpApV6-1)/(xsAsV6-2) 　 (in 4) type: As -- litre fall crock of force plunger area of 7, as= π Ds2/4, ds falls to rise crock of force plunger diameter of 7, ds=0.

2m. ③ rises fall 　 of crock of Qs=AsHs/t of 　 of discharge Qs 　 of 7 (in 5) type: Hs -- litre fall crock of journey of 7, hs=0.

2647m. foregone parameter era enters afore-mentioned various calculate so that be about parameter: Pp1=20.

5MPa; Pp2=18MPa; Qp=583L/min; Ps1=0; Ps2=7.

2MPa; Qs=208L/min. System of hydraulic pressure of lifting platform of rolling mill of 4 last words introduces drive of hydraulic pressure balance, hydraulic, compare with photograph of drive of linkage mechanism of the conventional balance that weigh hammer, brace, without the adverse effect of force, breakdown decreases, reliability is high. Through be being emulated to systematic computer, examined the validity that systematic parameter designs, pass imitating test, lifting platform job is smooth, positional control precision is tall. This one research laid good foundation for project application. CNC Milling CNC Machining