Created on:2021-08-06 09:40

Maintenance of roller_ Improved design of balance hydraulic control circuit

轧辊的维修_平衡液压控制回路改进设计
Maintenance of roller_ Improved design of balance hydraulic control circuit

为了方便换辊操作,设计了图4-36所示的轧辊平衡控制回路,其电磁铁动作如下表所示。
In order to facilitate roll changing operation, the roll balance control circuit shown in Fig. 4-36 is designed, and its electromagnet action is shown in the table below.

 

电磁铁动作表
Electromagnet action table

平 衡 缸 动 作
Balancing cylinder action

DT1

DT2

轧辊平衡

              平衡缸上升

位置控制 平衡缸下降

              平衡缸停止

-

-

+

+

-

+

-

+

 

当电磁铁DTI、DT2都不带电时,系统压力油一方面经3、2流向平衡缸的无杆腔,另一方面经电磁换向阀5流向平衡缸的有杆腔,形成差动连接。由于平衡缸两工作腔的面积差的存在,使平衡缸产生一个向上的推力F,起到平衡轧辊的作用;当平衡缸的活塞杆在轧机压下系统的作用下退回时,平衡缸无杆腔排出的液压油一方面流入平衡缸的有杆腔,另一方面多余的液压油可存储在蓄能器中。
When the electromagnets DTI and DT2 are not charged, the system pressure oil flows to the non rod chamber of the balance cylinder through 3 and 2 on the one hand, and to the rod chamber of the balance cylinder through the electromagnetic directional valve 5 on the other hand, forming a differential connection. Because of the area difference between the two working cavities of the balance cylinder, the balance cylinder generates an upward thrust f to balance the roll; When the piston rod of the balance cylinder returns under the action of the rolling mill screwdown system, the hydraulic oil discharged from the non rod chamber of the balance cylinder flows into the rod chamber of the balance cylinder on the one hand, and the excess hydraulic oil can be stored in the accumulator on the other hand.

    换辊操作时,为了方便对平衡缸位置的调整,该平衡缸的运动速度不需太快,通过调整节流阀6的开口度,可以满足这一要求;电磁铁DT1、DT2的不同组合可以实现平衡缸的上升、下降及停止动作。
During the roll changing operation, in order to facilitate the adjustment of the position of the balance cylinder, the movement speed of the balance cylinder does not need to be too fast. This requirement can be met by adjusting the opening degree of the throttle valve 6; Different combinations of electromagnets dt1 and DT2 can realize the rising, falling and stopping action of balancing cylinder.

(4)效果分析
(4) Effect analysis

    改进后的轧辊平衡回路与原回路相比,具有如下特点。
Compared with the original circuit, the improved roller balance circuit has the following characteristics.

    ①方便了换辊操作改进后的回路 具有力控制及位置控制两种工作状态可供选择,回路简单实用,换辊方便。
① The improved loop has two working states of force control and position control for selection. The loop is simple and practical, and the roll change is convenient.

    ②提高了系统的响应速度 由于采用了差动控制技术,在系统流量相同的情况下,改进后的回路比原回路具有更高的响应速度。
② Because of the differential control technology, the improved loop has higher response speed than the original loop under the same system flow.

    ③易于使用与维护 在原回路中,为了使系统正常工作,溢流阀的设定压力必须略高于减压阀的设定压力。如果溢流阀调整不合理(甚至完全关闭),其后果将十分严重,这种情况在轧机的使用现场偶有发生;改进后的回路取消了减压阀及溢流阀,因而不存在上述问题。
③ Easy to use and maintain in the original circuit, in order to make the system work normally, the set pressure of relief valve must be slightly higher than that of pressure reducing valve. If the relief valve is not properly adjusted (or even completely closed), the consequences will be very serious, which occasionally occurs in the use site of the rolling mill; The improved circuit cancels the pressure reducing valve and overflow valve, so the above problems do not exist.

    ④平衡力更加稳定 原回路因溢流阀的设定压力略高于减压阀的设定压力,当平衡缸的活塞杆在轧机压下系统的作用下回退时,平衡力略有增加,这导致平衡缸活塞杆在伸出及缩回时平衡力的变化。平衡力的波动对提高产品的质量不利。改进后的回路具有平衡力稳定的特点。
④ The balance force is more stable in the original circuit. Because the set pressure of the relief valve is slightly higher than that of the pressure reducing valve, when the piston rod of the balance cylinder retreats under the action of the rolling mill reduction system, the balance force increases slightly, which leads to the change of the balance force when the piston rod of the balance cylinder extends and retracts. The fluctuation of balance force is unfavorable to the improvement of product quality. The improved circuit has the characteristics of stable balance force.

    ⑤节能效果显著 原回路中油源来的系统压力油经减压后供给轧辊平衡回路使用,在减压阀处存在一个能量损失;而当平衡缸的活塞杆在轧机压下系统的作用下缩回时,平衡缸无杆腔的液压油经溢流阀2(图I)流回油箱,这部分能量主要变为热量而白白损失掉了。改进后,当平衡缸的活塞杆在轧机压下系统的作用下缩回时,平衡缸无杆腔排出的多余液压油可以回送到蓄能器中储存起来,避免了原回路中溢流阀及减压阀处的能量损失。
⑤ The energy-saving effect is remarkable. The system pressure oil from the oil source in the original circuit is supplied to the roller balance circuit after decompression, and there is an energy loss at the pressure reducing valve; When the piston rod of the balance cylinder retracts under the action of the rolling mill screwdown system, the hydraulic oil in the rodless chamber of the balance cylinder flows back to the oil tank through the relief valve 2 (Fig. I), and this part of energy is mainly turned into heat and lost in vain. After the improvement, when the piston rod of the balance cylinder retracts under the action of the rolling mill reduction system, the excess hydraulic oil discharged from the rodless cavity of the balance cylinder can be sent back to the accumulator for storage, thus avoiding the energy loss at the overflow valve and pressure reducing valve in the original circuit.

    采用液压差动回路控制的轧辊平衡装置大大方便了换辊操作,具有平衡力稳定、节能高效等特点。该回路不但适用于轧辊平衡系统,还适用于其他需要对力控制及位置控制进行切换的场合。
The roll balancing device controlled by hydraulic differential circuit is convenient for roll changing operation and has the characteristics of stable balancing force, energy saving and high efficiency. This circuit is not only suitable for roll balance system, but also suitable for other occasions where force control and position control need to be switched.

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