RU2667944C2 - Hydraulic installation device of rolling steel - Google Patents

Abstract

FIELD: rolling production.SUBSTANCE: invention relates to rolling production. Device contains pump-accumulator station, pressure and return cylinders, plungers of which are connected in pairs to each roll cushion, and the fluid flow control systems of pressure cylinders, each of which includes tracking, switching and two clamped spool, hydraulic gearbox and multiplier block. Hydraulic gearbox contains movable block of plungers and two high and low pressure cylinders. Multiplier block consists of two movable rigidly connected cylinder plungers, two fixed low-pressure cylinders, two fixed hollow plungers of high-pressure cylinders, four check valves and two-position valve with switching device.EFFECT: use of invention makes it possible to reduce energy losses and improve device efficiency.1 cl, 1 dwg

Description

The invention relates to rolling equipment, mainly to the mounting devices of the rolls of the working stands of crimping reversing mills.

A hydraulic blooming installation device 850 is known, comprising a pumping and storage station, pressure and return cylinders; fluid flow control systems for each pressure cylinder, including each servo spool, multiplier, switching spool, servo spool movement mechanism (Ivanchenko F.K., Polukhin P.I., Polukhin V.P., Tylkin M.A. Dynamics and strength rolling equipment. - M.: Metallurgy, 1970, S. 132, Fig. 63).

The disadvantages of this device are:

- Increased fluid flow from the battery when moving the roll down. This is due to the fact that this fluid is consumed not only to fill the pressure cylinders, but also to fill the high pressure cavities of the multipliers when their movable elements return to their original position;

- Significant energy losses due to throttling of the fluid flow in servo spools when the roll moves down. This is due to the fact that the dimensions of the pressure cylinders and the pressure of the liquid in the accumulator are determined by the rolling force and the value of these parameters is much larger than the values required for the installation movements of the roll down.

Both disadvantages together reduce the efficiency of the device.

The closest in technical essence and the achieved result is a hydraulic rolling mill mounting device containing a pump-storage station, pressure and return cylinders, the plungers of which are paired with each roll cushion; fluid flow control systems for each pressure cylinder, including each three-way three-position follow-up spool with a movement mechanism, covered by negative movement feedback, a three-way two-position change-over spool with hydraulic control, a multiplier unit consisting of two movable rigidly connected oppositely oriented cylinder plungers, two fixed rigidly connected low pressure cylinders, two fixed rigidly connected hollow plunger-cylinders high pressure, four check valves, four-way on / off slide valve with a switching device interacting with movable plunger-cylinders, while the pump-accumulator station is connected to return cylinders and to one of the inputs of the tracking spools, the second inputs of which are connected to the drain, and the outputs are connected to the inputs of the switching spools, the closed outputs of which are connected to one of the inputs of the four-way on-off spool, the second input of which is connected to the drain, and the plunger cylinders are multi the plator block separately through check valves are connected to the low-pressure cylinders interacting with them and then pairwise with one of the outputs of the four-way on-off spool and separately through check valves with pressure cylinders and with the open outputs of the switched spools (USSR AS No. 1435343, cl. B21B 31/32, 11/7/88. Bull. No. 41).

The disadvantage of this device is the significant energy loss due to the throttling of fluid flows in servo spools when the roll is moved down. This is due to the fact that the dimensions of the pressure cylinders and the pressure of the liquid in the accumulator are determined by the rolling force and the value of these parameters is much larger than the values required for the installation movements of the roll down, which ultimately reduces the efficiency of the device.

The task of the claimed device is to increase its efficiency by reducing the flow of liquid from the battery during installation movements of the roll down.

The task is achieved by the fact that in the hydraulic installation device of the rolling mill, containing a pump-storage station, pressure and return cylinders, the plungers of which are paired with each roll cushion; fluid flow control systems for each pressure cylinder, including each three-way three-position follow-up spool with a movement mechanism, covered by negative movement feedback, a three-way two-position change-over spool with hydraulic control, a multiplier unit consisting of two movable rigidly connected oppositely oriented cylinder plungers, two fixed rigidly connected low pressure cylinders, two fixed rigidly connected hollow plunger-cylinders high pressure, four check valves, a four-way on / off slide valve with a switching device interacting with movable plunger-cylinders, while the pump-accumulator station is connected to return cylinders and to one of the inlets of the follower spools, the second inputs are connected to the drain, and the outputs are connected to the inputs of the switching spools, the closed outputs of which are connected to one of the inputs of the four-way on-off spool, the second input of which is connected to the drain, and the plunger cylinders are multi the plicator unit is separately connected through check valves to the low-pressure cylinders interacting with them and then in pairs to one of the outputs of the four-way on-off slide valve and separately through check valves with pressure cylinders and with the open outputs of the switched spools.

According to the invention, the fluid flow control systems for each pressure cylinder are each equipped with two shut-off spools and a hydraulic gear comprising a movable block of plungers and two fixed high and low pressure cylinders, the high-pressure cylinders being connected to the open outputs of the switching spools and through normally closed shut-off spools with electromagnetic control - with pressure cylinders, and low pressure cylinders through normally open shut-off spools with hydraulic control phenomenon - with pressure cylinders.

The inclusion in the composition of the fluid flow control systems for each pressure cylinder of the hydraulic installation device of the rolling mill two cut-off spools and a hydraulic gearbox as part of a movable block of plungers and two stationary cylinders of high and low pressure; the connection of the high pressure cylinders with the open outputs of the switching spools and through normal closed cut-off spools with electromagnetic control - with pressure cylinders and the connection of low-pressure cylinders through normally open cut-off spools with hydraulic control with pressure cylinders significantly reduces the liquid flow from the accumulator during installation movements of the roll down and, as a result, increases the efficiency of the device.

The hydraulic installation device of the rolling mill is illustrated in the drawing, which shows the hydraulic circuit of the device.

The device consists of a pump-accumulator station (NAS) 1, pressure cylinders 2 and return cylinders 3, whose plungers are paired with cushions 4 of roll 5 (one of two cushions is shown). Between each pressure cylinder and the NAS there is a system for controlling fluid flows into pressure cylinders (elements of one system of two are shown), including a three-way three-position follow-up spool 6 with a movement mechanism 7 mounted on a crosshead 8 connected by rods 9 to the roll cushions. Traverse 8 and rod 9 provide coverage of the tracking spools with negative feedback on the movement. The pressure flow control system for the pressure cylinders also includes a three-way two-position switching spool 10 with hydraulic control, a hydraulic reducer 11, two cut-off spools, one of which is 12 with hydraulic control, the second one is 13 with electromagnetic control, and a multiplier block 14, which consists of movable plunger-cylinders 15 and 16 connected by rods 17, fixed cylinders 18 and 19 of low pressure, motionless hollow plungers 20 and 21 of high pressure cylinders connected by rods 22. The four-way two-position slide valve 27 with its switching device 28, with which the rod 29 interacts, rigidly connected with the movable plunger-cylinders 15 and 16. The hydraulic gearbox 11 includes a movable block of plungers 30, also includes four check valves 23, 24, 25, 26. and two stationary cylinders: high pressure - 31 and low pressure - 32. The extreme left position (according to the diagram) of the plunger block 30 is controlled by the limit switch 33, and the extreme upper position of the roll is controlled by the limit switch 34.

US pipelines are directly connected to return cylinders 3 and to one of the closed entrances of servo spools, the second entrances of which are connected to a drain. The closed outputs of the follower spools are connected to the inputs of the switching spools, the closed outputs of which are connected to one of the inputs of the spools 27, the second inputs of which are connected to the drain. The plunger cylinders 15 and 16 are connected to the low pressure cylinders 18 and 20 through the hollow plungers 20 and 21 and the check valves 25 and 26, respectively, and then in pairs with the low pressure cylinders they are connected separately to one of the outputs of the spool 27. The plunger cylinders 15 and 16 also connected through check valves 23 and 24, respectively, with a pressure cylinder.

The high-pressure cylinders 31 of the hydraulic gearboxes are connected to the open outputs of the switching spools 27 and through normally closed cut-off spools 13 to pressure cylinders. The low pressure cylinders 32 are connected through normally open cut-off spools 12 to pressure cylinders.

Hydraulic switching devices spools 10 and 12 are connected to the pressure cylinder. The switching solenoid 13 of the spool 13 (not shown) is connected to the limit switches 33 and 34 and to the drive mechanism 7.

The device operates as follows.

In the initial position, the switching spools 10 connect the follower spools 6 to the high pressure cylinders 31 of the hydraulic gearboxes and block the pipelines going to the multiplier units 14. The cut off spools 12 connect the low pressure cylinders 32 of the hydraulic gearboxes to the pressure cylinders. Switching spools and cut-off spools 12 under pressure in pressure cylinders change their positions, provided

P _H ≥P _a ⋅K _p ,

where P _H is the pressure in the pressure cylinder;

P _a - pressure in the battery;

- коэффициент редукции;

- reduction ratio;

d _p is the diameter of the plunger of the high pressure cylinder of the gearbox;

D _p - the diameter of the plunger of the low pressure cylinder of the gearbox.

In the absence of metal in the pressure rolls in the pressure cylinders is created by the force of the return cylinders 3 constantly connected to the NAS and its value can reach

,

,

where P _OH is the pressure in the pressure cylinders in the absence of metal in the rolls;

F _B - the area of the plungers of the return cylinders;

G _B is the force of the weight of the roll;

F _H - the area of the plungers of the pressure cylinders.

Providing the condition F _B / F _H <K _p , which is not difficult, the condition P _OH <P _a ⋅K _p will be satisfied, the switching spools 10 and the cut-off spools 12 will occupy the initial positions and during these periods the roll is set to the desired position in height by moving it down or up.

The roll is moved downward by shifting the follower spools from the middle position upwards, which is provided by mechanism 7. In this case, the NAS is connected to the high-pressure cylinders 31 of the pressure reducers and the pressure equal to P _N = P _a ⋅ K _p is established in the pressure cylinders and the resulting force R _{B is created} , acting on the roll.

R _B = P _a ⋅K _p ⋅F _H + G _B -P _a ⋅F _B

Since, based on the accepted conditions K _p ⋅ F _H > F _B , the resulting force is directed downward and the roll will move downward, the fluid from the NAS fills the high pressure cylinders 31 of the gearboxes, moves the blocks of plungers 30 to the right (according to the diagram), which displace fluid from low pressure cylinders 32 to pressure cylinders with flow rate Q _H ,

Q _H = F _H ⋅V _H ,

where V _H - the speed of the roll down.

The fluid flow rate from US Q _a will be equal to: Q _a = F _H ⋅V _H ⋅K _p .

Since K _p <1, then Q _a <Q _H.

Accordingly, reduced power consumption is N, which, when the pump-drive battery is defined as N = Q _a ⋅R _a.

The roll is moved upward by moving the follower spools from the middle position upwards, which is also provided by mechanism 7. In this case, the follower spool connects the high pressure cylinders 31 of the gearbox to the drain, in which the pressure decreases sharply. Accordingly, the pressure in the pressure cylinders decreases, and since the pressure in the return cylinders remains constant equal to P _a , the resulting force acts upward and the roller moves upward. In this case, the liquid from the pressure cylinder is poured into the low pressure cylinder of the gearbox by moving the cylinder block 30 to the left (according to the diagram), which displaces the liquid from the high pressure cylinders 31 to drain through the follower valve.

In both cases, when the roll moves up and down, the movement of the follower spools from the mechanism 7 is compensated by their movement together with the roll cushions due to the presence of negative feedback on the movement, the role of which is traverses 8 and rods 9. Under steady-state conditions, the speed of movement of the spools from the mechanism 7 and the speed of their movement together with the roll cushions become equal and oppositely directed.

When the mechanism 7 is turned off, the tracking spools, moving together with the roll cushions, go to the middle position, block their moves and the movement of the roll stops.

When the rolled strip is captured by rolls, the increasing rolling force _Rp , acting through the roll cushions on the plungers of the pressure cylinders, sharply increases the pressure in them up to

,

,

where P _mon - pressure in the cylinders during rolling pressing.

Upon reaching equality P = P _{a Mo} ⋅K _p changeover valve 10 and clipped spool 12 change their positions. The spool 12 cuts off the gearbox from the pressure cylinder, and the switching spool connects the follower spool to the spool 27, simultaneously blocking the pipeline going to the low pressure cylinder 31 of the gearbox. At the same time, when the follower slide valve is displaced upward, which occurs due to its movement together with the roll cushion, due to the compression of the liquid in the pressure cylinder, the liquid from the NAS enters, depending on the position of the slide valve 27, into the low pressure cylinder 18, or into the multiplier cylinder 19 block.

In accordance with the above diagram, the fluid enters the cylinder 18. Under the action of this fluid, the movable plunger-cylinder 15, and with it the plunger-cylinder 16 are moved down (according to the scheme). In this case, the liquid from the cavity of the plunger-cylinder 15 through the stationary hollow plunger 20 and the check valve 23 is forced into the pressure cylinder, which keeps the roll in its original position during the rolling period. The pressure of this fluid can reach

,

,

where D _m is the outer diameter of the plunger cylinder (15, 16);

d _m is the outer diameter of the hollow plunger (20, 21).

At the same time, the plunger cylinder 16 displaces the liquid from the low pressure cylinder 19, which partially enters the cavity of the plunger cylinder 16 through the check valve 26 and the hollow cylinder 21, and the rest enters the drain line through the spool 27.

When the plunger-cylinders 15 and 16 reach the extreme lower position of the rod 29, acting on the switching device 28, changes the position of the spool 27. Now the liquid from the NAS enters the low pressure cylinder 19. This ensures the movement of the plunger cylinders 15 and 16 up (according to the scheme). As a result, the fluid from the cavity of the plunger-cylinder 16 through the hollow plunger 21 and the check valve 24 enters the pressure cylinder under the pressure P _mon , ensuring the roll is held in its original position. At the same time, part of the fluid displaced by the plunger cylinder 15 from the cylinder 18? fills the cavity of the plunger-cylinder 15 through the hollow plunger 20 and the check valve 25, and the rest is supplied to the drain line through the spool 27.

When the plunger cylinders 15 and 16 reach their highest position, the spool 27 is switched and the operation of the multiplier block is repeated.

The spool 12, cutting off the gearbox from the pressure cylinder during the rolling periods, reduces the volume of fluid absorbing high pressure. This reduces the flow rate of the liquid (and accordingly reduces the energy loss) necessary to keep the roll in its original position.

When the rolled strip exits the rolls, the pressure in the pressure cylinders decreases sharply to P _OH and the spools 10 and 12 occupy the initial positions, connecting the pressure cylinders to the follower spools through a hydraulic gearbox. The compressed volume of fluid in the pressure cylinders expands, as a result of which the roll, and with it the follower spool, moves downward, connecting the switching spool with the drain. Under the action of the return cylinders, the roll cushions with the plungers of the pressure cylinders move upward; the fluid from the pressure cylinder fills the cavity of the low pressure cylinder 32 of the gearbox, moves the block of plungers 30 to the left (according to the diagram), forcing the fluid out of the high pressure cylinder 31 to drain through the switching and servo spools. The roll and tracking spool are in their original positions.

The shut-off spool 13 in the initial position cuts off the open output of the switching spool from the pressure cylinder, thereby ensuring the operation of the hydraulic gearbox in the installation movements of the roll.

By the end of the rolling cycle, the strips of the plunger plunger of the pressure cylinders will be in the lowest position and the volumes of liquid in the pressure cylinders that will be displaced from them when the roll is moved to the highest position will exceed the volumes that the gearboxes can take when their plunger blocks 16 are shifted to the far left position (according to the scheme). Therefore, when the gearbox plunger block exits to the leftmost position, a signal is sent (for example, from the limit switch 33) to switch the spool 13 and the remaining liquid from the pressure cylinders goes to drain, bypassing the gearbox, through the cut-off spool 13, which switches and monitors the spools. When the plungers of the pressure cylinders exit to their highest position, a signal is supplied (for example, from switch 34) to switch the spool 13 to its original position.

The introduction of hydraulic gearboxes and cut-off spools into the control systems for fluid flows into the pressure cylinders provides a significant reduction in the liquid flow from the batteries during installation movements of the roll, which reduces energy consumption and, ultimately, increases the efficiency of the device.

Claims (1)

A hydraulic installation device for a rolling mill, comprising a pump and storage station, pressure and return cylinders, the plungers of which are connected in pairs to each roll cushion, fluid flow control systems for each of the pressure cylinders, each of which includes a three-way three-position follow-up spool with a movement mechanism, covered by negative feedback on the movement, a three-way on / off switching spool with hydraulic control connected to the pressure cylinder, and mu multiplier block, which includes two movable oppositely oriented opposite cylinder plungers rigidly connected to each other, two fixed low pressure cylinders rigidly connected to each other, two fixed rigidly connected hollow plungers, high pressure cylinders, four non-return valves, a four-way on / off valve with a device its switching, installed with the possibility of interaction with movable plunger-cylinders, while the pump-storage station through pipelines connecting It is provided with return cylinders and one of the entrances of the follower spools, the second inputs of which are connected to the drain, and the outputs are to the input of the switching spools, whose closed outputs are connected to one of the inputs of the four-way two-position valve, the second input of which is connected to the drain, and the plunger-cylinders the multiplier block is separately connected through check valves to the low-pressure cylinders interacting with them, in pairs - to one of the outputs of the four-way on-off valve and separately through the check valves valves - with pressure cylinders and with open exits of switching spools, characterized in that each of the mentioned control systems is equipped with two shut-off spools and a hydraulic reducer, including a movable block of plungers and two stationary cylinders of high and low pressure, while the high-pressure cylinders are connected with open exits of switching spools and through normally closed shut-off spools with electromagnetic control - with pressure cylinders, and low pressure cylinders through normally open shut-off spools with hydraulic control are connected to pressure cylinders.

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