JPS6059045B2 - Automatic roll gap adjustment device for rolling mills - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for automatically adjusting the gap between rolls in a rolling mill, particularly in a roll stand.

The invention is most suitable for application in rolling mills for producing metal strips or plates. Conventionally,
An automatic roll gap adjustment device in a roll stand is known, which comprises a single-chamber hydraulic cylinder mounted under the axle box of the lower roll to provide a preliminary internal force to the roll stand.

The above-mentioned hydraulic cylinder is attached with an electric-hydraulic system for controlling the pressure of liquid (oil) supplied to the hydraulic cylinder from a high-pressure liquid source. This electric-hydraulic system consists of an electric roll cell to absorb rolling force, an electric load cell to record the reserve internal force of the roll stand, and a hydraulic cylinder input and supply to give the reserve internal force to the roll stand. a servo valve for regulating the pressure of the liquid flow, the servo valve having its own electrical control circuit. An electrical load cell for absorbing rolling forces is provided below the screw of the roll housing and above the upper roll axle box. An electrical load cell for recording the reserve internal force of the roll stand is provided between the upper housing separation and the lower roll axle box. The servovalve, along with the electrical control circuit and high pressure liquid source, is located outside the roll stand. The roll gap automatic adjustment device in the roll stand described above operates as follows.

During rolling of the metal strip, the rolling force changes, which is recorded by an electrical load cell. A signal from this load cell is transmitted to an electric-hydraulic system for adjusting the hydraulic pressure in the hydraulic cylinder. As a result, the servo valve operates to change the hydraulic pressure in the hydraulic cylinder, thereby changing the reserve internal force in the stand. That is, by varying the preliminary internal force within the stand in accordance with the rolling force as described above, the roll gap is automatically adjusted within the set range. The above-mentioned conventional apparatus allows almost accurate adjustment of the roll gap within the roll stand.

However, the servo valve is a very pure liquid (oil).
Otherwise, the operation of the servo valve will be very unstable and the operation of the device will be unreliable. Furthermore, servo valves are fairly complex in design, expensive to manufacture, and difficult to operate. Servovalves, like their electrical control circuits, must be handled by highly qualified personnel. USSR Inventor's Certificate No. 45238 describes a roll gap in a roll stand, in which on both sides of the roll stand at least one hydraulic load cell for absorbing rolling forces is installed under the axle box of one of the rolls. A self-adjusting device is disclosed.

In order to develop a reserve internal force in the stand, the device is equipped with hydraulic cylinders mounted separately on both sides of the stand so as not to affect the load cells. Additionally, in order to adjust the fluid (hydraulic) pressure within the hydraulic cylinder, this device is provided with a three-chamber hydraulic pressure regulator, one for each load cell. A first end chamber of the hydraulic pressure regulator communicates with a hydraulic chamber of a hydraulic cylinder on each side of the roll stand, and its intermediate chamber communicates with a load cell via a shut-off valve, and its second end chamber communicates with a load cell via a shut-off valve. The end chamber is in communication with a constant pressure fluid source.
The conventional device described above operates as follows.

During the rolling operation, the fluid pressure in the load cell changes with the rolling force as it passes between the metal strips and rolls. The fluid pressure in the middle chamber of the three-chamber fluid pressure regulator changes accordingly,
As a result, the valve spool of the hydraulic pressure regulator moves. This movement of the valve spool changes the hydraulic pressure in the hydraulic cylinder, which in turn changes the reserve internal force in the stand.
The specific parameters of the device have been preselected in such a way that the gap between the rolling rolls can be adjusted automatically by varying the reserve internal force in the stand depending on the rolling force within a preset range. . The adjustment range is determined by the manner in which the shutoff valve is adjusted in response to the hydraulic pressure in the constant pressure fluid source. However, in this device, during the movement of the valve spool in the three-chamber hydraulic pressure regulator, excessive flow of liquid from the liquid chamber of the load cell to the intermediate chamber of the three-chamber hydraulic pressure regulator occurs;
As a result, there is a problem in that the roll axle box moves, which adversely affects the accuracy of roll gap adjustment.

The present invention is intended to solve the above problems. By incorporating an additional unit, the present invention is simpler to manufacture and more reliable in operation than conventional devices, and has purity characteristics similar to those used in ordinary hydraulic devices. The present invention provides an automatic roll gap adjustment device in a roll stand that allows the use of hydraulic fluid (oil) and can be easily operated by an operator of ordinary skill.

Thus, the invention comprises two similar equipment parts arranged on either side of the roll stand and operating on the same principle, each said equipment part having at least one work roll mounted under the back-up member of one of the work rolls. One single-chamber load cell for detecting rolling force, and a plurality of load cells installed between the backup member of the other work roll and the roll housing to give a preliminary internal force to the roll stand without acting on the load cell. a hydraulic cylinder and a stepped spool movably housed within the casing to define a first end chamber, an intermediate chamber, and a second end chamber, the first end chamber communicating with the liquid chamber of the hydraulic cylinder. and a three-chamber type, wherein the intermediate chamber communicates with the liquid chamber of the load cell, and the second end chamber communicates with a constant pressure fluid source provided in at least one of the two device parts. An automatic roll gap adjustment device in a roll stand comprising a hydraulic pressure regulator, wherein each of the load cells is provided with one pressure regulating valve, and the throttle chamber of the pressure regulating valve is disposed on one side of the roll stand. one fluid pressure source provided for each of the device parts and an intermediate chamber of the three-chamber hydraulic pressure regulator, and a control chamber of the pressure regulating valve communicates with the liquid chamber of the load cell; There are things I did. In the device according to the invention, changes in the rolling force result in changes in the hydraulic pressure in the load cell and, at the same time, in the hydraulic cylinder chamber directly associated therewith.

As a result of this change, the valve spool of the pressure regulating valve is moved, thereby changing the direction of the liquid flow currently flowing through the throttling chamber of the pressure regulating valve, and at the same time pumping the fluid flowing directly through the throttling chamber. Now, the liquid will be pumped up to the middle chamber of the three-chamber hydraulic pressure regulator.

This causes the valve spool of the three-chamber hydraulic pressure regulator to move. Since the first end chamber of the three-chamber hydraulic pressure regulator communicates with the hydraulic chamber of the hydraulic cylinder for applying preliminary internal force to the stand, the hydraulic pressure within the hydraulic cylinder changes as the valve spool moves.

A change in the reserve internal force in the roll stand therefore occurs, which results in a change in the roll gap. Thus, by appropriately selecting the parameters for the hydraulic cylinder, load cell, pressure regulating valve, and three-chamber hydraulic regulator, the reserve internal force in the roll stand can be adjusted in response to changes in rolling force, as in conventional equipment. A predetermined variation is obtained, which allows automatic roll gap adjustment. Furthermore, the rolling forces occurring during rolling act and cause liquid to flow from the load cell into the control chamber of the pressure regulating valve, which has a valve spool with a diameter smaller than the diameter of the piston rod of the load cell.

Since the lateral movement of this spool is considerably restricted, fluid from the load cell is prevented from entering the intermediate chamber of the three-chamber hydraulic regulator, which causes the fluid to ride on the piston rod of the load cell. (to make the former roll axle box immobile). The pressure regulator is connected to the three-chamber hydraulic pressure regulator so that the intermediate chamber of the three-chamber hydraulic pressure regulator serves as one control chamber of the pressure regulator, and the first end chamber of the pressure regulator serves as the throttle chamber of the pressure regulator. It is convenient when combined with a regulator.

This substantially simplifies the design of the device of the invention. During rolling, fluid is supplied directly from a constant pressure fluid source to a hydraulic cylinder for providing a preliminary internal force to the roll stand.

Such a fluid supply eliminates the need to use a large number of units and piping in the device according to the invention, which makes the operation of the device easier and more reliable. The device of the invention is constructed as a hydraulic cylinder with a threaded rod;
and has a working chamber communicating with the sealed liquid chamber, and during rolling, the sealed liquid chamber formed by the first end chamber of the hydraulic pressure regulator and the liquid chamber of the hydraulic cylinder on the side of each stand. It is also desirable to provide a means for moderating the amount of fluid within the chamber.

This means is designed to allow modification of parameters in the device such that the stiffness of the stand is changed, thereby making the device easier to operate. According to the present invention, the structure is simple, the production cost is low, the fluid (oil) with the purity performance used in ordinary hydraulic equipment can be used, and the operation is easy and requires ordinary skill. An automatic roll gap adjustment device in a roll stand is realized that can be easily operated even by a staff member.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIGS. 1 and 2 show an embodiment of an automatic roll gap adjustment device in a roll stand according to the present invention, as viewed from one side of the roll stand.

The device has two similar device parts which are arranged symmetrically on either side of the roll stand 1 and which operate on the same principle. Each device part has a load cell 2 for absorbing the rolling force P, which is connected to a pressure regulating valve 3 via a fluid pressure line. This pressure regulating valve 3 is
It acts to change the pressure and flow rate of oil (fluid) supplied to the three-chamber hydraulic pressure regulator 4 by the pump 5 driven by the electric motor 6 in accordance with the rolling force. The hydraulic cylinder 7 is for applying a preliminary internal force to the roll stand, and is connected to the three-chamber hydraulic pressure regulator 4.

The hydraulic pressure regulator 4 is for changing the oil pressure in the hydraulic cylinder 7 according to the height of the pressure in the pump 8 driven by the electric motor 9 and in the pump 5 driven by the electric motor 6.
The electric motor 6 and pump 5 and the electric motor 9 and pump 8 are installed outside the roll stand.

The oil pressure generated by the pump 8 is held constant by a pressure control valve 10, while the oil pressure generated by the pump 5 is adjusted by a pressure regulating valve 3 according to the oil pressure in the load cell 2. The device according to the invention also comprises a shut-off valve 11 connecting the fluid chamber of the hydraulic cylinder 7 and the first end chamber of the hydraulic pressure regulator 4 to the pump 8 .

Furthermore, means 12 are provided for varying the amount of oil in the liquid chamber.

The device of the invention also includes a safety valve 13 attached to the discharge pipe of the pump 5, a fluid (oil) reservoir 14, and pressure fluid pipes 15 and 16 connecting the pumps 5 and 8, respectively, to the fluid reservoir 14. It is provided.

The load cell 2 has an outer cylinder 17, and a piston 20 is housed in its inner vagina, that is, a space between a cover 18 fixed to the outer cylinder 17 with screws 18a and an integral bottom wall 19. The wall 19 forms a liquid chamber a of the load cell. The outer cylinder 17 has a flow path b for oil to enter and exit the liquid chamber a.
has been formed. The outer cylinder 17 also interacts with the rocker plate 21 of the roll housing 22 at its supporting portion, and the piston rod 23 interacts with the axle box 24 of the lower backup roll 25. The load cell 2 may be constructed by interconnecting a plurality of liquid chambers, each of which is formed by the outer cylinder and piston of a given hydraulic cylinder.

In this case, what is the volume of the load cell liquid chamber a and the piston surface of the load cell? 'a' becomes equal to the total sum of the liquid chamber volumes and piston areas of the plurality of hydraulic cylinders constituting the load cell. Each of the hydraulic cylinders 7 has an outer cylinder 26 in which a plunger 27 is housed.
and the outer cylinder 26 form a liquid chamber c.

The outer cylinder 26 is formed with a flow path d through which oil enters and exits the liquid chamber c. The outer cylinder 26 is located within the axle box 28 of the upper backup roll 29 and interacts with the axle box with their support surfaces, while the plunger 27 interacts with the inner protrusion 30 of the roll housing 22. It's on.
The pressure regulating valve 3 for regulating the pressure and flow rate of oil delivered by the pump 5 has an outer cylinder 31, and a valve spool 32 is accommodated in the inner cavity of the outer cylinder. The cover 33 is pressed by a spring 34 that is abutted against the bottom wall of the lumen 31.

The cover 33 is fixed to the outer cylinder 31 with screws 35. The valve spool 32 together with the outer cylinder 31 forms a control chamber e, together with the cover 33 forms a throttle chamber, and together with the outer cylinder 31 and cover 33 forms a fluid outlet chamber g. are doing. Each of these chambers is provided with one flow path H, i, and j for fluid input and output.
The three-chamber hydraulic pressure regulator 4 has an outer cylinder 36 and a screw hole 35a attached thereto.
It has a cover 37 fixed to the outer cylinder 36, and a stepped spool 38 housed in the inner cavity of the outer cylinder 36. forming a chamber.

Each of these chambers has flow paths N, O, and P for oil input and output, respectively.
One by one. It is provided. The spool 38 has a spring 39 on the cover 37 side and a spring 4 on the outer cylinder 36 side.
0, it is spring biased. The shutoff valve 11 is an outer cylinder 41
, a cover 42 fixed to this with screws 35b, and a valve spool 43 pushed by a spring 45'' on the shaft portion 44 side.
It consists of.

The spool 43 forms a liquid chamber q together with the outer cylinder,
Further, together with the outer cylinder and the cover, a liquid chamber r is formed. The outer cylinder 41 has a flow path s for oil to enter and exit the liquid chamber q.
and a flow path u for oil to enter and exit the liquid chamber r. The means 12 is for changing the amount of oil in the sealed liquid chamber formed by the liquid chamber c of the hydraulic cylinder 7 and the first end chamber k of the pressure regulator 4. The cylinder has a structure in which a piston 47 is housed, and a threaded rod 48 is screwed into a cover 49 which is fixed to the outer cylinder 46 with screws 50 and connected to the piston 46. The piston 47 and the outer cylinder 46 form the working chamber v of this hydraulic cylinder. A flow path w for oil to enter and exit the working chamber v is formed in the outer cylinder 46. The liquid chamber a of the load cell 2 is connected to the control chamber e of the pressure regulating valve 3 through a pressure fluid pipe 51.

In order to fill these chambers a and e with oil, a fluid pressure pipe 53 is connected to the pipe 51 via a check valve 52.
Through the pump 8, oil is supplied under constant pressure to both chambers. The fluid pressure pipe 53 also includes a pipe 54 communicating with the second end chamber m of the hydraulic pressure regulator 4, a pipe 55 communicating with the liquid chamber q of the shutoff valve 11 by a flow path s, and a pressure A pipe 56 communicating with the fluid receiving tank 14 via the regulating valve 10 is connected.

The throttle chamber f of the pressure regulating valve 3 is connected to the pump 5 through a pipe 57, and
7 to the intermediate chamber ' of the hydraulic pressure regulator 4, by a pipe 59 likewise connected to the pipe 57 to the liquid chamber r of the shut-off valve 11, and further to the safety valve 13 and also to the pipe 57. At the same time, it is connected to the receiving tank 14 through a pipe 60. The liquid chamber c of the hydraulic cylinder 7 is connected to each other and to the first end chamber k of the hydraulic pressure regulator 4 by a pipe 61, and also to the working chamber V of the means (hydraulic cylinder) 12. is connected by a pipe 62 connected to the pipe 61, and further connected to the flow path t of the shutoff valve 11 by a pipe 63 also connected to the pipe 61.

The device described above operates as follows.

Prior to passing the metal strip between the rolls of the roll stand 1, the roll gap h between the upper work roll 65 and the lower work roll 66 is adjusted by turning the threaded rod 64. Next, the electric motor 9 of the pump 8 and the electric motor 6 of the pump 5 are started. The pump 8 is passed from the receiving tank 14 through the pipe 16.
The flow of oil (fluid) flowing by gravity into the pipe 5 then flows into the pipe 5.
3. From there, the oil flows through the check valve 52 and the pipe 51 into the liquid chamber a of the load cell 2, flows into the chamber a of the pressure regulating valve 3, and also passes through the pipes 55, 63, 61 and the flow paths A and t. It enters the chamber q of the shutoff valve 11, further flows into the liquid chamber c of the hydraulic cylinder 7, and further flows into the liquid chamber v of the means (hydraulic cylinder) 12 and the first end chamber k of the three-chamber hydraulic pressure regulator. It also flows into the second end chamber m of the three-chamber hydraulic pressure regulator 4 from the flow path p through the pipe 54. At this time, air or a mixture of air and oil from each of the liquid chambers and pipes is passed through the flow path x from the liquid chamber e of the pressure regulating valve 3 by opening the valve 67, and by opening the valve 68. From the tube 61, it can be easily discharged or drained into the receiving tank 14 through a tube, in each case not shown. Excess oil from pump 8 after filling all of the aforementioned chambers and pipes (with valves 67 and 68 closed) maintains a predetermined constant oil pressure (QO=-constant) during operation of pump 8. through the pressure control valve 10 and the pipe 56 into the receiving tank 14.

Oil pressure level Q in the discharge pipe of pump 8.

varies depending on the reserve internal force within the roll stand. The pump 5 pumps up oil that flows in from the receiving tank 14 by gravity, and this oil passes through a pipe 57 to the throttle chamber f of the pressure regulating valve 3, and passes through pipes 57 and 58 to the intermediate chamber e of the hydraulic pressure regulator 4. It also flows simultaneously into the liquid chamber r of the shutoff valve 11 through the pipes 57 and 59.

Excess oil from pump 5 is removed from valve spool 32 and cover 33.
The oil flows from the throttling chamber f to the oil outlet chamber g through the gap y formed by the above, and from there flows into the receiving tank 14 through the flow path j and the pipe 57a. The pressure in the discharge pipe of pump 5 is equal to the pressure of pump 8. This pressure equality results from the balanced state of the valve spool 32 of the pressure regulating valve 3. Therefore, the liquid chambers and fluid pressure pipes of each unit of the device are all Q.

filled with oil under a pressure equal to . As a result of this pressure, the part of the roll housing 22 of the roll stand 1 in which the threaded rod 64 and the axle box 28 of the upper backup roll 29 are provided has a hydraulic pressure Q in the fluid chamber c of the hydraulic cylinder 7 . A preliminary internal force is applied by the force Q generated by this, and the element is deformed by a dimension δh under the action of the internal force. At the same time, the position of the axle box 24 of the lower backup roll 25 supported by the piston 20 of the load cell 2 is fixed.

This means that one side of the piston 20 is at the pressure Q in the liquid chamber a. The other is the force generated by the weight of the rolls 25, 66 and the axle box (the thrust of the work roll axle box is also taken into account), and the force generated by the support pressure of the cover 18 and the outer cylinder 17. The valve spool 43 of the shutoff valve 11 is also in an equilibrium state.

The oil pressures in the liquid chambers q and r are equal, and the valve spool 43 is
5, it is at the rightmost position pressed against the cover 42. The flow paths S and t of the shutoff valve 11 are passed through the liquid chamber q, so that the hydraulic cylinder 9. "7 liquid chamber c and the first
An end chamber k is communicated with a pump 8. The valve spool 38 of the hydraulic pressure regulator 4 adjusts the oil pressure Q of the first end chamber k and the second end chamber m.

and is in equilibrium in the rightmost position under the action of the force caused by the hydraulic pressure in the intermediate chamber e and the action of the springs 39 and 40. Work roll 6 before the strip is fed
The gap between 5 and 66 is equal to the sum of the gap h of the unloaded rolls and the strain δh of the part of the roll housing subjected to the pre-internal force. When the metal strip passes between the work rolls 65 and 66 of the roll stand 1, a force P is generated due to the rolling pressure, which acts on each part of the stand, and also on the backup roll 25 and the axle box 2.
4 on the load cell 2. This happens when,
The roll stand δh1 is extended by the dimension, whereby the gap between the rolls increases to a larger dimension than before operation. The gap between the work rolls 65 and 66 is adjusted by adjusting the magnitude of the force P due to the rolling pressure applied to the load cell 2.
When the force P becomes slightly larger than the force due to the downward support pressure exerted on the piston 20 by the cover 18, the force P
It is started by the action of

When the force due to rolling pressure increases further, the liquid chamber a of the load cell 2
The hydraulic pressure inside increases further. The oil pressure is also generated in the pipe 51 and the control chamber e of the pressure regulating valve 3. As a result, the check valve 52 is closed, and the liquid chamber a of the load cell 2 and the pressure regulating valve 3 are closed.
A sealed chamber including a liquid chamber e is formed, and the hydraulic pressure in the sealed chamber is proportional to the force P due to the rolling pressure, and its magnitude is Q. That's all. The increase in oil pressure in the sealed chamber described above is due to the increase in valve spool 3.
overturning the equilibrium of 2, so that the spool is
3, thus valve spool 32 and cover 33
The dimension of the gap y between them becomes smaller.

As a result, the flow rate of oil flowing into the outlet chamber g from the throttle chamber f through the gap y is reduced, and the discharge pressure of the pump 5 is increased. The increase in the discharge pressure of the pump 5 is caused by the shutoff valve 1
1 spool 43 and the spool 38 of the hydraulic pressure regulator 4
will be displaced at the same time.

The spool 43 of the shutoff valve 11 is moved to the left, and its shaft portion 44 is pressed against the bottom surface of the outer cylinder 41. this is,
The force generated in the liquid chamber r by the pressure of the pump 5 is the pressure Q in the liquid chamber q. This is possible only after the force is greater than that exerted by spring 45. At that time, the spool 43 is in the liquid chamber q
The flow path S is cut off from the flow path S. As a result, a sealed chamber is formed by the liquid chamber c of the hydraulic cylinder 7 and the first end chamber k of the hydraulic pressure regulator 4. The oil pressure in the chamber is proportional to the movement range of the spool 38 of the three-chamber hydraulic pressure regulator 4 and the plunger 27 of the hydraulic cylinder 7, although the amount of oil remains unchanged. During the rolling operation, the roll gap changes with the rolling force P, which causes distortion of the roll stand. In order to keep the roll gap constant, it is necessary that the distortion of the roll stand is never influenced by variations in the rolling force P. This function is performed by the device as soon as a sealed chamber is formed by the liquid chamber c of the hydraulic cylinder 7 and the first end chamber k of the hydraulic pressure regulator 4. In the above device, the increase amount δh1 in the distortion of the roll stand that occurs as a result of the change in rolling force reaching the δP value is the distortion of a part of the roll housing that occurs as a result of the decrease amount in the reserve internal force within the roll stand. The function functions as if compensated by the amount of decrease δh.

This relationship is expressed by the following formula.

however,? = δh1, where δh1 is the distortion of the roll stand,
K1 is the stiffness coefficient of the stand, which depends on its configuration; and 4ε = δh, where δh is the strain on the part of the roll stand due to the decrease in force Q, and K is the stiffness coefficient of the stand, which also depends on its configuration. The stiffness coefficient of the part of the roll stand that is supported is shown.

From equation (1), the ratio of the coefficient K(5K1) should be equal to the ratio of the values δQ and δP.

Thus, due to the above-mentioned operating conditions of the device and because equation (1) is satisfied, the roll gap remains constant regardless of changes in the force P due to the rolling pressure.

The change value δP (increase) in the rolling force P is the liquid chamber a of the load cell.
It is easy to see that this will cause a change (increase) in the value of the oil pressure in the sealed chamber formed by the control chamber e of the pressure regulating valve 3.

However, Fa is the area of the piston 20 in the liquid chamber a of the load cell 2.

As a result, as mentioned above when discussing the equilibrium of the spool 32 of the pressure regulating valve 3, the change value (increase) δ of the pressure of the pump 5
h1 becomes equal to the value of δq.

5 In this case, the stepped spool 38 of the three-chamber hydraulic pressure regulator 4 moves towards the cover 37 , thereby causing the fluid chamber c of the hydraulic cylinder 7 and the first end chamber of the hydraulic pressure regulator 4 to be moved toward the cover 37 . Since the volume of the sealed chamber made up of k is increased, a change (reduction) in the pressure inside the sealed chamber occurs. The value of this change (decrease) δQ2 is 3
It can be determined from the equilibrium condition of the stepped spool 38 of the chamber type hydraulic pressure regulator 4, and is expressed by the following equation.

Note that Fm, Fe, and Fk are the cross-sectional areas of chambers M, e, and k, respectively, and equation (4) is simplified as follows.

From equation (5), it can be determined whether there is a relationship between the change in the oil pressure in the sealed chamber and the change in the pressure of the pump 5, and the following equation can be obtained. By substituting equation (3a) into equation (6), a relational expression between the value of the oil pressure change in the sealed chamber and the pressure change amount δP is obtained. The amount of change (decrease) in the reserve internal force within the roll stand can be found from the following equation. However, Fc is the area of the plunger 27 of the hydraulic cylinder 7.

By substituting equation (8) into equation (7), a relational expression between δQ and δP is obtained. The left-hand sides of equations (2) and (9) are equal, so the simultaneous solution of these equations is that equation (10) must be satisfied in order for the roll gap to be adjusted in a constant manner by the device described here. This is a necessary condition for equation (1) that does not hold.

The initial values used to select the parameters of the device are stiffness coefficient K (indicating the stiffness of the roll housing when applied with force Q), stiffness coefficient K1 (indicating the stiffness of the roll stand)
, the stiffness coefficient K2 (indicating the stiffness of the roll stand portion to which the force Q is not applied), and the ratio of the displacement value δS of the spool 38 of the three-chamber hydraulic pressure regulator 4 to the change value δP of the rolling force P. This is a coefficient K3 indicating.

According to equation (7), the difference between the oil pressure change value δQ2 in the sealed chamber formed by the liquid chamber c of the hydraulic cylinder 7 and the first end chamber k of the hydraulic pressure regulator 4 and the change amount δP of the rolling force P has a linear proportional relationship.

However, as long as the oil pressure change value δQ2 in the sealed chamber is proportional to the displacement δS of the spool 38 of the three-chamber hydraulic pressure regulator 4, there is also a linear relationship between δS and δP expressed by a proportionality coefficient K3. A proportional relationship exists. That is, the parameters of the sealed chamber formed by the liquid chamber c of the hydraulic cylinder 7 and the first end chamber k of the hydraulic pressure regulator 4 can be determined for specific values of K, Kl, K2 and K3. Next, the above-mentioned oil pressure change δQ2 in the sealed chamber W1 and the volume increase δW of this sealed chamber
1, it is known that there is a correlation when the oil amount there is constant.

If the compression coefficient of oil is β (reciprocal of the stiffness coefficient), the pressure change value is as follows. By substituting (12) into equation (8), the change value δQ of the reserve internal force Q is obtained by the following equation.

Based on the equation (1), the change δQ in the force Q can be obtained using the following equation.

As a simultaneous solution of equations (13) and (14), the correlation between the oil amount W1 in the sealed chamber and its increase amount δW1 is obtained as follows. Increase δ in closed chamber W1 resulting from change in rolling force
W1 is due to two factors.

One is the axle boxes 28 and 24 of the upper and lower backup rolls.
However, each part of the roll stand 1 to which the force Q is not applied (work rolls 65 and 66, backup rolls 29 and 25,
Lower backup roll 25 axle box 2 load cell 2,
The displacement δS1 of the plunger 27 with respect to the outer cylinder 26 of the hydraulic cylinder 7 causes an increase δW1 in the closed chamber W1 when the deflection strain value δH2 of the lower part of the roll housing is brought closer to matching the deflection strain value δH2 of the lower part of the roll housing. It is. The apparatus described here has the advantage that when the rolling force increases, the axle boxes 24 and 2
8 closer together, whereby the sealed chamber undergoes a volume reduction due to the displacement of the plunger 27.

On the other hand, the above increase δW1 is also caused by the displacement δS of the spool 38 of the three-chamber hydraulic pressure regulator 4.

In this case, an increase in rolling force causes a positive increase in the closed chamber volume W1. That is, the increase value δW1 of the sealed chamber is expressed as follows. By substituting equation (16) for equation (15), the following correlation equation between the amount of oil in the sealed chamber and the specific parameters K, Kl, K2, and K3 is obtained.

here If we substitute , then equation (17) becomes the following equation.

Equation (18) expresses the relationship between the liquid chamber c of the hydraulic cylinder 7 and the hydraulic pressure regulator 4.
This is the most important condition for selecting the volume of the sealed chamber formed by the first end chamber k.

The volumes of the above sealed chambers are analyzed as K, Kl, K2, K
3, it can be seen that it has specific values of Fc, Fk and β. However, in reality, these numbers may differ from the calculated values. Therefore, the required volume value W1 of the sealed chamber mentioned above is set before use, and if necessary, with the help of means 12 (hydraulic cylinder), the piston 47 is moved into the outer cylinder 46 by means of a threaded rod 48. It is adjusted by displacing it with respect to. In order to prevent overloading of the rolling stand 1 and the device according to the invention, the safety valve 13 of the pump 5 is set at a pressure corresponding to the maximum value of the rolling force. When the metal plate or strip comes out of the roll stand, the oil pressure in the sealed chamber consisting of the liquid chamber a of the load cell 2 and the control chamber e of the pressure regulating valve 3 decreases, and its value is Q. The above-mentioned sealed chamber comes to communicate with the pump 8. As a result, the pressure inside the sealed chamber is Q.

is equal to The pressure generated by pump 5 is therefore also Q. , whereby the valve spool 43 of the shutoff valve 11 is moved towards the cover 42 and pressed against it. At the same time, the liquid chamber C of the hydraulic cylinder 7, the liquid chamber v of the means 12, and the first end chamber k come to communicate with the pump 8 through the flow paths S, t and the liquid chamber q of the shutoff valve 11.
Thus, all liquid chambers and fluid pressure lines of the device are at pressure Q.

The device is then refilled with oil and is ready to begin the roll gap adjustment operating cycle again. The embodiment of the automatic roll gap adjustment device in the roll stand shown in FIGS. 1 and 3 is different from the device shown in FIGS. 1 and 2, and has a three-chamber hydraulic pressure regulator 4. The pressure regulator 69, which is a new unit that integrates the pressure regulating valve 3, is characterized in that it operates as a whole.

Furthermore, the integrated operation of the unit allows the elimination of units such as the means 12, the shut-off valve 11, the pressure fluid lines 55, 58, 59, 62 and 63.

Other units of the device according to the invention are: load cell 2, hydraulic cylinder 7, electric motor 6 and pump 5, electric motor 9 and pump 8, pressure control valve 10, safety valve 13, fluid reservoir 1 and pipes 51, 53, 54. , 57a, 61, as well as the check valve 57 and valves 67, 68, have the same functions as those described in the first embodiment and are given the same drawer numbers.

Regarding the newly configured unit, the regulating valve-pressure regulator 69, the chambers and flow paths that remain and are formed after the three-chamber hydraulic pressure regulator is combined with the regulating valve are the first.
It performs the same function as that described in the example,
In addition, the same drawer symbol with a subscript is attached.

Regulating Valve - Pressure regulator 69 has an outer cylinder 70, into which a two-stage valve spool 71 having a tapered small diameter end is fitted.

The outer cylinder 70 has a cover 74 on the pointed end side of the spool.
is attached by screws 73, and a cover 75 is attached to the large diameter side of the spool by screws 73a. The valve spool 71 forms a throttle chamber f1 together with the cover 74, and forms an outlet chamber g together with the outer cylinder 70 and the cover 74.
1, and at the same time together with the outer cylinder 70 form a control chamber e1, and together with the cover 75 and the outer cylinder 70 form a second end chamber m1. In order to cause oil to flow in and out of each of these chambers, flow paths Nl, il,
jl, hl and P1 are formed. The throttling chamber f1 of the regulating valve-pressure regulator 69 is connected to the flow path 1 as in the first embodiment.
1 and the variable pressure pump 5 through a fluid pressure pipe 57 . Further, the throttle chamber f1 communicates with the liquid chamber c of the hydraulic cylinder 7 through the flow path n1 and the pipe 61. The outlet chamber g1 communicates with the receiving tank 14 through the flow path J1 and the pipe 57a. The control chamber e1 communicates with the liquid chamber a of the load cell 2 through a flow path h1 and a pipe 51, and the pipe 51 communicates with the constant pressure pump 8 through a check valve 52 and a pipe 53. A second embodiment of the device according to the invention operates as follows.

In order to fill all the liquid chambers of each unit of the apparatus with oil, electric motors 9 and 6 are started to rotate pumps 8 and 5, respectively. The oil at pressure QO pumped up by pump 8 is transferred to pipes 53 and 5.
4 to fill the second end chamber M of the regulating valve-pressure regulator 69, and flowing through the pipe 53, check valve 52, and pipe 51 to fill the liquid chamber a of the load cell 2 and the regulating valve-pressure regulator 69. control room e1 is filled. By opening the valve 67, air is discharged from all piping to the receiving tank 14 through a single pipe (not shown).

The liquid chamber c of the hydraulic cylinder and the throttle chamber f1 of the regulating valve/pressure regulator 69 are filled with oil pumped up by the pump 5 and flowing through the pipes 57 and 61. Excess oil overflows from the throttle chamber f1 into the outlet chamber g1 through the gap y1 formed by the spool 71 and the cover 74, and further flows out into the receiving tank 14 through the flow path j1 and the pipe 57a. In this state, the oil pressure generated by the pump 5 is Q. is equal to This pressure equality arises from the equilibrium condition of the regulating valve and the spool 71 of the pressure regulator 69 if the following equation holds. F
fl+Fel-Fmeni0 ・(19
) However, Ffl, Fel, and Fml are the cross-sectional areas of the spool 71 in the filled liquid chambers Fl, el, and m1, respectively. Thus, the liquid chamber of all units in the above device is Q.

As a result, the roll housing is subjected to a preliminary internal force of force Q. The device is put into operation with a sheet or strip of metal fed between the rolls.

At the moment of start of operation, when the value of the rolling force causes a value of the reaction force at the cover 18 acting on the piston of the load cell 2,
It occurs in response to rolling force. When the rolling force is further increased,
The oil pressure in the liquid chamber a of the load cell 2 increases, and as a result, the pipe 5
1 and the pressure in the control chamber e1 of the pressure regulator 69 also increases. At the same time, the check valve shuts off each of these chambers from the pump 8, and as a result, a sealed chamber is formed by the liquid chamber a of the load cell 2 and the control chamber e1 of the regulating valve and pressure regulator 69. The rising pressure in the sealed chamber will cause the spool 71 of the regulating valve-pressure regulator 69 to become unbalanced, thereby causing its displacement. This is now spool 71
This will increase the gap y1 between the cover 74 and the cover 74. This reduces the resistance to the flow of oil pumped by the pump 5 and flowing out from the throttling chamber to the outlet chamber g1 through the gap y1, thereby reducing the hydraulic cylinder pressure for influencing the reserve internal force in the roll stand. The pressure in the liquid chamber c of 7 and the pressure in the pump 5 will also decrease.

As a result of this, an increase in rolling force P causes a decrease in reserve internal force Q in the support frame.

Conversely, if the rolling force P decreases, the preliminary internal force Q increases. Applying calculation methods similar to those used for parameter selection for the first embodiment of the invention, the parameters Fe, Fc, Fa, Ffl and their The relationship can be found by the following equation.

If this condition is met, the increase in strain resulting from the distortion of the roll stand will be compensated by the increase in strain resulting from the change in the reserve internal force within the roll stand.

That is, the condition at this time is shown by the following equation (1), and this condition is satisfied, and the equation is established for the given embodiment of the present invention.

If equation (1) holds, the gap between the work rolls remains unchanged, just as in the first embodiment of the invention.

That is, changes in rolling force and resulting distortions within the roll stand will never affect the side view of the roll nip.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a roll stand having a part of the automatic roll gap adjustment device according to the present invention, as viewed from one side of the stand, together with a sectional view of a hydraulic cylinder and a load cell, and FIG. 2 is a diagram according to the present invention. Figure 3 is a diagram showing the remaining parts of the automatic roll gap adjustment device shown in Figure 1 together with sectional views of each unit, and Figure 3 shows a part of the automatic roll gap adjustment device shown in Figure 2, which has three pressure regulating valves. FIG. 3 is a diagram showing an embodiment in combination with a type hydraulic pressure regulator. 1...Roll stand, 2...Load cell, 3...Pressure regulating valve, 4...3-chamber hydraulic pressure regulator, 5...Fluid Pressure source, 7...hydraulic cylinder, 11...closing valve, 12...flow rate adjustment means, a...hydraulic pressure of load cell, c...
...Liquid chamber of hydraulic cylinder 7, e...Pressure regulating valve 3
control room, f... throttle chamber of pressure regulating valve 3, k...
・First end chamber of the hydraulic pressure regulator 4, ′... intermediate chamber of the hydraulic pressure regulator 4, m... second end chamber of the hydraulic pressure regulator 4.

Claims (1)

[Claims] 1 comprising two similar equipment parts arranged on either side of the roll stand and operating on the same principle, each of which has at least one rolling force mounted below the back-up member of one of the work rolls; a single-chamber load cell for detection; a plurality of hydraulic cylinders installed between the backup member of the other work roll and the roll housing for applying preliminary internal force to the roll stand without acting on the load cell; , a stepped spool is movably housed within the casing and defines a first end chamber, an intermediate chamber, and a second end chamber, the first end chamber communicating with the fluid chamber of the hydraulic cylinder; a three-chamber hydraulic regulator, wherein the intermediate chamber communicates with the liquid chamber of the load cell and the second end chamber communicates with a constant pressure fluid source provided at least one for each of the two device parts; An automatic roll gap adjustment device in a roll stand, comprising: one pressure regulating valve 3 for each of the load cells 2, and a throttle chamber f of the pressure regulating valve 3 disposed on one side of the stand 1. The control chamber e of the pressure regulating valve 3 communicates with the fluid pressure source 5 provided for each of the device parts and the intermediate chamber l of the three-chamber hydraulic pressure regulator 4, and the control chamber e of the pressure regulating valve 3 communicates with the fluid chamber a of the load cell 2. An automatic roll gap adjustment device in a roll stand, characterized in that the device is in communication with the roll stand.