JPS6137002B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a rolling mill having one or more sleeve-fitting rolls in which a sleeve is loosely fitted into the roll body, in which the sleeve is moved in the axial direction or moved to a predetermined position in the axial direction. Regarding how to configure.

Conventionally, as a method for controlling plate flatness and crown in a well-known multi-high rolling mill, a method has been used to change the deflection of the work roll by applying roll bending force between the upper and lower work rolls. Since it comes into contact with the surface of the reinforcing roll, the control function is restricted and a sufficient effect cannot be expected. Furthermore, JP-A-51-103058 and JP-A-52-
No. 97353 proposes a method of controlling the crown of a plate by installing sleeves on the reinforcing roll of a four-high rolling mill at positions corresponding to the width of the plate. However, in these methods, it has been questionable whether the sleeve position can be changed when rolling materials with different widths. As a method for solving this problem, the inventions of JP-A-53-48051 and JP-A-53-48052 have been proposed by the inventors of the present application. These inventions are achieved by loosely fitting the sleeves 4, 4' onto the outer surfaces of the reinforcing rolls 3, 3' and adjusting the position of the supporting arms that hold the sleeves 4, 4', as shown in FIG. , the sleeves 4, 4' are moved in the axial direction of the rolls according to the rolled material 1, and the degree of restraint on the shoulders of the work rolls 2, 2' is changed, thereby controlling the deflection of the work rolls, and We have proposed a rolling mill that enhances the effect of the bending method and also significantly extends the life of the reinforcing rolls.
3' and sleeves 4, 4' are loosely fitted, and a support arm holding the sleeves 4, 4' by a spiral or a hydraulic cylinder is moved in the roll axis direction.

In contrast to the inventions of the former two, the latter two provide a clear gap between the sleeve 4 and the roll 3 and loosely fit the sleeve 4 to the roll axis according to the width of the rolled material 1. It has a structure that allows it to be moved in any direction.

However, when performing high-speed rolling with these rolling mills, there are the following difficulties. In other words, the force applied to the support arm that holds the sleeve is large, so the support arm must have great strength.
Particularly in the case of high-speed rolling, the contact element, that is, the mechanism that is attached to the support arm and directly applies a restraining force to hold the sleeve by contacting the sleeve, wears out quickly, and the frictional heat generated by the contact element is large. Therefore, strong cooling was required.

The object of the present invention is to advantageously solve these difficulties and complete the invention related to the above-mentioned rolling mill, as well as to propose a completely new method for retaining a loose sleeve in a rolling mill having a sleeve loose fit roll in general. The objective is to realize a sleeve retention method that can withstand high-speed, large-volume rolling.

The gist of the present invention is that at least one sleeve is loosely fitted to the outer peripheral surface of the body of at least one roll of a rolling mill so as to be freely rotatable and freely movable in the axial direction.
Rolling having a roll that receives a load directed toward the center of the sleeve on a straight line parallel to the roll axis where the outer circumferential surface of the roll body and the inner circumferential surface of the sleeve are in contact with each other, and receives a force that balances the load from the roll neck via a bearing. In the machine, when changing the position of the sleeve in the roll axis direction, a vector parallel to the rotation axis of the sleeve and in the same direction as the direction in which the sleeve is to be moved, and a circumferential speed vector of the roll at the load point. In the direction where the angle formed by
When the sleeve is moved in the roll axis direction by slightly tilting the axis of the sleeve, or when the sleeve is held at a predetermined position in the roll axis direction, slight deviation of the sleeve position from the predetermined position can be avoided. , a method for setting the position of a loose-fitting sleeve, which is characterized in that the sleeve position is maintained at approximately a predetermined position by correcting the sleeve position using the above-mentioned method of moving the sleeve position, and this method is realized. There are some new concrete methods for this.

The present invention will be explained in detail below.

In the present invention, [loose fit] means that when a sleeve is fitted into a roll, there is no restriction in the axial and circumferential directions, and the sleeve rotates at the same circumferential speed simply by the frictional force between the outer surface of the roll and the inner surface of the sleeve. At this time, there is a gap between the inner surface of the sleeve and the outer surface of the roll that can be easily seen visually, for example, a gap of 1 mm or more (actually 3 mm to 100 mm), so that the axis of the sleeve is aligned with the axis of the roll. This refers to fitting the sleeve into the roll in a state where it can be tilted against the sleeve.

[Load point] is a point where a sleeve loosely fitted into a roll receives a force directed toward the center of the sleeve due to rolling force from another roll or rolling material that comes into contact with the sleeve at one location on the outer surface. A contact area for transmitting the force between the inner surface of the sleeve and the outer surface of the roll into which the sleeve is loosely fitted, which is defined as a linear area substantially parallel to the roll axis, particularly in the circumferential direction of the sleeve. Let's focus on the position of

In order to clarify the effects of the present invention, the relationship between the inclination of the sleeve and the axial movement of the sleeve will be explained below using specific examples, focusing on the relationship with the rotational direction of the roll. do.

FIGS. 2a and 2b are diagrams showing the movement of the sleeve in an example in which the sleeve 4 is loosely fitted to the back-up roll 3 of a four-high rolling mill. The sleeve 4 receives a linear load extending in the axial direction from the work roll 2 at the line segment AoBo shown in FIG. 2a or at point a shown in FIG. The peripheral surface is in contact with the backup roll 3. During the rolling operation, the back-up roll 3 is shown by the arrow V in Fig. 2b.
is rotating in the direction of Therefore, the direction of movement of the sleeve 4 at the load point a is the direction indicated by the arrow W in FIG. 2a.

Setting of the sleeve position in this embodiment is performed by the method shown below. That is, the sleeve 4 is loosely guided at both ends by the contacts 7, 7', and the contacts 7, 7' are attached to the support arm 5, and by changing or holding the position of the support arm 5 in the roll axis direction. , the position of the sleeve 4 is changed or held.

In order to realize in this embodiment the relationship between the moving direction of the sleeve 4 and the direction in which its axis should be tilted, as described in the summary of the present invention, the sleeve 4 of the contacts 7, 7'
The position in the circumferential direction is as shown in Fig. 2b,
It is placed on a semicircular portion extending from point b on the opposite side of load point a to load point a along the rotational direction of the sleeve and roll (direction shown by arrow V).

First, align the sleeve 4 in the direction of the roll axis as indicated by the arrow y.
The case of moving in the direction will be explained. At this time, by moving the supporting arm 5 in the direction of arrow y, the contacts 7 and 7' are moved in the same direction. Then, the sleeve 4 receives a force from the contactor 7 in the direction of the arrow y, so that the sleeve 4 changes from the direction y in which it should be moved to the speed direction W of the sleeve 4 at the load point, as shown by the dashed line in FIG. 2a. The axis of the sleeve 4 is slightly tilted in the direction of rotation. When the sleeve 4 is in a tilted state, the line segment shown in FIG.
AoBo is moving to line segment AB. The part receiving the linear load shown by line segment AB is moving in the direction shown by arrow W, so line segment AB rotates for a short time and then moves to the position of line segment A'B'. do.

Although the sleeve 4 is rotating in an inclined state,
Assuming that it is not moving in the axial direction, line segment AB should be at the position of line segment A″B″ after rotating for an indeterminate amount of time, but in reality it is at the position of line segment A′B′. It can be seen that the sleeve 4 moves in the direction (arrow y) in which the sleeve 4 should be moved by an amount indicated by the vector A″A′ within that time.
In this case, within the time that line segment AB comes to line segment A′B′,
If the supporting arm 5, and therefore the contact 7, moves by the amount indicated by the vector A″A′, the inclination of the sleeve 4 remains parallel to that shown by the dashed line in FIG. 2a, and the sleeve 4 axial movement is carried out constantly.

When the sleeve is forcibly moved in this way, the sleeve 4 moves at an almost constant inclination, and the force required from the contactor 7 at this time is the force required to keep the sleeve 4 at a constant inclination. be. The slope of the sleeve 4 at this time is the length of the line segment A″A′ and the line segment
This ratio is expressed as a ratio to the length of AA', and as explained above, this ratio is determined by the axial movement speed V of the sleeve 4.
It is equal to the ratio V _S /V _R of _S and the roll circumferential speed V _R . The necessary moving speed V _S of the sleeve is smaller than the peripheral speed V _R of the roll, and usually a value of about 0.001 to 0.01 for V _S /V _R is sufficient.

Even when the sleeve 4 is forcibly moved in the axial direction in this way, the gradient of the inclination of the sleeve 4 is
Very small, 0.01 to 0.001. Due to the geometrical relationship between the sleeve 4 and roll 3, their axes are parallel in their natural state. It is necessary to have some degree of elastic deformation near point a. Therefore, the force applied to the contactor 7 is approximately proportional to the inclination of the sleeve 4, but as mentioned above, since the inclination of the sleeve 4 is small, the force is extremely small (for example, according to experiments, at most 0.005 x rolling force).
It is possible to move the sleeve 4 in the axial direction.

Next, a case will be described in which the sleeve 4 is held at a fixed position. In this case, the support arm 5, and thus the contacts 7, 7', are kept at predetermined positions.

Suppose now that the sleeve 4 has moved in the direction of the arrow x in FIG. 2a for some reason, such as asymmetric distribution of load in the axial direction or slight wear of the roll. In this case, since the sleeve 4 has shifted from the predetermined position in the direction of the arrow x, it is sufficient to move the sleeve 4 in the direction opposite to the arrow x, that is, in the direction of the arrow y. This is done by the following action. That is, when the sleeve 4 moves in the direction of the arrow
The axis is temporarily tilted as shown by the dashed line. This inclination is the same as when moving the supporting arm 5 in the direction of the arrow y in order to move the sleeve 4 in the same direction, and as already explained, the sleeve 4 is returned to the direction of the arrow y. However, in this case, contact 7
has not moved, so when the sleeve 4 is returned in the direction of the arrow y, the force applied to the sleeve 4 from the contactor 7 becomes smaller, and the inclination of the sleeve 4 becomes smaller. This situation is the same when the sleeve 4 moves in the direction of the arrow y and comes into contact with the contact 7' on the opposite side.
It will be held within the range guided by 7'.
In this way, when the position of the sleeve 4 is held at a constant position by the method of this embodiment, the inclination of the sleeve automatically moves in the direction to correct the positional deviation, and the positional deviation is corrected immediately. The slope of is suppressed to an extremely small value (according to experiments, the slope is less than 0.001), and correspondingly, the force applied to the contacts 7 and 7' is also extremely small.

The effects of the present invention have been explained above using an example in which a sleeve is loosely fitted into the back-up roll of a four-high rolling mill and the side surfaces of the sleeve are guided by the contacts 7, 7'. is not limited to this. That is, as is clear from the explanation in the above example, the conditions for implementing the present invention are:
The sleeve is loosely fitted to the roll so as to be freely rotatable and freely movable in the axial direction, and the sleeve and the roll are distributed on a straight line parallel to the roll axis where the outer circumferential surface of the roll body and the inner circumferential surface of the sleeve are in contact with each other. ,
In addition, it is in a state where it receives a load acting from the outside in a direction toward the center of the sleeve, and when the sleeve is moved in the axial direction under these conditions,
Movement of the sleeve by tilting the axis of the sleeve from the direction of movement of the sleeve in a direction that rotates it in the direction of the speed of the roll and sleeve at the point of load, or when the sleeve is held in a fixed position, movement of the sleeve as described above. The gist of the present invention is to use a method to correct sleeve position deviations.

Therefore, examples of the form of a rolling mill to which the technology of the present invention can be applied include, for example, a rolling mill in which a sleeve is loosely fitted into the roll of a two-high rolling mill and the object is rolled with the sleeve, or a final roll of a multi-high rolling mill; In other words, a four-high rolling mill is a rolling mill in which a sleeve is loosely fitted to the upper, lower, or one of the reinforcing rolls.

Hereinafter, in accordance with the gist of the present invention, in a rolling mill having a sleeve-fitting roll that satisfies the above conditions, embodiments in which the loose-fitting sleeve is moved or held at a fixed position will be specifically described.

Figures 3a and 3b show an embodiment of the method for changing the inclination of the sleeve. In the figure, the sleeve 4 is loosely fitted onto the back-up roll 3 and receives a load from the work roll 2 that rolls the rolled material 1. The rollers 22 and 23 are used to apply pressure to the outer peripheral portion of the sleeve 4 and change the inclination of the sleeve 4, and these rollers 22 and 23 increase the pressure within the hydraulic cylinder housed within the housing 21. Depending on the circumstances, a force is applied to the outer peripheral surface of the sleeve 4, thereby acting to change the inclination of the sleeve. The housing 21 is attached to the bar 20, which is attached to the housing post 1 of the rolling mill.
1 and 11', and the reaction force received by the rollers 22 and 23 is ultimately supported by the housing posts 11 and 11' of the rolling mill.

FIGS. 4a and 4b show the relationship between the pressure of the rollers 22 and 23 and the direction of movement of the sleeve 4 in the above embodiment. Backup roll 3 and sleeve 4 are rotating in the direction of arrow V,
Therefore, the speed of the back-up roll 3 and sleeve 4 at the load point a is as indicated by the arrow W shown in a and b in the figure.
Consider the case where the direction is . In this case, if the sleeve 4 is to be moved in the direction of the arrow y, the axis of the sleeve 4 should be
It is only necessary to tilt it slightly from the direction in which it should be moved (arrow y) to the direction in which it rotates in the direction of velocity at load point a (arrow W). That is, in this case, the pressure of the roller 22 shown in FIG. 4a may be increased. Conversely, when it is necessary to move in the direction opposite to the direction of the arrow y, the roller 23
It should be clear from the explanation so far that it is sufficient to increase the pressure.

FIG. 5 shows a control circuit for maintaining the sleeve position at a predetermined position in this embodiment. In the figure, solid lines indicate the flow of electrical signals, and dotted lines indicate the flow of pressure oil. In this embodiment, the axial position of the sleeve is detected using a sleeve position detector 30 such as a Magnescale, and the difference between the signal and the signal from the sleeve position setting device 32 is calculated by a comparator 33. , pressure regulating valves 36 and 3 which determine which pressure of the roller 22 and the roller 23 should be increased depending on the sign of the above-mentioned difference by the discrimination amplifier 34, and adjust the pressure of the respective rollers 22 and 23.
Send the pressure setting signal to 7. Pressure regulating valve 36, 37
is supplied with pressure oil from a hydraulic pressure source 38, and supplies the pressure oil reduced in pressure according to the above-mentioned pressure setting signal to the hydraulic cylinders that pressurize the respective rollers 22 and 23. The discrimination amplifier 34 also refers to the signal from the rolling direction changeover switch 35, and depending on the sign of the signals from the sleeve position detector 30 and the sleeve position setter 32 and the rolling direction, each roller 22 is selected. , 23 to determine which pressure to increase.

By configuring the control circuit in this way, if the sleeve position is held at a constant position, the signal from the sleeve position setting device 32 can be kept constant, and if a deviation from the actual sleeve position occurs, the sleeve position can be maintained at a constant position. ,
The inclination of the sleeve is automatically changed in a direction to correct the deviation, and the sleeve position can be held at a substantially constant position. In addition, if you want to change the sleeve position depending on the rolling state, change the signal from the sleeve position setting device 32 to a value corresponding to the new sleeve position, which will cause a deviation from the current sleeve position. Based on this, the inclination of the sleeve is adjusted and the sleeve can be moved to a predetermined position.

Figures 6a and 6b show another embodiment. In this embodiment, both ends of the sleeve 4 loosely fitted to the back-up roll 3 are guided by small rollers 41 and 42. These small rollers 41 and 42 are attached to a common support arm 5 together with large rollers 43 and 44 so as to be rotatable around pins 45 and 46, respectively.
is configured such that its position in the roll axis direction can be changed and maintained by a method not shown. Here, the positions of the small rollers 41, 42 and the large rollers 43, 44 in the sleeve circumferential direction are positions past the load point a shown in FIG. 6b along the rotational direction V of the backup roll 3 and the sleeve 4. It is located as shown in FIG. 6b.

In this embodiment, the movement and holding of the position of the sleeve 4 is performed as follows. First, when attempting to move the position of the sleeve 4 in the direction of the arrow y, the supporting arm 5 is moved in the same direction. Then, the small roller 41 comes into contact with the side surface of the sleeve 4, and the small roller 41 receives a force from the sleeve 4. Since the small roller 41 and the large roller 43 are rotatable around the pin 45, these rollers 41, 43 rotate around the pin 45, and the large roller 43 applies pressure to the outer peripheral surface of the sleeve 4.

The appropriate inclination of the sleeve axis to move the sleeve 4 in the direction of arrow y is the direction shown in FIG. The force exerts a tilting action in the opposite direction. Therefore, in the method of this embodiment, the pressure of the large roller 43 increases the force applied to the small roller 41, so that the large roller 4
3 is designed to have a dominant effect on the inclination of the sleeve. For example, in this embodiment, the force caused by the small roller 41 and the large roller 43
By setting the distance between the line of pressure action and the pin 45 at a ratio of approximately 3:1, the force applied from the large roller 43 to the outer peripheral surface of the sleeve 4 is three times the force applied from the small roller 41 to the side surface of the sleeve 4. It is designed to. By increasing the force applied to the small roller 41 and applying force from the large roller 43 to the outer peripheral surface of the sleeve 4, the axis of the sleeve 4 is tilted.
The sleeve 4 can be moved in the direction in which the support arm 5 is moved.

Next, a case will be described in which the sleeve 4 is held at a predetermined position in the axial direction. In order to hold the sleeve 4 in a fixed position, the supporting arm 5 is kept in a fixed position.
At this time, if for some reason the sleeve 4 moves in the opposite direction to the arrow y, the side surface of the sleeve 4 will hit the small roller 41, similar to the case explained when the sleeve 4 is moved in the direction of the arrow y. Then, the large roller 43 applies force to the outer peripheral surface of the sleeve 4, the axis of the sleeve 4 is tilted, and the sleeve 4 is moved in the direction of the arrow y. In this way, when the position of the sleeve 4 returns to the predetermined position, the force applied to the sleeve 4 by the small roller 41 and the large roller 43, and therefore the inclination of the sleeve 4, decreases, and the sleeve 4 is maintained almost at the predetermined position. dripping

Furthermore, an embodiment in which the sleeve position detection end is provided on the presser roller support frame will be described below.

FIG. 7 shows the configuration of the device.

In FIG. 7, 3 is a backup roll arbor, and 4 is a sleeve. 52 and 53 are press rollers that apply a radial pressing force to the body of the sleeve 4. Reference numeral 61 denotes a non-contact type gap sensor, which is fixed to the frame for supporting the presser rollers 52 and 53. A gap sensor amplifier 62 amplifies the sleeve position signal from the non-contact gap sensor. 65 is a changeover switch for reversing the mill. 66 and 67 are power amplifiers. 68 and 69 are proportional electromagnetic relief valves. 70 and 71 are hydraulic power sources. Hydraulic cylinders 72 and 73 support presser rollers 52 and 53 at one end of their piston rods, and move the presser rollers 52 and 53 back and forth in the radial direction of the sleeve. 74 and 75 are cylinders for moving the sleeve. 76 and 77 are valves. 78 is an electromagnetic switching valve, 79 and 80 are relief valves, 81 and 82
is the hydraulic power source. 83 is a flow control valve.

Next, the operation of the sleeve positioning device configured as described above will be explained.

The position of the sleeve 4 is determined by a non-contact gap sensor 6 fixed to either one of the presser rollers 52, 53.
1 is detected. When the relative position between the sleeve 4 and the non-contact gap sensor 61 changes from a certain equilibrium state, a signal 6 proportional to the amount of change is generated.
3 to the proportional solenoid relief valve 69, and the signal 6
A signal 64 whose sign is opposite to 3 is input to the proportional electromagnetic relief valve 68. As a result, two presser rollers 5
There is a difference in the pressing force between 2 and 53, and the sleeve 4
is tilted with respect to the axis of the arbor 3, and the relative position (in the axial direction) between the non-contact type gap sensor 61 and the sleeve 4 is controlled to be maintained in an equilibrium state.

By configuring and operating in this way,
Compared to a device configuration in which the position detection end of the sleeve 4 is fixedly installed, for example, in the mill housing, there is an effect that not only control is simplified but also a detection end with a small measurement range can be applied.

When the mill is reversed to reverse the rolling direction of a rolled material such as a strip, the direction of axial movement of the sleeve 4 is opposite to the inclination of the sleeve 4.
and 64.

By displacing the sleeve 4 as a unit in the axial direction of the sleeve 4, the position of the sleeve 4 in the steady state in the axial direction can be changed.

In this embodiment, the shift mechanism for displacing the unit includes hydraulic sources 81 and 82, a relief valve 79, a hydraulic cylinder 74, an electromagnetic switching valve 78, and a flow control valve 83.
The shift is turned on and off by an electromagnetic switching valve 78, and the shift speed is controlled by adjusting a flow rate control valve 83.

In addition, the valve 76 is normally in the "closed" state.
When changing the positional relationship (in the axial direction) of the lower sleeve, the sleeve moving cylinder 75 is operated in the "open" state to displace only the sleeve loosely fitted to the lower back-up roll, for example, in the axial direction. , the relative positions of the upper and lower sleeves in the axial direction are changed. Valve 77 is normally “open”
In this state, the back pressure when retracting the presser rollers 52 and 53 in the radial direction of the sleeve 4 is
2. The relief valve 80 functions to provide relief.

Further, a bias voltage is applied in advance to the power amplifiers 66, 67 of the proportional electromagnetic relief valves 68, 69, and the presser rollers 52, 53 are
Make sure that it does not come off the sleeve 4.

As seen in the above embodiments, the sleeve can be moved axially by slightly tilting the axis of the sleeve, or held in place by correcting slight deviations in the sleeve position in this way. This method can be carried out while maintaining the same speed of the sleeve and roll at the loading point, so there is no slippage at the loading point, so it can be carried out with very little force, and the required strength of the retaining device for the sleeve position is reduced. At the same time, frictional heat generation is also reduced, making it possible to perform high-speed rolling using a rolling mill with sleeve-fitting rolls.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an example of a rolling mill with sleeve loosely fitted rolls, Fig. 2 is a diagram for explaining the relationship between sleeve inclination and sleeve movement, and Fig. 3 is an example of a method for changing the sleeve inclination. Illustration showing an example, 4th
The figures are diagrams for explaining the relationship between the force applied to the outer circumferential surface of the sleeve and the direction of movement of the sleeve. In Figures 1 to 4, a is a front view viewed from the rolling direction, and b is a side view viewed from a certain cross section. , FIG. 5 is a diagram showing a control method in the embodiment shown in FIG. 3, and FIG. 6 is a diagram showing another embodiment, in which a is a front view and b is a side view. FIG. 7 is a diagram showing the device configuration of an embodiment in which the sleeve position detection end is provided on the presser roller support frame. 1...Rolled material, 2, 2'...Work roll, 3,
3'...Backup roll, 4,4'...Sleeve,
5... Support arm, 7, 7'... Contact, 10, 11, 1
1'...Housing post, 20...Bar, 21...Housing, 22, 23...Roller, 30...Sleeve position detector, 32...Sleeve position setting device, 33
...Comparator, 34...Discrimination amplifier, 35...Rolling direction switching switch, 36, 37...Pressure control valve, 38...Hydraulic pressure source, 41, 42...Small roller, 43, 44...Large roller, 45, 46...Pin.

Claims (1)

[Scope of Claims] 1. At least one sleeve is loosely fitted to the outer peripheral surface of the body of at least one roll of a rolling mill so as to be rotatable and movable in the axial direction, and the outer peripheral surface of the roll body and the inside of the sleeve are freely fitted. In a rolling mill having a roll that receives a load directed toward the center of the sleeve on a straight line parallel to the roll axis in contact with the peripheral surface, and receives a force that balances the load from the roll neck via a bearing, the roll axis of the sleeve When changing the position in the direction, move the sleeve in the direction where the angle between the vector parallel to the axis of rotation of the sleeve and in the same direction as the direction in which the sleeve is to be moved and the circumferential speed vector of the roll at the load point becomes smaller. When the sleeve is moved in the roll axis direction by slightly tilting the sleeve axis, or when the sleeve is held in a predetermined position in the roll axis direction, the slight deviation of the sleeve position from the predetermined position can be A method for setting the position of a loose-fitting sleeve, characterized in that the sleeve position is maintained at approximately a predetermined position by correcting the sleeve position using the above-mentioned method of moving the sleeve position. 2. The position setting method according to claim 1, wherein pressure is applied to the sleeve body surface at a plurality of locations on the sleeve body, and the axis of the sleeve is tilted by changing the pressure at each location. 3 Detects the position of the sleeve in the roll axis direction and changes the inclination of the sleeve based on the difference between this detection signal and the command signal for the target position to maintain the sleeve position at a predetermined position or change the sleeve position. Claim 1 or 2 characterized by
Positioning method described in section. 4 When a difference occurs between the position of the sleeve in the roll axis direction and the predetermined position, apply a force in the direction parallel to the roll axis to return the sleeve position to the predetermined position according to the difference from the predetermined position. Claim 2, characterized in that a sleeve restraint mechanism is provided to apply to the sleeve, and pressure is applied to the sleeve body by the amplified force through a force amplification mechanism that amplifies the reaction force applied to the sleeve restraint mechanism. Position setting method described in section.