KR102125173B1 - Straightening apparatus - Google Patents

Abstract

The present invention relates to a calibration apparatus. The present invention can obtain an advantageous effect of minimizing damage and deformation of an object to be calibrated by comprising: a cylinder member provided at an upper part of the object to be calibrated; a hitting unit provided to be selectively elevated along the cylinder member; and a hammer provided at the cylinder member so as to be hit by the hitting unit, and hammering a deformation portion of the object to be calibrated using a hitting load from the hitting unit.

Description

Correction device {STRAIGHTENING APPARATUS}

The present invention relates to a calibration device, and more particularly, to a calibration device capable of minimizing damage during a calibration process of a calibration object, and improving stability and reliability.

If deformation occurs in the rotor (or shaft) used in industrial turbines (for example, deformation due to deterioration during operation or bending deformation due to an increase in the number of stoppages), it is impossible to start with high vibration. It must be correctable.

Conventionally, when a turbine rotor bending occurs, a rotor calibration process is performed by applying heat to the rotor, such as a heat immersion method, a heat lathe method, or a calibration method to process after welding. There is a problem that it is restored and bent again, and there is a problem that the rotor is damaged during the calibration process of applying heat.

In particular, according to the existing calibration method of applying heat to the rotor, cracks due to fatigue stress increase occur during long-term operation of the turbine, and there is a problem in that the life of the rotor is shortened. In addition, since a long annealing heat treatment process must be performed due to a change in the structure of the heating part of the rotor bending part, a high level of skill of the operator is required, and there is a problem that a lot of time is required for the rotor calibration process.

Accordingly, in recent years, various studies have been conducted to minimize damage to the object to be calibrated, to simplify the calibration process, and to improve accuracy, but it is still insufficient to develop it.

An object of the present invention is to provide a calibration device capable of minimizing damage to a calibration object and improving stability and reliability.

In particular, the present invention aims to make it possible to accurately correct deformation of a calibration object without applying heat to the calibration object.

In addition, an object of the present invention is to make it possible to minimize re-deformation (restore amount) after calibration of the object to be calibrated.

In addition, it is an object of the present invention to simplify the calibration process and to shorten the time required for the calibration process.

In addition, the present invention aims to make it possible to objectively and accurately correct the deformation of the object to be calibrated without being greatly limited by the operator's experience and capabilities.

According to a preferred embodiment of the present invention for achieving the objects of the present invention described above, the calibration device, a cylinder member provided on the upper portion of the object to be calibrated, a striking unit provided to be selectively elevated along the cylinder member, and a striking unit It is provided on the cylinder member so as to be hit by a hammer, and includes a hammer that hammers a deformation part of the object to be corrected by a hitting load by the hitting unit.

This is to minimize damage to the calibration object, and to improve stability and reliability.

In other words, conventionally, as the rotor is subjected to the calibration process by applying heat to the object to be calibrated, there is a problem that the calibrated rotor is restored and bent again during operation of the turbine, and the rotor is damaged during the calibration process of applying heat. Moreover, since a long-time annealing heat treatment process must be performed due to a change in the structure of a heating part of a deformed portion of the object to be calibrated, a high skill level of the operator is required, and there is a problem that a lot of time is required for the process of calibrating the object to be calibrated.

However, the present invention does not apply heat to the object to be calibrated, and by hammering the deformed portion of the object to be calibrated by using a hitting load, an advantageous effect of minimizing damage to the object to be calibrated and re-deformation (restored amount) after calibration can be obtained. have.

Moreover, since the present invention can exclude a post-treatment process such as an annealing heat treatment process, it is possible to obtain an advantageous effect of simplifying the calibration process and shortening the time required for the calibration process.

The striking unit may be formed in various structures capable of striking the hammer. As an example, the striking unit includes a striking member that is removably accommodated inside the cylinder member and strikes the hammer, and a weight body provided on the striking member and imparting an axial load to the striking member.

Preferably, the weight body is selectively detachably mounted to the striking member. In this way, by allowing the weight body to be selectively detachably mounted on the striking member, the weight of the weight body is adjusted according to the required calibration condition (for example, a deformed state of the object to be calibrated). By replacing it with a weight having), the striking member can adjust the striking load hitting the hammer.

The weight body may be formed in various structures capable of imparting an axial load to the striking member. For example, the weight body includes a plurality of weight members that can be independently separated. At this time, the plurality of weight members may be configured to have the same weight with each other. According to another embodiment of the present invention, it is also possible to configure one or more of the plurality of weight members to have different weights.

In this way, by adjusting the number of the plurality of weight members or by adjusting the sum of the weights of the plurality of weight members, the hitting unit can control the hitting load hitting the hammer.

According to a preferred embodiment of the present invention, the calibration device includes an accumulator provided on the cylinder and supplying compressed air for forcibly striking the striking unit to the hammer.

Preferably, in the lower part of the cylinder, while the striking unit descends along the cylinder, an exhaust valve for exhausting air (air charged in the lower part of the striking unit) from the lower part of the cylinder to the outside of the cylinder while the striking unit descends along the cylinder. Is prepared.

As described above, while the striking unit descends along the cylinder, the air filled in the lower part of the striking unit is rapidly exhausted to the outside of the cylinder through the exhaust valve, thereby filling the lower part of the striking unit during free fall of the striking unit. Since resistance by air can be minimized, it is possible to obtain an advantageous effect of further improving the instantaneous hitting effect by the hitting unit.

In addition, according to a preferred embodiment of the present invention, the orthodontic device includes a constraining member that temporarily constrains the state in which the striking unit is disposed on the top of the cylinder to be spaced apart from the hammer.

For example, the constraining member is formed of a magnet that acts as a striking unit and mutual attraction.

Preferably, a sensing sensor is provided at the top of the hammer to detect the amount of impact by the hammer (the force by which the hammer hammers the object to be calibrated).

According to a preferred embodiment of the present invention, the calibration device includes a moving unit that selectively moves the cylinder member with respect to the object to be calibrated.

The moving unit may be formed of various structures capable of moving the cylinder member with respect to the object to be calibrated. As an example, the moving unit includes: a first moving part for moving the cylinder member with respect to the object to be calibrated along the vertical direction, a second moving part for moving the cylinder member with respect to the object to be calibrated along the circumferential direction of the object to be calibrated, and the object of calibration It may include any one or more of the third moving portion for moving the cylinder member with respect to the object to be calibrated along the axial direction.

More specifically, the first moving part includes a base member, and a first moving member connected to the cylinder member and linearly moving with respect to the base member along the vertical direction.

The second moving part includes a guide rail disposed along the circumferential direction of the object to be calibrated, and a second moving member connected to the cylinder member and moving along the guide rail.

The third moving part includes a third moving member connected to the fixed member and the cylinder member and moving linearly with respect to the fixed member along the axial direction of the object to be calibrated.

According to the present invention as described above, it is possible to obtain an advantageous effect of minimizing damage to the object to be calibrated and improving stability and reliability.

In particular, according to the present invention, it is possible to obtain an advantageous effect of accurately correcting deformation of the calibration object without applying heat to the calibration object.

Further, according to the present invention, it is possible to obtain an advantageous effect of minimizing re-deformation (restore amount) after calibration of the object to be corrected.

Further, according to the present invention, it is possible to obtain an advantageous effect of simplifying the calibration process and shortening the time required for the calibration process.

In addition, according to the present invention, it is possible to obtain an advantageous effect of objectively accurately correcting the deformation of the object to be calibrated without being greatly limited by the experience and capabilities of the operator.

1 is a view for explaining an example of use of the calibration device according to the present invention.
2 is a view for explaining a calibration device according to the present invention.
Figure 3 is a calibration device according to the invention, a partial cut-away perspective view for explaining the internal structure of the cylinder member.
4 is a calibration device according to the present invention, a view for explaining a striking unit.
5 and 6 is a calibration apparatus according to the present invention, a view for explaining the first moving unit.
7 to 9 are diagrams for explaining the second moving unit as a calibration device according to the present invention.
10 and 11 is a calibration apparatus according to the present invention, a view for explaining the third moving unit.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited or limited by the embodiments. For reference, in this description, the same numbers refer to substantially the same elements, and the contents described in other drawings may be cited and explained under these rules, and repeated contents that are determined or apparent to those skilled in the art may be omitted.

1 is a view for explaining an example of use of a calibration device according to the present invention, and FIG. 2 is a view for explaining a calibration device according to the present invention. In addition, Figure 3 is a calibration device according to the present invention, a partial cut-away perspective view for explaining the internal structure of the cylinder member, Figure 4 is a calibration device according to the present invention, a view for explaining the striking unit. And, Figures 5 and 6 is a calibration device according to the invention, a view for explaining the first mobile unit, Figures 7 to 9 are drawings for explaining a second mobile unit as a calibration device according to the present invention, 10 and 11 is a calibration apparatus according to the present invention, a view for explaining the third moving unit.

1 to 11, the calibration device 100 according to the present invention is provided to be selectively liftable along the cylinder member 110 and the cylinder member 110 provided on the top of the object to be calibrated 10 The hitting unit 120 and the hitting unit 120 are provided on the cylinder member 110 to enable hitting, and hammering a deformation portion of the object to be corrected 10 by the hitting load by the hitting unit 120 It includes a hammer 130.

For reference, the orthodontic apparatus 100 according to the present invention is used to straighten deformation generated in the object 10 to be calibrated, and the present invention is not limited or limited by the type of object 10 to be calibrated. .

As an example, the calibration apparatus 100 according to the present invention corrects deformation (eg, deformation due to deterioration during operation or bending deformation due to an increase in the number of stoppages) generated in a rotor (or shaft) used in an industrial turbine. It can be used to, and the object to be calibrated 10 can be supported on the chuck (not shown) of the shelf 30 provided on the bed 20.

The cylinder member 110 may be supported by a frame member (not shown) provided on the bed 20 so as to be disposed on the top of the object to be calibrated 10.

For example, the cylinder member 110 may be formed in the shape of a hollow cylinder having an accommodation space therein, and the striking unit 120 may be selectively accommodated in the interior of the cylinder member 110.

The striking unit 120 is provided to be selectively elevated along the cylinder member 110, and when the striking unit 120 is lowered (falling), the hammer 130 is provided below the cylinder member 110. It is configured to.

The lifting method of the striking unit 120 may be variously changed according to required conditions and design specifications. For example, the upward movement (rise) of the striking unit 120 is performed by pneumatic pressure supplied to the cylinder member 110, and the downward movement (falling) of the striking unit 120 is at the own weight of the striking unit 120. Can be done by

More specifically, the lower end of the cylinder member 110 is provided with a suction valve 114 for selectively supplying air pressure to the inner space of the cylinder member 110, the lower portion of the striking unit 120 through the suction valve 114 As the air pressure is supplied to the striking unit 120 may be raised along the cylinder member 110.

The striking unit 120 may be formed of various structures capable of striking the hammer 130, and the present invention is not limited or limited by the striking unit 120.

As an example, referring to FIGS. 3 and 4, the striking unit 120 is accommodated in the interior of the cylinder member 110 so as to be elevated, and the striking member 122 striking the hammer 130 and the striking member 122 ), and includes a weight body 124 that imparts an axial load to the striking member 122.

The striking member 122 is provided to form the bottom of the striking unit 120, and is configured to strike (contact) the upper end of the hammer 130 when the striking unit 120 descends.

For example, the lower end of the striking member 122 may be configured to be in surface contact with the upper end of the hacker, and the shape and structure of the striking member 122 may be variously changed according to required conditions and design specifications.

For reference, in the present invention, imparting an axial load to the striking member 122 means that the load of the weight 124 along the axial direction (for example, the vertical direction) of the striking member 122 is applied to the striking member ( 122).

Preferably, the weight body 124 is selectively detachably mounted to the striking member 122. As such, by allowing the weight body 124 to be selectively detachably mounted on the striking member 122, the weight of the weight body 124 according to the required calibration conditions (for example, a deformation state of the object to be calibrated) By adjusting (for example, replacing with a weight having a different weight), the striking member 122 can adjust the striking load hitting the hammer 130.

The weight body 124 may be formed of various structures capable of imparting an axial load to the striking member 122, and the present invention is not limited or limited by the structure of the weight body 124.

For example, referring to FIG. 4, the weight body 124 includes a plurality of independently detachable weight members 124a and 124b, and the hitting unit 120 hitting the hammer 130 has a plurality of hitting loads. It can be determined by the total load of the weight member (124a, 124b).

The weight members 124a and 124b may be formed in various structures according to required conditions and design specifications. For example, the weight member 124a, 124b is formed in a cylindrical weight form in which a receiving groove (not shown) in which a guide pin (not shown) is accommodated may be sequentially stacked on the upper portion of the striking member 122. According to another embodiment of the present invention, it is also possible to form the weight member in other forms, such as a linear or ring weight.

At this time, the plurality of weight members (124a, 124b) may be configured to have the same weight with each other. According to another embodiment of the present invention, it is also possible to configure any one or more of the plurality of weight members (124a, 124b) to have a different weight.

In this way, by adjusting the number of the plurality of weight members (124a, 124b) or by adjusting the total weight of the plurality of weight members (124a, 124b), the hitting unit 120 hits the hammer 130. Can be adjusted.

In addition, according to the present invention, by using the weight of the weight 124, the hitting unit 120 hits the hammer 130 so that the hitting load is adjusted, so that the hitting unit 120 hits the hammer 130. It is possible to maintain a uniform hitting load, and an advantageous effect of facilitating the control of the hitting load can be obtained.

The hammer 130 is provided at the lower end of the cylinder member 110 so as to be able to contact the deformed portion of the object to be calibrated 10, and the deformed portion of the object to be calibrated 10 by the hitting load as the striking unit 120 is hit It is configured to hammer.

For example, the upper end of the hammer 130 is disposed inside the cylinder member 110 so that it can be hit by the striking unit 120, and the lower end of the hammer 130 can hammer the deformed part of the object to be calibrated 10. So that it is disposed on the outside of the cylinder member 110.

Preferably, the lower end of the hammer 130 is spherical (or hemispherical) so that the hitting unit 120 can concentrate the hitting load hitting the hammer 130 to the deformed part of the object to be corrected 10 through the hammer 130. ).

When the hammer 130 collides with the deformed part of the object to be calibrated 10, the kinetic energy possessed by the hammer 130 is transferred to the surface of the object to be calibrated 10 in a short moment when the impact occurs and the surface of the object to be calibrated 10 A thin plastic deformation layer is formed on the part, and a reaction force to maintain the state before deformation is applied to the object to be corrected 10. Accordingly, the residual compressive stress on the surface of the object to be calibrated 10 and the tensile stress inside the object to be calibrated are balanced.

According to a preferred embodiment of the present invention, the calibration device 100 is provided on a cylinder and an accumulator 140 that supplies compressed air for forcibly striking the striking unit 120 to the hammer 130. Includes.

The accumulator 140 is provided to maximize the free fall effect of the striking unit 120 by storing fluid pressure energy (eg, air) and then supplying compressed air to the upper part of the striking unit 120 instantaneously. .

As the accumulator 140, a conventional accumulator 140 such as a spring loaded type, a central load type, or a gas oil type may be used, and the present invention is not limited or limited by the type and structure of the accumulator 140. .

Preferably, in the lower part of the cylinder, while the striking unit 120 descends along the cylinder, the air charged in the inside of the cylinder (air filled in the lower part of the strike unit) is external to the cylinder from the lower part of the striking unit 120. An exhaust valve 112 for exhausting the furnace is provided.

As such, while the striking unit 120 descends along the cylinder, the air filled in the lower portion of the striking unit 120 is rapidly exhausted to the outside of the cylinder through the exhaust valve 112, thereby striking the unit 120 ), it is possible to minimize the resistance caused by air filled in the lower portion of the striking unit 120 in the free fall, thereby obtaining an advantageous effect of further improving the instantaneous striking effect by the striking unit.

In addition, according to a preferred embodiment of the present invention, the orthodontic device 100 includes a constraining member 150 that temporarily constrains the state in which the striking unit 120 is disposed on the top of the cylinder to be spaced apart from the hammer 130. can do.

The restraining member 150 is provided to constrain the state in which the striking unit 120 is disposed at the top of the cylinder, until compressed air by the accumulator 140 is supplied to the upper end of the striking unit 120, When compressed air is supplied by 140, the restraint by the restraining member 150 is released.

The restraint member 150 may be formed of various structures that can temporarily restrain the cylinder, and the present invention is not limited or limited by the type and structure of the restraint member 150.

For example, the constraining member 150 is formed of a magnet that interacts with the striking unit 120 and mutual attraction, and may be disposed inside the upper end of the cylinder.

Preferably, a sensing sensor 160 is provided at an upper end of the hammer 130 to detect the amount of impact (the force by which the hammer hammers the object to be calibrated) by the hammer 130.

As the sensing sensor 160, a conventional force sensor capable of sensing the amount of impact by the hammer 130 may be used, and the present invention is limited or limited by the type and sensing method of the sensing sensor 160. It is not.

Through the signal detected by the detection sensor 160, the amount of impact by the hammer 130 can be monitored in real time during the calibration process of the object to be calibrated 10, and based on this, the hitting load or the number of hitting by the hitting unit 120 By controlling the back and the like, it is possible to suppress that the object to be calibrated 10 is over peening.

5 to 11, according to a preferred embodiment of the present invention, the calibration device 100 includes a moving unit 200 that selectively moves the cylinder member 110 with respect to the object to be calibrated 10. .

The moving unit 200 is provided to adjust or align the position of the cylinder member 110 (hammer) in correspondence with the calibration part of the object to be calibrated 10.

The moving unit 200 may be formed of various structures capable of moving the cylinder member 110 with respect to the object to be calibrated 10, and the present invention is limited or limited by the structure and movement method of the moving unit 200. It is not.

For example, the moving unit 200, the first moving unit 210 for moving the cylinder member 110 with respect to the object to be calibrated along the vertical direction, 210, the object to be calibrated along the circumferential direction of the object (10) 10) a second moving part 220 for moving the cylinder member 110, and a third moving part for moving the cylinder member 110 with respect to the calibration object 10 along the axial direction of the calibration object 10 It may include any one or more of (230). Hereinafter, an example in which the mobile unit 200 includes all of the first mobile unit 210, the second mobile unit 220, and the third mobile unit 230 will be described.

More specifically, referring to FIGS. 5 and 6, the first moving part 210 is connected to the base member 212 and the cylinder member and is firstly moved linearly with respect to the base member 212 along the vertical direction. It includes a moving member (214).

The base member 212 is mounted to the frame member provided on the bed, and the first moving member 214 is coupled to the base member 212 in a linear motion in the vertical direction.

At this time, the linear movement of the first moving member 214 can be made by various known driving means. For example, the first moving member 214 may be configured to move linearly with respect to the base member 212 using a conventional air cylinder.

According to another embodiment of the present invention, permanent magnets (not shown) of the N pole and the S pole are alternately disposed on the base member, the coil may be mounted on the first moving member, and the current applied to the coil may be controlled. Thus, the first moving member can be configured to move linearly with respect to the base member on the principle of a linear motor. Alternatively, it is also possible to configure the first moving member to move linearly by a lead screw or other conventional linear motion system rotating by a driving force to the driving motor.

7 to 9, the second moving part 220 is a guide rail 222 disposed along the circumferential direction of the object to be calibrated, and a second rail connected to the cylinder member and moving along the guide rail 222 It includes a moving member (224).

The guide rail 222 may be mounted on a frame member provided on the bed, and is formed to form an arc shape along the circumferential direction of the object to be calibrated. For example, a plurality of guide rails 222 may be provided spaced apart in the vertical direction. The number and spacing of the guide rails 222 may be variously changed according to required conditions and design specifications.

The second moving member 224 is provided to slide along the guide rail 222. In addition, the base member 212 of the first moving member 214 may be coupled to the second moving member 224, the base member 212 is coupled to the guide rail 222 with the second moving member 224. It can be configured to move along.

At this time, the slide movement of the second moving member 224 along the guide rail 222 may be performed by various known driving means. For example, the frame member is formed with an arc-shaped rack gear portion, meshed with the rack gear portion, and the second moving member by a gear (eg, spur gear) rotated by a drive motor coupled to the base member 212. 224 may be configured to slide along the guide rail 222.

Preferably, the movement section of the second moving member 224 that slides along the guide rail 222 is limited to a range of approximately 20 degrees left and right (based on FIG. 9) based on a vertical line passing through the center of the object to be calibrated (eg For example, it may be constrained by a stopper). As described above, the placement angle of the cylinder member 110 is corrected by allowing the moving section of the second moving member 224 to be performed in a range of approximately 20 degrees from left to right based on a vertical line passing through the center of the object to be calibrated 10. Since it can be determined in a range of approximately 20 degrees to the left and right based on the vertical line passing through the center of the object 10, the drop of the free fall effect of the striking unit 120 due to the excessively inclined cylinder member 110 is minimized. Advantageous effects can be obtained.

10 and 11, the third moving part 230 is connected to the fixing member 232 and the cylinder member, and is moved in a linear manner relative to the fixing member 232 along the axial direction of the object to be calibrated. It includes a member 234.

The fixing member 232 is mounted on the frame member provided on the bed, and the third moving member 234 is coupled to the fixing member 232 to be linearly movable along the axial direction of the object to be calibrated.

At this time, the linear movement of the third moving member 234 may be made by various known driving means. For example, a fixed member 232 is formed with a linear rack gear portion of a linear shape along the axial direction of the object to be calibrated, meshes with the linear rack gear portion, and rotates by a driving motor coupled to the third moving member 234 The third moving member 234 may be configured to move along the axial direction of the object to be calibrated (for example, a spur gear).

According to another embodiment of the present invention, it is also possible to configure the third moving member to move linearly by a lead screw or other conventional linear motion system rotating by a driving force to the driving motor.

As described above, it has been described with reference to preferred embodiments of the present invention, but those skilled in the art can variously modify the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that you can change it.

10: calibration target
20: bed
30: shelf
100: calibration device
110: cylinder member
112: exhaust valve
114: suction valve
120: striking unit
122: striking member
124: weight
124a, 124b: Weight member
130: hammer
140: accumulator
150: restraint member
160: detection sensor
200: mobile unit
210: first mobile unit
212: base member
214: first moving member
220: second mobile unit
222: guide rail
224: second moving member
230: 3rd mobile
232: fixing member
234: third moving member

Claims (17)

A cylinder member provided on an upper part of the object to be calibrated;
A striking unit which is provided on the striking member and is provided on the inside of the cylinder member, and a weight unit provided on the striking member to impart an axial load to the striking member; And
It is provided on the cylinder member so as to be able to strike by the striking member, and a hammer for hammering the deformed part of the object to be corrected by the striking load by the striking member.
The weight body includes a plurality of weight members that are detachably mounted to the striking member, and a calibration device for selectively adjusting the sum of loads by the plurality of weight members to adjust the striking load.
delete delete delete delete According to claim 1,
The plurality of weight members are calibration devices having the same weight to each other.
According to claim 1,
Any one or more of the plurality of weight members orthodontic devices having different weights.
According to claim 1,
A calibration device provided in the cylinder and comprising an accumulator for supplying compressed air for forcibly striking the striking unit to the hammer.
The method of claim 8,
A calibration device provided at a lower portion of the cylinder and including an exhaust valve that exhausts air filled in the cylinder from the lower portion of the striking unit to the outside of the cylinder while the striking unit descends along the cylinder.
The method of claim 8,
Correction device including a constraining member for temporarily constraining the state disposed on the upper end of the cylinder so that the striking unit is spaced from the hammer.
The method of claim 10,
The restraining member is a correction device formed of a magnet that interacts with the striking unit.
According to claim 1,
It is provided on the top of the hammer, the calibration device including a detection sensor for detecting the amount of impact by the hammer.
According to claim 1,
A calibration device comprising a moving unit that selectively moves the cylinder member with respect to the object to be calibrated.
The method of claim 13,
The mobile unit,
A first moving unit moving the cylinder member with respect to the object to be calibrated along the vertical direction;
A second moving part moving the cylinder member with respect to the calibration object along a circumferential direction of the calibration object; And
A third moving part moving the cylinder member with respect to the calibration object along an axial direction of the calibration object;
Correction device comprising any one or more of.
The method of claim 14,
The first mobile unit,
Base member; And
A first moving member connected to the cylinder member and moving linearly with respect to the base member along a vertical direction;
Correction device comprising a.
The method of claim 14,
The second moving part,
A guide rail disposed along the circumferential direction of the object to be calibrated; And
A second moving member connected to the cylinder member and moving along the guide rail;
Correction device comprising a.
The method of claim 14,
The third moving part,
Fixing member; And
A third moving member connected to the cylinder member and moving linearly with respect to the fixing member along an axial direction of the object to be calibrated;
Correction device comprising a.

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