JP2601073B2 - Method and apparatus for suppressing roll vibration in plating bath - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll in a plating bath which is immersed in a bath of a hot-dip plating line to stabilize the path of a steel strip to be plated and correct its shape such as warpage. The present invention relates to a method and an apparatus for suppressing the above.

[0002]

2. Description of the Related Art In recent years, demand for surface-treated steel sheets such as hot-dip coated steel sheets having excellent corrosion resistance, weldability and paintability has been rapidly expanding. A typical method for producing a hot-dip coated steel sheet of this surface-treated steel sheet is as shown in FIG. 4, and the steel strip 21 whose surface is cleaned and activated by a continuous annealing furnace (not shown) is used.
Is immersed in a plating bath 22, its traveling direction is changed by a sink roll 23 in the bath, and passes through a collecting roll 24 and a stabilizing roll 25 to form a plating bath 2.
Pulled upward from 2. And wiping nozzle 2
A compressed gas such as air is injected from 6 to squeeze out excess plating solution to adjust the amount of plating applied.

[0003] The collecting roll 24 of the hot-dip plating line is a shape correcting roll for correcting warpage of the plated steel strip, and the stabilizing roll 25 is a pass stabilizing roll of the plated steel strip. It is generally called a support role. These support rolls are most ideal when used in a non-driven state in terms of the surface quality of the coated steel strip. However, since the winding angle and the roll diameter around the roll are small, the thickness and When the width is small or when the tension of the plated steel strip is small, it is difficult to rotate in synchronization with the line speed in a non-driven state. In addition, in the event that rotation failure occurs due to damage to the roll bearings, etc., where abrasion occurs in the plated steel strip, a drive system that drives the roll in the bath from outside the plating bath via a drive shaft in many cases is adopted. ing.

As shown in FIG. 5, the driving device for the support rolls in the plating bath has a structure in which the support rolls 24, 25 are immersed in the plating bath 22, so that the drive shafts 27, 28 It has penetration angles α ₁ and α ₂ with respect to the bath. For this reason, the drive motor 29 reduces the speed reducer 30, the constant velocity joint 31, the drive shaft 2
7, 28, cross pin type in-bath coupling 32, 3
The rotation speed transmitted to the roll shaft via 3 does not result in constant speed transmission due to the penetration angles α ₁ , α ₂ of the drive shafts 27, 28, but induces a pulsation of the angular speed described later in detail. Therefore, vibration occurs in the support rolls 24 and 25, and as a result, chatter marks,
Surface quality defects such as chatter marks and dross defects are generated, and particularly when a plated steel strip for an automobile exterior material is manufactured, its commercial value has been significantly impaired.

[0005] As a known technique for preventing the vibration of the coated steel strip in the hot-dip coating line, there is known a technique in which a permanent magnet is used to face the edge of the coated steel strip from the outside in the width direction and to be located near a wiping nozzle. (Japanese Unexamined Patent Publication No. 57-85964) in which a non-contact magnetic member for applying a tension in the width direction is provided in a non-contact state, and a support frame is disposed horizontally above a wiping nozzle with both sides of a plated steel strip interposed therebetween. Then, it contacts the both ends of the plated steel strip in a horizontally rotatable manner via a bearing on a vertical shaft vertically downwardly mounted on two bases supported horizontally on both sides of the support frame. A pair of upper and lower vibration preventing rolls is provided, one of the vibrating rolls projecting obliquely from one end toward one surface of the plated steel strip, and the other obliquely extending from the end toward the other surface of the plated steel strip. Protrude from each other Insert by placing the device (JP-A-62-
238357) has been proposed.

[0006]

Problems to be Solved by the Invention
The devices disclosed in Japanese Patent Application Publication No. 964 and Japanese Patent Application Laid-Open No. Sho 62-238357 are for suppressing the vibration of the plated steel strip, and do not suppress the cause of the vibration of the plated steel strip itself. However, since it cannot be a fundamental solution to the above problem, a sufficient effect cannot be achieved.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method and an apparatus for suppressing the generation of vibration of a plated steel strip due to a roll in a plating bath of a hot dip coating line. is there.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object. As a result, the vibration of the roll in the plating bath occurs because the drive shaft of the roll in the bath has an angle of penetration with respect to the plating bath. The reason is that the pulsation becomes a vibration source and induces vibration between the roll in the bath having a large moment of inertia and the drive motor.
The vibration of the roll in the bath is caused by the fact that the circumferential speed of the roll in the bath rotated by the movement of the plated steel strip is the circumferential speed of the roll in the bath rotated by the driving force of the drive motor (hereinafter referred to as the drive speed).
Found that it is remarkably occur when larger) that. If its is the peripheral speed of the bath roll which is rotated by the movement of the plated steel strip is bath larger roll driving speed of the driving motor, the driving force is applied to the drive motor side opposite from the bath roll side, the drive Excessive rotation of the motor promotes the generation of vibration. To prevent the peripheral speed of the roll in the bath from being greater than the roll drive speed of the drive motor, or to prevent the peripheral speed of the roll in the bath from being significantly lower than the moving speed of the plated steel strip (hereinafter referred to as the line speed) Incorporating a one-way clutch that transmits the driving load only in a specific direction to the driving system of the bath roll, when the roll peripheral speed of the bath roll rotated by the movement of the plated steel strip exceeds the roll drive speed of the drive motor The inventors have found that it is effective to idle the one-way clutch, and have reached the present invention.

That is, the present invention relates to a drive outside the plating bath.
Entrance angle to motor, constant velocity joint, plating bath
Drive shaft with cross-pin coupling in bath
In a plating bath driven through a driving force transmission system consisting of
In the middle of the driving force transmission system of the roll, provided a one-way clutch for transmitting the driving load only in a specific direction, set the roll drive speed of the drive motor 65 to 100% of the line speed, the movement of the plated steel strip Of rolling rolls in the bath
Peripheral speed exceeds the set drive motor roll drive speed
With that, the one-way clutch is idling, a bath during the coupling part
Than is you block the transmission of the pulsation of the generated angular velocity.

Further, a driving motor outside the plating bath,
Drive shaft with a penetration angle to the plating bath
Drive consisting of shaft and cross pin type in-bath coupling
The drive of a roll in a plating bath driven via a force transmission system;
In the middle of the power transmission system, rotating by the movement of the plated steel strip
The peripheral speed of the roll in the bath is the roll drive speed of the drive motor.
A vibration suppressing device for a roll in a plating bath, comprising a one-way clutch that idles when exceeding a degree .

[0011]

The in-bath coupling for connecting the roll shaft of the plating-bath roll and the drive shaft is a four-pin type shown in FIG. Is often adopted. In this case, as shown in FIG. 6B, the angle ψ ₁ projected from the y-axis direction of the I axis (θ ₁ ) is tan ψ ₁ = tan θ ₁ · cos γ,
Similarly, the angle ψ ₂ projected from the y direction of the J axis is tan ψ ₂
= Tan θ ₁ × 1 / cosγ. FIGS. 7A and 7B show ψ ₁ , ψ ₂ , and − _i -θ ₁ (i = 1, 2) using θ ₁ as a variable. For this reason,
In contact with the groove in the cross pin of the output shaft (D axis) side of the bath during the coupling, Max | give clearance as initial clearance | ψ ₁ -ψ _2. Consider power transmission with a cross pin in this bath. In this case, for simplicity, assuming that the output shaft side (D-axis side) always brakes on the input shaft side (E-axis side), the relationship between the D-axis and the cross pin viewed from the y-axis direction is as follows. , Θ = 0, θ = π / 2, θ = π, the I-axis and the J-axis both contact the power transmission surface, and if 0 ≦ θ ≦ π / 2, only the J-axis transmits power and the I-axis Is away from the power transmission surface and π / 2 ≦
When θ ≦ π, only the I-axis side transmits power and the J-axis is separated from the power transmission surface. FIG. 8 shows this in an angle diagram.
(A) As shown in the figure, the input axis (E axis) to the output axis (D axis)
8 (b) due to the angle variation when transmitting rotation to the
As shown in the drawing, a pulsation of angular velocity occurs in the cross pin in the bath.

Looking at the drive system of the in-bath roll of the hot-dip plating line, as the transfer characteristics of the universal joint, the drive is performed by the motor-side coupling between the reduction gear and the drive shaft and the in-bath coupling between the drive shaft and the roll shaft. In any case, the transfer characteristics between the motor and the roll in the bath cause a pulsation of angular velocity, and the pulsation acts as an excitation source to cause a large inertia (GD ² ) between the roll in the bath and the drive motor. Induces vibration as shown in FIG. Or the use of cross pin type coupling bath, pulsation of the angular velocity is inevitable, causing between the drive motor and roll the pulsation becomes GD ² large, to induce vibration, pulsation of the shafting Edge cutting is the gist of the present invention.

According to the present invention, a one-way clutch for transmitting a driving load only in a specific direction is provided between the driving motor and the roll shaft in the bath, and the roll driving speed of the driving motor is set to 65 to 100% of the line speed. When the peripheral speed of the roll in the bath exceeds the set drive speed of the drive motor,
That is, when the roll in the bath is rotating sufficiently in synchronization with the line speed with the driving force due to the movement of the plated steel strip, the one-way clutch is automatically idled to cut off the gap between the roll in the bath and the drive motor, The transmission of the angular velocity pulsation generated in the coupling portion is prevented, the vibration is not induced, and the vibration of the roll in the bath is suppressed. Further, the roll drive speed of the drive motor is set to 65 to 100% of the line speed, and the drive is performed via the one-way clutch at a speed lower than the speed pulsation transmitted from the roll in the bath to the drive motor. The angular velocity pulsation generated in the coupling portion occurs only in the spindle portion having a small inertia moment, and does not occur between the motor reducer having a large inertia moment and the roll in the bath. In addition, when the roll in the bath is difficult to synchronize with the line speed, for example, when the tension of the plated steel strip is small, or when the roll drive speed of the drive motor is reduced to the set drive speed due to damage to the bearing of the roll in the bath, the one-way clutch is used. Automatically engages and the drive motor acts as a helper to apply a driving force to the roll in the bath, so that the roll in the bath rotates smoothly and prevents the occurrence of scratches on the plated steel strip due to poor rotation of the roll in the bath. can do.

As the one-way clutch for transmitting the drive load only in the specific direction, for example, a type shown in Japanese Patent Publication No. 3-43499 is suitable. However, the present invention is not limited to this. Any communication can be used.
In addition, the roll drive speed of the drive motor is set to a line speed of 65.
If the roll drive speed of the drive motor is set to 65% or less of the line speed, chatter marks are generated, and the roll in the bath is insufficiently rotated, so that the coated steel strip is scratched. Further, when the roll drive speed of the drive motor exceeds 100% of the line speed, vibration due to angular velocity pulsation between the bath roll having a large moment of inertia and the reducer becomes remarkable, and chatter marks are generated on the surface of the plated steel strip. Because.

[0015]

【Example】

Embodiment 1 Hereinafter, a method of preventing vibration of a support roll in a hot-dip plating bath according to the present invention will be described with reference to an example of an embodiment based on a vibration preventing device shown in FIG. FIG. 1 is an explanatory view of a vibration suppressing device for a roll in a plating bath according to the present invention. In FIG. 1, since the support rolls 1 and 2 are used by being immersed in a plating bath, the drive shafts 3 and 4 have penetration angles α ₁ and α ₂ with respect to the plating bath, respectively. Therefore, the rotational power transmitted from the drive motor 5 to the roll shaft via the speed reducer 6, the constant velocity joint 7, the drive shafts 3, 4 and the cross-pin type in-bath couplings 8, 9 is transmitted to the drive shafts 3, 4 Because of the penetration angles α ₁ and α ₂ , the pulsation of the angular velocity is derived instead of the constant speed transmission as described above.

As a countermeasure, a one-way clutch 10 for transmitting a driving load only in a specific direction is incorporated in place of the Loveflex coupling in front of the speed reducer 6. And
The roll drive speed of the drive motor 5 is set to 65-1 of the line speed.
When the peripheral speed of the support rolls 1 and 2 is set to 00% and exceeds the set drive speed of the drive motor, that is, the support rolls 1 and 2 are sufficiently synchronized with the line speed by the driving force due to the movement of the plated steel strip. During the rotation, the one-way clutch 10 is automatically idled to cut off the support rolls 1 and 2 and the drive motor 5. Conversely, when the support rolls 1 and 2 are difficult to follow the line speed and the peripheral speed of the support rolls 1 and 2 reaches the set roll drive speed of the drive motor 5, the one-way clutch 10 automatically engages, and the support rolls The driving force of the driving motor 5 is applied to the first and second motors 2 in an auxiliary manner.

With the above configuration, when the support rolls 1 and 2 are rotating sufficiently in synchronization with the line speed by the power from the plated steel strip, the one-way clutch 10 automatically idles and rotates. Since the support rolls 1 and 2 are cut off from the drive motor 5, the rotational force of the support rolls 1 and 2 is not transmitted to the drive motor 5, so that the drive motor 5 is prevented from over-rotating and the couplings 8 and 9 in the bath are provided. Is generated only in the drive shafts 3 and 4 having a small moment of inertia, and is not generated between the speed reducer 6 having a large moment of inertia and the support rolls 1 and 2. For this reason, the generation of vibration between the drive motor 5 and the support rolls 1 and 2 due to the pulsation of the angular velocity caused by the penetration angles of the drive shafts 3 and 4 is suppressed. Conversely, support roll 1
And 2 become difficult to follow the line speed, and when the peripheral speed of the support rolls 1 and 2 decreases to the set roll drive speed of the drive motor 5, the one-way clutch 10 automatically engages, and the drive motor 5 Since the driving force is applied to the support rolls 1 and 2 at a stage where the load torque is small, the pulsation of the angular velocity such as the coupling in the bath is relaxed, and the support rolls 1 and 2 rotate smoothly, and the plated steel strip is rotated. The occurrence of chatter marks on the surface is prevented, and the occurrence of scratches on the plated steel strip due to poor rotation of the support rolls 1 and 2 is prevented.

Example 2 The apparatus of the present invention described in Example 1 was used, and the plate thickness was 0.8 m.
m, the steel roll having a plate width of 1800 mm is subjected to changing the roll drive speed in the bath of the drive motor with respect to the line speed under the conditions of a collecting roll pushing amount of 25 mm, a stabilizing roll offset amount of about 3 mm, and a line speed of 75 m / min. This was passed through a hot-dip plating bath to produce a plated steel strip. In this case, the ratio of the drive speed of the drive motor in the bath to the line speed, that is, the relationship between the peripheral speed ratio and the vibration speed, was measured, and the peripheral speed ratio and the occurrence of chatter marks on the surface of the plated steel strip were investigated. The results are shown in FIGS. In FIG. 3, in the chatter mark occurrence status, ○ indicates no occurrence, Δ indicates slight occurrence, and X indicates large occurrence.

As shown in FIGS. 2 and 3, the driving speed of the support roll of the driving motor with respect to the line speed is 65-65.
In the case of 100%, the vibration speed was low, and no chatter mark was generated on the surface of the plated steel strip, or even if it was generated, it was extremely slight. This indicates that the generation of vibration due to the pulsation of the angular velocity between the support roll and the drive motor was prevented, and the generation of vibration of the plated steel strip was suppressed.

[0020]

As described above, according to the method and apparatus of the present invention, the cause of vibration of the roll in the hot-dip bath can be suppressed, and chatter marks and the like of the plated steel strip caused by the roll in the bath can be suppressed. Generation can be prevented or significantly suppressed, and the surface quality of the plated steel strip can be significantly improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a vibration suppressing device for a roll in a plating bath according to the present invention.

FIG. 2 is a graph showing a relationship between a peripheral speed ratio and a vibration speed in Example 2.

FIG. 3 is a graph showing a relationship between a peripheral speed ratio and occurrence of chatter ama on the surface of a plated steel strip in Example 2.

FIG. 4 is an explanatory diagram of a general hot-dip plating line.

FIG. 5 is an explanatory diagram of a drive system of a support roll of a general hot-dip plating line.

6A and 6B are explanatory diagrams of a four-pin type cross pin, in which FIG. 6A is a diagram illustrating the structure, and FIG. 6B is a diagram illustrating the angles of the I axis and the J axis projected from the y-axis direction.

7A and 7B are angle diagrams of the I axis and the J axis. FIG. 7A is an angle diagram of ψ ₁ and ψ ₂ using θ ₁ as a variable, and FIG. 7B is a diagram of ψ _i −θ.
FIG. 3 is an angle diagram of ₁ (i = 1, 2).

FIG. 8A is an angle diagram showing a relationship between an output shaft and a cross pin, and FIG. 8B is an angle diagram showing pulsation of angular velocity.

FIG. 9 is a diagram illustrating transmission characteristics from a motor-side cross pin, a bath-side cross pin, and a drive motor to a bath roll.

[Explanation of symbols]

 1, 2 Support roll 3, 4, 27, 28 Drive shaft 5, 29 Drive motor 6, 30 Reduction gear 7, 31 Constant velocity joint 8, 9, 32, 33 Coupling in bath 10 One-way clutch 21 Steel plate to be plated 22 Plating bath 23 Sink roll 24 Collecting roll 25 Stabilizing roll 26 Wiping nozzle

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Minoru Iwahashi 4-5-33 Kitahama, Chuo-ku, Osaka-shi, Osaka Sumitomo Metal Industries, Ltd. (56) References JP-A-3-219061 (JP, A) JP-A-4-145231 (JP, A) JP-A-4-341548 (JP, A) JP-A-3-106350 (JP, U) JP-A-4-33648 (JP, U)

Claims (2)

(57) [Claims] 1. A driving motor outside the plating bath and a constant speed joy
Drive shaft with a penetration angle to the plating bath
G, driving force consisting of cross-pin type in-bath coupling
Driving of the roll in the plating bath driven via a transmission system
A one-way clutch that transmits the driving load only in a specific direction is provided in the middle of the force transmission system, and the roll driving speed of the driving motor is reduced.
Set to 65 to 100% of the movement speed of the plated steel strip, message
Peripheral speed of roll in bath rotating by moving steel strip
Corners but Exceeding roll driving speed of the driving motor set idle unidirectional clutch, resulting in a bath coupling portion
Vibration suppressing method of plating bath rolls characterized that you block the transmission of pulsations of the speed. 2. A constant speed joy, a driving motor outside the plating bath.
Drive shaft with a penetration angle to the plating bath
G, driving force consisting of cross-pin type in-bath coupling
Driving of the roll in the plating bath driven via a transmission system
In the middle of the force transmission system, it is rotating due to the movement of the plated steel strip.
The peripheral speed of the roll in the bath is the roll drive speed of the drive motor.
A vibration suppressing device for a roll in a plating bath, comprising a one-way clutch that idles when the pressure exceeds the limit .