JP2572016B2 - Speed and suction force control system for steel plate suspended conveyance - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for controlling a conveying speed and a magnetic attraction force required for suspending and conveying a steel plate.

[Conventional technology]

Generally, as one of the electromagnetic force application devices that apply the theory of the linear motor, a transfer device having high speed, non-contact or non-maintenance, which is not provided by a conventional mechanical system, is applied to various types of transfer. .

In this case, when the present invention is applied to the transport of a steel sheet, if the transported steel sheet is used as a reaction plate, a direct thrust is applied, so that the transported steel sheet can be driven in a non-contact manner. An example is shown in FIG.

That is, FIG. 4 is a schematic view showing an example of a conventional steel sheet conveying apparatus, wherein 1 is a stator of a one-sided linear induction motor, 2 is a steel sheet, 3 is a roller, and 4 is a gap support mechanism.

In FIG. 4, a primary-side stator 1 is disposed on the ground Q side, and a secondary-side steel plate 2 has a gap supporting mechanism 4 for supporting a gap.
Is disposed on the roller 3 provided in the first position.

The steel plate transport device having such a structure transports the steel plate 2 by a constant thrust and magnetic attraction generated from the stator 1.

[Problems to be solved by the invention]

However, since the steel plate 2 as a magnetic body is disposed above the roller 3 and the gap support mechanism 4, these must have a structure that can sufficiently withstand the sum of the weight of the steel plate 2 and the magnetic attractive force. Further, when the thickness of the steel plate 2 is reduced, the steel plate 2 hangs down between the rollers 3 and is attracted to the stator 1, so that there is a drawback that the conveyance is impossible unless the mounting pitch of the rollers 6 is reduced.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a speed at which a steel plate 2 can be transported without the weight of the steel plate 2 being applied and the mounting pitch of the rollers 3 need not be reduced. , A suction force control device.

[Means for solving the problem]

Means to achieve the object is to provide a signal on the primary side stator for suspending the secondary side steel plate of the single-sided linear induction motor to a signal that repeats the full voltage or the reduced voltage so that the thrust of the motor and the magnetic attraction force are reduced. The purpose of the present invention is to control the steel sheet on the secondary side to give a required amount of suspension conveyance speed and magnetic attraction required for suspension conveyance.

In other words, in order to be able to suspend and transport a magnetic steel sheet with a secondary steel sheet suspended, the thrust and magnetic attraction generated by the stator of a one-sided linear induction motor are controlled, and the magnetic attraction and the weight of the steel sheet are controlled. It is only necessary that the difference be positive so that the steel sheet does not fall and that the sheet can be conveyed by applying a thrust in the moving direction. For this purpose, the voltage of the power supply applied to the stator of the one-side linear induction motor is controlled, and the steel sheet is conveyed by the thrust and the magnetic attraction.

Next, the conditions for transporting the steel sheet will be described with reference to FIG.

Fig. 2 is a vector diagram of the force applied to the magnetic steel sheet.
The magnetic attraction force f _{A is} on the positive side of the Y-axis and the weight of the steel sheet is mg on the negative side.
(Hereinafter referred to as W), the frictional resistance μmg is shown on the positive side of the X-axis, and the thrust f is shown on the negative side.

In FIG. 2, the condition for enabling the conveyance is determined by the thrust f of the one-side linear induction motor received by the conveyed steel plate.
Is greater than the rolling frictional resistance μmg (μ: rolling friction coefficient) between the rollers and the magnetic force f _{A in} the direction perpendicular to the direction of the thrust between the one-side linear induction motor and the steel sheet. What is necessary is just to become larger than self-weight W. The thrust and magnetic attraction force of the one-sided linear induction motor vary according to the value of the magnetic flux density Bgap in the gap between the induction motor and the steel plate.Thus, by adjusting the gap length g, the thrust f and the magnetic attraction force are adjusted. f _A is variable, but
It is advantageous in terms of efficiency and power factor of the linear induction motor that the gap clearance of the gap length g be as short as possible.

From the above, the gap length g is adjusted by the magnetic attraction force f _{A so} that the steel sheet can be transported without being attracted to the stator surface of the one-sided linear induction, and the steel sheet is (f _A −W)
With a certain force, it can be transported in the traveling magnetic field direction. Therefore, it is possible to suspended transport by giving requirements thrust f and the magnetic attraction force f _A by controlling the voltage applied single-sided linear induction motor. Next, the present invention will be described with reference to the drawings, and its operation will be described in detail.

〔Example〕

FIG. 1 is a configuration diagram showing one embodiment of a speed and suction force control device for suspending and conveying a steel plate according to the present invention, and FIG. 3 is a characteristic diagram showing one example of a control method thereof.

In FIG. 1, the point different from the conventional apparatus is that the iron plate 2 'on the secondary side is suspended, and the stator 1' according to the characteristics shown in FIG.
Is to control.

That is, the stator 1 ′ is not disposed on the ground side as in the conventional device, but is suspended from the gap support mechanism 5. The roller 6 is attached to the gap support mechanism 5 below the stator 1 '. The steel plate 2 ′ moves in the direction of arrow A while suspending the surface of the roller 6.

In the single-sided linear induction motor including such a device, the conventional device employs on / off control as a simple speed control method because the steel plate 2 slides on the roller 3. Then, the entire voltage was applied during the on-time, and zero voltage was applied during the off-time. However, in the case of the suspended conveyance applying the magnetic attraction force as in the present invention, the zero voltage was applied during the off-time. It falls without generating magnetic attraction. Therefore, it is a basic requirement to apply a minimum voltage necessary for suspension, that is, a reduced voltage during the off-time.

Now, such a control device will be described with reference to FIG.

First, 'when approaches, the stator 1' steel plate 2 on one side type induction motor magnetic attraction force by applying a full voltage E ₁ to the
f Generates _A1 and ensures magnetic attraction for suspension. Then, it generates the thrust f ₂ when the applied total voltage E ₂ if the gap length g is retained, the rate is accelerated.

When the steel plate 2 'is a stator 1' starts reliably transport operation by, a reduced voltage E ₁ and then time subtracting the voltage at t _1, to generate a suspended possible magnetic attraction force f _A1 of the steel plate 2 ', Thrust is f ₁
Decreased becomes, speed is decelerated from V _2. Speed below the required average speed, for example, time to apply the full voltage E ₂ When turned t _2, and f _A2 increases the magnetic attraction force, safely performed reliably pendant suction movement. And, time is the same action as the state at t ₂ Once you become t _3, repeat the full voltage E ₂ or reduced voltage E _1. The minimum magnetic attraction force capable of sucking the transport is slightly lower than the magnetic attraction force f _A1 as shown.

At this time, if the gap length g of the steel plate 2 'expands due to some influence during the reduced voltage time and the magnetic attraction cannot be performed, the steel plate 2'
Although the suspended state can be maintained for a short time due to the inertia, if the reduced voltage is not maintained, the suspended state cannot be achieved, resulting in a drop. This fall short applying a full voltage E ₂ was repeated operate to prevent the suspended conveyance and secure a speed suction force control device that allows also the speed control. Further the steel plate 2 pass through the first total voltage application time t ₁ and a voltage reduction time t ₁ ~t ₂ 'and the total voltage, t _3, t ₄ to repeat the reduced voltage, can control the transport speed by adjusting the ... time It is not necessary to employ an expensive speed control method. Further, since the force applied to the steel plate 2 'by the suspended conveyance is only the difference between the magnetic attraction force and its own weight, the mechanical damage by the roller 6 is reduced as compared with the conventional apparatus, and there are many advantages in quality control.

〔The invention's effect〕

As described above, according to the present invention, the steel sheet has been conventionally conveyed by driving a belt conveyor, a roller table or a roller, or the non-contact conveyance has been performed by a linear induction motor. In this case, a magnetic attraction force acts between the linear induction motor and the magnetic steel sheet, and this force is about 10 times the thrust, and a large force is applied to the steel sheet. However, these disadvantages have been resolved.

In other words, if the transport is suspended as in the present invention, the steel plate operates as if it were floating with far less force only by the difference between the magnetic attraction force and its own weight, and the friction coefficient μ with the roller also decreased. In addition, it is possible to convey with less thrust, and it is not necessary to strengthen the gap support mechanism. And all voltages,
By repeatedly applying the reduced voltage, the steel sheet can be conveyed while giving a slight vibration to the steel sheet, so that the jamming state, which often occurs in the conventional apparatus, is reduced, and stable conveyance is possible.

Therefore, the apparatus for controlling the speed and the suction force of the suspended transfer of the steel sheet of the present invention exerts an excellent effect in practical use.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a speed control apparatus for suspending and conveying a steel sheet according to the present invention, FIG. 2 is a vector diagram of a force applied to a magnetic steel sheet, and FIG. FIG. 4 is a configuration diagram showing an example of a conventional apparatus. 1,1 ′… Stator, 2,2 ′… Steel plate, 3,6… Roller, 4,5
… Gap support mechanism, E ₁ …… Decrease voltage, E ₂ …… Full voltage, f…
… Thrust, f _A …… magnetic attraction.

Claims (1)

(57) [Claims] In a steel sheet transporting apparatus using a single-sided linear induction motor, a signal that repeats a full voltage or a reduced voltage is given to a primary-side stator that suspends a secondary-side steel sheet of the single-sided linear induction motor, Controlling the thrust and the magnetic attraction force of the motor so as to give the secondary steel plate a required amount of the suspension conveyance speed and the magnetic attraction force required for the suspension conveyance, Suction force control device.