JPS6214037Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a control device for a metal strip feed roll in a painted metal strip production facility.

Generally, as shown in Fig. 1, painted metal strips are coated with paint by a coating device 3 on both sides of a metal strip 2 that is wound and runs between feed rolls 1 and 1' on the inlet and outlet sides. It is manufactured by baking the paint in the oven 4.

Although it varies depending on the equipment, the oven 4 is very long, and the long one is 40 to 40cm long.
It is 50m or more long. Furthermore, it would be uneconomical to make the volume larger than the required energy. In other words, the oven has to be long but small in volume.

Therefore, the metal strip passed through this oven must be held and fed within a narrow space between the top and bottom of the oven without touching it, and the drive of the feed roll must be controlled very delicately. It must be.

In Fig. 1, A indicates the float zone in which the metal strip is supported by hot air jetted from above and below in the oven, and B indicates the float zone on the inlet side where the paint has not yet dried and hot air cannot be sprayed. Since this is not possible, a catenary zone in which a metal strip is stretched naturally is shown, but an oven having such a float zone is called a floater oven.

Now, the conventional drive control of the feed roll is as follows: (1) The tension value of the metal strip in the oven is maintained at a predetermined value (tension control).

(2) Detect the catenary of the metal strip and maintain it in a predetermined position (catenary control).

(3) The feed rolls on the exit and entry sides of the oven are given uniform speed to maintain the metal strip present in the oven at one constant length per unit time (carrying speed control).

The following methods were considered.

However, although each of these means has its own merits, it also has the following drawbacks, and has not been able to achieve even more reliable control.

(1) The tension of a metal strip is determined by its cross-sectional area, so even if you try to maintain the tension of the metal strip in the oven at a predetermined value, when passing metal strips of different sizes, The tension setting must be changed each time.

(1') The tension applied to the feed rolls installed on the inlet and outlet sides of the oven is the difference between the front and rear tensions of the feed rolls, and generally these front and rear tensions depend on the length of the oven. Therefore, the tension torque of the motor that controls the feed roll is so small that it is indistinguishable from the mechanical detection torque, and it is difficult to accurately maintain the tension at a predetermined value.

(2) Since the span is very large compared to the amount of tension of the catenary, the conversion gain of the amount of tension relative to the varying length of the metal strip inside the oven becomes very large, making it difficult to stabilize the control system.

(3) In order to maintain uniform speed, speed detectors are installed on the feed rolls on the entrance and exit sides of the oven, and the detected speed difference is controlled to be 0. However, changes in diameter or speed due to wear of the feed rolls Since there is a cumulative error due to relative error in detector resolution, etc.
As a result, the length of the metal strip present in the oven changes over time, and the condition of the metal strip inside the oven cannot be maintained permanently constant over the operating period.

The present invention combines the above-mentioned catenary control and uniform speed control to perform simultaneous control, thereby eliminating the disadvantages of controlling each separately and creating an excellent feed roll control device that can perform fine control. This is what we provide.

The following will explain the embodiments shown in the drawings.

In FIG. 2, parts equivalent to those in FIG. 1 are denoted by the same numbers, and their explanation will be omitted.

5 and 5' are feed rolls 1 on the input side and output side, respectively.
The electric motor 6, 6' that drives the feed roll 1' is also a speed detector that detects the rotational speed of the feed roll 1, 1', and in this case, it is directly connected to the feed roll, but if it is difficult to connect to the feed roll, , may be connected to an electric motor, and the rotational speed of the feed roll may be detected from this in consideration of the reduction ratio. 9 is a feeding speed command for the metal strip 2, 8, 8' are control amplifiers, and 7, 7' are electric motors 5, 5, 7, 7' based on the commands from the control amplifiers 8, 8'.
5', and these constant speed command units, control amplifiers, and power supplies are collectively referred to as a control system.

Reference numeral 10 denotes a position detection device using an infrared method or a capacitance method, which detects the position of the catenary portion B of the metal strip 2 in a non-contact manner. 11 is a catenary reference position command device, and 12 is a comparison circuit, which divides and compares the detected value of the output of the position detection device 10 by a reference value set in the catenary reference position command device 11 of the catenary. 13 is a multiplication circuit,
The difference value between the catenary reference value and the detected value is multiplied by the rotational speed of the feed roll 1. A comparison circuit 14 compares the signal from the multiplication circuit 13 with the rotational speed of the feed roll 1' on the outgoing side, and generates a signal for correcting and controlling the rotation of the feed roll 1' on the inlet side.

The structure of the present invention is as described above, and its operation will be explained next.

The speed command from the feed speed command device 9 is sent to the electric motors 5, 7, 7' via control amplifiers 8, 8' and power supplies 7, 7'.
5', and feed rolls 1 on the inlet and outlet sides.
1' are rotated at designated speeds.

Here, the rotational speeds of the feed rolls 1, 1' on the input side and the output side are always detected by speed detectors 6, 6', and these detected values are compared in the comparator circuit 14, When there is a difference in the rotational speed between rollers 1 and 1', a correction signal is output to correct the rotational speed of the electric motor 5 on the input side, thereby controlling the rotations of both feed rolls at the same speed.

At this time, the position detection device 10 simultaneously detects the amount of tension of the catenary portion B of the metal strip 2, and this detected value is detected by the catenary reference position command device 11.
is compared with the command value from the comparison circuit 12,
The difference value is multiplied by the rotational speed detected value of the feed roll 1 on the input side in a multiplier 13. and,
This value is compared with the detected rotational speed of the feed roll 1' on the output side in a comparator circuit 14, and a control correction signal is generated.

That is, (1) when the catenary section is at the reference position, the command value in the catenary reference position command device 11 and the detected value of the position detection device 10 are equal, and the comparison result by division is outputted as "1" from the comparison circuit 12. Ru.

Therefore, the input side feed roll rotational speed of the speed detector 6 inputted to the multiplication circuit 13 is inputted as is to the comparison circuit 14, and this comparison circuit 1
4 is compared with the output feed roll rotational speed of the speed detector 6', which is the other input. In this way, the deviation of the speed detectors 6, 6' is output as an incoming feed roll correction control signal.

(2) When the catenary part B falls below the reference position, the output of the comparator circuit 12 becomes a<1, and the multiplier circuit 13
The output value of the speed detector 6 corrected by the value a is input to the comparator circuit 14. In this way, when the comparison circuit 14 compares the outputs of the speed detectors 6 and 6', the incoming feed roll deceleration correction by the coefficient a is taken into account.

(3) When the catenary part B rises above the reference position, the output of the comparator circuit 12 becomes 1<a, and as in the case (2) above, the speed detector 6 in the comparator circuit 14,
6' When comparing the outputs, the input side feed roll correction corresponding to the coefficient a is taken into account.

Therefore, in the present invention controlled in this manner, the metal strip present in the oven is maintained at one constant length based on constant speed control,
If the catenary tension position of the metal strip inside the oven changes due to changes over time, this will be detected and dealt with.Furthermore, since the speed is basically controlled at the same speed, the amount of change in the catenary of the metal strip will be reduced. Therefore, the correction signal based on the amount of stretching for the varying length of the metal strip in the oven can be made on the small order, and reliable and stable rotational drive control of the feed roll can be obtained.

In this embodiment, the correction signal is input to the control system of the inlet motor to control the rotational speed of the inlet motor, but this is similar to controlling the rotational speed of the outlet motor. It is equally effective.

[Brief explanation of the drawing]

Figure 1 shows the schematic configuration of a painted metal strip manufacturing facility. FIG. 2 is a block diagram of a feed roll control device according to the present invention. 1, 1'...Feed roll, 2...Metal strip, 3
...Coating device, 4...Oven, 5,5'
...Electric motor, 6,6'...Speed detector, 10...
Position detection device, 12, 14... Comparison circuit, 13...
...Multiplication circuit.

Claims (1)

[Scope of utility model registration request] In painted metal strip manufacturing equipment, a speed detector is provided on both sides of the coating device and the oven, and detects the rotational speed of the input and output feed rolls around which the metal strip is wound and fed. a position detection device that detects the position of the catenary portion of the metal strip; a comparison circuit that is connected to the position detection device and the catenary reference position command device and that compares the detected catenary position value and the catenary reference position command value; a multiplier circuit that receives the signal from the comparison circuit and the rotation speed value of the inlet feed roll from the detector and multiplies them; and a multiplier circuit that receives the signal from the comparison circuit and the rotation speed value of the inlet feed roll from the detector, and multiplies the signals from the multiplier circuit and the output feed roll from the detector. Feed roll control in painted metal strip manufacturing equipment, characterized in that a comparison circuit is provided which inputs a rotational speed value of , compares these values, and sends a control correction signal to a control system of a drive motor of the feed roll. Device.