JPS6033625B2 - Strip surface treatment control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides high-pressure water or high-pressure water and other substances, such as iron sand, etc.
The present invention relates to a surface treatment control method in which a fluid mixed with a cleaning agent is projected onto a strip to descale, remove roughness, etc. from the strip.

As a strip surface treatment method, as shown in Fig. 1, high pressure water or a mixed fluid of high pressure water and abrasive particles is applied to the strip S moving in the direction of the arrow from a fluid projection nozzle provided in the width direction of the strip. There is a method of continuously removing the surface scale or surface roughness of the strip by projecting it on the surface of the strip.

In this method {1} For example, the width W of the strip is W
', the projection nozzle 1 must be rotated 8 times so that the strip width W' and the length of the projection nozzle 1 match. {2} The moving speed of the strip is affected by the front and rear equipment. There is a problem in that the amount of fluid projected per unit area of the strip changes due to changes in response to the change in the amount of water, and in such a case, it is not possible to perform a predetermined process.

An object of the present invention is to solve the problems in such surface treatment methods, and details of the present invention will be explained below with reference to embodiments shown in the drawings.

In FIG. 2, S is a moving strip, and 1 is a projection nozzle that projects a mixed fluid of high-pressure water and iron sand, etc. onto the strip S by a pump 3 driven by an electric motor 2.

4 is a speed detection circuit for the strip S, 5 is an angle detection circuit for detecting the angle 8 (FIG. 1) of the projection nozzle 1, and 6 is a fluid pressure in the piping 7 near the fluid projection end, that is, the projection nozzle, and the projection nozzle angle. A setting device 8 sets the relationship with the stripping speed, and a first pressure calculation unit 8 receives each setting value of the setting device 6 and detection signals from the speed detection circuit 4 and the angle detection circuit 5 to calculate a fluid pressure command value. The controller 9 is a function generating circuit in which the relationship between the fluid pressure value and the rotation speed of the electric motor 2 is set, and receives the fluid pressure command value from the first pressure calculation controller 8 and outputs the motor rotation speed command value. do.

10 is a speed control circuit that receives a signal of the rotation speed command value and controls the rotation speed of the electric motor 2; 11 is a rotation speed detector that detects the rotation speed of the electric motor;
The rotation speed command value is compared with the rotation speed command value, and the deviation signal is added to the rotation speed command value to control the electric motor 2.

Next, a series of controls will be explained.

Depending on the fluid pressure value, projection nozzle angle, and stripping speed preset in the setting device 6 by the pressure calculation controller 8 and the actual projection nozzle angle and stripping speed from each detection circuit 4 and 5, the necessary fluid A fluid pressure command value for obtaining pressure is calculated and output. The fluid pressure command value is input to the function generator 9, and from the relationship between the preset fluid pressure value and the motor rotation speed N, a motor rotation speed command value for obtaining the required fluid pressure is output, and speed control is performed. The speed of the electric motor 2 and the pump 3 is controlled so that the fluid pressure in the projection end, that is, the fluid conduit 5 reaches the target value.In this way, the present invention directly converts pressure into rotational speed. Since it is configured with a circuit, it can perform pressure control with very good responsiveness.

In addition, in this embodiment, the piping from the pump 3 to the projection end? Since pressure loss of the fluid occurs in the projection nozzle 1 and the like, it is necessary to take pressure loss into consideration when setting the function of the fluid pressure P and the motor rotation speed N in the function generator 9.

However, since the pressure loss changes over time due to performance deterioration of the pump 3, etc., it is necessary to correct the settings of the function generator 9 over time, which is inconvenient. Embodiments of the present invention eliminate these disadvantages.

An embodiment of the invention is shown in FIG.

Figure 3 shows the circuit shown in Figure 2, which detects the fluid pressure in the fluid conduit 7 located at the projection end and configures a feedback circuit that corrects the motor rotation speed command value. In Fig. 3, the pressure detector 12 attached to the end of the fluid conduit 7 detects the actual fluid pressure value.
The actual pressure value is compared with the fluid pressure command value from the first pressure calculation controller 8, and if there is a deviation in the actual pressure value from the pressure command value, a deviation signal is sent from the second pressure calculation controller 13. is output, a correction signal is input to the speed control circuit 101, and the speed of the electric motor 2 and pump 3 is controlled.

In this way, the present invention is comprised of a circuit that directly converts pressure into rotational speed and a feedback circuit that detects the actual pressure and corrects the target pressure, resulting in extremely responsive and highly accurate pressure control. can be done.

Note that if the relationship between the pressure and speed of the function generator 9 is set accurately, operation is possible even without a pressure feedback circuit. Further, by providing an upper and lower limiter for the output value of the first pressure calculation controller 8, the system operation can be continued even if the output of the pressure detector 12 decreases due to a failure or the like during operation.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the surface treatment method, FIG. 2 is a flow diagram of the present invention, and FIG. 3 is a flow diagram of another embodiment of the present invention. 1: Projection nozzle, 4: Strip speed detection circuit, 5; Projection nozzle angle detection circuit, 11; Motor rotation speed detector, 1
3; Pressure calculation control. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. A method of projecting high-pressure water or a mixed fluid of high-pressure water and another substance onto a moving strip from a projection nozzle by a drive source consisting of an electric motor, which comprises The fluid pressure command value is determined from the relationship between the projection nozzle angle and the fluid pressure value at the projection end, and from each detected value of the strip speed and projection nozzle angle, and then from the relationship between the preset fluid pressure value and the motor rotation speed. 1. A strip surface treatment control method comprising: determining a motor rotation speed command value; and controlling the rotation speed of the electric motor using the rotation speed command value. 2. The strip surface treatment control method according to claim 1, wherein the motor rotational speed command value is corrected by a deviation signal between the fluid pressure detected value at the fluid projection end and the fluid pressure command value.