JPS6232647Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a winding device in a down coiler of a hot strip mill, which is an improved pressing device for the wrapper roll that presses the strip.

In the down coiler of a hot strip mill, as shown in FIG. 1, when winding a strip 2 onto a mandrel 1, a wrapper roll 3 presses the strip 2 onto the mandrel 1. By the way, when the mandrel 1 rotates in the direction of the arrow in Fig. 1 and the part that overlaps the tip of the strip 2 (hereinafter referred to as the stepped part) rotates to the wrapper roll 3, the coil radius changes suddenly at this stepped part. Therefore, when the stepped portion passes the wrapper roll 3, the wrapper roll 3 is pushed up violently and a large reaction force is applied to the strip 2, which may damage the strip 2 and cause it to lose its commercial value. . In order to prevent this, a device has been devised in which the wrapper roll 3 is moved back by the thickness of the strip 2 just before the stepped portion of the strip 2 passes, thereby avoiding the generation of reaction force.

An example of such a conventional device is illustrated in FIG. 2, in which a wrapper roll 3 is rotatably supported on an arm 4, which is connected to a piston rod 6 of a hydraulic cylinder 5.
When the piston rod 6 moves in and out of the hydraulic cylinder 5, the arm 4 is moved to the support rotation shaft 7.
It rotates around , and its movement is detected by an angle detector 8. hydraulic cylinder 5
A cylinder chamber 9 on the side closer to the wrapper roll 3 and a cylinder chamber 10 on the side farther from the wrapper roll 3.
is connected to a hydraulic supply pipe 12 and a hydraulic discharge pipe 13 via a servo valve 11.

When the amount of movement of the wrapper roll 3 is given to the setting input circuit 14 at any time, this input signal is output to the control circuit 16 through the controller 15, which operates the servo valve 11 to supply and discharge liquid to and from the cylinder chambers 9 and 10. control. The movement of the arm 4 is fed back from the angle detector 8 via the feedback circuit 17, and compared with the input signal of the setting input circuit 14 in the controller 15. This allows the position of the wrapper roll 3 to be controlled as desired.

However, in this device, the timing for retracting the wrapper roll 3 was incorrect, and the wrapper roll 3
When the stepped portion of the strip 2 reaches the wrapper roll 3 before the strip 2 retreats, the wrapper roll 3 is pushed up violently, the pressure inside the cylinder chamber 10 becomes excessive, and a very large reaction force is applied to the strip 2, causing the strip to move more than before. There is a risk of causing deep scratches on Strip 2. Such a cylinder chamber 10
The high pressure generated on the side can be prevented to some extent by providing an accumulator 18.
However, when the wrapper roll 3 is pushed up violently, the cylinder chamber 9 on the side closer to the wrapper roll 3 becomes negative pressure, which may cause air bubbles to be generated in the cylinder chamber 9 or the hydraulic cylinder 5 to be destroyed due to cavitation. . If the air bubbles generated in the cylinder chamber 9 are not absorbed by the liquid immediately, they will increase the apparent compressibility of the liquid in the hydraulic cylinder 5, and this will significantly deteriorate the rigidity of the support provided by the hydraulic cylinder 5, making control difficult. It makes it unstable.

Normally, excessive pressure can be absorbed by installing an accumulator, and by appropriately increasing the gas pressure sealed in the accumulator, it is possible to prevent liquid from flowing into or out of the accumulator during normal operation. Even if an accumulator is provided, the response of the control will not be impaired.

By the way, in order to prevent the generation of negative pressure in the cylinder chamber, which has negative pressure, connect an accumulator filled with low-pressure gas to the cylinder chamber, which has negative pressure, and when the volume of the cylinder chamber increases due to the movement of the piston, the accumulator It is clear that it is sufficient if the liquid is supplied.

However, with this method, fluid flows in and out of the accumulator due to pressure fluctuations in the cylinder chamber over time, so the fluid from the servo valve is not effectively used to move the piston, but is absorbed into the accumulator, resulting in control problems. This will impair response speed. For this purpose, in a device as shown in FIG.
It is impossible to prevent the generation of negative pressure while at the same time not impairing the response speed of the control. In other words, in the configuration shown in FIG. 2, if an accumulator is connected to prevent the generation of negative pressure in the cylinder chamber 9, the liquid sent from the servo valve 11 will not be effectively used to move the piston. It will be absorbed by the accumulator, and the power will be wasted completely.

In other words, if an attempt is made to prevent the generation of negative pressure in the cylinder chamber 9 with such a configuration, it is completely meaningless to supply liquid from the servo valve 11 to the cylinder chamber 9, and simply results in power loss. Only.

The present invention eliminates these drawbacks and effectively prevents the pressure inside the hydraulic cylinder from becoming excessive or negative when the wrapper roll is pressed against the stripping coil using the hydraulic cylinder. A wrapper roll that presses the strip wound around the mandrel is connected to a piston rod of a hydraulic cylinder, and the thickness of the strip is adjusted by the hydraulic cylinder just before the strip passes through the step. In the winding device configured to retract the wrapper roll by a certain amount, the cylinder chamber of the hydraulic cylinder on the side farther from the wrapper roll is connected to a servo valve connected to a hydraulic pressure supply pipe, and the hydraulic pressure is supplied from the servo valve to a servo valve connected to a hydraulic pressure supply pipe. An accumulator is connected to a predetermined position of a pipe line leading to a cylinder chamber on the side farther from the wrapper roll of the cylinder, and the pipe line connected to the cylinder chamber on the side closer to the wrapper roll of the hydraulic cylinder is connected to the cylinder chamber on the upstream side of the servo valve. The gist of the winding device is characterized in that an accumulator is connected to a pipeline connected to a hydraulic pressure supply pipe and leading to a cylinder chamber on a side closer to the wrapper roll.

Next, an embodiment of the present invention will be described with reference to FIG. 3. Similar to the device shown in FIG. 2, the wrapper roll 3 is rotatably supported by an arm 4.
is connected to the piston rod 6 of the hydraulic cylinder 5. When the piston rod 6 moves in and out of the hydraulic cylinder 5, the arm 4 rotates about the support rotation shaft 7, and this movement is detected by the angle detector 8.

By the way, in the embodiment of the present invention, the cylinder chamber 10 on the side farther from the wrapper roll 3 of the hydraulic cylinder 5 is connected to the hydraulic supply pipe 2 via the servo valve 19.
However, the cylinder chamber 9 of the hydraulic cylinder 5 on the side closer to the wrapper roll 3 is directly connected to the hydraulic supply pipe 20 without passing through the servo valve 19. has been done. Accumulators 22 and 23 are connected to the cylinder chambers 9 and 10, respectively. In FIG. 3, 14 is a setting input circuit, 15 is a controller, 16 is a control circuit, and 17 is a feedback circuit.

In the embodiment of the present invention shown in FIG.
As with the conventional device shown in the figure, the position of the wrapper roll 3 can be controlled arbitrarily, but even if the wrapper roll 3 is pushed up violently, the cylinder near the wrapper roll 3 in the hydraulic cylinder 5 Since the chamber 9 is directly connected to the accumulator 22 and the hydraulic pressure supply pipe 20 which is a hydraulic pressure supply source, it can receive a sufficient flow rate of hydraulic pressure supply, thereby avoiding negative pressure.

The above description has been made regarding an embodiment in which the cylinder chamber 9 and the accumulator 22 are directly connected to the hydraulic pressure supply pipe 20. However, as shown by the chain line in FIG. It may also be connected to the hydraulic supply pipe 20 via the control valve 24. In this case, the cylinder chamber 9 when the wrapper roll 3 is lifted up is
All of the liquid is supplied from the accumulator 22, and the amount of liquid flowing out from the accumulator 22 is slowly supplemented via the pressure control valve 24.

As mentioned above, this invention can prevent the generation of negative pressure in the cylinder chamber on the side closer to the wrapper roll of the hydraulic cylinder that controls the position of the wrapper roll, so the gas dissolved in the liquid can separate and cause unstable control. It is possible to prevent damage to the equipment due to cavitation, and the same hydraulic cylinder can absorb the impact acting on the wrapper roll and retract the wrapper roll (adjust the gap amount), making the equipment more efficient. It becomes easy.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view showing the state of winding the strip, Fig. 2 is a system diagram of a conventional winding device, and Fig. 3
The figure is a system diagram of an embodiment of the present invention. 1...Mandrel, 2...Strip, 3...
Ratsupar roll, 5... Hydraulic cylinder, 6...
Piston rod, 9, 10...Cylinder chamber, 1
9... Servo valve, 20... Hydraulic pressure supply pipe.

Claims (1)

[Scope of utility model registration request] A winding device in which a wrapper roll that presses the strip wound around a mandrel is coupled to a piston rod of a hydraulic cylinder, and the hydraulic cylinder moves the wrapper roll backward by the thickness of the strip just before the strip passes through the step. , a cylinder chamber on the side farther from the wrapper roll of the hydraulic cylinder is connected to a servo valve connected to a hydraulic pressure supply pipe, and a pipe line from the servo valve to the cylinder chamber on the side farther from the wrapper roll of the hydraulic cylinder; Connect an accumulator to a required position, connect a pipe line connected to the cylinder chamber on the side closer to the wrapper roll of the hydraulic cylinder to the hydraulic pressure supply pipe on the upstream side of the servo valve, and A winding device characterized in that an accumulator is connected to a conduit leading to a cylinder chamber.