JP2001058208A - Method for controlling rotational position of main motor in cold pilger rolling mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of electric parts by synchronously running three main motors of a main motor, a feed motor and a turning motor, to simplify the electric control system by using electric parts for general use, and to improve the maintainability. SOLUTION: Three main motors of a main motor 20, a feed motor 23 and a turning motor 26 are synchronously run. The feed timing is determined by a feed cam 29 driven by the turning motor 26, the feed is determined by the number of revolution of a feed lever 30 which is a feed adjusting mechanism and the feed motor 23, and the rotational quantity is determined by a rotational cam 27 driven by the turning motor 26. This control method of the rotational position of the main motor simplifies the electric control system. A control method of a cold Pilger rolling mill which is compatible with the electric control method and the mechanical direct-coupling method for a rolling mechanism by the motor, excellent in economy and maintainability, and stable in operation can be obtained, while operating three driving devices composed of a rolling mechanism, a feed mechanism and a rotational mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION In a general cold pilga mill, a device for driving a roll stand 13 as a rolling mechanism, a mandrel chuck 5, an inlet chuck 10, and an outlet chuck 1 as a feed mechanism for a raw tube 9.
A device that drives the device 1 and has the above three mechanisms, and the drive device is a method that is mechanically directly connected to the drive unit of another device, or an electric motor is used as a drive device for each of the three mechanisms, and these are electrically controlled to control the timing. There is a way to take. The latter method of independently controlling electric power is a newer technology. The present invention relates to three driving devices of a rolling mechanism, a feed mechanism, and a rotating mechanism, and relates to an electric control method using an electric motor and a mechanical direct connection method. The present invention relates to a method for controlling a cold pilgammill that is compatible with the balance, is economical and easy to maintain, and can be expected to operate stably.

[0002]

2. Description of the Related Art Cold pill gamills are one of the machines for producing seamless steel pipes, and are widely used in the production of pipes requiring particularly high dimensional accuracy.
The mechanical structure or driving method of the rotating mechanism is known in various patent publications relating to cold pilgamills.

[0003] As one of the driving methods of the rolling, feeding and rotating mechanism of the cold pilga mill, Japanese Patent Publication No.
There is known a rotational position control device for a shell driving motor in a bilger mill, which is described as an example in Japanese Patent Application Laid-Open No. 0-205. For example, an electric control system shown in a device configuration diagram of the electric control system in FIG. 5 is known.

In this embodiment, in order to accurately synchronize a rolling mechanism, a feed mechanism, and a rotating mechanism, a cold pill gamill in which each mechanism has a mechanical power transmission mechanism is replaced with a rolling mechanism, a feed mechanism, The rotation mechanism is driven by independent motors to reduce the power transmission mechanism, simplify the mechanical structure, reduce initial costs and machine maintenance costs, and accurately synchronize the three mechanisms. Has invented a control method and apparatus. That is, it has a main motor 20 as a rolling mechanism, a roll stand driving crank 15 connected to the main motor 20, a feed-only hydraulic motor (feed motor) 46 as a feed mechanism,
It has a feed carriage driving spindle 8 connected to a feed motor 46, a rotation-only motor (turning motor) 47 as a rotating mechanism, a mandrel chuck 5 connected to the turning motor 47, and an inlet chuck 1
0, in a cold pilga mill having a rotating shaft of the outlet chuck 11, the control device controls the feed motor 46 and the turning motor 47 during an idle period from the end of one rolling process to the start of the next rolling process. An operation command will be sent. That is, as shown in FIG.
The controller 48 outputs an operation command signal during an idle period from the end of one rolling process to the start of the rolling process, by the rotation motor 4.
7 and to the hydraulic motor 46 via the servo amplifier 49 and the servo valve 50. A position detector 53 is attached to the hydraulic motor 46, and detects the rotational position of the hydraulic motor 46 and sends a position detection signal to the controller 48. The pressure detector 51 is attached to a pipeline that connects the servo valve 50 and the hydraulic motor 46, and uses the difference between the oil supply pressure and the return pressure as a pressure control signal via a pressure amplifier 52 as a controller 48. Send to

[0005] In Japanese Patent Publication No. 03-54010,
The operation principle of the feed motor and its control method are explained in detail, but for the purpose of accurate synchronization, feedback control is performed using many electric devices such as a target value generator, subtractor, and compensator as a control device. Since the feed motor is moved to the target feed amount instantaneously during the idle period, the control system is inevitably complicated.

In the embodiment disclosed in Japanese Patent Publication No. 03-60563, the rotating mechanism is further subdivided into a material rotating mechanism and a mandrel rotating mechanism, and a mandrel rotating motor, an inlet chuck rotating motor, and an outlet chuck rotating motor are installed. By doing so, the number of rotating power transmission shafts is reduced. That is, it goes without saying that the control system is further complicated.

[0007]

In the conventional method of driving a rolling mechanism, a feed mechanism, and a rotating mechanism according to the present invention, the mechanical power transmission mechanism for accurately synchronizing the respective mechanisms is reduced to reduce the mechanical structure. Can reduce the initial cost and machine maintenance cost, but on the other hand, the rolling mechanism,
As the feed mechanism and the rotation mechanism are driven by independent electric motors, accurate synchronization of the three mechanisms must be electrically performed.

As a result, the electric control system becomes complicated, and it takes a long time to identify a failure factor when a failure occurs.
In addition, the conventional mechanical parts were visible, so the operator could perform a daily visual inspection.However, since the electricity was not visible, the daily inspection could not be performed. The rate may increase. It is conceivable that the number of electrical components increases and the number of causes of failure increases.

In particular, according to the conventional invention, since the feed mechanism and the rotation mechanism are instantaneously started and stopped during a short period of time during an idle period, it is evident that electric parts are greatly consumed by the inching operation. Also, since the idle period becomes shorter as the number of revolutions of the main motor increases, the delay of the control response needs to be reduced, but the number of parts increases and the control system becomes complicated, and the delay of the control response becomes longer. I can't deny it. This malfunction due to the control delay is nothing but accurate synchronization, but in the case of electricity, it is difficult to determine whether accurate synchronization has been achieved. The instability of synchronous operation, that is, the instability of the control system, will have an adverse effect on dimensions, etc., but it cannot be determined whether or not this is due to the instability of synchronous operation. You'll fall behind for replacement and repair. Therefore, as a countermeasure against the control response delay, a dedicated control device having a quick control response is introduced. However, since there is no versatility, the maintainability is further deteriorated.

[0010]

A method for solving the above problems is to reduce the number of electric parts, improve the maintainability by using general-purpose electric parts, and improve the mechanical power transmission of the prior invention. It is to take advantage of the reduced mechanism.

[0011] Further, instead of starting and stopping the feed motor and the turning motor at the timing of the idle period, which requires a high-speed control response, the feed motor and the turning motor are constantly rotated at a low speed, and the feed mechanism is used. The timing is controlled by the feed cam connected to the feed motor, and the rotating mechanism is controlled by the rotating cam connected to the turning motor. The parts requiring control responsiveness are replaced with machine parts that are easier to inspect. Is to further simplify the control system.

That is, the power of the main motor 20 is supplied to the drive crank 1 of the roll stand 13 through the main clutch 19.
5, the power of the feed motor 23 is transmitted to the drive spindle 8 of the feed carriage 7 via the feed clutch 24 and the rapid feed clutch 25, and the power of the turning motor 26 is transmitted via the rotary cam 27 to the mandrel chuck 5, In a cold pill gamill that transmits rolling to the rotation shafts 28 of the inlet chuck 10 and the outlet chuck 11 and also transmits to the feed lever 30 as a feed amount adjusting mechanism via the feed cam 29, the main motor 2
0, a feed motor 23, and a turning motor 26 in a synchronized manner. More specifically, in the cold pilga mill,
0, the feed motor 23 and the turning motor 26 are tuned, the feed timing is determined by a feed cam 29 driven by the turning motor 26, and the feed amount is a feed lever 30 which is a feed amount adjusting mechanism and the rotation speed of the feed motor 23. And the amount of rotation is determined by a rotating cam 27 driven by a turning motor 26.
This is a method for controlling the rotational position of a main motor in which an electric control system is simplified.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to an embodiment of the present invention, a rolling mechanism transmits power of a main motor 20 to a driving crank 15 of a roll stand 13 via a main clutch 19, and incorporates a feed mechanism and a rotation mechanism from the crank. In comparison with a cold pill gamill of the type that transmits the power of the main motor to the C-BOX via a line shaft, a dedicated feed mechanism is used instead of reducing the line shaft between the crank 15 and the C-BOX 4 of the present invention. The feed timing is determined by the feed cam 29 driven by the turning motor 26, and the feed amount is adjusted by the feed amount adjusting mechanism. Is determined by the number of rotations of the feed lever 30 and the feed motor 23, and the amount of rotation is It is determined by the rotating cam 27 to be.

In such a cold pilga mill, it is only necessary to continuously rotate the feed motor 23 and the turning motor 26 at the speed at which the conventional line shaft was rotating. It is only necessary to tune the rotation angle of the line shaft.

That is, the rotation speed of each motor is as follows: main motor rotation speed (rpm) = crankshaft rotation speed command × pulley ratio turning motor rotation speed (rpm) = actual crankshaft rotation speed × turning gear ratio feed motor rotation Speed (rpm) = Actual rotation speed of the crankshaft x Feed amount x Feed gear ratio / Spindle pitch only need to be continuous rotation, and the timing is detected by the angle detection encoder attached to the crankshaft shaft and rotary cam shaft. The vehicle is driven with the adjusted angles synchronized.

Therefore, since the operation is basically performed at a constant speed according to the speed command, the control system can be simplified as follows.

Main motor drive: Speed feedback control is performed by a general-purpose inverter using a general-purpose inverter and a rotation speed detection encoder. Command: A speed command is given from a general-purpose sequencer using the above formula. Status: The actual rotation speed is taken into the sequencer from the general-purpose inverter. Feed motor drive: Speed feedback control is performed by a general-purpose inverter using a general-purpose inverter and a rotation speed detection encoder. Command: A speed command is given from a general-purpose sequencer using the above formula. Turning motor drive: Speed feedback control is performed by a general-purpose inverter using a general-purpose inverter and a rotation speed detection encoder. In addition, an angle detection encoder is attached to the crankshaft shaft and the rotary cam shaft, and the signal is taken into a general-purpose sequencer. Command: A speed command is given from the general-purpose sequencer according to the above formula, and the tuning correction speed obtained from the deviation angle between the crankshaft and the rotating cam is increased or decreased.

The signal transmission between the general-purpose sequencer and the three general-purpose inverters can be reduced in wiring by connecting the general-purpose sequencer and the three general-purpose inverters.

From the above, the number of electric components is reduced,
The use of general-purpose electrical components has improved the maintainability, and has realized a cold pilga mill utilizing the advantages of the reduction of the mechanical power transmission mechanism of the conventional invention.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The power of a main motor 20 is transmitted to a drive crank 15 of a roll stand 13 via a main clutch 19, and the power of a feed motor 23 is driven via a feed clutch 24 and a rapid feed clutch 25 to drive the feed carriage 7. To the mandrel chuck 5, the inlet chuck 10, and the rotating shaft 28 of the outlet chuck 11 via a rotary cam 27, and a feed amount adjusting mechanism via a feed cam 29. The main motor 20, the feed motor 23, and the turning motor 26 are tuned, and the feed timing is determined by a feed cam 29 driven by the turning motor 26. The rotation of the feed lever 30 and the feed motor 23 as the amount adjustment mechanism Determined by the number, amount of rotation in the cold pilger mill is determined by a rotating cam 27 which is driven by the turning motor 26, an example embodying the present invention.

According to the specifications of the cold pill gamil of this embodiment, the rotation speed of each motor is as follows: main motor rotation speed (rpm) = crank shaft rotation speed command × 7.254 (pulley ratio) turning motor rotation speed (rpm) ) = Actual crankshaft rotation speed x 8.265 (turning gear ratio) Feed motor rotation speed (rpm) = Actual crankshaft rotation speed x feed amount x 10.59 (= feed gear ratio)
It is given by the formula of # 36 (spindle pitch), and each is operated continuously at a constant speed.

The rotation speed of the crankshaft can be arbitrarily set by an operator, and is automatically changed to a rolling speed at the seam, a rolling speed before stopping rolling, and the like during automatic operation.

For example, if the rotation speed command of the crankshaft is 110 rpm and the feed amount is 24 mm, the rotation speed of the main motor is 110 × 7.254 = 798 rpm, and the rotation speed of the turning motor is 110 × 8.265 = 90.
9 rpm Feed motor rotation speed = 110 x 24 x 10.59 ÷
36 = 776 rpm.

FIG. 1 shows the electric control system. The motor uses a general-purpose vector inverter and an encoder for detecting the number of revolutions (1024 pulses / r in this embodiment). The speed feedback control is performed by the inverter itself by inputting it to the vector inverter.

On the other hand, a general-purpose sequencer is used to calculate the rotation speed and the following tuning correction speed, and by connecting the sequencer to each vector inverter by a sequencer link, a signal line for a speed command, actual speed, and the like is obtained. Wiring was reduced, and maintenance was improved.

Next, regarding the timing, a PLG of 3600 pulses / r is attached to the crankshaft shaft and the rotary cam shaft, and the PLG signal is input to the general-purpose sequencer.
The correction speed for tuning was calculated from the deviation angle between the two axes, and the turning motor rotation speed command was increased or decreased as shown in FIG.

[0027]

As described above, the present invention has the advantages of the reduction of the mechanical power transmission mechanism of the prior art, namely, the equipment cost is low, the mechanical maintenance is easy, and the precision is improved. By reducing the number of parts and using general-purpose electric parts, the electric control system can be simplified, the rotational position control of the main motor and the turning motor can be simplified, and the effect of improving maintainability can be achieved.

[Brief description of the drawings]

FIG. 1 is a device configuration diagram of an electric control system according to the present invention.

FIG. 2 is an electric tuning circuit flow according to the present invention.

FIG. 3 is a side view of the overall configuration according to the present invention.

FIG. 4 is a mechanism diagram of a C-BOX in the present invention.

FIG. 5 is a configuration diagram of an electric control system according to a conventional invention.

FIG. 6 shows a rotational position control device according to a conventional invention.

[Explanation of symbols]

1 pusher 2 pusher base 3
Next, raw tube 4 C-BOX 5 Mandrel chuck 6
Mandrel rod 7 Feed carriage 8 Spindle 9
Raw tube 10 Inlet chuck 11 Outlet chuck 12 Rolling roll 13 Roll stand 1
4 Connecting rod 15 Crank 16 Large pulley 1
7 Small pulley 18 Belt 19 Main clutch 2
0 main motor 21 speed detection encoder 22 rotation angle detector 23 feed motor 24 feed clutch 2
5 Fast forward clutch 26 Turning motor 27 Rotating cam 2
8 Rotating shaft 29 Feed cam 30 Feed lever 3
1 Brake 32 General-purpose Sequencer 33 General-purpose Vector Inverter 34 General-purpose Vector Inverter 35 General-purpose Vector Inverter 36 Command / Result 37 Sequencer Link 3
8 pulses 39 pulses 40 pulses 4
1 output 42 pulse 43 output 4
4 pulse 45 output 46 hydraulic motor 4
7 Rotation dedicated motor 48 Controller 49 Servo amplifier 5
0 Servo valve 51 Pressure detector 52 Pressure amplifier 5
3 Position detector

Claims (2)

[Claims] The power of a main motor (20) is transmitted to a roll stand (13) driving crank (15) via a main clutch (19).
Further, the power of the feed motor 23 is transmitted to the spindle 8 for driving the feed carriage 7 via the feed clutch 24 and the fast-forward clutch 25, and the power of the turning motor 26 is transmitted via the rotary cam 27 to the mandrel chuck 5, the inlet chuck 10, A main motor 20, a feed motor 23 and a turning motor are provided in a cold pill gamill which performs rolling by transmitting to a rotation shaft 28 of the outlet chuck 11 and to a feed lever 30 as a feed amount adjusting mechanism via a feed cam 29. 26. A method for controlling the rotational position of a main motor in a cold pilga mill, comprising operating the three main motors in synchronization with each other. 2. In the cold pilga mill, the main motor 20, the feed motor 23, and the turning motor 26 are provided.
And the feed timing is adjusted by turning motor 26.
The feed amount is determined by the feed cam 29 which is driven by the feed motor 30 and the feed lever 30 which is a feed amount adjusting mechanism.
3. An electric control system is simplified by determining the number of rotations by the number of rotations and by determining the amount of rotation by a rotating cam driven by a turning motor. A method for controlling the rotational position of an electric motor.