JPS6144524A - Method of cutting off metal material - Google Patents

Abstract

PURPOSE:To prevent damage to a cutting tool provided on a traveling cutoff machine, by stopping the cutoff of a metal material when the difference between the conveyance speed of the metal material and the moving speed of the traveling cutoff machine is larger than an allowable value. CONSTITUTION:In a method of cutting off a continuously conveyed metal material to a prescribed dimension by using a traveling cutoff machine, the absolute value ¦Vm-Vc¦ of the difference between the conveyance speed Vm of a steel pipe 1 as the metal material and the moving speed Vc of a casing 21 is detected so that the steel pipe is not cutoff when the detected absolute value is larger than an allowable level a set on a comparator 31. A thrusting force which would damage a cutting tool 28 is thus prevented from being caused. As a result, the cutting tool 28 provided on the traveling cutoff machine 2 is not damaged. Althrough the cutoff machine 2 is provided with a clamp 27, this invention can be also applied to a traveling cutoff machine not provided with such a clamp.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method of cutting continuously conveyed metal materials into predetermined dimensions using a traveling cutting machine, and more specifically, the present invention relates to a method for cutting continuously conveyed metal materials into predetermined dimensions using a traveling cutting machine. The speed deviation between the speed deviation and the traveling speed of the traveling cutter IIfr machine is detected, and if the speed deviation during cutting is larger than a predetermined tolerance range, cutting is stopped and the blade of the traveling cutting machine is damaged. This paper proposes a method for cutting metal materials that can prevent this.

[Prior art]

After manufacturing, steel products such as electric resistance welded steel pipes and shaped steel are cut into predetermined lengths. For this type of cutting method, it is necessary to improve the efficiency of operation (continuously transport the manufactured steel products downstream, and synchronize the traveling cutting machine located downstream with the transport speed of the steel products). A method of cutting by running at a high speed is often used.

A method of cutting the steel products by synchronizing the traveling speed of the traveling cutting machine with the conveying speed of the steel products is disclosed in Japanese Patent Application Laid-open No. 49
There is a method disclosed in No.-13792.

In this method, the conveyance speed and amount of movement of the steel product are detected by a rotary encoder connected to a measuring roll, and the steel product is moved downstream from the position where the measuring roll is placed.
When the steel product moves, the regular 9j cutting machine is driven to follow it, and when the tip of the steel product protrudes beyond the traveling cutting machine by the product dimension (cutting dimension), the traveling speed of the traveling cutting machine is changed to The cutting is performed by controlling the speed to synchronize with the conveyance speed.

[Problem that the invention seeks to solve]

However, when synchronizing the traveling speed of the traveling cutting machine with the conveyance speed of the steel product as in this method, for example, if the drive mechanism of the traveling cutting machine wears out or an abnormality occurs in the control system that controls this speed. In this case, it becomes difficult to synchronize the speeds of the two, and a speed deviation (slip) occurs between the two.6And when cutting steel products when such a speed deviation exists, There is a fear that a thrust force corresponding to the magnitude of the speed deviation is generated in the blade provided in the traveling cutting machine, leading to breakage of the blade.

[Means for solving problems]

The present invention has been made in view of the above circumstances, and the lul! To solve the above problem by detecting a speed deviation between the feed speed and the traveling speed of a traveling cutting machine, and stopping cutting if the speed deviation when cutting a metal material is larger than a predetermined value. With the goal.

The method of cutting a gold mud material according to the present invention is a method of cutting a metal material into a predetermined size by making the traveling speed of a traveling cutting machine follow the transport speed of the metal material that is continuously transported. The present invention is characterized in that the deviation between the conveyance speed and the traveling speed of the traveling cutting machine is detected, and if the deviation during cutting is larger than a predetermined value, cutting of the metal material is stopped.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings showing embodiments thereof. FIG. 1 is a schematic side view showing an embodiment in which the method for cutting metal materials according to the present invention is applied to cutting an electric resistance welded steel pipe.

An electric resistance welded steel pipe 1 manufactured by a pipe making machine (not shown) is conveyed at a constant speed in the direction shown by the white arrow, and has a built-in clamp 27 and cutter 28 of a traveling cutter 2 located downstream of the pipe making machine. The casing 21 is inserted through holes 22 and 22 provided in the upstream and downstream side walls, and is transported further downstream.

The casing 21 is attached to a rack 23, and can be reciprocated in the transport direction of the steel pipe 1 by forward and reverse rotation of a pinion 26 meshed with the rank 23. The forward and reverse rotation of the pinion 26 is controlled by the electric motor 2 connected via the reducer 24.
This is done by forward/reverse drive of 5. The casing 21 follows the movement of the steel pipe 1 in response to a drive start command signal given to the electric motor 25 from the traveling cutter drive control device 5, which will be described later.When the tip of the steel pipe 1 protrudes from the center of the cutter 28 by the size of the product, the drive control device 5 It is held by the clamp 27 according to the applied clamp execution signal, and then cut to a specified size by the cutter 28 to form a finished product.

A rotor IJ encoder 29 is connected to the electric motor 25, and the rotation speed of the electric motor 25, in other words, the casing 21
The number of pulses corresponding to the amount of movement of is emitted, and these pulses are applied to the traveling cutting machine drive control device 5. This pulse is also applied to the pulse/voltage conversion circuit 16, where it is converted into an analog voltage signal, further amplified by the amplifier 17, and applied to the subtracter 30 as the traveling speed VC of the casing 21.

A measuring roll 3 is arranged on the upstream side of the traveling cutter 2 so as to face the conveying area of the steel pipe 1, and when the steel pipe 1 comes into sliding contact with the measuring roll 3, it rotates according to the IM feed speed of the steel pipe 1.

A row encoder 4 is installed at the shaft end of the measuring roll 3.
are connected to each other, and emit a number of pulses corresponding to the number of rotations of the measuring roll 3, in other words, the amount of movement of the steel pipe 1,
The signal is applied to the traveling cutter drive control device 5. This pulse is also given to the pulse/voltage conversion circuit 6, where it is converted into an analog voltage signal, and further amplified by the amplifier 7.
It is given to the subtractor 30 as the transport speed Vm of the steel pipe 1.

The subtracter 30 calculates the absolute value IVmVcl of the difference between the transport speed VII+ and the above-mentioned traveling speed VC, and outputs the calculation result to the comparator 31. A tolerance value a is set in the comparator 31. The allowable value a is determined by the subtractor 30 when a speed deviation occurs that is sufficient to generate a thrust force that causes damage to the cutter 28.
It is set to a value slightly smaller than the output. Comparison 531 is l
If Vm −Vc l >a, the AND gate 32
issue an alarm signal.

A clamp completion signal is input to the AND gate 32 from the drive control device 5 as described later, and if the alarm signal is input when the clamp completion signal is input, the switch 33 is closed and the alarm is activated. 34 and also gives a clamp release signal to the drive control device 5.

Next, the traveling cutting machine drive control device 5 will be explained. The drive control device 5 uses pulses from the rotary encoder 4 to determine the amount of movement l of the steel pipe 1, and also uses these pulses within a predetermined time to determine the transport speed Vm of the steel pipe 1. Then, when the amount of movement β reaches a predetermined value, a drive start command signal is issued to the electric fi 25 to drive it and cause the casing 21 to follow the steel pipe l. Next, when the tip of the steel pipe 1 protrudes from the center of the cutter 28 by 20 minutes, a clamp execution signal is issued to the clamp 27, the steel pipe 1 is held by the clamp 27, and then the AND gate 32
Gives a clamp completion signal to. Then, as described above, if the switch 33 is in an open state at that point, that is, if the clamp release signal is not input, a cutting signal is issued to the cutter 2, and the steel pipe 1 is cut into finished product dimensions. On the other hand, switch 3
3 is in an open state, that is, when a clamp release signal is input, the clamp is released, no cutting is performed, and a production stop command signal is issued to the pipe making machine to stop the pipe making machine.

Next, the control operation of the traveling cutting machine drive control device 5 from the end of cutting to the end of the next cutting will be explained based on the flowchart shown in FIG. 2 and FIG. 3.

As shown in Fig. 3 ta+, the steel pipe 1 has a finished product size l. When the cut is completed, the cutter 28 notifies the traveling cutter drive control device 5 that the cut has been completed. In response to this, the drive control device 5 issues a reverse rotation command' signal to the electric motor 25. Then, the casing 21 returns to the standby position and stops. While the casing 21 is moving, the drive control device 5 calculates the distance L1 between the cutting position and the standby position based on the output of the row encoder 29.

On the other hand, the drive control device 5 calculates the amount of movement 1 of the steel pipe 1 after cutting by counting the number of pulses from the rotary encoder 4.
1 is calculated sequentially. Therefore, when the casing 21 is in the standby position, the steel pipe 1 is moved from the center of the cutter 28 to J, +L,
It will only stand out.

Further, the drive control device 5 controls the running speed Vc of the casing 21 after it starts running based on the transport speed Vm of the steel pipe 1.
However, when the drive mechanism is normal, the conveyance speed Vm of the steel pipe l is
Calculate the time t1 (=Vm/α) required until the time is reached. However, α is the specific acceleration (constant) of the casing 21.

The amount of movement 12 of the steel pipe 1 and the casing 21 within this time t1
The difference Δ12 between the moving amount L2 and the moving amount L2 is calculated and stored.

Vm 2 Tomi □ ... (1) , 2α " Then, as shown in Fig. 3 (al), 6, -j!o-Δ62-L, ・(At the point when 21 is reached, the electric motor is activated to run the casing 21. A drive start command signal is issued to the steel pipe 25. Then, the speed of the casing 21 is increased by an acceleration α, and assuming that the drive mechanism is normal, the speed becomes Vm after t1 has elapsed.
As shown in FIG.
j from the ceremony! , +L, =l! o−Δi2+ΔR2=j
! o) Therefore, the drive control device 5 issues a clamp execution signal to the clamp 27 when L1 has passed, and holds the steel pipe 1,
A clamp completion signal is then provided to AND gate 32.

Therefore, if an abnormality such as wear occurs in the drive mechanism of the traveling cutting machine 2, the traveling speed VC of the casing 21 will not match the conveying speed Vm of the steel pipe 1 after t1 has passed. The speed deviation between the two cases is calculated by the subtracter 30 as described above, and is provided to the - comparator 31, where it is compared with the allowable value a. and AND gate 32
When the clamp completion signal is input to
If ≦a, that is, if the clamp release signal is not input from the AND gate 32, a cutting execution signal is issued to the knife 28, and the steel pipe 1 is cut to the finished product size IO. And knife 2
When the completion of cutting is reported from 8, the casing 21 is returned to the standby position in order to perform the next cutting. On the other hand, lV
When m-Vcl>a, that is, when a clamp release signal is input from the AND gate 32, a production stop command signal is issued to the pipe making machine to stop the pipe making machine.

In the case of such an embodiment, the absolute value l of the speed deviation between the conveyance speed Vm of the steel pipe 1 and the running speed Vc of the casing 2I
Vm-Vcl is detected, and if the speed deviation IV+1-VCI when cutting the steel pipe l is larger than the tolerance value a set in the comparator 31, the steel pipe l will not be cut, so the cutter 28 A thrust force that would cause damage is not generated, and therefore, damage to the cutter 28 can be prevented.

In the above-described embodiment, the traveling cutting machine 2 is equipped with a clamp 27, but the present invention can also be applied to a machine not equipped with a clamp. That is,
In this case, after the aforementioned t1 has elapsed, the traveling cutting machine drive control device 5 issues a cutting preparation completion signal to the AND gate 32, and if the speed deviation is larger than the allowable value when this signal is input, the AND gate 32 starts driving. The configuration may be such that a disconnection prohibition signal is given to the control device 5.

In addition, the drive control device 5 gives a production stop command signal to the pipe making machine, and if the speed deviation is larger than the allowable value, the pipe making machine is automatically stopped. It is also possible to have a simple configuration that notifies the person.

[Effects] As detailed above, the method for cutting a metal material according to the present invention is such that the speed deviation between the conveyance speed of the metal material and the traveling speed of the traveling cutting machine when cutting the metal material is larger than the allowable value. If the cutting machine stops cutting metal materials, the cutting machine will stop cutting even if the drive mechanism of the traveling cutting machine is worn out or a foreign item occurs in the control system of the traveling cutting machine, causing a speed deviation between the two. The present invention has excellent effects, such as there being no risk of damage to the blades installed in the cutting machine.

In addition, in the above-mentioned embodiment, the present invention is applied to cutting of electric HL steel pipe.
Although the present invention has been described with reference to the case where it is applied to cutting, it goes without saying that it can also be applied to cutting other steel materials such as shaped steel and steel bars, or other long metal materials.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic side view showing an embodiment in which the present invention is applied to cutting an electric resistance welded steel pipe, and FIG. 2 shows a control procedure of a traveling cutting machine drive control device. The flowchart shown in FIG. 3 is a schematic diagram for specifically explaining the control operation. 1... ERW steel pipe 2... Running cutting Ia4.29...
- Row re-encoder 5...Traveling cutting machine drive control device 28...Knife 30...Subtractor 31...Comparator 32...AND gate

Claims (1)

[Claims] 1. A method of cutting a metal material into a predetermined size by making the traveling speed of a traveling cutter follow the transport speed of a continuously transported metal material, comprising: A method for cutting a metal material, characterized in that a deviation from a traveling speed of a traveling cutting machine is detected, and cutting of the metal material is stopped if the deviation during cutting is larger than a predetermined value.