JP2626506B2 - Marking device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marking apparatus for performing normal marking even when there is an abnormality in the posture of a marking object such as an inclined marking surface, and for marking a moving marking object. .

[0002]

2. Description of the Related Art Steel materials produced in steel factories and the like are marked with a management number or the like to indicate the attributes of the products. The marking is often made on the end face of the steel material so that the management number or the like can be read while the steel materials are stacked. In addition, the marking characters need to be written as large as possible for automatic reading in a later process. Since the number of characters is large, the entire end face is often used as a marking area.

[0003]

The end face of a square rod-shaped steel material or a round bar-shaped steel material has a small area, and the end face may be greatly deformed at the time of shear cutting. In addition, since the entire material is bent, when the material arrives at the marking position, the end surface to be marked is often shifted from the reference position of the marking. If the end face is square or circular, there is no problem if it rolls during transport. However, if it is rectangular or distorted and trapezoidal, it is necessary to recognize the rolled state and mark it accordingly. Further, marking is often performed while these materials are moving on a conveyor, and it is necessary to allow the marking portion to move at the same speed as the marking target.

FIG. 9 is a view showing the posture and the state where the end face is correctly marked when the rectangular bar-shaped steel material is conveyed.
Arrows indicate the transport direction. The end face is originally a square or a rectangle, but is distorted due to cutting or the like and has a trapezoidal shape, indicating a normal posture. The management number and the like are planned to be performed in the character arrangement shown in the following. In the case of the posture, if the characters are arranged in the same manner as described above, the characters protrude. In the case of, it also protrudes.

FIG. 10 is a plan view showing the vicinity of an end surface of a conveyed marking object to be marked. Arrows indicate the transport direction. The bar-shaped steel material has a bent shape near the end face, and the end face is often not converged and is conveyed in and out. For this reason, as shown at point A, the detector for detecting the marking target needs to be provided to the center of the marking target to some extent from the position of the normal end face. However, when the detector is installed at such a position, if the tip has a bend, the position of the end surface estimated from the position detected by the detector and the position of the actual end surface will be shifted as shown in FIG. A point occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has an image of an end face of a marking object, confirms the position and orientation of the end face, performs appropriate marking, and further runs in parallel with the traveling marking object. It is an object of the present invention to provide a marking device capable of performing marking.

[0007]

In order to achieve the above object, a marking section for marking a marking surface of an object to be marked and a reference marking surface of the marking surface based on image data obtained by imaging the marking surface. An image control unit that calculates a shift, and a marking control unit that creates marking data in consideration of the shift calculated by the image control unit and controls the marking unit.

[0008] Further, a parallel running portion that runs in parallel with the moving marking object, a marking portion mounted on the parallel running portion for marking a marking surface of the marking object, and the marking by image data obtained by imaging the marking surface. An image control unit that calculates a shift of a surface from a reference marking surface, a marking control unit that creates marking data in consideration of the calculated shift of the image control unit and controls the marking unit, and And a following mechanism for following the parallel running section.

[0009] Further, the following mechanism includes a distance detector for measuring a relative distance between the parallel running portion and the marking object,
A relative distance control unit for controlling the parallel running unit so as to keep the measured relative distance at a predetermined value.

[0010] The tracking mechanism may further include a contact mechanism having one end connected to the parallel running section and the other end contacting the object to be marked during the parallel running so as to be able to be pressed in the parallel running direction. And a pressing control unit that controls the traveling of the parallel running unit so as to press against an object.

[0011]

An image of the marking surface of the marking object is obtained to obtain image data. The image controller compares the marking surface obtained from the image data with a preset reference marking surface to calculate a deviation such as a position or an inclination.
The marking control unit determines the center, inclination, character direction, and the like of the marking in consideration of the deviation, and causes the marking unit to perform marking. Thereby, appropriate marking can be performed corresponding to the marking surface of the marking object.

The follow-up mechanism causes the parallel running section to move in parallel with the moving marking object. The marking part is mounted on the parallel running part, the marking part and the marking object are relatively stationary, and the image control unit uses the image data obtained by imaging to shift the marking surface of the marking object from the reference marking surface. Is calculated, the marking control unit determines the center, inclination, character direction, and the like of the marking in consideration of the deviation, and causes the marking unit to perform marking. This makes it possible to appropriately mark a moving marking target.

The relative distance between the parallel running section and the marking target is measured by a distance detector, and the relative distance control section controls the running of the parallel running section so as to keep the relative distance at a predetermined value. And the marking portion mounted on the parallel running portion follows the marking target.

At the time of parallel running, the running of the parallel running unit is controlled by the pressing control unit so that the other end of the contact mechanism is pressed against the object to be marked. As a result, the parallel running section connected to the contact mechanism runs together with the marking object, so that the marking section completely follows the marking object.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment of the present invention. The billet 2 is mounted on the conveyor 1 and continuously sent at a constant speed. The billet 2 is a rectangular bar-shaped steel material, and is mounted on the conveyor 1 with its length direction perpendicular to the conveying direction of the conveyor 1 indicated by an arrow and with the end faces aligned as much as possible. The position No. 1 is a position where the end face of the billet 2 is imaged, and the position No. 2 is a position where marking is started on the end face of the billet.

A side detector 3 for detecting the side surface of the billet 2 is provided at the No. 1 position, and a strobe lighting lamp which emits a flash light when the side detector 3 detects the side surface of the billet in front of the end surface of the billet. 4. When the strobe illumination lamp 4 emits light, a video camera 5 for imaging the end face of the billet 2 and an ultrasonic distance meter 12 for measuring a distance between the billet end face and itself are provided.

The image controller 6 stores the image data of the video camera 5 in a built-in image memory, and calculates data of the shape and posture of the end face of the billet 2 using the data. Open window 8 on the screen of monitor 7,
An image 9 of the billet end face is displayed, and the calculation process and the result are displayed.

An encoder 11 is provided on the drive shaft of the conveyor 1 and generates a pulse proportional to the moving distance of the conveyor 1 to measure the moving distance. An ultrasonic range finder 13 for measuring the distance between the side surface of the billet 2 and a parallel carriage 17 described below is provided downstream of the No. 2 position. Ultrasonic rangefinder 1
Numeral 3 is rotated by a motor 14 so that the billet 2 rotates and does not contact when the billet 2 passes right beside the ultrasonic range finder 13.

The first servo motor 15 rotates a first ball screw 16 provided in parallel with the conveyor 1. The first ball screw 16 meshes with a helical screw provided on the parallel traveling vehicle 17, and causes the parallel traveling vehicle 17 to travel in the transport direction or the reverse direction depending on the rotation direction of the first ball screw 16.

The parallel running vehicle 17 is provided with a second servo motor 18 for rotating a second ball screw 19 provided in a direction perpendicular to the first ball screw 16. The second ball screw 19 meshes with a helical screw provided on the traversing carriage 20, and the billet 2 is rotated by the rotation direction of the second ball screw 19.
The traversing carriage 20 is moved in the direction of the end face or in the opposite direction.

An XY stage 21 is mounted on the trolley 20. The X direction is set as the conveying direction of the conveyor 1, the Y direction is set as the vertical direction, and the marking nozzle 22 is moved on the X, Y secondary plane. And marking on the end face of the billet 2. The second ball screw 19, the trolley 20, the XY stage 21, and the marking nozzle 22 constitute a marking unit.

The servo controller 31 includes a first servomotor 15, a second servomotor 18, and the XY stage 2.
Control 1 The control unit 30 obtains data on the shape and posture of the end face of the billet 2 from the image controller 6, and controls the parallel running vehicle 17, the traversing vehicle 20, and the XY stage 21 by the servo controller 31 to perform marking.

Next, the operation will be described. First, the analysis of the shape and posture of the billet end face by the image controller 6 will be described. The billet 2 moves in the transport direction at a substantially constant speed. When the billet 2 reaches the No. 1 position, the side detector 3 detects the side of the billet 2. When this detection signal is input to the image controller 6, the strobe illumination lamp 4 is turned on for a moment, and the video output signal of the billet end surface starting from the camera readout signal VD immediately after that is output at a predetermined threshold level by two.
The value is converted to a value and stored in the image memory in the image controller 6.
Note that writing of the video signal starting from the next start signal VD to the image memory is prohibited until the processing of the currently captured screen is completed. That is, the billet side is the side detector 3
In If detected, strobe illumination lamp 4 is turned on immediately, billet end face shape when the posture is taken to the video camera 5, the image data is stored in the image memory.

Since the field of view of the video camera 5 is adjusted to the reference position of the No. 1 position, when a normal billet 2 without bending is conveyed, an image of the billet end face is taken at the center of the video camera 5, The billet end face image is set to be displayed at the center of the screen of the monitor 7. Since the binarized data in the image memory and the binarized image of the billet end face on the screen of the monitor 7 are assumed to be the same, there is no problem. Therefore, for convenience of explanation, the following description will be made on the screen of the monitor 7.

2 to 5 show windows on the monitor screen. The window is a measurement range within a certain visual field in the camera visual field. In the present embodiment, the viewing area of 350 × 350 mm is defined as the window area. In order to obtain the position and orientation information of the billet end face, the image controller 6 has the following known function as an image discriminating function.

Center-of-gravity / principal axis angle measurement function A function for obtaining the position of the centroid and the angle of the principal axis with respect to the X-axis in the binarized image of the billet 2 in the window. Here, the main axis is the major axis of the ellipse including the outer shape of the end face of the billet 2, and the X axis is shown in FIGS. Length measurement function by edge detection A function to measure the length of the billet end face in the window with an edge detection line that can be set at an arbitrary position at an arbitrary pitch in parallel with the X and Y axes of the window.

As shown in FIG. 2, a window 8 is set on the screen of the monitor 7 in a range corresponding to a visual field of 350 × 350 mm. Angle measurement function is activated,
As shown in FIG. 2, the center of gravity G (x, y) of the billet end face shape
And the principal axis angle θ between the principal axis M and the X axis is calculated. If the principal axis angle θ is within ± 20 °, it is determined that the billet 2 is in the normal posture or in the 180 ° rotation state shown in FIG.

Next, using a function for determining whether the posture is normal or rotated by 180 °, an edge detection line m in the X-axis direction is determined based on the center of gravity G (x, y) as shown in FIGS. , N are set, the lengths of the edge detection lines m, n passing through the billet binarized image are measured, and the lengths are compared.

[0029] The length of the m from the comparison of measurement results (a1 a2) <If the length of n of (b1 b2) an upper (m) is shorter than the lower (n), bi LESSON <br /> DOO 2 Is determined to be a normal posture, and based on the center of gravity G (x, y),
The control unit 30 is instructed to perform marking as shown in the right side of FIG. 2 in accordance with the inclination of the main axis angle θ.

When the length of m (a 1 a 2)> the length of n (b 1 b 2), the upper part (m) is longer than the lower part (n).
Bi LESSON DOO 2 determines that the state of being rotated 180 ° from the normal posture, the center of gravity G (X, Y) based on, and rotated 180 ° as shown in the right side of the slope to the mating Figure 3 the main shaft angle θ The control unit 30 is instructed to perform marking in the state.

When the length of m (a1 a2) = the length of n (b1 b2), the end face shape is determined to be a rectangle. In this case, since the postures of 0 ° and 180 ° are the same, marking processing is performed as a normal posture.

If the main axis angle θ exceeds ± 20 °, it is determined that the main body has rotated ± 90 ° from the normal posture. 4 and 5
Indicates this case. Next, as shown in FIGS. 4 and 5, an edge is determined in the Y-axis direction with respect to the center of gravity G (x, y) as shown in FIGS. The detection lines p and q are set, the lengths of the p and q lines passing through the billet binarized image are measured, and the lengths are compared.

According to the measurement result, when the length of p (c1 c2) <the length of q (d1 d2), it is determined that the body has rotated 90 ° counterclockwise from the normal posture, and the center of gravity G is determined as shown in FIG. The control unit 30 is instructed to perform marking with the direction of the character as the edge line p side in accordance with the inclination of the principal axis angle θ based on (x, y).

When the length of p (c 1 c 2)> the length of q (d 1 d 2), it is determined that the posture has been rotated clockwise by 90 ° from the normal posture, and the center of gravity G (x, y) as shown in FIG. ), The direction of the character is changed to the edge line q according to the inclination of the principal axis angle θ.
The control unit 30 is instructed to perform the marking as the side.

When the length of p (c 1 c 2) = the length of q (d 1 d 2), the shape of the end face is determined to be a rectangle, and 9
The same processing as when rotating by 0 ° is performed. Note that clockwise 9
The same processing as when rotating by 0 ° may be performed.

As described above, the position of the center of gravity of the billet end face with respect to the window coordinate origin, the principal axis angle θ, and the direction of the character can be determined in the image controller 6. Next, these data are transferred to the control unit 30 in order to convert the data into data necessary for actually marking.

The control unit 30 sets the center of gravity of the billet binarized image measured by the image controller 6 to be the center position of the marking area. For the direction and inclination of the character, a character pattern corresponding to the inclination is created on the memory at a constant pitch, and the data closest to the inclination data of the main axis angle θ determined by the image controller 6 and the determination of the character direction are selected. Billet 2 is the marking start position N
Wait to arrive at the O.2 location.

The moving distance of the billet 2 from the time when the billet 2 is detected by the side detector 3 is measured by counting the number of pulses of the encoder 11, and the distance is the position of No. 1 and the position of No. 2.
Marking is started when the distance from the position is reached. Prior to marking, when the billet 2 passes the No. 1 position, the end face position of the billet 2 is measured by the ultrasonic distance meter 12, and the second servomotor 18 is driven by the control unit 30 via the servo controller 31, and the second 2 The trolley 20 is moved by rotating the ball screw 19 and the XY stage 21 is moved.
Is adjusted so that the position of the marking nozzle 22 mounted on the billet can be marked on the billet end surface.

When the billet 2 reaches the position No. 2, the ultrasonic range finder 13 and the side of the billet 2
7 is measured by the controller 30 via the servo controller 31 so that the distance always becomes a constant value.
The servo motor 15 is driven to rotate the first ball screw 16 so that the parallel running carriage 17 runs together with the billet 2.

The marking is performed by the control unit 30 in the X direction and the Y direction.
Movement data for the direction is transmitted via the servo controller 31.
And given to the XY stage 21
This is performed by discharging the paint while moving the marking nozzle 22 according to the character shape by an X-axis servo motor and a Y-axis servo motor built in the printer. When the marking is completed, the ultrasonic range finder 13 is rotated by the motor 14 so as not to hit the billet 2, the XY stage 21 is moved backward by the traversing carriage 20, and the parallel traveling carriage 17 is set to NO by the first servo motor 15. Return to position 2.

The operation of the billet 2 following the carriage 17 will be described in more detail. FIG. 6 is a diagram extracting and showing functions necessary for the following operation of the following mechanism shown in FIG.
An encoder 11 for measuring the amount of movement of the conveyor 1 from the time when the side detector 3 shown in FIG.
Is counted by the counter 32. Setting device 33
Is set to a reference distance between the No. 1 position and the No. 2 position. The comparator 35 compares the value of the counter 32 with the value of the setter 33, and outputs a latch signal to the latch 36 when the values match. The latch 36 latches the output data D1 of the amplifier 34 of the ultrasonic distance meter 13 at the rise of the latch signal.

The subtracter 37 calculates a difference DV between the data D1 and the distance data DX, converts the difference DV into a voltage output AV by the D / A converter 38, and outputs the voltage output AV to the servo controller 31. The servo controller 31 amplifies the deviation signal AV,
The first servomotor 15 is rotated in a direction in which the value becomes zero, and the parallel running carriage 17 is moved via the first ball screw 16. That is, the movement of the parallel running vehicle 17 is controlled so that the billet 2 reaches the No. 2 position and the distance between the billet 2 and the parallel running vehicle 17 measured by the ultrasonic distance meter 13 at that time is always maintained.

The sampling cycle of the ultrasonic distance meter 13 used in this embodiment is 100 Hz, and the repetition reproducibility is ± 0.1.
mm (at a distance of 150 mm), and the marking could be performed with a relative position accuracy of about ± 0.2 mm as an overall accuracy. In this embodiment, good results were obtained when the billet 2 was at room temperature. However, when the billet 2 was heated to a high temperature, the ultrasonic distance meter had a problem in terms of measurement principle. Laser-type instruments and mechanical displacement gauges also require temperature countermeasures, and are large in shape.

FIG. 7 is a block diagram showing a configuration of a follow-up mechanism which is also effective for high-temperature billets. As in FIG. 6, only the elements related to the follow-up mechanism are extracted and described. The image controller 6 recognizes the position and orientation of the end face of the billet 2 at the timing when the side face detector 3 detects the side face of the billet 2 that has reached the No. 1 position, and recognizes the result as an XY stage constituting a marking unit. 21 and the position of the marking nozzle 22 is corrected.

That is, when the side face of the billet 2 is detected by the side face detector 3, the number of pulses of the encoder 11 is counted by the counter 32 at that timing. The setting unit 33 sets a reference distance between the No. 1 position and the No. 2 position, and the value is read by the control unit 30 and stored in the memory. Counter 3
The count value of No. 2 is read by the control unit 30 in a very short period and compared with the set value of the setting device 33, and it is recognized that the billet 2 has reached the position No. 2 when the value matches or exceeds the set value. I do.

The parallel running vehicle 17 is provided with a contact mechanism. The contact mechanism is an arm 23 and a rotation shaft 24 of the arm 23.
And a motor 26 that rotates the rotating shaft 24 and a support fitting 25 that supports the rotating shaft 24, and applies an arm 23 to the billet 2 and operates to avoid the billet 2 from passing therethrough. The arm 23 is normally kept in a state in which the billet 2 does not pass, and when the billet 2 arrives at the No. 2 position, it rotates and rises as shown in FIG.

After the raising of the arm 23 is completed, a speed command A and a torque command B are issued from the control unit 30, and D / D
After conversion by the A converters 39 and 40, the servo controller 31
At the same time, and the activation and movement direction command C are output at the same time. The speed command A is the rotation speed R. P. M. is set at the arbitrary rotation speed.
It is possible to rotate the servo motor 15. In this embodiment, a counter 3 for counting the pulses of the encoder 11 is used.
2 is read out in a very short period, the speed of the conveyor 1 is calculated from the value, and a speed command A is issued by adding an arbitrarily settable bias value to the value. The torque command B is for setting the upper limit value of the motor output torque irrespective of the rotation speed, and the control unit 30 sets data according to the operation pattern.

When the billet 2 arrives at the position No. 2, the control unit 30 controls the contact mechanism and the X
-A trolley 17 equipped with a Y stage 21 (not shown)
At the same speed as the conveyor 1 at that time.
When the arm 23 of the contact mechanism is raised while following the above, and the completion of the rise is confirmed, a speed increase command A is issued, and the arm 23 is pressed against the side surface of the billet 2.

When the arm 23 hits the side surface of the billet 2, the load on the first servomotor 15 suddenly increases, and the servo controller 31 attempts to supply a large current. When this value is reached, the upper limit of the current value is limited by that value, and the parallel running vehicle 17 follows the billet 2 without heating the first servomotor 15.

That is, the first servo motor 15 controls the parallel running carriage 17 at a speed higher than the transport speed of the billet 2. However, since the arm 23 of the contact mechanism is in contact with the billet 2, the first servo motor 15 is completely different from the billet 2. It will move at the same speed, and the X-
The Y stage 21 makes it possible to mark the billet end face without deformation.

FIG. 8 is a timing chart of the follow-up control using the contact mechanism. The speed command data A is obtained based on the moving speed of the conveyor 1 before the billet 2 arrives at the No. 2 position. The torque command data B is set to a constant value based on an experimental value. In the speed command data A, a
Is the speed of the conveyor 1, b is the following speed, c is the return speed, and d is the conveyor speed. In the torque command data B, e is the set torque, f is the maximum torque set value at the time of following,
g is the set value of the starting torque at the start of the return, and h is the set torque.

An ascending command is issued to the arm 23 of the contact mechanism,
When it is recognized that the ascent is completed (point), the speed command data is set to a value b larger than a, and the arm 23 is brought into contact with the billet side surface. When the speed rises to b and enters the following speed, the torque command data is reduced from e to f, and the first servomotor 15
Do not allow overcurrent to flow (dot). As soon as the marking is completed, the first servomotor 15 is stopped (point), then reversed, and the traveling carriage 17 is returned to the origin. At that time, the speed command data A is increased to reduce the time (point), and the torque command data B is increased to g from f to obtain the starting torque (point). A reverse rotation signal is input to the servo controller 31 (dot).
When the parallel carriage 17 completes the return to origin, the carriage 17 waits for the next billet 2 (dot).

[0053]

As is apparent from the above description, according to the present invention, an image of a marking surface is taken, and marking is performed in consideration of deformation and posture of the marking surface based on the data, so that appropriate marking can be performed. . In addition, when marking the marking target being conveyed, the parallel running portion is caused to run along with the marking target by the follow-up mechanism, so that appropriate marking can be performed. As a follow-up mechanism, the distance between the marking object and the parallel running part is kept constant by a distance meter for low-temperature marking objects, and a part of the parallel running part is marked for high-temperature marking objects. Since the object is pressed against the object, a stable following operation can be performed over a wide temperature range.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of the present embodiment.

FIG. 2 is a diagram showing a billet end surface within a range of a normal posture.

FIG. 3 is a view showing a billet end face within a range of a 180 ° rotation posture;

FIG. 4 is a view showing a billet end face within a range of a 90 ° counterclockwise rotation posture;

FIG. 5 is a view showing a billet end face within a range of a 90 ° clockwise rotation posture.

FIG. 6 is a block diagram showing a configuration of a tracking mechanism using an ultrasonic range finder.

FIG. 7 is a block diagram showing a configuration of a follow-up mechanism using a contact mechanism.

FIG. 8 is a timing chart of a follow-up mechanism using a contact mechanism.

FIG. 9 is a diagram showing a posture and a state in which an end face is correctly marked when the rectangular bar-shaped steel material is conveyed.

FIG. 10 is a plan view showing the vicinity of an end surface of a conveyed marking object to be marked.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conveyor 2 Billet 3 Side detector 4 Strobe lighting lamp 5 Video camera 6 Image controller 7 Monitor 11 Encoder 12,13 Ultrasonic rangefinder 14,26 Motor 15 First servo motor 16 First ball screw 17 Parallel trolley 18 Second servo motor Reference Signs List 19 second ball screw 20 traversing carriage 21 XY stage 22 marking nozzle 23 arm 24 rotation axis 25 support bracket 30 control unit 31 servo controller 32 counter 33 setting unit 34 amplifier 35 comparator 36 latch 37 subtractor 38, 39, 40 D / A converter

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Kazuomi Tomita 12 Nakamachi, Muroran, Hokkaido Nippon Steel Corporation Muroran Works (72) Inventor Akio Ishiwatari 12 Nakamachi, Muroran, Hokkaido Nippon Steel Corporation Inside the Muroran Works

Claims (4)

(57) [Claims] A marking unit for marking a marking surface of a marking object; an image control unit for calculating a deviation of the marking surface from a reference marking surface based on image data obtained by imaging the marking surface; A marking device comprising: a marking control unit that creates marking data in consideration of a shift calculated by a control unit and controls the marking unit. 2. A parallel running section which runs along with a moving marking object, a marking section mounted on the parallel running section for marking a marking surface of the marking object, and said marking by image data obtained by imaging said marking surface. An image control unit that calculates a shift of a surface from a reference marking surface, a marking control unit that creates marking data in consideration of the calculated shift of the image control unit and controls the marking unit, and A marking device comprising a follow-up mechanism for following a parallel running section. 3. The tracking mechanism according to claim 1, further comprising: a distance detector configured to measure a relative distance between the parallel running unit and the marking target; and a relative distance control unit configured to control the parallel running unit to maintain the measured relative distance at a predetermined value. 3. The method according to claim 2, further comprising:
A marking device as described. 4. The following mechanism includes: a contact mechanism having one end connected to the parallel running portion and the other end contacting the marking target at the time of parallel running so as to be able to be pressed in the parallel running direction; 3. The marking device according to claim 2, further comprising: a pressing control unit that controls running of the parallel running unit so as to press against an object.