JP7262420B2 - Conveyor and its control method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a conveying device for supplying billets to an induction heating furnace and a control method thereof, and more particularly to a conveying device capable of detecting foreign matter mixed in a billet and a control method thereof.

Various transfer devices for supplying billets to an induction heating furnace have been proposed (see Patent Document 1, for example). The conveying apparatus described in Patent Document 1 includes a conveyer that supplies billets to an induction heating furnace that is positioned forward with respect to the axial direction of the rod-shaped billet in the conveying direction, and a conveyor that feeds billets from a position above and behind the conveyer. It has a chute section for conveying to.

Foreign matter such as bolts and offcuts of billets may be mixed in a plurality of billets continuously conveyed by a conveying device.

The bolt, which is a foreign object, is greatly different in shape from the billet. As a result, the magnetic flux passing through the billet inside the induction heating furnace is in a different state than initially assumed. Magnetic flux concentrates on the ends of the billet, resulting in excessive heating. Partially overheated billets were discarded due to poor product quality.

Also, bolts are often of a different kind of metal than the billet. In the forging process after the induction heating furnace, bolts, which are foreign objects, are supplied to the die for forging, causing the die to break.

Japanese Patent Application Laid-Open No. 58-107419

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a conveying apparatus and a control method thereof that can detect foreign matter mixed in a billet.

A conveying apparatus for achieving the above object is a conveying apparatus for conveying a rod-shaped billet to an induction heating furnace located forward with respect to the axial direction of the billet, wherein the billets are arranged front to back along the conveying direction. an outline acquisition mechanism for acquiring an outline, and detecting edges of the front end of the billet on the front side and the front end of the billet on the rear side based on the outline acquired by the outline acquisition mechanism, and determining the two edges. a measuring mechanism for measuring the interval in the conveying direction; and a judging mechanism for judging that there is no foreign matter when the interval obtained by the measuring mechanism is equal to or greater than a predetermined threshold, and judging that no foreign matter exists when the interval is smaller than the threshold. characterized by comprising

A method for controlling a conveying device for achieving the above object is a method for controlling a conveying device for conveying a rod-shaped billet to an induction heating furnace that is positioned forward with respect to the axial direction of the billet in the conveying direction. The outer shape of the billets arranged in the front-rear direction is acquired by an outer shape acquisition mechanism, and based on the outer shape, the edges of the front end of the billet on the front side and the front end of the billet on the rear side are detected, and The distance between the two edges is measured, and if the distance is equal to or greater than a predetermined threshold, it is determined that there is a foreign object, if the distance is smaller than the threshold , it is determined that there is no foreign matter, and if it is determined that there is a foreign object , control to stop the conveyance of the billet, control to remove foreign matter from the conveying device, or control to cause the conveying device to issue an alarm.

According to the present invention, the conveying device can measure the interval in the conveying direction between a plurality of billets that are continuously conveyed. Thereby, the conveying device can detect whether or not a foreign object is sandwiched between the billets.

It is explanatory drawing which illustrates a conveying apparatus by the side view. FIG. 2 is an explanatory diagram illustrating the conveying device of FIG. 1 in a plan view; FIG. 10 is an explanatory diagram illustrating how an edge of a billet is detected; FIG. 4 is an explanatory diagram illustrating the state of a foreign object sandwiched between billets; FIG. 4 is an explanatory diagram illustrating a modification of FIG. 3; FIG. 4 is an explanatory diagram illustrating an arrangement position of an outline acquisition mechanism with respect to a billet;

A conveying apparatus and a control method thereof will be described below based on an embodiment shown in the drawings. In the drawing, the billet transport direction is indicated by an arrow x, the width direction perpendicular to the billet transport direction is indicated by an arrow y, and the vertical direction is indicated by an arrow z.

As illustrated in FIGS. 1 and 2, the conveying device 1 is connected to an induction heating furnace 2 and has a structure for supplying rod-shaped billets 3 to the induction heating furnace 2 . The billet 3 is formed in, for example, a columnar shape or a prismatic shape. The billet 3 is transported with its axial direction as the transport direction x. In FIG. 1, the direction in which the billet 3 moves is indicated by an outline arrow for explanation.

The conveying device 1 has a conveyor 4 arranged on the rear side (left side in FIG. 1) of the induction heating furnace 2 in the conveying direction x. The conveyor 4 is arranged in a horizontal state, and conveys the billet 3 in a state in which the axial direction thereof is horizontal. The conveyor 4 is composed of, for example, a chain conveyor. The configuration of the conveyor 4 is not limited to a chain conveyor. Any configuration is acceptable as long as the billet 3 can be conveyed in its axial direction, and may be configured by a belt conveyor, for example. A pair of pinch rollers 5 are arranged in front of the conveyor 4 (on the right side in FIG. 1) so as to sandwich the billet 3 in the vertical direction z. The billets 3 are sequentially pushed into the induction heating furnace 2 by the pinch rollers 5 .

The conveying device 1 has a chute portion 6 that slopes down from the rear side toward the rear end portion of the conveyor 4 . The chute portion 6 is arranged at a position on the rear side of the conveyor 4 and on the upper side. The chute portion 6 is arranged in a downwardly inclined state toward the front side. The chute portion 6 is composed of, for example, a skid rail consisting of a pair of rod-like members extending in the conveying direction x and arranged with a gap in the width direction y. The billet 3 slides and moves with the vicinity of the lower end sandwiched between the pair of rod-like members. The configuration of the chute portion 6 is not limited to skid rails. The chute section 6 may be constructed of a V-shaped or U-shaped member with its upper side widened, as long as it can convey the billet 3 in the axial direction. A skid rail can be arranged between the conveyor 4 and the induction heating furnace 2 as well.

The conveying device 1 has an outline acquisition mechanism 7 that acquires outlines of a plurality of billets 3 that are conveyed in a state of being aligned along the conveying direction x. In this embodiment, an outer shape acquisition mechanism 7 is arranged between the pinch roller 5 and the induction heating furnace 2 . The outer shape acquisition mechanism 7 can be composed of, for example, a camera that acquires the outer shape of the billet 3 as an image.

The camera that constitutes the outer shape acquisition mechanism 7 has a configuration for photographing the rear end of the billet 3 on the front side and the front end of the billet 3 on the rear side. That is, the camera photographs the ends of the billets 3 that are continuously conveyed. The camera is configured to acquire images at predetermined time intervals. A camera may detect the approach of the billet 3 and acquire an image. In this specification, the front side and the rear side are defined based on the direction in which the billet 3 advances in the conveying direction x. For example, in FIG. 1, the right side is the front side, and the left side is the rear side.

The outer shape acquisition mechanism 7 may be composed of a laser sensor. This laser sensor has, for example, a transmitting section and a receiving section that are opposed to each other with a gap in the width direction y, and is configured to acquire the outer shape of the billet 3 passing between the transmitting section and the receiving section. ing. The laser sensor may have a configuration for acquiring the shape of the billet 3 as image information from numerical values obtained by measurement. For example, the transmitter may have a configuration for irradiating belt-shaped laser light that is widened in the transport direction x, the width direction y, or the vertical direction z.

The configuration of the outline acquisition mechanism 7 is not limited to the camera or laser sensor described above. The outline acquiring mechanism 7 may have a configuration capable of acquiring at least part of the outline of the billet 3 .

The conveying device 1 has a measuring mechanism 8 connected to the outer shape acquisition mechanism 7 via a signal line, and a determination mechanism 9 connected to the measuring mechanism 8 via a signal line. In FIGS. 1 and 2, signal lines are indicated by dashed lines for the sake of explanation. The signal line may be wired or wireless.

The measurement mechanism 8 acquires an image or shape of the end portion of the billet 3 from an outline acquisition mechanism 7 such as a camera. The measuring mechanism 8 has a configuration for detecting the edge 10 of the end portion of the billet 3 based on the image captured by the camera or the shape obtained by the laser sensor. The end of the billet 3 refers to the front end or rear end of the billet 3 in the transport direction x. The measuring mechanism 8 uses the detected edge 10 to measure the length of the gap between the billets 3 arranged in the front-rear direction.

The determination mechanism 9 is configured to acquire the length of the gap between the billets 3 from the measurement mechanism 8 . A determination mechanism 9 determines whether or not a foreign object is caught between the billets 3 according to the length of the gap.

As illustrated in FIG. 3, when the bolt 11a as the foreign matter 11 is sandwiched between the billets 3, the length of the gap between the billets 3 increases. When the camera that constitutes the outer shape acquisition mechanism 7 has a configuration for acquiring an image from the side of the billet 3, the camera acquires the image shown in the lower part of FIG. The side of the billet 3 is a direction orthogonal to the transport direction x. In this embodiment, the camera acquires an image while looking through in the width direction y. That is, the camera is set so that the optical axis direction of the camera is parallel to the width direction y.

A measurement mechanism 8 acquires an image captured by a camera. The measuring mechanism 8 detects the edge 10 of the billet 3 by image processing. The rear end of the billet 3a on the front side and the front end of the billet 3b on the rear side are detected as edges 10a. This edge 10a extends in the vertical direction z. The measuring mechanism 8 may be configured to selectively detect only the edge 10a extending in the vertical direction z. In FIG. 3, the detected edge 10a in the vertical direction z is hatched for explanation.

When the size of the foreign matter 11 in the vertical direction z is smaller than that of the billet 3, the edge 10a can be detected with high accuracy. Foreign matter 11 can be detected with high accuracy.

When the pair of edges 10a aligned in the transport direction x is detected, the measuring mechanism 8 measures the distance D between the pair of edges 10 in the transport direction x. The size of this interval D is calculated based on the image. A value indicating the size of the distance D is sent from the measuring mechanism 8 to the judging mechanism 9 .

A determination mechanism 9 acquires a value indicating the size of the interval D from the measurement mechanism 8 . A determination mechanism 9 compares the value of the interval D with a predetermined threshold. This threshold is predetermined and stored in the determination mechanism 9, for example. The threshold is set to a value of 5.0 mm or less, for example. The threshold can be set to 1.0 mm, for example. The threshold can be appropriately set according to the expected size of the foreign object 11 .

The determination mechanism 9 determines that there is a foreign object when the value of the interval D is equal to or greater than a predetermined threshold value, and determines that there is no foreign object when the value of the interval D is smaller than the threshold value.

When the foreign matter 11 is present, for example, control can be performed to stop the transport of the billet 3 by the transport device 1 . Further, control may be performed to remove the foreign matter 11 from the conveying device 1 . A configuration may be adopted in which the conveying device 1 issues an alarm to notify the operator of the presence of the foreign matter 11 .

The conveying device 1 can detect foreign matter 11 existing between a plurality of billets 3 conveyed in series in the axial direction. The conveying device 1 can avoid the problem that the billet 3 is partially overheated due to the influence of the foreign matter 11 . It is advantageous to keep the billet 3 in a good heating state.

It is also advantageous for avoiding accidents such as damage to the forging die due to the foreign matter 11 such as the bolt 11a being sent to the forging process.

When the value of the interval D is smaller than the threshold value, the determination mechanism 9 determines that there is no foreign object. In some cases, the edge 10a may not be detected because there is no foreign matter 11 and the billets 3 are in close contact with each other in the transport direction x. If the edge 10a is not detected, it may be determined that there is no foreign matter, and the transfer by the transfer device 1 may be continued.

A configuration in which the top edge 10b of the billet 3 is detected as a supplement may be employed. This edge 10b is the edge 10b extending in the transport direction x, and is basically perpendicular to the edge 10a extending in the vertical direction z. Therefore, by detecting the top edge 10b together, it is possible to verify whether or not the edge 10a extending in the vertical direction z is correctly detected. It becomes easy to avoid detection of an erroneous portion as the edge 10a in the vertical direction z. In FIG. 3, the edge 10b is hatched for explanation.

If the outer shape acquisition mechanism 7 has a configuration that irradiates a laser beam that widens in the vertical direction z, the top edge 10b can be detected in addition to the edge 10a.

The position where the outline acquisition mechanism 7 is installed is not limited to the above. The outer shape acquisition mechanism 7 can be installed at any position along the route along which the billet 3 is conveyed. For example, the outer shape acquisition mechanism 7 may be installed in the middle of the chute 6 or the conveyor 4 or behind the pinch rollers 5 .

It is desirable to install the outer shape acquisition mechanism 7 at a position on the front side of the chute portion 6 . As illustrated in the upper part of FIG. 4, the billet 3 may be formed short in the axial direction to become the offcuts 3c. This scrap material 3c may be caught between the billets 3 as a foreign matter 11 in some cases. By passing through the chute portion 6, the remnants 3c tend to fall in a direction in which the height thereof decreases, as illustrated in the lower portion of FIG. The overturning of the offcuts 3c makes it easier for the measuring mechanism 8 to detect the edges 10 of the billets 3a and 3b. The foreign matter 11, not limited to the offcuts 3c, slides through the chute 6, and tends to assume a posture smaller than the billet 3 in the vertical direction z. This is advantageous for improving accuracy when detecting the foreign object 11 . However, the configuration in which the outer shape acquiring mechanism 7 is installed on the rear side of the chute portion 6 is not excluded.

The outline acquiring mechanism 7 may have a configuration for acquiring the outline from above or below the billet 3 . At this time, the camera or the like that constitutes the outer shape acquisition mechanism 7 acquires an image while looking through in the vertical direction z. The camera is set so that the optical axis direction is parallel to the vertical direction z.

In this embodiment, an image illustrated in the upper part of FIG. 5 is acquired by an outline acquisition mechanism 7 such as a camera. The measuring mechanism 8 detects the edge 10c extending in the width direction y of the billet 3 by image processing. In FIG. 5, the detected edge 10c in the width direction y is hatched for explanation. When the size of the foreign matter 11 in the width direction y is smaller than that of the billet 3, the edge 10c can be detected with high accuracy. As illustrated in the lower part of FIG. 5, even if the size of the foreign matter 11 in the vertical direction z is approximately the same as that of the billet 3, the foreign matter 11 can be detected.

As in the embodiment illustrated in FIG. 3, the configuration may be such that the edge 10d extending in the transport direction x of the billet 3 is detected as a supplement. In FIG. 5, the edge 10d is hatched for explanation. By detecting the edge 10d extending in the transport direction x together with the edge 10c, it is possible to verify whether the edge 10c extending in the width direction y is correctly detected. This is advantageous for improving the detection accuracy of the foreign matter 11 .

When the outer shape acquisition mechanism 7 is composed of a laser sensor, the transmitter and the receiver are opposed to each other with a space therebetween in the vertical direction z. If the outer shape acquisition mechanism 7 has a configuration that irradiates a laser beam that widens in the width direction y, the top edge 10d can be detected in addition to the edge 10c.

The conveying device 1 may be configured to include both the outer shape acquiring mechanism 7 for acquiring an image on the side of the billet 3 and the outer shape acquiring mechanism 7 for acquiring an image above the billet 3 . This is advantageous for improving the detection accuracy of the foreign matter 11 .

The camera or the like that constitutes the outer shape acquisition mechanism 7 is not limited to a configuration in which the optical axis direction is parallel to the width direction y or the vertical direction z. As exemplified in FIG. 6, the outer shape acquisition mechanism 7 may be installed in a state in which the optical axis direction is a direction inclined upward from the width direction y by an angle θ with the transport direction x as the central axis. In FIG. 6, for the sake of explanation, the outer shape obtaining mechanism 7 whose optical axis direction is the width direction y and the vertical direction z is indicated by a broken line, and the optical axis direction of the outer shape obtaining mechanism 7 is indicated by an arrow.

1 Conveying device 2 Induction heating furnace 3 Billet 3a (Front side) Billet 3b (Back side) Billet 3c End material 4 Conveyor 5 Pinch roller 6 Chute section 7 Outline acquisition mechanism 8 Measurement mechanism 9 Judgment mechanism 10 Edge 10a (up and down Extending) edge 10b (upper edge) 10c (extending in width direction) Edge 10d (extending in conveying direction) edge 11 Foreign object 11a Bolt x Conveying direction y Width direction z Vertical direction D Space

Claims (6)

In a conveying device for conveying the billet to an induction heating furnace on the front side with the axial direction of the rod-shaped billet as the conveying direction,
an outline acquiring mechanism for acquiring outlines of the billets arranged in the forward and rearward directions along the conveying direction; a measuring mechanism for detecting each edge and measuring the distance between the two edges in the conveying direction; and a determination mechanism for determining that there is no foreign matter when the particle size is smaller than the particle size. 2. The conveying apparatus according to claim 1, wherein the measuring mechanism has a configuration for detecting the edge extending in the vertical direction at the end portion in the axial direction of the billet. 3. The conveying apparatus according to claim 1, wherein said judging mechanism has a configuration for judging that there is no foreign matter when said distance cannot be obtained from said measuring mechanism. Pinch rollers for sandwiching the billet in a direction orthogonal to the conveying direction and feeding it forward are arranged on the rear side of the induction heating furnace, and the outer shape is obtained at a position between the pinch roller and the induction heating furnace. A conveying device according to any one of claims 1 to 3, wherein a mechanism is arranged. 5. The conveying apparatus according to any one of claims 1 to 4, wherein the measuring mechanism has a configuration for detecting the edge extending in the width direction perpendicular to the conveying direction at the end of the billet. In a method for controlling a conveying device for conveying a rod-shaped billet to an induction heating furnace on the front side with respect to the conveying direction of the axial direction of the billet,
An outline acquisition mechanism acquires outlines of the billets arranged in the front-rear direction along the conveying direction, and based on the outlines, detects edges between the rear end of the billet on the front side and the front end of the billet on the rear side. measuring the interval between the two edges in the conveying direction, determining that there is a foreign object when the interval is equal to or greater than a predetermined threshold value, and determining that there is no foreign object when the interval is smaller than the threshold value;
A method of controlling a conveying device, characterized in that, when it is determined that there is a foreign object, control is performed to stop conveying the billet, or to remove the foreign matter from the conveying device, or to cause the conveying device to issue an alarm. .

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