JPH0441284Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a reflective detection device for conveyed objects, which is used, for example, to optically discriminate and sort the size, type, etc. of conveyed objects during transportation.

BACKGROUND OF THE INVENTION Conventional conveyance object detection devices using image sensors emit light onto the conveyance object from below and detect the size of the conveyance object from the shaded state. However, depending on the conveyance device, it may not be possible to emit light from below, and when detecting by reflected light, if the surface of the conveyed object is dark-colored or has a matte rubber-like surface, it may reflect light. The light may be so weak that it may be undetectable.

Problems that the invention aims to solve The purpose of this invention is to illuminate the conveyed object from above and detect it using the reflected light.The purpose of this invention is to use a reflective method for detecting conveyed objects, which is particularly effective when there is little reflection from the conveyed object itself. There is a device to suggest.

Means for Solving the Problems The present invention provides a projector for a tray that can be tilted to the side of a sorting and conveying device, and that illuminates the conveyed items with low reflectivity placed on the tray loading surface from above toward the reflector plate. and an image sensor that scans the irradiated reflecting plate across the conveyance direction.

Effect When the conveyed object is placed on the reflector installed in the conveyance device and conveyed and reaches the position of the image sensor, the light reflected from the reflector is much stronger than the reflected light of the conveyed object due to irradiation from the projector. Since the reflected light is strong, the difference in brightness between the two reflected lights becomes noticeable, and the image sensor clearly detects the outline of the conveyed object. This detection signal is calculated by, for example, a computer to determine the size, shape, etc. of the transported object, and based on this discrimination signal, a required gate is opened to perform a sorting operation in which the transported object is discharged.

Embodiment The drawings show an embodiment in which the present invention is detected on a conveyor that sorts automobile tires into large and small inner diameters.
A vertical frame 3 is provided at a conveyance object detection point in the middle of a tray conveyor 2 formed by connecting trays 1 which can be tilted laterally, a video camera 4 is attached as an image sensor to the upper part of the frame 3, and a floodlight 5 is attached to both sides of the frame.

The tray 1 has a shallow box shape, and has a front wall 6 and a partition 7.
A large number of free rollers 10 and 11 are supported parallel to the traveling direction between the rear wall 8 and the inner partition 9, respectively, so as to form a common loading surface 12. In between, a reflecting plate 13 is fixed upward slightly lower than the loading surface 12. The loading surface 12 is tilted slightly downward to one side with respect to the running direction and is attached to a drive chain (not shown) in a well-known manner so as to be tiltable laterally. A fall prevention piece 14 is provided on the downwardly inclined front side surface of the tray 1, and the front corner of an automobile tire T, which is a conveyed object, comes into contact with a falling prevention piece 14.
It prevents it from falling off. The dimensions of the reflector 13 and the tire loading position are determined so that the reflector 13 is exposed to most of the tire center hole 15 in this blocked state. When tray 1 tilts,
The tire T is ejected from the tray 1 while rotating the rollers 10 and 11 due to its own weight, avoiding the falling-off prevention piece 14.

When detecting the size of the center hole 15 of the tire T, the floodlight 5 only needs to illuminate the inside of the center hole 15.
When detecting the rubber portion of the tire T, the direction of the projector 5 may be determined so as to illuminate the inner and outer reflective plate portions of the rubber portion.

The video camera 4 scans the irradiated portion of the reflection plate 13 in a direction transverse to the conveying direction, and
5, a bidet signal e is generated based on the difference in intensity between the light reflected within the center hole 15 and the light reflected from the rubber portion of the tire. Since the width b of the video signal e changes as the conveyor 2 moves, if the signal e is processed by the CPU via the controller to find its maximum width, this signal represents the diameter of the center hole 15. Using this signal, the tires T can be sorted by selectively tilting the tray 1 according to the center hole diameter.

The arrangement of the projector 5 is determined according to the shape and size of the conveyed object so that its outline can be accurately captured. As an example of such determination, the height and field of view of camera 4 are determined as shown in Figure 4, and the other conditions are as follows: Lens f = 50 mm, number of picture elements 2048
When the conveyor speed is 30 m/min, the resolution in the running direction and in the direction perpendicular to this is 0.3 mm and 2.5 mm/sec, respectively. Therefore, in practice, the shape and size of the conveyed object can be determined with considerable accuracy.

Effects of the invention This invention has the above-mentioned configuration and is convenient for installing a floodlight because it illuminates the conveyed object from above, and when detecting the reflected light with an image sensor, the reflected light of the reflector and the low reflectance Not only is the difference in brightness between the light reflected from the conveyed object and the reflected light of the conveyed object large, making it easy to detect the conveyed object, but also when the conveyed article slides down on the tray due to the sideward tilting of the tray at the sorting position, the reflective plate Because it is located at a lower position than the loading surface of the tray, the conveyed items will not come into sliding contact with the surface of the reflector when it slides and falls, so there is no risk of scratches occurring on the surface of the reflector. As a result, the drawbacks that lead to a reduction or disappearance of the reflective function are eliminated, the conveyed object identification function is maintained for a long time, and detection accuracy sufficient for practical use can be obtained.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and Fig. 1 is an overall perspective view, Fig. 2 is a plan view of the tray, Fig. 3 is an elevation view of the tray, Fig. 4 is an explanatory diagram of the mounting state of the video camera, and Fig. FIG. 5 is an explanatory diagram of the relationship between the rubber tire and the video signal at the time of detecting its center hole. 1...Tray, 2...Transfer device, 4...Image sensor, 5...Light emitter, 12...Loading surface, 13
……a reflector.

Claims (1)

[Scope of utility model registration request] A laterally tiltable tray of the sorting and conveying device is provided with an upward reflecting plate provided at a position lower than the loading surface of the tray, and a low-reflectance conveyed object placed on the loading surface of the tray is directed to the reflecting plate from above. A reflective detection device for conveyed objects, which includes a projector that emits light toward the object, and an image sensor that scans the illuminated reflector across the conveyance direction.