JP3090160B2 - Positioning and unloading method of hollow work having light transmitting part and apparatus therefor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for carrying out fixed positioning of a hollow work having a light-transmitting portion formed of a through hole or a notch and then carrying it out to the next step, and an apparatus capable of suitably carrying out the method. Things.

[0002]

2. Description of the Related Art As shown in FIG. 4, a dome-shaped work 12 having a through hole 10 having a required diameter at a position deviated from the top is provided.
Flanges 12a, 1 are attached to cylinder 14 prepared separately.
There are many demands in the industry for welding at the portion 4a to produce, for example, tubular equipment for plants. In this type of plant equipment, when the work 12 is attached to the opening of the cylinder 14, it is necessary to accurately position both of the through holes 10 so that the through hole 10 reaches a predetermined position with respect to the cylinder body. There is.

[0003]

As described above, equipment in which the work 12 having the through hole 10 is attached to the cylinder 14 is mass-produced according to the demand. Therefore, as shown in FIG. 5, a large number of works 12 are stacked one upon another before the assembling, and the works 12 are sent out one by one to the next process. In this case, if the work 12 is simply sent out, it can be easily achieved by a normal transfer means such as a magnetic attraction type arm. However, since the workpieces 12 have a dome-shaped outer shape, even if they are stacked one on another, they do not slide in each other to maintain the parallelism in the vertical direction, and the positions of the through holes 10 are different for each workpiece. It often happens. That is, even if the work 12 is transferred by a transfer means such as a robot arm and is to be mounted on the cylinder 14 in the next process, the positions of the through holes 10 are already different at the stage before the transfer. Therefore, even if the work 12 is conveyed and adhered to the cylinder 14 by the conveyance means, it is necessary to perform a complicated adjustment operation so that the through hole 10 of the work 12 comes to a fixed position of the cylinder 14 thereafter.

Conventionally, therefore, it is necessary to manually transport the work 12 to the cylinder 14 and set the through hole 10 of the work 12 at a fixed position of the cylinder 14, which has not been automated in this part. Is the actual situation. As described above, serious problems such as wastage of human labor, variation in fixed positioning, reduction in production efficiency and quality due to an increase in processing time required, and occurrence of dangers due to manual labor are problems to be solved. Was inherent. Not only when the through hole 10 is formed in the work 12, the work 12
There is a demand that the notch be mounted in a state where the notch is fixedly positioned on a cylinder or the like, but in this case, the same problem is faced.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems inherent in the prior art, and has been proposed in order to solve the problem suitably. Provided is a method for automatically positioning a hollow work having the same, supplying the work to a next process without relying on humans, thereby saving labor and improving production efficiency, and an apparatus capable of suitably implementing the method. With the goal.

[0006]

SUMMARY OF THE INVENTION In order to overcome the above-mentioned problems and achieve the intended object, a method for positioning and carrying out a hollow work according to the present invention comprises: a hollow work having a light transmitting portion; A light-emitting source provided in relation to this rotary table is turned on to irradiate the hollow work from inside or outside, thereby causing light leakage or shadow in the light-transmitting portion. A required lightness difference is generated between the rotating table and the outer surface of the work, and the rotary table is rotated.
The outer surface of the hollow work is imaged by a CD camera, and from the time when the CCD camera detects the brightness difference caused by the light transmitting portion of the work, the taking of information on the rotation angle or the distance of the table is started, A set value relating to a rotation angle or a distance between the unloading reference position of the hollow work previously known and the imaging position by the CCD camera,
Compare the information on the rotation angle or the distance of the table where the loading is started, and give a stop command to the table driving motor at the time when the set value and the information related to the comparison match, to rotate the rotation table. Stop instantly,
The hollow work indexed to a predetermined carry-out reference position by stopping the rotary table is carried out toward the next process while maintaining its posture.

In this case, if the area of the light leakage or shadow imaged by the CCD camera is large enough to prevent spot imaging by the camera, the center of gravity of the light leakage or shadow is calculated from this area. Then, the acquisition of information on the rotation angle or the distance of the table may be started from the point of detection of the center of gravity.

In order to preferably carry out the above-mentioned method, a positioning and carrying-out device for a hollow work according to another invention of the present application comprises:
A rotary table for mounting a hollow work having a light-transmitting part with the hollow part facing downward, and rotating the rotary table in a predetermined direction, and immediately stopping the table upon receiving a required stop command. Motor with brake
It is disposed in relation to the rotary table, and illuminates the hollow work placed on the table from the inside or the outside by turning on the light, and between the light leakage or shadow in the light transmitting portion and the work outer surface. A light emitting source for producing a required brightness difference, a CCD camera disposed at a fixed position outside the rotary table, and for imaging an outer surface of the hollow work placed on the table; A rotation detecting means provided in a related rotating system for transmitting information relating to a rotation angle or a distance of the table, and an electric signal obtained by imaging by the CCD camera is supplied, and the brightness difference caused by a light transmitting portion of the hollow work is supplied. A controller that takes in only information regarding the rotation angle or distance between the reference position for unloading the hollow workpiece and the imaging position of the CCD camera that is known in advance. The set value is compared with the information on the rotation angle or the distance of the rotary table from which the take-in has been started, and when the set value matches the information, a stop command is given to the motor with brake to instantly change the table. It is characterized by comprising a sequencer to be stopped and supply means for supplying a fixedly positioned hollow work from its rotary table to the next process.

In this case, it is recommended that the controller further calculates the barycenter of light leakage or shadow caused by the through hole of the hollow work, and transmits the detection of the barycenter to the sequencer.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a method and an apparatus for positioning and unloading a hollow work according to the present invention will be described below with reference to the accompanying drawings by way of preferred embodiments. As an example,
As shown in FIG. 4, a dome-shaped work 12 having a through hole 10 at a position deviated from the top will be described as an example. The work 12 is not necessarily dome-shaped, but a required hollow portion is formed. Anything can be used. Instead of the perforation of the through hole 10, a hollow work 12 having a "notch" may be used. As described later, the present invention irradiates a hollow workpiece from inside or outside by a light emitting source, and performs fixed positioning of the workpiece by using light leakage or shadow generated in the “through hole” or “notch”. That's why. Therefore, "through holes"
In this specification, the term “light-transmitting portion” is also used as a concept widely including “notch”.

FIG. 1 is a schematic view of a work positioning / unloading apparatus according to an embodiment. A rotary table 18 is provided on a base 16 so as to be horizontally rotatable. This table 18
The motor 20 is rotated by a motor 20 with a brake, and is stopped by a stop command from a sequencer 30 described later.
Is instantaneously braked, and the table 18 is stopped. A means for detecting information about the rotation angle or the distance of the rotary table 18 as a signal such as a pulse, for example, a rotary encoder 22 is connected to the rotation system of the motor 20, and the detection signal obtained by this is supplied to the sequencer 30. ing. In general, the power transmission to the table 18 by the motor 20 is preferably performed by using a gear train formed by meshing gears. Alternatively, a chain sprocket, a timing belt pulley, or a belt pulley may be used.

The diameter of the rotary table 18 is set to a size that allows the dome-shaped work 12 described above with reference to FIG. 4 to be stably mounted on the table upper surface with the hollow portion facing downward. . Note that a step 18a that is slightly inclined downward is provided around the outer periphery of the table upper surface so that the inner peripheral edge of the flange 12a formed on the outer peripheral edge of the work is received almost in close contact with the step 18a. When the work 12 is supplied to the table 18, the position of the work 12 on the X and Y coordinates is automatically determined, which is more convenient. However, it is needless to say that the relative position between the through hole 10 in the work 12 and the reference position for unloading the work is not fixed.

At the center of the upper surface of the rotary table 18, a light emitting source 24 represented by, for example, a ball is disposed. By turning on the light emitting source 24, the hollow work 12 placed on the table 18 is moved inward. , And as a result, light can leak outward from the through hole 10 of the work 12. Therefore, in the case of this embodiment, a remarkable lightness difference occurs between the light leaking from the through hole 10 of the work 12 and the part of the dome-shaped outer surface of the work 12, and this lightness difference is described later. CCD camera 26
Is imaged. The light-emitting source 24 may be any light source that emits light uniformly and the light illuminates the inner surface of the work 12 completely. For example, a circular fluorescent tube is preferably used.

At a fixed position obliquely above the turntable 18,
A CCD camera 26 is fixedly provided, and its imaging lens is directed to the dome-shaped outer surface of the hollow work 12 placed on the table 18. This CCD camera 26
Uses a solid-state image sensor made of a semiconductor, and detects a light leaking from the through hole 10 of the hollow work 12 to the outside by the image sensor and a brightness difference between the dome-shaped surface of the work 12. Has become. The electric signal of the video information related to the brightness difference obtained by the CCD camera 26 is
The data is input to a controller 28 shown in the drawing, where necessary electric processing is performed. The electric command from the controller 28 is given to the drive motor 20 of the turntable 18 via the sequencer 30 to which the rotary encoder 22 is connected.

The controller 28 includes the CCD camera 2
6 senses the image information related to the brightness difference by the light leaking from the through hole 10 of the hollow work 12,
It is determined whether or not there is light leakage from the device, and the acquisition of only the information relating thereto is started. If the light leaked from the through-hole 10 sensed by the CCD camera 26 has an area that occupies a large amount of the pixels of the camera and is large enough to prevent so-called spot imaging, the controller The calculation based on the area of the light leakage is performed by 28 to determine the center of gravity of the light leakage, and the detection of the center of gravity is transmitted to the sequencer 30.

As shown in FIG. 2, the sequencer 30
A set value relating to the rotation angle or distance between the unloading reference position P of the hollow workpiece 12 and the imaging position by the CCD camera 26, which is known in advance, and information relating to the rotation angle or distance of the table 18 at which the loading has been started. It is designed to compare. When the set value and the information match, a stop command is given to the motor with brake 20 to stop the table 18 instantaneously.

Further, on the side or above the rotary table 18, there is provided a supply means 32 for feeding out the hollow work 12 which has been fixedly positioned on the table 18 in the same attitude toward the next assembly line. Has been established. As the supply means, for example, a suction cup type overhead traveling crane using an electromagnet or a vacuum is preferably employed. That is,
The suction cup of the crane descends to just above the rotary table 18 and, after sucking the hollow work 12 for which fixed positioning has been completed, rises, and travels horizontally along the work unloading reference position P as it is, not shown. It is supplied to the cylinder waiting for the next process.

[0018]

Next, a method of positioning and unloading a hollow workpiece according to the embodiment will be described in relation to the operation of the above-described positioning and unloading device. At the outer fixed position of the turntable 18, the reference point P for carrying out the work 12 to the next step (not shown) is set as described above.
First, the hollow work 12 is randomly supplied to the rotary table 18. At this time, the inner peripheral edge portion of the flange of the work 12 is received almost in close contact with the inclined step 18a provided on the outer periphery of the table 18, so that the X and Y coordinates at the work supply location on the work 12 are automatically determined. become. However,
The through hole 10 formed in the hollow work 12 is located at the unloading reference position P.
Exists at an undefined position. CCD camera 26
Is fixed diagonally above the rotary table 18 as described above, and images the dome-shaped outer surface of the hollow work 12 placed on the table 18.

In this state, the light source 24 provided on the rotary table 18 is turned on, and the table 18 is rotated horizontally in a required direction. As a result, the light emitting source 24 irradiates the inner surface of the hollow work 12, and light leaks outward from the through hole 10 formed in the work 12. As a result, a lightness difference occurs between the light leakage and the dome-shaped outer surface of the work 12. Due to the rotation of the work 12 caused by the rotation of the table 18, the light leakage part is changed to the CCD camera 26.
When the camera 26 arrives at the image pickup area, the camera 26 senses the brightness difference, and its electric signal is sent to the controller 28. The controller 28 detects that this brightness difference is caused by the through hole 10, and thereafter calculates the center of gravity of the light leakage (circular or oval). The sequencer 30 that has received the detection of the center of gravity,
Of the information on the rotation angle or distance of the table 18 is started. The acquisition of this information is performed by, for example, a counter (not shown) built in the sequencer 30.

As described above, the image pickup position of the CCD camera 26 and the work unloading reference position P outside the table are set.
The setting value relating to the rotation angle (or distance) between them is known in advance. Therefore, the sequencer 30 compares the set value with information on the rotation angle or distance of the table 18. Then, when the number of pulses generated by the rotary encoder 22 matches the predetermined set value, the sequencer 30 issues a rotation stop command to the table driving motor 20, and the rotary table 18 is stopped instantaneously. As a result, the through hole 10 of the hollow work 12 placed on the turntable 18 has reached the work supply reference position P as shown in FIG.

As described above, the work 1 on the rotary table 18
Is completed, for example, the suction cup type overhead traveling crane 3 provided above the table 18.
2 starts operation. That is, the suction cup descends to just above the rotary table 18 and, after sucking the hollow work 12, rises and travels horizontally along the work unloading reference position P, and is supplied to the cylinder waiting for the next process. You. Accordingly, in the next step, the work is set at the fixed position on the cylinder, and it is possible to perform an assembly operation such as automatic welding. In the preferred embodiment, the light leaking outward from the through hole 10 formed in the hollow work 12 is
The brightness difference is detected by the D camera 26, but is not limited to this. For example, as shown in FIG. 3, the hollow work 12 is illuminated from the outside by the light emitting source 24, and the brightness difference between the shadow generated in the through hole 10 and the outer surface of the dome of the work 12 is detected by the CCD camera 26. It may be. In addition, not only the through hole but also a work having a notch or a work having a plurality of through holes or notches having different sizes can be similarly fixedly positioned.

[0022]

As described above, according to the method and the apparatus for positioning and unloading a hollow work according to the present invention, a hollow work having a light-transmitting portion such as a through hole or a notch is automatically fixed to a fixed position. Is carried out to the next process without relying on humans, thereby enabling accurate setting of a work. In addition, the achievement of automation has a beneficial effect that safety can be ensured, labor can be saved, and production efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of an apparatus capable of suitably executing a method for positioning and carrying out a hollow work according to the present invention.

FIG. 2 is an explanatory plan view showing that a work placed on the table reaches a carry-out reference position by rotating the table.

FIG. 3 is an explanatory diagram showing a state in which a light emitting source provided outside a work irradiates an outer surface of the work.

FIG. 4 is an explanatory view showing an example of manufacturing a tubular device for a plant by welding a dome-shaped workpiece having a through hole to a cylinder at both flange portions.

FIG. 5 is an explanatory diagram showing a state in which when a large number of dome-shaped works are stacked one upon another, the parallelism in the vertical direction is not maintained.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Translucent part (through hole or notch) 12 Hollow work 18 Rotary table 20 Motor with brake 22 Rotation detecting means (Rotary encoder) 24 Light emission source 26 CCD camera 28 Controller 30 Sequencer 32 Supply means

Claims (4)

(57) [Claims] 1. A hollow work (12) having a light-transmitting part (10),
It is placed on a rotary table (18) with its hollow part facing down, and a light source (24) provided in relation to the rotary table (18) is turned on to put the hollow work (12) inside. By irradiating from outside or outside, a required lightness difference is generated between the light leakage or shading in the light transmitting portion (10) and the outer surface of the work, and the rotary table (18) is rotated, and the table is rotated.
(18) An outer surface of the hollow work (12) is imaged by a CCD camera (26) disposed at a fixed position outside of the work (12). ) Is detected, the table (18)
Start to take in information about the rotation angle or distance of the set value of the rotation angle or distance between the previously determined unloading reference position (P) of the hollow workpiece (12) and the imaging position by the CCD camera (26). And the information on the rotation angle or the distance of the table (18) where the loading is started, and when the set value and the information related to the comparison match, a stop command is given to the table driving motor (20). Then, the rotation of the rotary table (18) is stopped instantaneously, and the hollow work (12) indexed to a predetermined unloading reference position by the stop of the rotary table (18) is held in the next step while maintaining its posture. A method for positioning and carrying out a hollow work having a light transmitting part, wherein the work is carried out. 2. When the area of the light leakage or the shadow imaged by the CCD camera (26) is large enough to prevent spot imaging by the camera (26), the area of the light leakage or the shadow is calculated from this area. 2. The method according to claim 1, wherein the center of gravity of the workpiece is calculated, and information on the rotation angle or the distance of the table is started from the time of detection of the center of gravity. 3. A hollow work (12) having a light-transmitting portion (10),
Rotary table with its hollow part facing down
(18), while rotating the turntable (18) in a predetermined direction,
A motor with a brake (20) that stops the table (18) instantaneously upon receiving a required stop command, and is disposed in relation to the rotary table (18), and is mounted on the table (18) by lighting. A light emitting source (24) that irradiates the hollow work (12) from inside or outside to generate a required lightness difference between light leakage or shading in the light transmitting part (10) and the work outer surface. A CCD camera (26) arranged at a fixed position outside of the rotary table (18) and for capturing an outer surface of the hollow work (12) placed on the table (18); A rotation detection means (22) provided in a rotation system related to the table (18) and transmitting information on a rotation angle or a distance of the table (18), and an electric signal obtained by imaging by the CCD camera (26) are supplied. And a controller that takes in only information on the brightness difference caused by the light transmitting portion (10) of the hollow work (12). Roller (28), a set value relating to a rotation angle or a distance between a predetermined reference position (P) for unloading the hollow workpiece (12) and an imaging position by the CCD camera (26), and the loading is started. The information about the rotation angle or the distance of the rotating table (18) is compared, and when the set value and the information match, a stop command is given to the motor with brake (20) and the table is given.
(18) a sequencer (30) for instantaneously stopping, and a supply means (32) for supplying a fixedly positioned hollow work (12) from the rotary table (18) to the next process. A positioning and unloading device for hollow workpieces having a light transmitting part. 4. The method according to claim 1, wherein the controller (28) further comprises a hollow workpiece.
4. The apparatus according to claim 3, wherein the center of gravity of light leakage or shadow caused by the through-hole (10) is calculated, and the detection of the center of gravity is transmitted to the sequencer (30).