JP3923145B2 - Method of attitude control of rectangular flat article - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for controlling the posture of a rectangular flat article such as a book, and in particular, using a belt conveyor with a rail having a conveyor belt provided with a rail perpendicular to the conveying direction on the conveying surface, the direction of the article is controlled during conveyance. It relates to the method of aligning.
[0002]
[Prior art]
Conventionally, when a label is attached to a book with a label, or when an ISBN code (an identification code combining alphanumeric characters printed on a book cover or the like) is read with an OCR, the book is properly aligned in a predetermined direction. There is a need.
[0003]
In particular, the work of reading the ISBN code by OCR is, for example, when the book is read by the OCR installed at a fixed position while the book is being conveyed by a conveyor that is intermittently fed at a feeding cycle of 1.1 sec. Otherwise, it cannot be read correctly, and if the posture error becomes large, it takes time to read, so conventionally, a skilled worker manually performed using a handy scanner.
[0004]
[Problems to be solved by the invention]
However, manual ISBN code reading using a handy scanner has a low work efficiency and increases labor costs.
In order to solve this problem, a posture correction plate is erected along the conveyance direction on the side of the belt conveyor, and the conveyance surface of the belt conveyor is inclined to the side so that the posture correction plate side is lowered. The book can be transported by its own weight by sliding the book by the above-mentioned inclination and bringing it into contact with the posture correcting plate to align the direction, or by transporting the book by a steeply inclined belt conveyor having a cross perpendicular to the transport direction. A method is conceivable in which the ISBN code is automatically read by the OCR installed on the downstream side of the belt conveyor in a state where the surface is slid and the one side is brought into contact with a crosspiece at the rear of the conveying direction and the direction thereof is aligned.
[0005]
However, in any of these methods, it is necessary to increase the inclination of the conveyor surface of the belt conveyor more than the angle at which the book slides down, the conveyance state becomes unstable, and the inclination angle at which the book begins to slide down depends on the state of the book surface. Since it is mixed, there is a problem that it is difficult to align the directions accurately.
[0006]
Therefore, the present invention aims to solve the problems of the conventional techniques as described above, and to provide a posture control method capable of efficiently and accurately aligning the directions of rectangular flat articles such as books during transportation. And
[0007]
[Means for Solving the Problems]
For the above purpose, the method for controlling the posture of a rectangular flat article according to the present invention uses the belt conveyor with a crosspiece having a crosspiece having a crosspiece orthogonal to the transfer direction on the transfer surface, and the direction of the rectangular flat article is set. The coefficient of static friction between the conveying surface of the conveying belt and the article is μ, the acceleration when accelerating the conveying belt is α, the acceleration when decelerating the conveying belt is β (negative value), An acceleration part that satisfies the condition of α> G (μCOSθ−SINθ) and a deceleration part that satisfies the condition of −β <G (μCOSθ + SINθ), where θ is the forward tilt angle in the transport direction and G is the gravitational acceleration, By driving the conveying belt with a speed pattern that includes alternating and periodically changing, the articles placed on the conveying surface are slid backward in the conveying direction with respect to the conveying surface, and one side of the article is used as a back rail. To align the direction by contacting Those were.
[0008]
In the posture control method for a rectangular flat article according to the present invention, the absolute value of the acceleration α when the conveyor belt is accelerated is larger than the absolute value of the acceleration β when the conveyor belt is decelerated, and the upper surface of the conveyor surface is moved forward in the conveying direction. It is preferable to align the direction of the article at the inclined portion.
[0009]
[Action]
When a rectangular flat article such as a book is placed on the upstream side of the belt conveyor with a crosspiece, the speed of the conveyance belt of the belt conveyor with the crosspiece periodically changes. Force acts.
[0010]
The inertial force causes the article to slide backward in the conveyance direction with respect to the conveyance surface of the conveyance belt when the acceleration α when accelerating the conveyance belt satisfies the condition of α> G (μCOSθ−SINθ). One side of the article is pressed to correct its orientation.
[0011]
On the other hand, as long as the acceleration β (which is a negative value) when decelerating the conveying belt satisfies the condition of −β <G (μCOSθ + SINθ), the article once pressed against one side against the crosspiece is decelerated by the conveying belt. At times, the inertial force acting on the article does not leave the rail again and the orientation of the article being conveyed is maintained in a stable state.
[0012]
In particular, the absolute value of the acceleration α when accelerating the conveyance belt is larger than the absolute value of the acceleration β when decelerating, and the direction of the article is aligned at a portion inclined upward in the conveyance direction on the conveyance surface. If the acceleration α is small, the resultant force of the inertial force acting on the article and the gravity direction component of the gravity easily exceeds the maximum static friction force acting between the article and the carrying surface. In this case, the power consumption of the motor that drives the conveyor belt is reduced.
[0013]
In addition, since the article once in contact with the crosspiece is subjected to the component of gravity in the conveyance direction, the article and the crosspiece are maintained in a more stable contact state during the deceleration of the conveyance belt.
[0014]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a side view of a belt conveyor with a crosspiece that controls the posture of a book, which is an example of a rectangular flat article, during conveyance, and the belt conveyor 1 with a crosspiece aligns the direction of the book W, It is used for automatically and continuously reading the attached ISBN code and applying a label.
[0015]
The cross-belt conveyor 1 has a conveyor belt 2 whose intermediate surface is inclined forwardly and upwardly at an angle of approximately 40 degrees, and on the conveyor surface of the conveyor belt 2 in the conveyance direction. The crosspieces 3 are oriented at equal intervals along the conveying direction.
[0016]
FIG. 2 is a cross-sectional view seen in the direction of the arrow at the position AA in FIG. 1, and as shown in FIG. 2, is opposed to the lower side of the forward side of the conveyor belt 2 in the housing 4 of the belt conveyor 1 with a crosspiece. A belt support plate 5 for supporting the weight of the book W applied to the transport belt 2 is disposed along the transport direction.
[0017]
On both sides of the transport belt 2 in the housing 4, there are provided rotatable guide rollers 6 that are paired up and down at regular intervals along the transport direction and are formed on both side edges of the transport belt 2. The roller receiving portion 2A is sandwiched and held by these guide rollers 6 from above and below to prevent meandering and bending when the conveyor belt 2 is running.
[0018]
Further, the crosspieces 3 attached to the conveying surface of the conveying belt 2 are alternately arranged in a comb-tooth shape at the end of the transfer plate that communicates between the unloading position X of the conveying belt 2 in FIG. Comb-like convex portions 3A and concave portions 3B passing through the convex portions and the convex portions are formed alternately, and the crosspiece 3 is conveyed without increasing the gap between the transfer plate and the conveying belt 2. The belt 2 can be reversed to the return side.
[0019]
In addition, the conveyance belt 2 of the present embodiment has a conveyance surface on which a book W can be placed having an effective width of 300 mm and a distance between the crosspieces 3 before and after the conveyance direction is 475 mm.
Further, the length of the crosspiece 3 is substantially equal to the effective width, and the height of the convex portion 3A is 20 mm, and can correspond to books of various sizes currently published.
[0020]
The book W placed on the conveyance surface of the conveyance belt 2 includes a pair of ridges 2 </ b> B extending in the conveyance direction and protruding in the vicinity of both left and right sides of the conveyance surface, and a housing 4 facing both sides of the conveyance surface. A pair of side guides 7 attached to the side restricts lateral movement during conveyance.
[0021]
As shown in FIG. 1, an OCR (optical reader) 8 and a labeler 9 for reading an ISBN code attached to a book W are arranged on the inclined portion of the housing 4 of the belt conveyor 1 with a cross. Yes.
[0022]
Further, the transport belt 2 is driven by a motor 10 provided at the upper end portion of the housing 4, and the book W passing through the OCR 8 and the labeler 9 is in front of them, as shown in FIG. One side of the book W comes into contact with the crosspiece 3 and is held in an aligned state.
[0023]
The motor 10 is controlled so that its rotational speed fluctuates periodically. As a result, the conveyor belt 2 is driven with a speed pattern shown in FIG. That is, the conveyor speed of the belt conveyor 1 (conveying speed of the conveying belt 2) fluctuates between 20 m / min and 30 m / min with a period of 0.2 sec, and acceleration from 20 m / min to 0.4 G The speed pattern is accelerated to 30 m / min, then decelerated with an acceleration of -0.2 G and returned to 20 m / min.
Here, G represents gravitational acceleration.
[0024]
When the book W loaded from the carry-in position Y at the lower end of the housing 4 onto the transport belt 2 that is driven and controlled by the speed pattern described above is transported to the inclined portion of the transport belt 2, the book W and the transport belt 2. When the friction with the transport surface is small, the book W slides on the transport surface, hits the crosspiece 3 that moves from the rear, and one side is supported by the crosspiece 3 to correct the direction.
[0025]
Further, even when the friction between the book W and the transport surface is large, when the transport belt 2 accelerates rapidly, an inertial force due to the acceleration of the transport belt 2 is added to the component of the gravity direction of the gravity acting on the book W. Thus, the book W slips instantaneously with respect to the conveyance surface, and the frictional force acting between the two decreases from the static friction state to the sliding friction state. It slides down along and is supported in the same manner by the back rail 3.
[0026]
On the other hand, when the conveyor belt 2 decelerates, the inertial force acting on the book W is half that during acceleration, and further acts in the direction opposite to the component of the gravitational conveyance surface in the direction of inclination. The book W does not leave the crosspiece 3 forward in the transport direction.
[0027]
Thus, the book W whose orientation is correctly corrected by the crosspiece 3 is read by the OCR 8 on the ISBN code on the upper surface thereof, and further, a label is attached to a predetermined position on the upper surface when passing through the labeler 9.
[0028]
When the coefficient of static friction between the conveyance surface of the conveyance belt 2 and the book W is μ, the acceleration when accelerating the conveyance belt 2 is α, and the inclination angle of the conveyance surface forward in the conveyance direction is θ, When the transport belt 2 is accelerated, the condition for the book W, which is on the transport surface away from the back rail 3 and slides on the transport surface, to move to the rail 3 during transport is α> G (μCOSθ−SINθ). .
[0029]
On the other hand, when the acceleration when the conveyor belt 2 decelerates is β (negative value for deceleration), the condition for the book W once abutted and supported on the crosspiece 3 not to be separated again is −β <G (μCOSθ + SINθ )
[0030]
In the present embodiment, the direction of the book W is corrected at a portion where the conveyance surface of the conveyance belt 2 is inclined by approximately 40 degrees, and α = 4G and β = −2G. If α / G> μ and −β / G <μ depending on the conditions, the orientation of the book W can be corrected when the transport surface of the transport belt 2 is horizontal (θ = 0).
[0031]
Further, the conveyor belt 2 is driven with a speed pattern that fluctuates sinusoidally such as, for example, V = V ₀ sin (2πt / T) (where V _{0 is a} flat speed, t is an elapsed time, and T is a fluctuation period). In this case, the maximum value of acceleration during acceleration is α _max = (2πV ₀ / T), and the maximum value of acceleration during deceleration is β _max = − (2πV ₀ / T). In this case, the condition for the book W, which is separated from the rear beam 3 and placed on the conveyance surface, to slide to the beam 3 during conveyance is α _max > G (μCOSθ−SINθ).
[0032]
In addition, the condition for the book W once contacted and supported by the crosspiece 3 not to leave again is as follows:
−β _max <G (μCOSθ + SINθ).
However, in the case of using a sinusoidally varying speed pattern in this way, it does not hold when the transport surface is horizontal (θ = 0), and therefore it is necessary to incline the transport surface. The speed of the conveyor belt 2 can be easily changed by using an inconstant speed gear or the like.
[0033]
In the above-described embodiment, the book is described as an example of a rectangular flat article. However, the application of the present invention is not limited to the book, and the orientation of a box or other article having a similar shape is conveyed. It can be widely used when aligning inside.
[0034]
【The invention's effect】
As described above, according to the attitude control method for a rectangular flat article of the present invention, the direction of a rectangular flat article such as a book can be efficiently and accurately aligned during transportation. The work efficiency can be improved by automating the work of pasting and the work of reading the ISBN code by OCR.
[0035]
In particular, the absolute value of the acceleration when accelerating the conveyance belt is larger than the absolute value of the acceleration when decelerating, and the direction of the articles is aligned at a portion inclined upward in the conveyance direction on the conveyance surface. In this case, even if the acceleration when accelerating the conveyor belt is small, the maximum static frictional force that acts between the article and the conveyance surface is easily obtained by the resultant force of the inertial force acting on the article and the component of gravity in the conveyance direction. The product can be slid toward the back rail, and the power consumption of the motor that drives the transport belt can be reduced. Therefore, the article and the crosspiece can be kept in a more stable contact state during the deceleration of the conveyor belt.
[Brief description of the drawings]
FIG. 1 is a side view of a belt conveyor with crosspieces showing one embodiment of a method for controlling the posture of a rectangular flat article according to the present invention.
2 is a cross-sectional view taken in the direction of the arrow at the position AA in FIG. 1;
FIG. 3 is a diagram illustrating a contact state between a crosspiece and a book on a conveyance surface of a conveyance belt.
FIG. 4 is a diagram showing a speed pattern of a conveyor speed of a conveyor belt.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Belt conveyor with crosspiece 2 Conveyor belt 2A Roller receiving part 2B Projection 3 Crosspiece 3A Convex part 3B Concave part 4 Housing 5 Belt support plate 6 Guide roller 7 Side guide 8 OCR
9 Labeler 10 Motor

Claims (2)

A method for controlling the posture of a rectangular flat article using a belt conveyor with bars having a conveying belt provided on a conveying surface with a beam perpendicular to the conveying direction,
The coefficient of static friction between the conveying surface of the conveying belt and the rectangular flat article is μ, the acceleration when accelerating the conveying belt is α, the acceleration when decelerating the conveying belt is β (negative value), and the conveying surface is in front of the conveying direction. A period including an acceleration portion satisfying the condition of α> G (μCOSθ−SINθ) and a deceleration portion satisfying the condition of −β <G (μCOSθ + SINθ), where θ is an upward inclination angle and G is a gravitational acceleration. By driving the conveyor belt with a fluctuating speed pattern, the article placed on the conveyor surface is slid backward in the conveyance direction with respect to the conveyor surface, and one side of the article is brought into contact with the rear rail. A posture control method for a rectangular flat article, characterized in that:   The absolute value of the acceleration α when accelerating the conveyance belt is larger than the absolute value of the acceleration β when decelerating, and the direction of the article is aligned at a portion inclined upward in the conveyance direction on the conveyance surface. The method for controlling the posture of a rectangular flat article according to claim 1.

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