JPH05246528A - Interval control device for carrying system - Google Patents

Abstract

PURPOSE:To control an adequate carrying interval reflecting overrun in a drive stop, without requiring a difficult adjust operation even if a moving condition is changed, in a carrying system which controls the carrying interval by the drive stop of a conveyer for carrying goods to be carried. CONSTITUTION:A first photo-sensor 19 for detecting goods to be carried is installed downstream in the carrying direction of a supply conveyer 2 for supply goods to be carried to a measuring conveyer 1 and also a second photo-sensor 21 for detecting the carrying interval of goods to be carried is installed between the supply conveyer 2 and the measuring conveyer 1. The stop time of the supply conveyer 2 is corrected based on the output of this second photo-sensor 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interval control device for adjusting the transfer interval of objects to be transferred on a transfer conveyor such as a belt conveyor.

[0002]

2. Description of the Related Art In a product manufacturing line or the like, a weighing conveyor device for automatically measuring the weight of a product and checking a quantity and a sorting device for switching a transportation route of an object to be transported according to the weighing result are incorporated. However, in that case, the conveyance interval of the conveyed objects on the line is limited by the processing capacity of the weighing conveyor device and the sorting device.

For example, taking as an example a weighing conveyor device in which the weight of an object to be conveyed on a conveyor is weighed on the way of conveyance, a succeeding object to be conveyed before the weighing operation of the object to be conveyed is completed. Is fed to the conveyor, the so-called two-carrying state is entered, and the weight of the transported object cannot be accurately detected. On the other hand, if the conveyance interval of the conveyed object is set longer than necessary, then the operating efficiency of the line will decrease.

To solve such a problem, for example, as disclosed in Japanese Patent Publication No. Sho 61-14047, a detector for detecting an object to be conveyed is installed on the downstream side of the belt conveyor, and the detector is also provided. There is a system in which the belt conveyor is driven and stopped so that the objects to be conveyed are supplied at a predetermined conveying interval onto the measuring conveyor on the downstream side based on the detection result. According to this, the conveyance interval of the conveyed object is adjusted so as to be substantially the preset conveyance interval. Therefore, for example, the above-mentioned conveyance interval is shortened to near the processing capacity of the weighing conveyor device and set. It will be possible to improve the operation efficiency of the line.

[0005]

However, as in the prior art described in the above publication, in the case where the conveying interval of the conveyed objects is adjusted by stopping the driving of the conveyer, inertia occurs during the stopping operation of the conveyer. This may cause an overrun state in which the transported object does not stop at the proper position. When the overrun occurs in this way, the interval between the preceding conveyed object becomes small, and the conveying interval is not accurately controlled. In particular, in the case where the measuring conveyor device is provided on the line, there is a problem that the two-carrying state is likely to occur due to variations in the transportation interval.

Regarding the problem of such overrun, the above publication also discloses an improvement measure for keeping the stopped state of the conveyor for a fixed correction time. Since it changes depending on the convey speed of the conveyer, there is a trouble that the correction time must be manually determined by trial and error each time the type or convey speed of the conveyed object is changed.

The present invention addresses the above-mentioned problems in a transfer system in which the transfer interval is controlled by stopping the driving of a conveyor for transferring an object to be transferred, and requires a troublesome adjustment operation even if the operating conditions change. The purpose is to be able to control an appropriate transport interval that reflects overrun.

[0008]

That is, an interval control device of a transfer system according to the invention of claim 1 of the present application (hereinafter referred to as the first invention) is a transfer conveyor which is continuously driven, and a transfer conveyor. A supply conveyor for supplying an object to be conveyed, a detection means for detecting an object to be conveyed conveyed on the supply conveyor, and a time interval of the object to be conveyed detected by the detecting means to measure a subsequent conveyed object. In a transport system having a conveyor control means for driving and stopping the supply conveyor so that the article is transported on the transport conveyor at a predetermined transport interval with respect to the preceding transported object,
A time interval detecting means for detecting a time interval of the transported object conveyed on the conveyor and a time interval detected by the detecting means and a set time set according to the interval are compared, and the comparison is made. Stop time correction means for correcting the stop time for stopping the supply operation of the transported object by the supply conveyor according to the result.

According to a second aspect of the invention of the present application (hereinafter referred to as the second invention), the interval control device of the transport system has the configuration of the first aspect of the invention, in which the transport conveyor weighs the object to be transported. Being a conveyor,
It is characterized in that the predetermined conveyance interval is set to an interval such that a succeeding conveyed object is not supplied onto the conveyor before the measurement operation of the conveyed object conveyed on the measuring conveyor is completed.

[0010]

According to the first and second aspects of the invention, even if the conveyed object overruns when the supply conveyor is stopped, the start timing of the supply conveyor is corrected in a self-learning manner in accordance with the overrun amount. Therefore, the conveyance interval can be properly adjusted without requiring a troublesome adjustment operation.

In particular, according to the second aspect of the invention, even if the supply conveyor is repeatedly stopped and driven, the conveying interval on the measuring conveyor is controlled to an interval that does not cause a two-carrying state. There is a real benefit that it is possible to perform weight measurement without making mistakes while making maximum use of the processing capacity.

[0012]

EXAMPLES Examples of the present invention will be described below.

As shown in FIGS. 1 and 2, the transport system according to this embodiment comprises a weighing conveyor 1 for measuring the weight of an object X to be transported, and a supply conveyor 2 arranged upstream of the weighing conveyor 1. And a discharge conveyor 3 that is also arranged on the downstream side of the weighing conveyor 1, so that the articles X are sequentially loaded into the supply conveyor 2 via an upstream conveyor 4 that is continuously driven. Is becoming

The weighing conveyor 1 is composed of a weighing instrument 6 installed on a pedestal 5 and a carrying unit 7 placed on the weighing instrument 6. This transport unit 7
Is a drive roller 9 axially supported on the front end sides of the frames 8a and 8b, a driven roller 10 axially supported on the rear end sides of the frames 8a and 8b, and a transport roller wound between the rollers 9 and 10. It has a belt 11 and a first motor 12 that drives the drive roller 10.

Further, the supply conveyor 2 has left and right frames 14a and 14b fixed to an upper portion of a pedestal 13, a drive roller 15 axially supported on the front end sides of both frames 14a and 14b, and both frames. 14a, 14
b, a driven roller 16 axially supported on the rear end side and both rollers 1
It has a conveyor belt 17 wound between 5 and 16 and a second motor 18 for driving the drive roller 15.

A first photo sensor 19 for detecting the object X to be conveyed is provided downstream of the supply conveyor 2 in the conveying direction.
Is provided. The first photo sensor 19 is of a photo interrupter type, and as shown in FIG. 2, a light emitting portion 19a attached to one frame 14a via a stay 20a, and the conveyor belt 1 for the light emitting portion 19a.
7 and a light receiving portion 19b fixed to the frame 14b via a stay 20b at opposing positions with the light receiving portion 1 being irradiated by the light emitting portion 19a.
The object X to be conveyed is detected by the change in the amount of received light of the beam B ₁ incident on 9b.

Further, between the supply conveyor 2 and the weighing conveyor 1, the objects X to be transported, which are transported on the weighing conveyor 1,
The second of the photo interrupter type for detecting the X interval
A photo sensor 21 is installed. That is, as shown in FIG. 2, the second photo sensor 21 also has a light emitting portion 21a attached to one of the frames 8a via a stay 22a and a facing position where the conveyor belt 11 is sandwiched with respect to the light emitting portion 21a. And a light receiving portion 21b fixed to the frame 8b via a stay 22b, the change in the amount of received light of the beam B ₂ emitted from the light emitting portion 21a and incident on the light receiving portion 21b causes the object X to be transported.
It is designed to detect

On the other hand, the discharge conveyor 3 has substantially the same construction as the supply conveyor 2 and has left and right frames 24a and 24b fixed to the upper part of the pedestal 23, and the front ends of both frames 24a and 24b. A driving roller 25 axially supported, a driven roller 26 also axially supported on the rear end sides of both frames 24a, 24b, and both rollers 25, 2
The conveyor belt 27 wound between 6 and the drive roller 2
And a second motor 28 for driving the motor 5.

The transport system is equipped with a console 29 for controlling the system. A display 30 for displaying various data and a key operation unit 3 for inputting various commands and numerical values are provided on the front surface of the console 29.
1 and are provided.

Next, the control system of this transport system will be described. As shown in FIG. 3, the control unit 32 built in the console 29 is provided with a weighing signal from the weighing machine 6 provided in the weighing conveyor 1. , The first and second photosensors 19 and 21, and the first to third motors 12, which drive the weighing conveyor 1, the supply conveyor 2 and the discharge conveyor 3, respectively, based on these signals. 1
The weight value indicated by the weighing signal is displayed on the display 30 while controlling the operations of the sensors 8 and 28.

Further, the control unit 32 includes a two-seater monitoring section D _M starting from the first photosensor 19 and
A sampling section D _S from the second photo sensor 21 to the end of the weighing conveyor 1 is stored. Therefore, for example, when the transport speed of the weighing conveyor 1 is input from the key operation unit 31, the control unit 32 calculates the sampling time T _S corresponding to the sampling section D _S based on this transport speed and the above-mentioned 2 The metering interval time T _M corresponding to the individual riding monitoring section D _M is set. As the measurement interval time T _M , for example, a value obtained by adding a predetermined margin time α (for example, 10 ms) to the sampling time T _S is used.

Further, in this carrying system, the target carrying distance D ₀ for maintaining the carrying interval of the objects X, X carried on the weighing conveyor 1 at a predetermined interval is set, and accordingly, the key operation section is set. When the transport speed of the weighing conveyor 1 is input from 31, the target interval time T ₀ corresponding to this transport speed is calculated.

In this embodiment, as shown in FIG. 1, the target conveyance interval D ₀ is set so as to match the sampling section D _S , but this section D _S is prohibited from riding two cars. Since it is the minimum range that must be set, the target interval time T _{0 is set} to a sampling time T _S with a margin added to the target interval time T ₀ if necessary.
It is desirable to set it longer than.

Next, a method of operating the above-mentioned transfer system will be described.

The above-mentioned control unit 32 carries out a take-in control for taking in the object X to be conveyed on the supply conveyor 2 onto the measuring conveyor. Specifically, this take-in control is carried out as follows in accordance with the flowchart of FIG. Be seen.

That is, the control unit 32 constantly monitors the detection signal from the first photo sensor 19, and when the object X is detected, the metering interval time T _M is set to the initial value and the timer value of the first timer is set. It is determined whether T ₁ is reduced to 0 (steps S1 and S2). Then, if the timer value T ₁ has not decreased to 0, a two-seater state will occur. Therefore, after proceeding to step S3, the supply conveyor 2 is stopped and the operation of taking in the transported object X is stopped. , Wait until the timer value T ₁ is reduced to 0 in step S4. After that, step S5 is executed to wait for the delay time T _D for delaying the start by the amount that the conveyed object X overruns when the supply conveyor 2 is stopped,
After the delay time T _D has elapsed, the process proceeds to step S6 to restart the supply conveyor 2 to restart the loading operation of the transported object X, and then in step S7, the measurement interval is set as the timer value T ₁ of the first timer. The time T _M is set, and the elapse of the predetermined re-detection prohibition time T _K is waited in step S8. This re-detection prohibition time T _K is the first time for the transported object X.
The sensor 1 until it passes the detection position of the photo sensor 19
The re-detection by 9 is prohibited.
Is determined by the length L ₀ in the transport direction and the transport speed.

On the other hand, the control unit 32 executes the above step S.
If it is determined that the timer value T ₁ of the first timer has decreased to 0 in step 2, it is normal, and therefore steps S3 to
The process skips S7 and moves to step S7 to set the measurement interval time T _M as the timer value T ₁ of the first timer.

On the other hand, the control unit 32 is adapted to execute the interval determination processing shown in the flow chart of FIG. 5 in parallel with the above-mentioned intake control.

That is, the control unit 32 constantly monitors the detection signal from the second photosensor 21, and when the object X is detected, the target interval time T ₀ is set to the initial value and the timer value of the second timer is set. It is determined whether T ₂ is reduced to 0 (steps T1 and T2). That is, when the succeeding transported object X is transferred to the weighing conveyor 1, it is determined whether or not the weight measurement of the preceding transported object X has already been completed. If the timer value T ₂ has not decreased to 0, a two-seater state will occur. Therefore, the routine proceeds to step T3, where a predetermined alarm process is executed, and then the target interval time T ₀ remains at step T4. The timer value T _{2 at} that time is added to the delay time T _D as a time, that is, a value at which the two-passage cannot be resolved. As a result, the timing of restarting the supply conveyor 2 is delayed and the two-seat state is eliminated. Then, in step T5, the target interval time T ₀ is set as the timer value T ₂ , and the process returns to step T1.

On the other hand, the control unit 32 executes the above step T.
When it is determined in ₂ that the timer value T 2 of the second timer has decreased to 0, the two-seater state has not occurred, so steps T3 and T4 are skipped and the process proceeds to step T5, where the timer value T Target interval time T ₀ as ₂
Set.

Further, the control unit 32 is adapted to execute the timer check processing shown in the flow chart of FIG. 6 independently of the above-mentioned acquisition control and interval determination processing.

That is, the control unit 32 executes step U
In 1, it is determined whether or not the timer value T ₂ of the second timer has changed to 0. If YES is determined, the weighing of the transported object X has been completed, so in step U2, the supply conveyor 2
It is determined whether or not is stopped. When it is determined that the supply conveyor 2 is also stopped, step U3
Then, it is determined whether the value of the delay time T _D is 0, and if it is not 0, the restart of the supply conveyor 2 is delayed, so this time the process proceeds to step U4 and the delay time T _D is set by the predetermined amount β. The amount is reduced and the process returns to step U1. That is, the restart time of the supply conveyor 2 is adjusted according to the situation of occurrence or non-occurrence of two-passage.

Next, the operation of this embodiment will be described.

That is, as shown in FIG. 7, after the preceding conveyed object X ₁ has passed through the first photosensor 19, before the measured interval time T _M elapses, the succeeding conveyed object X ₂ becomes 1 Photo sensor 19 is reached and supply conveyor 2
Is stopped, and the transported object X ₂ is overrun by the distance δD _{1 at} that time. Next, the measurement interval time T
_It is assumed that the supply conveyor 2 is activated after _M has elapsed, and the second photo sensor 21 is reached at the time when the object X ₂ being stopped has started moving and has traveled a distance δD ₂ . If the preceding conveyed object X ₁ has left the remaining distance δD ₃ by the time the target conveying distance D ₀ has been conveyed, the time corresponding to the afterimage distance δD ₃ is set as the delay time T _D ,
The restart timing of the supply conveyor 2 will be delayed.

In this case, while the transported object X ₂ is stopped on the supply conveyor 2, the third transported object X ₃ is transported by the upstream conveyor 4 within the target transportation interval D _0. Even in that case, the transported object X ₃ is stopped on the supply conveyor 2 as shown in FIG. Moreover, the transported object X ₂ preceding the transported object X ₃ passes through the second photosensor 21 and then reaches the distance L _M corresponding to the measurement interval time T _M to the remaining distance δD.
It means that it has been transported by the distance that ₃ is added. Therefore, it is possible to completely prevent the two-carrying state on the weighing conveyor 1.

[0036]

As described above, according to the present invention, even if the conveyed object overruns when the supply conveyor is stopped, the restart timing of the supply conveyor is corrected in a self-learning manner corresponding to the overrun amount. Therefore, the conveyance interval can be appropriately adjusted without requiring a troublesome adjustment operation.

In particular, by applying the present invention to the weighing conveyor, even if the supply conveyor is repeatedly stopped and driven, the transporting interval on the weighing conveyor is controlled to an interval that does not cause the two-carrying state. Therefore, it is possible to perform weight measurement without making mistakes while maximizing the processing capacity of the weighing conveyor.

[Brief description of drawings]

FIG. 1 is an overall schematic front view of a carrying system embodying the present invention.

FIG. 2 is an overall schematic plan view of a transfer system.

FIG. 3 is a control system diagram of the transfer system.

FIG. 4 is a flow chart showing the intake control executed in the transport system.

FIG. 5 is a flowchart showing an interval determination process which is also executed in the transport system.

FIG. 6 is a flowchart showing a timer check process which is also executed in the sending system.

FIG. 7 is a schematic diagram showing the operation of the embodiment.

FIG. 8 is a schematic view showing the operation of the embodiment.

[Explanation of symbols]

 1 Measuring Conveyor 2 Supply Conveyor 19 First Photo Sensor 21 Second Photo Sensor 32 Control Unit

Claims (2)

[Claims] 1. A conveyor which is continuously driven, a supply conveyor which supplies an object to be conveyed onto the conveyor, a detection unit which detects an object conveyed on the supply conveyor, and a detecting unit. By measuring the time interval of the transported object detected in, the following conveyer conveys the supply conveyor so as to be conveyed on the conveyer conveyor at a predetermined conveying interval with respect to the preceding conveyed object. An interval control device for a transport system having a conveyor control means for stopping driving, a time interval detection means for detecting a time interval of a transported object transported on the transport conveyor, and a time detected by this detection means. At the time of stop, which compares the interval and the set time set according to the transfer interval, and corrects the stop time at which the operation of supplying the transported object by the supply conveyor is stopped according to the comparison result. An interval control device for a transport system, characterized in that the interval control device is provided. 2. The transport conveyor is a weighing conveyor for weighing the transported object, and the subsequent transported object is transported before the weighing operation of the transported object transported on the weighing conveyor at a predetermined transport interval is completed. 2. The interval control device for the transport system according to claim 1, wherein the interval is set so that the sheet is not supplied onto the conveyor.