JP5408724B2 - Article conveying device - Google Patents

Description

The present invention relates to an article conveying device such as a roller conveyor device or a belt conveyor device.
The present invention can be applied to an article conveying apparatus having a branching section and having a structure for transferring an article from a main conveying path to a branched conveying path.

In an assembly factory, a courier sorting area, a storage warehouse, or the like, an article conveying device such as a roller conveyor is circulated in the vertical and horizontal directions, and the article is automatically conveyed to a desired position.
For example, in an automobile assembly factory, an article conveying device is arranged on a line for assembling a chassis or a line for assembling an engine. And in the line which integrates an engine in a chassis, the article conveyance apparatus which branches an engine assembly line and reaches the vicinity of a chassis assembly line is provided, for example.

  In the courier sorting area, an article transportation network that has many branches and is finely branched like a mesh is constructed, and the terminal branch transportation path is a package determined according to the destination of the package. It has reached the storage site.

  In storage warehouses such as multi-story parking lots and multi-story warehouses, an article transport network having a large number of branch portions and finely branched like a mesh is constructed, and the branch transport path at the end is defined. It leads to the address storage area.

As described above, many article conveying apparatuses in recent years not only simply convey an article in a straight line, but also have a function of individually providing an article to a plurality of destinations by providing a branch conveyance path.
That is, in recent article conveying apparatuses, a plurality of branch conveying paths are provided with respect to the main conveying path, and the conveying path is branched, and the articles are transferred at the branching section and conveyed to a target place. Some have a configuration.

In this type of article conveyance device, a transfer device as disclosed in, for example, Patent Document 1 is adopted, and the transfer device is installed at a branch portion between the main conveyance path and the branch conveyance path. When the article to be transferred to the branch conveyance path reaches the branch section, the article is stopped on the branch section, the transfer device is activated, the article is moved in the direction perpendicular to the main conveyance direction, and the article is may replacement placed on the branched transport path from the transport path.

  Moreover, it is determined by the sensor provided in the article conveying apparatus whether the conveyed product has been carried on the branch part. For example, a reflective photoelectric sensor is provided in the vicinity of the branch portion, and light is irradiated from the photoelectric sensor toward the branch portion. If an article is present on the branching portion, the light emitted from the photoelectric sensor is reflected and returns to the photoelectric sensor, so it can be determined whether or not the article is present on the branching portion by the presence or absence of the reflected light. .

Moreover, the thing of the structure disclosed by patent document 2 is known as a reflection type sensor which detects the presence or absence of the article | item on a branch part.
The reflective sensor disclosed in Patent Document 2 includes one light emitting element and four light receiving elements. In the conventional reflective sensor, all of the four light receiving elements are arranged around one light emitting element. Further, the distance between each light receiving element and the central light emitting element is different.

  In the reflection type sensor of the prior art, the central light emitting element emits light to irradiate the article, and the reflected light is received by the four surrounding light receiving elements. Only when two or more light receiving elements detect the reflected light, the presence of the article is affirmed, and the malfunctioning area of the light receiving element or the like is covered.

JP-A-6-312832 JP 2008-103969 A

As described above, when the article is transferred from the main conveyance path to the branch conveyance path, the article is stopped at the branching section, and the transfer device installed in the branching section is driven to discharge the article to the branch conveyance path.
That is, as shown in FIG. 9, the article 1 is stopped at the center of the branching section 2, the transfer device (not shown) provided in the branching section 2 is driven to move the article 1 to the right side of the drawing, The article 1 is discharged to the branch conveyance path 3.

  However, for example, when it is assumed that the main conveyance path 5 conveys the article 1 from the lower side of the drawing toward the upper side of the drawing as shown by an arrow as shown in FIG. 12, the article 1 reaches the center of the branch portion 2. If stopped halfway, the article 1 collides with the entrance portion of the branch conveyance path 3 when the transfer device (not shown) is driven to move the article 1 to the right side of the drawing.

  Further, as shown in FIG. 15, the same is true when the article 1 goes too far in the center of the branching portion 2, and when the article 1 is moved to the right side of the drawing by driving a transfer device (not shown), The article 1 collides with the entrance portion of the branch conveyance path 3.

  Further, the same applies to the case where the posture of the article 1 is inclined as shown in FIG. 18, and the article 1 is branched and conveyed when the article 1 is moved to the right side of the drawing by driving a transfer device (not shown). Collides with the entrance portion of the road 3.

  If the article 1 collides with the entrance of the branch conveyance path 3 and cannot be normally transferred to the branch conveyance path 3, the operator manually corrects the position and posture of the article 1 and manually transfers it again. The apparatus (not shown) is driven, the article 1 is moved to the right side of the drawing, and transferred to the branch conveyance path 3.

  However, when the article is an article having a considerable weight as in the case of an automobile chassis or an engine, correction by human power becomes difficult. Furthermore, when the article has a considerable weight, the article itself or the article transport device may be damaged by the collision of the article. For this reason, it takes a considerable time to recover the damaged portion, and there is a problem that the production line stops for a long time.

  Accordingly, the present invention focuses on the above-described problems of the prior art, and provides an article transport apparatus that can accurately determine the position and orientation of an article and smoothly transfer the article to a branch conveyance path. Objective.

The invention according to claim 1 for solving the above-described problem is an article transporting device that has an article transporting section and places the article on the article transporting section to transport the article. A reflective sensor is installed at a position where the upper part can be seen . The reflective sensor includes three or more light emitting elements, a number of light receiving elements smaller than the number of light emitting elements, and a control device. The control device includes a CPU. And an amplification switching circuit, a center recognition comparator, and an inventory recognition comparator. The light emitting elements are pulsed one by one or for each group based on a signal output from the CPU. It is possible to control individual light emission that emits light simultaneously and simultaneous light emission control that causes all light emitting elements to emit light simultaneously. The light receiving element mainly receives light reflected by a reflecting member provided on the article. , The amplification switching circuit amplifies the signal output from the light receiving element and outputs it. The amplification factor for individual light emission is the amplification for simultaneous light emission. The amplification factor lower than the rate is selected, and the center recognition comparator and the inventory recognition comparator are inputted with the amplified signal through the amplification switching circuit, and the individual light emission is performed. In this case, the signal is input to the center recognition comparator, and when simultaneous light emission is performed, the signal is input to the inventory recognition comparator, and the signal is input to the center recognition comparator. In this case, the CPU compares the input signal with a higher threshold value as compared with the case where the signal is input to the inventory detection comparator and determines which light emitting element or group. An article carrying apparatus, characterized in that identifying whether the emission based on the emission individually.

The article transporting apparatus of the present invention has three or more light emitting elements, and if the light emitted from the light emitting elements is reflected on the article, the light receiving element receives the light and the presence of the article is confirmed.
Here, in the article transporting apparatus of the present invention, since the light emitting elements emit light in a pulse or one group, the light received by the light receiving element is radiated from which light emitting element. Can be determined. Since the reflective sensor of the present invention has three or more light emitting elements, the proximity state and posture of the article can be determined by analyzing which light emitting element reflects the light emitted. For this reason, when the reflective sensor of the present invention is installed in the branch portion of the article transport apparatus, the proximity state and posture of the article can be determined, and the article can be smoothly transferred to the branch transport path.
In the present invention, since the number of light receiving elements is small, the number of parts is small and the manufacturing cost is low.

According to the article transporting apparatus of the present invention, it is possible to determine the proximity state and posture of an article.

In the article conveying apparatus of the present invention, in addition to the individual light emission described above, simultaneous light emission that causes all the light emitting elements to emit light simultaneously can also be performed.
The simultaneous light emission is performed, for example, in order to confirm that an article is present at the branch portion. That is, the individual light emission described above is an operation of causing the light emitting elements to emit light one by one or for each group, and therefore the total amount of light is small. On the other hand, simultaneous light emission causes more light-emitting elements to emit light, so that the amount of light is large and there are few false detections and malfunctions.
When performing simultaneous light emission, it is desirable to increase the light quantity of each light emitting element. That is, when performing simultaneous light emission, the power supplied to each light emitting element is increased.
It is also recommended to increase the sensitivity of the light receiving element. For example, it is recommended to amplify the current generated by the light receiving element and use it for the determination, or to use the determination with the amplification factor increased. Similarly, a configuration that lowers the threshold for determination is also recommended.

In the article transporting apparatus of the present invention, since the reflective sensor is provided at a position where the lower or upper part of the article can be seen, the planar position and posture of the article can be accurately determined.

In the article conveying apparatus of the present invention, since the reflecting member is provided on the article, the position and presence of the article can be detected even if the article has a poor reflectance.
Moreover, the precision which confirms the position of articles | goods can be raised by selecting the magnitude | size of a reflection member suitably.

According to the present invention, the position and presence of an article can be confirmed.

The invention of claim 2 is an article carrying apparatus according to claim 1, characterized in that it is constituted 4 and more light-emitting elements, by a single light receiving element.

  The present invention shows a reflective sensor having the most recommended configuration when employed in an article conveying device that crosses in a cross shape, for example.

The invention according to claim 3 is the article transporting apparatus according to claim 1 or 2 , wherein the light emitting element is provided at a position surrounding the light receiving element.

  In the present invention, since the light emitting element is provided at a position surrounding the light receiving element, the positional relationship between each light emitting element and the light receiving element is uniform. Therefore, the accuracy in determining the proximity state and posture of the article is high.

According to a fourth aspect of the present invention, there is provided the article transporting apparatus according to any one of the first to third aspects, wherein the distances between all the light emitting elements and the light receiving elements are equal.

  Also in the reflection type sensor of the present invention, since the positional relationship between each light emitting element and the light receiving element is uniform, the accuracy in determining the proximity state and posture of the article is high.

The invention according to claim 5 has a branching section for changing the conveyance direction of the article, the reflection type sensor is installed in the branching section, the position of the article is confirmed by the reflection type sensor, and the position of the article is corrected. comprising a position correction function of a product transport apparatus according to any one of claims 1 to 4, characterized in that for conveying the articles after correcting the position of an article by the position correction function.

  In the present invention, since the reflective sensor is installed at the branch portion, the position of the article and the posture of the article with respect to the branch portion can be recognized. Since the article conveying apparatus of the present invention has a position correcting function for correcting the position of the article, the article can be conveyed after the position of the article is corrected by the position correcting function. Therefore, the article conveying apparatus of the present invention can smoothly transfer from the branching portion.

The invention described in claim 6, the article is a transport pallet, the conveying pallet has a recess on the back side, according to claim 1 to 5, characterized in that the reflecting member is provided in the recess It is an article conveyance apparatus in any one of.

  The present invention shows a form suitable when a reflective sensor is provided on the lower side of an article transport unit. In the article conveying apparatus of the present invention, a reflecting member is provided on the back surface of the conveying pallet. And the recessed part is provided in the back surface of the pallet, and the reflective member is provided in the said recessed part. Therefore, the distance between the reflective sensor and the article can be ensured, and the incident angle of the light reflected by the reflecting member to the light receiving element can be increased.

According to the seventh aspect of the invention, the position of the article and the presence of the article are confirmed by the reflective sensor, and the light emitting element performs the light emission for confirming the position of the article and the presence of the article. emitting individually performed for, is an article conveying device according to any one of claims 1 to 6, characterized in that the sensitivity of the light receiving element when light emission for performing presence check of the article is changed to high sensitivity .

  According to the article conveying apparatus of the present invention, even an article having a low reflectance can be reliably confirmed.

The invention of claim 8 includes a plurality of articles serving conveying pallet, according to any one of claims 1 to 7 to the transport pallet, characterized in that the height of the back surface differ coexist It is an article conveying apparatus.

The present invention shows a form suitable when a reflective sensor is provided on the lower side of an article transport unit. In the case of adopting a configuration in which the reflective sensor is provided on the lower side of the article conveyance unit, the light emitted from the light emitting element is reflected on the back surface of the conveyance pallet. However, the color of the pallet for conveyance varies, and some have a low reflectance such as black and others have a high reflectance such as white.
In such a case, the difference in reflectance can be corrected to some extent by adjusting the height of the transport pallet. For example, a palette with a low reflectance such as black has a lower back surface height, and a white palette with a high reflectance has a lower back surface height. As a result, the conveyance pallets are mixed with different back surface heights.

  The article conveyance device of the present invention can accurately determine the position and posture of an article and smoothly transfer the article to the branch conveyance path.

It is a top view of the article conveyance apparatus of the embodiment of the present invention. It is a disassembled perspective view of the conveying apparatus of FIG. It is a front view of the reflection type sensor of embodiment of this invention. It is a block diagram of the control apparatus of the reflection type sensor of embodiment of this invention. It is a time chart which shows operation | movement of the reflection type sensor shown in FIG. It is a perspective view of the pallet for conveyance used with the article conveyance apparatus of FIG. It is a cross-sectional perspective view of the pallet for conveyance of FIG. It is the top view which expressed typically the positional relationship of each member of the article conveyance apparatus of FIG. It is the top view which expressed typically the state where the goods stopped at the regular position of the branching part of the goods conveyance device of Drawing 1. FIG. 10 is a plan view schematically illustrating the positional relationship between the reflective sensor of the article transport device and the reflecting member of the article in the state of FIG. 9. It is a time chart which shows operation | movement of the reflection type sensor in the state of FIG. FIG. 2 is a plan view schematically illustrating a state in which an article is stopped at a position before a normal position of a branch portion of the article conveyance device in FIG. FIG. 13 is a plan view schematically representing the positional relationship between the reflective sensor of the article transport device and the reflective member of the article in the state of FIG. 12. It is a time chart which shows operation | movement of the reflection type sensor in the state of FIG. It is the top view which expressed typically the state where the goods stopped in the position which passed the regular position of the branching part of the goods conveyance device of Drawing 1 in the advancing direction. FIG. 16 is a plan view schematically illustrating the positional relationship between the reflective sensor of the article transport device and the reflective member of the article in the state of FIG. 15. It is a time chart which shows operation | movement of the reflection type sensor in the state of FIG. FIG. 2 is a plan view schematically illustrating a state in which an article is stopped in an inclined posture at a branching portion of the article conveyance device in FIG. 1. It is the top view which expressed typically the positional relationship of the reflective sensor of the article conveyance apparatus in the state of FIG. 18, and the reflective member of an article. 20 is a time chart showing the operation of the reflective sensor in the state of FIG. It is explanatory drawing explaining comparatively the reflection in a pallet surface, and the reflection in a reflection member. It is a front view which shows the modification of a reflection type sensor. It is a front view which shows the other modification of a reflection type sensor. It is a front view which shows the other modification of a reflection type sensor. It is a time chart which shows operation | movement of the reflection type sensor in the modification of this invention. It is a time chart which shows the operation | movement of the reflection type sensor in the other modification of this invention.

Embodiments of the present invention will be further described below.
The article transport apparatus 10 according to the present embodiment includes a mechanical structure section 14 that actually places and transports an article, and an electrical structure section such as a reflective sensor 12 that detects the position and posture of the article 1 at the branch section 2. doing.
Since the mechanical structure unit 14 has a known configuration, the configuration and operation of the mechanical structure unit 14 will be described prior to the description of the reflective sensor 12 and the like.
The mechanical structure unit 14 of the article conveyance device 10 according to the present embodiment is a roller conveyor device having the branching unit 2.

In the mechanical structure unit 14 of the article conveying apparatus 1 according to the present embodiment, the main conveying path 5 and the branched conveying paths 3 and 6 intersect in a cross shape.
That is, the mechanical structure part 14 has the main conveyance path 5 extended in the drawing up-down direction. The main transport path 5 is provided with a large number of rollers 8 arranged in parallel. The rollers 8 constituting the main transport path 5 are rotated by a motor (not shown). The main conveyance path 5 is configured to convey the article from the lower side to the upper side as shown by the arrow in the drawing by placing the article 1 on the surface of the roller 8 and rotating the roller 8 by a motor (not shown). It is.
In the article conveying apparatus 1 of the present embodiment, a branching section 2 is provided in the middle of the main conveying path 5, and two branching conveying paths 3 and 6 are provided in the branching section 2. Here, the branch conveyance path 3 is a conveyance path extending to the right side of the drawing starting from the branch portion 2. On the other hand, the branch conveyance path 6 is a conveyance path extending to the left side of the drawing starting from the branch portion 2. Rollers 9 are arranged in parallel on the branch conveyance paths 3 and 6, and the rollers 9 are rotated by a motor (not shown).

The branching section 2 is provided with a transfer device 11 and a reflective sensor 12 (main body section 25).
As shown in FIG. 2, the transfer device 11 includes a main transport side travel device 15 and a discharge travel device 16. The main transport side travel device 15 has four rollers 17. The four rollers 17 are all rotated by a motor (not shown), and are arranged in parallel with the rollers 8 of the main conveyance path 5 described above.
The main transport side travel device 15 is attached to a lifting device (not shown), and the four rollers 17 of the main transport side travel device 15 are lifted and lowered integrally by a lifting device (not shown).

The discharge traveling device 16 is constituted by three rows of strip-shaped members 20, 21, and 22. Each of the strip-shaped members 20, 21, and 22 is provided with four short rollers 23 in parallel. The axis of each roller 23 of the discharge travel device 16 is orthogonal to the axis of the roller 17 of the main transport side travel device 15 described above.
Each roller 23 of the discharge traveling device 16 is also rotated by a motor (not shown). A spherical roller 24 that freely rotates is provided between the rollers 23 of the discharging traveling device 16.
Of the three rows of strip-shaped members 20, 21, and 22, the strip-shaped member 21 provided at the center has an opening 27 at the center. The opening 27 is located at the center of the transfer device 11.
The above-described three rows of strip-shaped members 20, 21, and 22 are housed in a portion between the four rollers 17 of the main transport side travel device 15.
The discharge traveling device 16 is also connected to a lifting device (not shown), and the three rows of strip-shaped members 20, 21, 22 are lifted and lowered integrally by the lifting device.

As described above, the main transport side travel device 15 and the discharge travel device 16 of the transfer device 11 are moved up and down by a lifting device (not shown), but the main transport side travel device 15 is in the raised position, and the discharge travel device 16. Is in the lowered position, the roller 17 of the main transport side travel device 15 protrudes above the roller 23 and the spherical roller 24 of the discharge travel device 16.
On the other hand, when the discharge traveling device 16 is in the raised position and the main transport side traveling device 15 is in the lowered position, the strip-shaped members 20, 21, and 22 of the discharge traveling device 16 are connected to the main transport side traveling device 15. Ascending from between the rollers 17, the roller 23 and the spherical roller 24 of the discharge traveling device 16 protrude above the roller 17 of the main transport side traveling device 15.

As described above, the mechanical structure unit 14 of this embodiment can carry the article 1 on the main conveyance path 5 and convey it from the lower side to the upper side of the drawing.
When the article 1 is caused to travel straight and pass through the branch portion 2 as it is, the main transport side travel device 15 of the transfer device 11 is raised and the discharge travel device 16 is lowered. As a result, the article 1 passes over the main transport side travel device 15 and is transported downstream.

  On the other hand, when it is desired to discharge the article 1 to the branch conveyance paths 3 and 6, the article 1 is temporarily stopped at the branching section 2, the discharge traveling device 16 is raised, and the article 1 is placed on the roller 23 of the discharge traveling device 16. Put. Then, the roller 23 of the discharging traveling device 16 is rotated, the article 1 is moved in the lateral direction of the drawing, and the article 1 is delivered to one of the branch conveyance paths 3 and 6.

Next, an electrical structure part such as the reflective sensor 12 will be described.
The reflective sensor 12 includes a main body 25 and a control device 26 (FIG. 4). The main body 25 of the reflective sensor 12 includes four light emitting elements 31a, b, c, d, one light receiving element 32, and four pilot lamps 33a, b, c, d on a substrate 30 as shown in FIG. d is attached.
All of the four light emitting elements 31a, b, c, and d are light emitting diodes. Light emitting diodes are also used for the pilot lamps 33a, b, c, d.
As the light receiving element 32, an element such as a cadmium sulfide cell (CdS cell) or a photodiode that receives light and changes its electric resistance, or an element that receives light and generates electricity is used.
In the present embodiment, the shape of the substrate 30 is a square. The size of the substrate is about 30 mm square to 100 mm square.
In the present embodiment, a 40 mm square to 60 mm square substrate is employed.

  The main body 25 of the reflective sensor 12 has four light emitting elements 31a, b, c, d, one light receiving element 32 and four pilot lamps 33a, b on the surface of the square substrate 30. , C, d are attached. The four light emitting elements 31a, b, c, d, the one light receiving element 32, and the four pilot lamps 33a, b, c, d are all exposed from the surface of the substrate 30.

Here, paying attention to the arrangement of the four light emitting elements 31a, b, c, d and the one light receiving element 32, the four light emitting elements 31a, b, c, d are circles centered on the light receiving element 32. It is arranged at equal intervals on the top. That is, the four light emitting elements 31a, 31b, 31c, and 31d are positioned so as to surround the light receiving element 32, and the distances between the light emitting elements 31a, 31b, 31c, and 31d are equal.
In the present embodiment, the four light emitting elements 31 a, b, c, and d are arranged at positions facing each side of the square substrate 30. That is, of the four light emitting elements 31 a, b, c, d, straight lines connecting the light emitting elements 31 a, b, c, d at adjacent positions face each corner of the substrate 30.
More specifically, as shown in FIG. 3, the AB line connecting the light emitting elements 31a and 31b, the BC line connecting the light emitting elements 31b and 31c, the CD line connecting the light emitting elements 31c and 31d, and the light emitting element. Both the DA lines connecting 31d and 31a face each corner of the substrate 30.

  The pilot lamps 33 a, b, c, and d are similar to the arrangement of the four light emitting elements 31 a, b, c, and d and are arranged in a small size, and are installed on the side portions of the substrate 30. .

The control device 26 of the reflective sensor 12 has a CPU as shown in FIG. 4, and further includes an amplification switching circuit, a center recognition comparator, and a stock recognition comparator as peripheral circuits.
As an input signal to the CPU, there are the above-mentioned center recognition comparator signal and the stock recognition comparator signal.
The center recognition comparator and the inventory recognition comparator determine whether the signal output from the light receiving element 32 is equal to or greater than a certain threshold value. That is, the center recognition comparator and the inventory recognition comparator compare the reference voltage (threshold value) with the signal voltage output from the light receiving element 32, and when the signal voltage is higher, an ON signal is transmitted. In this embodiment, the threshold value of the center recognition comparator is higher than the threshold value of the stock recognition comparator.

  The signal output from the light receiving element 32 is input to the center recognition comparator and the inventory recognition comparator through an amplifier circuit (amplification switching circuit). If the amplified signal intensity exceeds a predetermined threshold value, an ON signal is transmitted from the center recognition comparator or the stock recognition comparator to the CPU as described above.

  In addition, an activation signal for causing each light emitting element 31a, b, c, d to emit light is transmitted from the CPU. The signal is a pulse signal. As will be described later, the individual light emission signals for sequentially emitting the light emitting elements 31a, b, c, and d in a pulsed manner and the light emitting elements 31a, b, c, and d simultaneously. There is simultaneous light emission. In the present embodiment, the light emitting elements 31a, b, c, and d are sequentially caused to emit light, and subsequently, the light emitting elements 31a, b, c, and d are simultaneously emitted, and then the light emitting elements 31a, b, c, and d are further emitted. Are programmed to repeat the operation of sequentially emitting light.

Further, a switching signal is transmitted from the CPU to the amplification switching circuit. The switching signal is a signal for changing the amplification factor of the amplification circuit (amplification switching circuit). As will be described later, the reflective sensor 12 of the present embodiment has a function of measuring the center position of the article and a function of confirming the presence of the article. When measuring the center position of the former article, The amplification factor of the amplification circuit (amplification switching circuit) is suppressed, and when the presence of the former article is confirmed, a high amplification factor is set.
More specifically, it is programmed to have a low amplification factor in individual light emission and a high amplification factor in simultaneous light emission.

Further, the CPU outputs a light reception record for each light emitting element 31a, b, c, d as a calculation result. That is, the CPU determines which light emitting element 31a, b, c, d received light, and received the light emitted from which light emitting element 31a, b, c, d from the CPU. A signal indicating whether it is a thing is output individually.
This signal is indicated as “center recognition output” in FIG. Further, a signal for confirming the presence of the article is output. This signal is output ON when the light receiving element emits a light receiving signal when simultaneous light emission is performed.

Next, the function of the reflective sensor 12 will be described.
In the reflective sensor 12 of the present embodiment, as shown in the time chart of FIG. 5, the light emitting elements 31a, b, c, and d emit light in order for a short time, and subsequently, the light emitting elements 31a, b, c, and d. Let all emit light all at once.
That is, a signal for causing the light emitting element 31a to emit light is transmitted from the CPU for a short time. Then, after the light emitting element 31a is turned off, a signal for causing the next light emitting element 31b to emit light is transmitted for a short time after a while. Further, after the light emitting element 31b is turned off, a signal for causing the next light emitting element 31c to emit light is transmitted for a short time after a while. Further, after the light emitting element 31c is turned off, a signal for causing the next light emitting element 31d to emit light is transmitted for a short time after a while.
Then, when the individual light emission of the light emitting elements 31a, b, c, d is completed, the light emitting elements 31a, b, c, d are caused to emit light all at once after a while.

  The light emission time and interval of each light emitting element 31a, b, c, d is a short time of about 1 msec to 30 msec, and is pulsed light emission.

At the same time as the light emitting elements 31a, 31b, 31c, and 31d emit light, the light receiving element 32 receives light. When the light receiving element 32 receives light, a signal transmitted from the light receiving element 32 is amplified by an amplifier circuit (amplification switching circuit) and further transmitted to a center recognition comparator or a stock recognition comparator.
Here, in the individual light emission stage in which the light emitting elements 31a, b, c, and d emit light in order for a short time, a signal for selecting a low amplification factor from the CPU to the amplifier circuit (amplification switching circuit) (in FIG. 5, Amplification switching signal OFF) is transmitted. As the comparator, a center recognition comparator is selected.

As a result, the light reception signal transmitted from the light receiving element 32 is amplified with a low amplification factor in the amplifier circuit (amplification switching circuit), and further, the center recognition comparator determines ON / OFF selection with a high threshold.
This ON / OFF signal is sent to the CPU. In the CPU, considering the timing of light emission of the light emitting elements 31a, b, c, d and the timing of signal transmission from the light receiving element 32, the current ON signal is the light emission of any of the light emitting elements 31a, b, c, d. To determine whether it is caused by.

This will be described with reference to the time chart of FIG.
In the time chart shown in FIG. 5, during the period when “normal palette” is displayed, the normal color palette passes through the upper part of the reflective sensor 12, and the period when “ black iron plate palette” is displayed is the reflectance. A low black pallet passes through the top of the reflective sensor 12. Further, it is assumed that the reflective member 45 described later passes through the upper part of the reflective sensor 12 during the period displayed as “reflector”.

“Projecting LEDs a, b, c, d” in the upper part of the time chart are signals transmitted from the CPU to the light emitting elements (more precisely, switching circuits). When this signal is ON, the light emitting elements 31a, b, c, d are emitting light.
On the other hand, “light receiving element output” represents an output of the light receiving element output. As described above, since the light emitting elements 31a, b, c, and d emit light for a short time in order, when the light emitting elements 31a, b, c, and d emit light, the surroundings become bright, and the light receiving element 32 recognizes the light. Then, a voltage corresponding to the amount of received light is output.
However, the light emitted from the light emitting elements 31a, b, c, and d is reflected on an object and directly incident on the light receiving element 32, and the case where the light emitted from the light emitting elements 31a, b, c, and d indirectly enters the light receiving element 32 due to light scattering. Since the amount of light is different, the signal intensity (voltage) when reflected by an object and incident on the light receiving element 32 is higher than that by scattered light.

  If it demonstrates according to a flowchart, when seeing individual light emission and simultaneous light emission once, according to light emission of light emitting element 31a, b, c, d, a light reception signal will come out from the light receiving element 32 5 times (5 peaks). The first signal is weak (peaks are low), the next two times are strong (peaks are high), the following are weak (peaks are low), and the last signals are strong (peaks are high).

In the second, third and fifth light emission, the light receiving element 32 directly receives the reflected light emitted from the object, and the first and fourth times received the scattered light. It is shown that.
Therefore, the center recognition comparator selects only when this strong signal is output, and sends an ON signal to the CPU.
In the CPU, the time when a strong signal is output is compared with the time when the light emitting elements 31a, b, c, and d are transmitted to the light emitting elements 31a, b, c, and d. It is discriminated whether it is caused by the light emission of 31a, b, c, d.
More specifically, a time chart of “light emitting LEDs a, b, c, d” and a time chart of “light receiving element output” are compared, and “light receiving element output” is high output. The light emitting elements 31a, b, c, d whose “LEDa, b, c, d” are ON are selected, and the “center recognition output” corresponding to the light emitting elements a, b, c, d is turned ON.
When the “light receiving element output” is high and all the “light emitting LEDs a, b, c, d” are ON, the stock recognition output is turned ON.

The discrimination results are output individually. However, when the signal from the light receiving element 32 is ON as a result of discrimination, the signal is temporarily held in the CPU temporarily and at a certain time as shown in the time chart. The state of ON continues across.
The discrimination signal output from the CPU is transmitted to the main body 25 of the reflective sensor 12, and the corresponding pilot lamps 33a, b, c, d are turned on. As described above, since the light emission times of the light emitting elements 31a, b, c, and d are extremely short, the light emission cannot be confirmed with the naked eye. However, as a result of the determination, the signal transmitted from the CPU is self-held. Therefore, the pilot lamps 33a, b, c, and d are lit for a while and can be confirmed with the naked eye.

  Following the individual light emission, simultaneous light emission in which the light emitting elements 31a, b, c and d emit light simultaneously is performed. At the time of simultaneous light emission, a signal (in FIG. 5, an amplification switching signal ON) for selecting a high amplification factor is transmitted from the CPU to the amplification circuit (amplification switching circuit). As the comparator, a stock recognition comparator is selected.

As a result, the light reception signal transmitted from the light receiving element 32 is amplified with a high amplification factor in the amplification circuit (amplification switching circuit), and further, the ON / OFF selection is determined with a low threshold in the inventory recognition comparator.
This ON / OFF signal is sent to the CPU. The ON / OFF signal due to simultaneous light emission is output to the outside via the CPU, but the signal when the signal from the light receiving element 32 is ON is temporarily held in the CPU and time The ON state continues for a certain time as shown in the chart.

  For example, when a black pallet with low reflectivity is an article, the light reflected from the article is weak, so the voltage output from the light receiving element is low even if all the light is emitted as in the latter half of the time chart of FIG. . However, in the present embodiment, during simultaneous light emission, the light reception signal transmitted from the light receiving element 32 is amplified with a high amplification factor in the amplification circuit (amplification switching circuit), and further ON with a low threshold in the inventory recognition comparator. Since the determination of OFF selection is made, the sensitivity of the light receiving element is changed to high sensitivity, and the presence recognition output is turned ON.

  Next, the relationship between the reflective sensor 12 and the mechanical structure 14 will be described. In the article transporting apparatus 10 of the present embodiment, the main body 25 of the reflective sensor 12 is disposed at the center of the branch part 2 of the mechanical structure part 14. That is, in the mechanical structure section 14 employed in the present embodiment, the main transport path 5 and the branch transport paths 3 and 6 intersect in a cross shape, so that the shape of the branch section 2 is a square as shown in FIG. As described above, the transfer device 11 is provided in the branch portion 2, but an opening 27 is provided in the strip-shaped member 21 at the center of the transfer device 11, and reflection is performed at a position facing the opening 27. A main body 25 of the shape sensor 12 is provided.

Since the opening 27 is at the center of the transfer device 11 as described above, the main body portion 25 of the reflective sensor 12 is provided at the center of the transfer device 11, and this position is also the center position of the branch portion 2. .
Since the article 1 is placed and transported on the main transport side traveling device 15 or the discharging traveling device 16 as described above, when looking up from the opening 27, the lower part of the article 1 is directly visible. That is, the main body 25 of the reflective sensor 12 is installed at a position where the lower part of the article 1 can be seen.
Therefore, when looking upward from the opening 27, the planar position of the article 1 can be known, and it is possible to determine what positional relationship the article 1 is in the branching portion 2 and what kind of posture it is. it can.

The main body 25 of the reflective sensor 12 is attached in a posture inclined by 90 degrees with respect to the square branch portion 2. That is, as described above, the main body 25 of the reflective sensor 12 is square, and the four light emitting elements 31 a, b, c, and d are arranged at positions facing each side of the square substrate 30. On the other hand, since the main body 25 of the reflective sensor 12 is mounted in a posture inclined by 45 degrees with respect to the branching portion 2, the four light emitting elements 31a, b, c, and d are as shown in FIG. Are arranged at positions facing each corner of the square branch 2.
Therefore, any straight line connecting adjacent light emitting elements 31 is parallel to each side of the branching portion 2.
Specifically, an AB line connecting the light emitting elements 31a and 31b, a BC line connecting the light emitting elements 31b and 31c, a CD line connecting the light emitting elements 31c and 31d, and a D line connecting the light emitting elements 31d and 31a. Both A lines are parallel to each side of the branching section 2.

  That is, the AB line connecting the light emitting elements 31a and 31b is parallel to the boundary line between the branching portion 2 and the upstream side of the main transport path 5 (upstream side in the transport direction of the article 1). The B-C line connecting the light emitting elements 31b and 31c is parallel to the boundary line between the branch portion 2 and the branch conveyance path 6 on the left side of the drawing. A CD line connecting the light emitting elements 31c and 31d is parallel to a boundary line between the branch portion 2 and the upstream side of the main transport path 5 (downstream side in the transport direction of the article 1). A DA line connecting the light emitting elements 31d and 31a is parallel to a boundary line between the branch portion 2 and the branch conveyance path 3 on the right side of the drawing.

Next, the overall operation of the article conveyance device 10 of the present embodiment will be described.
In this embodiment, the conveyed product is placed on a pallet 35 as shown in FIGS. Therefore, in the present embodiment, the pallet 35 is recognized as the article 1 by the reflective sensor 12.
The pallet 35 is a low-profile housing made of resin or metal. The pallet 35 has a top plate 36 and four side walls 37, 38, 39, 40 connected to the top plate 36. In the pallet 35, the bottom portion is open, and a space 41 is provided under the top plate 36 as shown in FIG.
In the present embodiment, a reflecting member 45 is provided at the center of the back of the top plate 36. The reflecting member 45 is a member having a higher reflectance than the other parts of the article 1. That is, the reflecting member 45 is a member having a high reflectance such as a metal plate or a metal foil, and in this embodiment, an aluminum foil is used.

  The reflecting member 45 is actually not much different from the size of the main body 25 of the reflective sensor 12 described above, and is about 50 mm square. On the other hand, the pallet 35 is actually about 1000 mm square, but in order to facilitate understanding, the size of the reflecting member 45 is drawn large in the drawing.

In the following, description will be made with reference to the article conveying apparatus 10 shown in FIG. Note that FIG. 8 is drawn for explaining the operation of the article conveying device 10 and illustrates the periphery of the branching unit 2, but the transfer device 11 is not shown.
Further, in the following description, the article 1 is placed on the main conveyance path 5 and conveyed from the lower side to the upper side of the drawing, stopped once at the branch portion 2, and then the discharge traveling device 16 is raised to travel for discharge. It is assumed that the article 1 is placed on the roller 23 of the apparatus 16, the article 1 is moved in the right direction of the drawing, and the article 1 is delivered to the branch conveyance path 3.

  As described above, in order to move the article 1 to the right in the drawing and deliver the article 1 to the branch conveyance path 3, it is important that the article 1 is stopped at the center of the branch portion 2 as shown in FIG. 9. It is.

That is, FIG. 9 is a plan view schematically showing a state in which the article 1 (pallet 35) is stopped at a regular position. The reflecting member 45 attached to the back surface of the pallet 35 at this time, and the reflective sensor The relationship with the 12 main body portions 25 is as shown in FIG. That is, when the pallet 35 is in the center of the branching portion 2, the reflecting member 45 is located at a position directly above the main body portion 25 of the reflective sensor 12.
In this state, the light emitting elements 31a, b, c, and d of the main body 25 repeat individual light emission and simultaneous light emission.
In the individual light emission stage, as shown in the time chart of FIG. 11, the light emitting elements 31a, b, c, and d of the main body 25 emit light sequentially in a short time. Here, since there is a reflecting member 45 at a position directly above the main body 25, the reflected light enters the central light receiving element 32 regardless of which light emitting element 31 a, b, c, d emits light. Is done.

For this reason, when the light emitting elements 31a, 31b, 31c, and 31d sequentially emit light by individual light emission, these lights are respectively incident on the light receiving element 32, and as shown in the graph of “light receiving element output” in the time chart of FIG. 32 emits a light reception signal in response to each light emission timing. This received light signal is input to the center recognition comparator through the amplifier circuit (amplification switching circuit), and an ON signal is generated by the center recognition comparator. This ON signal is sent to the CPU, and the ON / OFF signal of this time is determined in consideration of the light emission timing of the light emitting elements 31a, b, c, d and the timing of signal transmission from the light receiving element 32. It is determined whether the light emission is caused by the light emission of the light emitting elements 31a, b, c, d, and as a result, it is confirmed that the light emission from all the light emitting elements 31a, b, c, d is received.
That is, as shown in the time chart of FIG. 11, the center recognition outputs a, b, c, and d are all turned on.
In addition, since light is incident on the light receiving element 32 also during simultaneous light emission, the stock recognition signal is also turned ON, and it is reconfirmed that the article 1 (pallet 35) is present on the branch portion 2.

In the present embodiment, the main body 25 of the reflective sensor 12 constantly repeats individual light emission and simultaneous light emission. Conversely, the output pattern from the CPU has center recognition outputs a, If all of b, c, and d are in the ON state, it can be seen that the center of the article 1 (pallet 35) is coincident with the branch portion 2. Therefore, if the output pattern from the CPU confirms that the center recognition outputs a, b, c, d are all turned on and the transfer device 11 is operated, the article 1 (pallet 35) Does not collide with other members.
If the output pattern from the CPU is not in a state where all the center recognition outputs a, b, c, d are ON, the main transport side travel device 15 of the transfer device 11 is driven in the forward direction or the reverse direction. Then, the article 1 (pallet 35) is finely adjusted so that the center of the article 1 (pallet 35) and the center of the branch portion 2 coincide. In the article conveying apparatus 10 of the present embodiment, when the article 1 (pallet 35) is placed on the transfer apparatus 11 and the main conveying side traveling apparatus 15 is stopped, the output patterns from the CPU are the center recognition outputs a and b. , C, d are not in the ON state, the main transport side travel device 15 is automatically driven in the forward direction or the reverse direction, and the position of the article 1 (pallet 35) is finely adjusted.

  For example, assuming that the article 1 has stopped before reaching the center of the branch portion 2 as shown in FIG. 12, the output pattern from the CPU is the center recognition output a as shown in FIG. , B, are ON, and the center recognition outputs c, d are OFF.

That is, the relationship between the reflective member 45 and the main body 25 of the reflective sensor 12 when the article 1 stops until reaching the center of the branching portion 2 is as shown in FIG. 45 exceeds the AB line connecting the light emitting elements 31a and 31b, but does not reach the CD line connecting the light emitting elements 31c and 31d. Therefore, the light emitted by the light emitting elements 31a and 31b is incident on the light receiving element 32, but the light emitted by the light emitting elements 31c and 31d is not incident on the light receiving element 32, and the center recognition outputs a and b are ON. The center recognition outputs c and d are turned off.
Therefore, as shown in the output pattern of FIG. 14, when the center recognition outputs a and b are ON and the center recognition outputs c and d are OFF, the main transport side travel device 15 of the transfer device 11 is slightly moved in the forward direction. To move the article 1 (pallet 35) forward and bring the article 1 (pallet 35) to the center. When the output pattern from the CPU changes to a state in which the center recognition outputs a, b, c, d are all turned on, the transfer device 11 is operated and the article 1 is discharged to the branch conveyance path 3 side.

  As shown in FIG. 15, when the article 1 has passed the center of the branching portion 2, the output pattern from the CPU is such that the center recognition outputs c and d are ON as shown in FIG. Outputs a and b are turned off.

  That is, the relationship between the reflecting member 45 and the main body portion 25 of the reflective sensor 12 when the article 1 has passed the branch portion 2 is as shown in FIG. 16, and the reflecting member 45 emits light from the light emitting element 31c. Although it is on the CD line that connects the element 31d, the AB line that connects the light emitting element 31a and the light emitting element 31b has gone beyond. Therefore, the light emitted from the light emitting element 31c and the light emitting element 31d enters the light receiving element 32, but the light emitted from the light emitting element 31a and the light emitting element 31b does not enter the light receiving element 32, and the center recognition output c, When d is ON, the center recognition outputs a and b are OFF.

  Therefore, as shown in the output pattern of FIG. 17, when the center recognition outputs c and d are ON and the center recognition outputs a and b are OFF, the main transport side travel device 15 of the transfer device 11 is slightly retracted. To move the article 1 (pallet 35) back to the center. When the output pattern from the CPU changes to a state in which the center recognition outputs a, b, c, d are all turned on, the transfer device 11 is operated and the article 1 is discharged to the branch conveyance path 3 side.

As shown in FIG. 18, when the article 1 enters the branching section 2 in an inclined posture, the output pattern from the CPU is only the center recognition output d as shown in FIG. Outputs a, b, and c are turned off.
That is, the relationship between the reflective member 45 and the main body 25 of the reflective sensor 12 when the article 1 enters the branching portion 2 in the posture as shown in FIG. 18 is as shown in FIG. Only the light emitting element 31d is engaged, and is separated from the other light emitting elements 31a, 31b, and 31c. Therefore, the light emitted from the light emitting element 31d enters the light receiving element 32, but the light emitted from the other light emitting elements 31a, 31b, and 31c does not enter the light receiving element 32, and only the center recognition output d is ON. Thus, the center recognition outputs a, b, and c are turned off.
Therefore, as in the output pattern of FIG. 20, the center recognition output d is ON and the center recognition outputs a, b, and c are OFF.

  In the article conveying apparatus 10 of the present embodiment, correction when entering the branching section 2 in the posture as shown in FIG. 18 cannot be automatically performed, and some warning is issued to alert the operator, The posture will be corrected by human power.

In this embodiment, not only the individual light emission described above but also the simultaneous light emission is performed. As described above, the individual light emission is used to adjust the center position of the article 1 to a predetermined position. On the other hand, the simultaneous light emission is simply used to check whether or not the article 1 exists on the branch portion 2.
In the case of the individual light emission described above, in order to accurately match the center position of the article 1 with the center position of the branch portion 2, the reflection member 45 is used as a reflection target, and reflection from other members can be removed as noise as much as possible. It is devised to. That is, as described above, in the case of individual light emission, the light reception signal transmitted from the light receiving element 32 is amplified with a low amplification factor, and the ON / OFF selection is determined with a high threshold in the center recognition comparator.

  On the other hand, when simply confirming whether or not something is present on the branching section 2. Reflection from not only the reflection member 45 but also any part of the article 1 should not be excluded as noise. For this reason, when simply checking whether or not something is present on the branch portion 2, stronger reflected light should be obtained even from a part of the article 1. Further, when simply confirming whether or not something is present on the branch portion 2, it is necessary to further increase the sensitivity of the light receiving element 32.

Therefore, in the present embodiment, the light emitting elements 31a, 31b, 31c, and 31d emit light all at once in order to confirm whether or not something is present on the branch portion 2. In response to simultaneous light emission, an amplification switching signal ON signal is transmitted from the CPU. As the comparator, a stock recognition comparator is selected.
As a result, the light reception signal transmitted from the light receiving element 32 is amplified with a high amplification factor in the amplification circuit (amplification switching circuit), and further, ON / OFF selection is made with a low threshold in the center recognition comparator.

  In simultaneous light emission, since all the light emitting elements 31a, b, c, and d emit light, the light amount per se is large. As described above, in the case of simultaneous light emission, since the light emission amount is large, the amplification factor is high, and the threshold value is small, the presence or absence of an article can be reliably detected. In the article conveying apparatus 10 according to the present embodiment, since the above-described device has been devised, even if the color of the pallet 35 is a color that hardly reflects light such as black or gray, the pallet 35 is provided on the branch portion 2. It can be recognized that it exists.

In the embodiment described above, a shape having the top plate 36 and the four side walls 37, 38, 39, 40 connected thereto is adopted as the shape of the pallet 35, and the reflection member 45 is provided on the back of the top plate 36. That is, a recess was provided on the back surface of the pallet 35, and the mounting position of the reflecting member 45 was separated from the main body 25 of the reflective sensor 12. This configuration has the effect of improving the accuracy when detecting the center position, and is a recommended configuration.
That is, assuming that the pallet 35 is placed on the main transport path 5 and transported and is approaching the branching portion 2, first, the lower surface of any one of the side walls 37, 38, 39, and 40 of the pallet 35 is reflected. It passes over the main body 25 of the shape sensor 12.
As described above, in the present embodiment, since the reflective sensor 12 always repeats individual light emission and simultaneous light emission, the light of the individual light emission is reflected by the lower surfaces of the side walls 37, 38, 39, 40 and received. There is a concern that light may enter the element 32. Such erroneous detection is strongly concerned when the pallet 35 is made of a material that is easily reflected, such as metal.

However, in this embodiment, the attachment position of the reflection member 45 is higher than the lower surfaces of the side walls 37, 38, 39, and 40 of the pallet 35, and thus such erroneous detection is unlikely to occur.
That is, as shown in FIG. 21, when a path through which light emitted from the light emitting element (light emitting LED) 31 enters the light receiving element 32, the light reflected by the reflecting member 45 enters the light receiving element 32. The radiation angle X and the incident angle X from the light emitting element (light emitting LED) 31 in FIG. 2 are the radiation angle Y and the light reflected by the side walls 37, 38, 39, 40 of the pallet 35 entering the light receiving element 32. Smaller than the incident angle Y. Therefore, if the light quantity of the light emitting element (light emitting LED) 31 is constant and the reflectance of the reflecting member 45 and the lower surfaces of the side walls 37, 38, 39, 40 of the pallet 35 is the same, the light is reflected by the reflecting member 45. The light is much stronger than the light reflected by the palette 35.

In reality, the reflectance of the reflecting member 45 is much higher than the side walls 37, 38, 39, 40 of the pallet 35, so that the light reflected by the reflecting member 45 is reflected by the pallet 35. It is much stronger than light.
Therefore, by appropriately selecting the threshold value of the center recognition comparator and the amplification factor of the amplification switching circuit, the reflection from the lower surfaces of the side walls 37, 38, 39, and 40 can be excluded as noise, and erroneous detection can be prevented. Can be prevented.

  In the above-described embodiment, the concave portion is provided on the back surface of the pallet 35 and the attachment position of the reflection member 45 is separated from the main body portion 25 of the reflection type sensor 12. However, the distance between the reflection member 45 and the reflection type sensor 12 is as follows. And the material of the reflecting member 45, and are determined by actual adjustment. Therefore, pallets 35 having different back surface heights may be mixed.

  In the embodiment described above, the light emitting elements 31a, 31b, 31c, and 31d are sequentially made to emit light counterclockwise during individual light emission, but the order of light emission is arbitrary. Further, each light emitting element 31a, b, c, d may emit light at random.

  In the embodiment described above, the configuration in which four light emitting elements 31 and one light receiving element 32 are provided is illustrated, but the number of light emitting elements 31 may be three or more. The number of light receiving elements may be two or more, but it is useless to increase the number of light receiving elements 31, and the number of light receiving elements 32 needs to be smaller than the number of light emitting elements 31. is there.

FIG. 22 shows an example in which three light emitting elements 31 are provided and arranged at the position of an equilateral triangle, and one light receiving element 32 is provided at the center thereof.
FIG. 23 shows an example in which a large number of light emitting elements 31 are provided and arranged in a circle, and one light receiving element 32 is provided at the center thereof.
FIG. 24 shows an example in which a large number of light emitting elements 31 are provided and arranged in a matrix, and one light receiving element 32 is provided at the center thereof.

When a large number of light emitting elements 31 are provided as shown in FIGS. 23 and 24, the light emitting elements 31 may be grouped to emit light for each group.
For example, in the reflection type sensor shown in FIG. 24, grouping is performed for each column such as “E” column and “Ro” column, or grouping is performed for each row such as “H” and “To”. The light emitting elements 31 belonging to the group may emit light at the same time when performing individual light emission.

  In the previous embodiment, the light emission of the light emitting element 31 at the time of individual light emission is one pulse each time. However, as shown in FIG. 25, a plurality of pulses may be emitted each time. In the embodiment shown in FIG. 25, three pulses are emitted each time, and the last pulse has a shorter emission time than the other two times.

  In the previous embodiment, the four light emitting elements 31a, b, c, and d are individually emitted sequentially and then simultaneously emitted. However, after the light emitting element 31a emits light, simultaneous emission is performed, and the following light emission is performed. Individual light emission and simultaneous light emission may be performed in parallel, such as simultaneous light emission after the light emitting element 31b emits light.

In the above-described embodiment, in the case of individual light emission, the light emitting elements 31a, b, c, d emit light at intervals. That is, the time during which none of the light emitting elements 31a, 31b, 31c, and 31d emits light is intentionally made. However, this configuration is not essential, and one light emitting element 31a may start light emission of the next light emitting element 31b during light emission. That is, there may be a timing at which a plurality of light emitting elements 31 emit light simultaneously as shown in the time chart of FIG. In short, it is only necessary to create a timing at which only one or a light emitting element belonging to one group emits light.
When this configuration is adopted, it is determined which light emitting element 31a, b, c, d has received the light from the light receiving element signal when only the light emitting element 31 belonging to one or a group emits light. .

In the above-described embodiment, a line connecting adjacent light emitting elements 31 is arranged so as to be parallel to each side of the branch portion 2. In this configuration, when the article 1 approaches the branching section 2 in the correct posture, the light from the two light emitting elements 31 is reflected at the same time, regardless of the direction from which the article 1 is approached. There is an advantage that can be performed accurately.
However, the present invention is not limited to this configuration, and the light emitting element 31 may be disposed at a position facing the corner of the branch portion 2.

  Although the reflection type sensor has been developed for the purpose of being installed at the branch portion of the article conveying apparatus, the application of the reflection type sensor is not limited to the article conveying apparatus. For example, the reflective sensor can also be used for detecting the approach of a person or animal.

DESCRIPTION OF SYMBOLS 1 Article 2 Branch part 3 Branch conveyance path 5 Main conveyance path 6 Branch conveyance path 8 Roller 9 Roller 10 Article conveyance apparatus 11 Transfer apparatus 12 Reflection type sensor 15 Main conveyance side traveling apparatus 16 Discharge traveling apparatus 17 Rollers 20, 21, 22 Strip member 23 Roller 25 Reflective sensor main body 26 Control device 27 Opening 30 Substrate 31a, b, c, d Light emitting element 32 Light receiving element 33a, b, c, d Pilot lamp 35 Pallet 36 Top plate 41 Space 45 Reflection Element

Claims (8)

In an article conveying apparatus that has an article conveying unit and places an article on the article conveying unit to convey an article,
Install a reflective sensor at a position where the lower or upper part of the article can be seen ,
The reflective sensor includes three or more light emitting elements, a number of light receiving elements smaller than the number of light emitting elements, and a control device.
The control device includes a CPU, an amplification switching circuit, a center recognition comparator, and a stock recognition comparator.
Based on the signal output from the CPU, the light emitting element performs control of individual light emission that causes the light emitting elements to emit light one by one or in groups, and simultaneous light emission control that causes all the light emitting elements to emit light simultaneously. Is possible,
The light receiving element mainly receives the light reflected by the reflecting member provided in the article, and outputs a signal corresponding to the amount of light,
The amplification switching circuit amplifies and outputs the signal output from the light receiving element, and the amplification factor for individual light emission is selected to be lower than the amplification factor for simultaneous light emission. And
The center recognition comparator and the inventory recognition comparator receive a signal amplified through an amplification switching circuit, and when individual light emission is performed, the signal is input to the center recognition comparator. When the light is emitted, the signal is input to the inventory recognition comparator.
When the signal is input to the center recognition comparator, the CPU compares the input signal with a higher threshold as compared with the case where the signal is input to the inventory detection comparator, and which light emitting element Alternatively, an article transporting apparatus that individually identifies whether the light emission is based on light emission of a group . The article transporting apparatus according to claim 1, comprising four or more light emitting elements and one light receiving element. Light-article carrying apparatus according to claim 1 or 2, characterized in that provided at a position surrounding the light receiving elements. And all the light emitting elements, product transport apparatus according to any one of claims 1 to 3, characterized in that the distance between the light receiving element are equal. A branch part that changes the conveyance direction of the article, the reflection type sensor is installed at the branch part, the position of the article is confirmed by the reflection type sensor, and a position correction function for correcting the position of the article is provided; an article carrying apparatus according to any one of claims 1 to 4, characterized in that for conveying the articles after correcting the position of the article by a modification function. The article conveying apparatus according to any one of claims 1 to 5 , wherein the article is a conveying pallet, the conveying pallet has a concave portion on a back surface side, and a reflecting member is provided in the concave portion. . The reflective sensor is used to confirm the position of the article and the presence of the article. The light emitting element separately emits light for confirming the position of the article and light emission for confirming the presence of the article. an article carrying apparatus according to any one of claims 1 to 6 the sensitivity of the light-receiving element when light emission for performing presence confirmation is characterized in that it is changed to high sensitivity. The article conveying apparatus according to any one of claims 1 to 7 , wherein the article conveying apparatus includes a plurality of conveying pallets, and the conveying pallets have different back surface heights.

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