JP2000255754A - Load deviation detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a non-detection zone and quickly response to the change in size of load by providing a distance measuring means measuring the distance to a material to be carried with no contact in both sides of a carrier means in a device detecting the deviation of the material to be carried mounted on a pallet carried by a carrier means. SOLUTION: A plurality of range finding sensors 15 are attached to the both side columns of a gate 13 installed across a conveyer 11 in such a state as arranged in their height direction respectively. A set value A for setting in a signal processing part is set to A=L1-L2, where the distance between a load 14 mounted on a pallet 12 and a distance sensor 15 is set to L1 and the maximum value of tolerable deviation is set to L2. When the load 14 mounted on the pallet 12 carried by a conveyer 11 is deviated more than the tolerance in passing the gate 13, the distance sensor 15 outputs a detection signal of the load deviation. If the set value A is set individually relative to each distance sensor 15, even the deviation of a load having distorted shape can be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load shift detecting device and, more particularly, to a load shift detecting device for detecting that a load placed on a pallet carried by a transfer device has shifted from a predetermined position.

[0002]

2. Description of the Related Art In the field of logistics, there are many cases where a load is transferred by a transfer device such as a conveyor. There are various types of conveyors, such as a belt conveyor, in which a load can be directly placed, and a type in which a pallet is placed on a conveyor, and the load is placed on the pallet and transported.

[0003] In order to automate the handling of a load, there are cases where a load conveyed by a conveyor needs to pass a predetermined position. This can be realized, for example, by locating the load at the center of the conveyor in the width direction. However, when a transfer device such as a belt conveyor is used, the load placed on the conveyor moves during the transfer,
There is a high possibility of rotation. Therefore, in such a case, a pallet-type conveyor is used, in which the possibility of positional displacement of the load during transportation is small.

Even if a pallet-type conveyor is used, the position of the load may shift. As described above, unless the position of the load is removed or the position is not corrected, a problem occurs in the subsequent processing. Therefore, a load shift detecting device that detects a position shift of the load is used.

As shown in FIGS. 4A and 4B, the conventional load shift detecting device has two sets of detectors arranged on both sides of a conveyor 41. Each detector has light-emitting elements 42a and 42b and light-receiving elements 43a and 43b. Are arranged at a predetermined angle with respect to.

[0006] In this load shift detecting device, when the pallet 44 on which the load 45 is placed is conveyed by the conveyor 11 and reaches a predetermined position, light from the light emitting element 42a (or 42b) is received by the light receiving element 43a ( Alternatively, if the light cannot be received in 43b), it is determined that a load shift has occurred, and a notification operation such as issuing an alarm is performed.

Here, the detection of the load shift when the pallet 44 reaches a predetermined position is performed by using the pallet 44 as an upper surface having an area larger than the bottom surface of the load 45 to be conveyed. This is because two sets of detectors must be arranged at an interval smaller than the width of the pallet 44 in order to detect a load shift, since the one provided may be used. That is, in this load shift detector, the pallet 44 necessarily passes between the light-emitting elements 42a and 42b and the light-receiving elements 43a and 43b, so that the position shift of the load cannot be detected during this time. Note that the two sets of detectors do not start the detection operation at the same time, but operate independently of each other. For example, in the state shown in FIG. 4A, it is assumed that the load 45 is being conveyed rightward, and the light emitting element 42a
This is a state immediately before the end of the detection operation of the set of the light receiving element 43a and the light receiving element 43a, and just after the start of the detection operation of the set of the light emitting element 42b and the light receiving element 43b.

[0008]

As described above, in the conventional load shift detecting device, the load shift cannot be detected while the pallet is located between the light emitting element and the light receiving element. That is, the conventional load shift detecting device has an undetectable area, and a position shift of a load existing in this area, for example, a load having a low height or a load partially protruding when a large number of small loads are stacked. Cannot be detected.

Further, in the conventional load shift detecting device, when the size of the load to be detected is changed, the mounting position of the detector must be changed, and the change in the load size cannot be quickly responded. There is also a problem.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a load shift detecting device which has substantially no undetectable area and can quickly respond to a change in load size.

[0011]

According to the present invention, a load shift detecting device for detecting that a transferred object placed on a pallet conveyed by a conveying means is shifted from a predetermined position on the pallet. In the apparatus, a load shift detecting device is provided, in which distance measuring means for measuring the distance to the article without contact is provided on both sides of the conveying means.

Here, it is preferable that a plurality of the distance measuring means are arranged in a height direction.

As the distance measuring means, a means for outputting a first load shift detection signal when the distance measured is smaller than a first set value set in advance can be used. Compares the measured distance with a first set value stored in advance in the storage means, and outputs a first displacement detection signal when the distance measured by the distance measurement means is smaller than the set value. A determination means may be provided.

Further, when the distance measuring means or the determining means determines that the distance measured by the distance measuring means is equal to or greater than the first set value and smaller than a second set value set in advance, May be output.

In the case where there are a plurality of distance measuring means, when the distance measured is smaller than a preset individually set value, each of the plurality of distance measuring means may output a load shift detection signal. The distance measured by the distance measuring means is compared with a set value corresponding to each of the plurality of distance measuring means stored in the storage means in advance, and when the distance measured by at least one distance measuring means is smaller than the corresponding set value. In addition, a determination means for outputting a load shift detection signal may be provided.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1A and 1B show a load shift detecting apparatus according to an embodiment of the present invention. The load shift detecting device is applied to a transfer device of a type that transfers a pallet 12 by a conveyor 11. The load to be detected is pallet 1
2 at a predetermined position.

As shown in FIGS. 1 (a) and 1 (b), the load shift detecting device has a gate 13 installed so as to straddle a conveyor 11. The gate 13 is composed of two pillars standing on the side of the conveyor, and a beam connecting the two pillars. The size of the gate 13 is set so that the load 14 to be detected can pass through the conveyor 11 without contacting a distance sensor described later.

A plurality of distance sensors 15 arranged in the height direction are attached to the two pillar portions of the gate 13. The direction of each distance sensor 15 is a horizontal direction, a direction orthogonal to the transport direction of the conveyor 11, and a direction toward the conveyor side. The number and interval of the distance sensors 15 may be determined according to the size and shape of the load 14 that can be detected.
The denser arrangement of can accommodate loads of various sizes and shapes. In addition, the number and the interval of the distance sensors 15 attached to one pillar portion do not necessarily need to match the number and the interval of the distance sensors 15 attached to the other pillar portion.

The distance sensor 15 emits electromagnetic waves such as light and infrared rays and ultrasonic waves, detects reflected waves, and uses the time from emission to detection, the phase difference between emitted waves and detected waves, and the like. To detect the distance to the load. For this reason, the distance sensor 15 includes a wave transmitting unit that emits light and the like, a wave receiving unit that detects reflected light and the like, and a signal processing unit that is connected to the wave transmitting unit and the wave receiving unit and calculates the distance to the load. have.

The signal processing section of each distance sensor 15 has a storage means for storing the set value, compares the measured distance with the set value, and, when the measured distance is smaller than the set value,
Outputs a detection signal. In other words, when the set value is A, the load 14 is closer to the distance sensor 15 than the state shown in FIG.
The detection signal is output when approaching.

The set value A set in the signal processing unit of each distance sensor 15 is a distance L1 between the load 14 placed at a predetermined position on the pallet 12 and the distance sensor 15, and a maximum allowable deviation. Is L2, A = L1−L2. In this way, the distance sensor 15 can detect the load 14 placed on the pallet 12 conveyed by the conveyor 11.
Outputs a detection signal indicating that a load shift has occurred if it shifts by more than an allowable value when passing through the gate 13. Here, since the set value A is individually set for each distance sensor 15, even if the load 16 has an irregular shape as indicated by a dashed line in FIG. It is possible. The set value A is set for each distance sensor 1
5 in consideration of the accuracy.

The detection signal from the distance sensor 15 is sent to the control unit of the transporting device and used for displaying on a control panel, for turning on a warning light, or for notifying that a load shift has occurred due to an alarm or the like. Is done.

Thereafter, the position of the load that has shifted is corrected. In the position correction, the position of the load 14 is corrected by stopping the conveyor 11. Alternatively, as shown in FIG.
A U-shaped reject line 32 is provided on the side of the transport line 31 (defined by the conveyor 11) to connect the downstream side and the upstream side of the load shift detecting device, and the pallet 14 having the load shift is automatically set. After the transfer to the reject line 32 and the position correction, the return to the transfer line 31 upstream of the gate 13 may be performed.

As described above, in the present embodiment, by using the distance sensor 15 to detect a load shift from the side of the load 14, the load shift can be detected without being affected by the pallet 12. It is possible, and the undetectable area can be substantially eliminated.

Further, it is possible to cope with loads of various sizes and shapes only by changing the set values set in the signal processing section.

Further, a first set value (corresponding to the above-mentioned set value A) and a second set value larger than that (substantially equal to the above-mentioned L1) are provided as set values set in the signal processing section. As a result, the first need to correct the position of the load immediately
It is not necessary to notify the operator and correct the position of the load immediately,
A second notification operation for notifying that a small load shift has occurred can be executed.

In the above embodiment, the distance sensor compares the set value with the set value. However, a distance sensor that outputs a signal indicating the detected distance is used, and each distance sensor is connected to the distance sensor. In a comparison device provided with a storage unit for storing setting values individually corresponding to the distances, the distance detected by the distance sensor may be compared with the setting value. In this case, since it is not necessary to set a set value for each distance sensor, it is easy to set and change the set value. In particular, when the set values of all the distance sensors are the same, the setting is easy. When the distance detected by any one of the distance sensors is smaller than a corresponding set value, the comparison device outputs a detection signal indicating occurrence of a position shift.

Further, in the above-described embodiment, the load shift is detected by a single gate, but a plurality of gates may be provided. In this case, by making the allowable range small on the upstream side and large on the downstream side, multi-stage detection becomes possible.

[0030]

According to the present invention, a distance sensor for measuring the distance to the object without contact is provided on both sides of the conveying means so as to detect a load shift. And can respond quickly to changes in load size.

[Brief description of the drawings]

FIGS. 1A and 1B are schematic diagrams of a load shift detecting device according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining an operation of the load shift detecting device of FIG. 1;

FIG. 3 is a diagram showing an example of a position correcting method when a load shift is detected by the load shift detecting device of FIG. 1;

FIGS. 4A and 4B are schematic diagrams of a conventional load shift detecting device.

[Explanation of symbols]

 11 Conveyor 12 Pallet 13 Gate 14 Load 15 Distance Sensor 16 Load 31 Transport Line 32 Reject Line 41 Conveyor 42a, 42b Light Emitting Element 43a, 43b Light Receiving Element 44 Pallet 45 Load

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F065 AA01 AA37 CC00 DD00 FF11 FF13 FF41 JJ05 JJ22 JJ25 PP15 QQ00 TT03 2F069 AA01 AA03 AA06 AA93 BB36 BB40 DD12 DD20 GG04 GG07 GG09 GG12 AGG13 GG58 GG12 A FA12 FA16 3F081 AA40 BB05 BC04 BD14 EA09 EA10

Claims (8)

[Claims] 1. A load shift detecting device for detecting that a transferred object placed on a pallet conveyed by a conveying unit is shifted from a predetermined position on the pallet, A load shift detecting device provided with a distance measuring means for measuring a distance to the transported object in a non-contact manner. 2. The load deviation detecting device according to claim 1, wherein a plurality of the distance measuring means are arranged in a height direction. 3. The apparatus according to claim 1, wherein said distance measuring means outputs a first load shift detection signal when the distance measured is smaller than a preset first set value. Or 2) a load shift detecting device. 4. The method according to claim 1, wherein the distance measuring unit detects a second load shift when the distance measured by the distance measuring unit is equal to or greater than the first set value and smaller than a second set value set in advance. The load shift detecting device according to claim 3, wherein a signal is output. 5. When the distance measured by the distance measuring means is compared with a first set value stored in a storage means in advance, and the distance measured by the distance measuring means is smaller than the first set value. 3. The load shift detecting device according to claim 1, further comprising a determination unit that outputs a first load shift detection signal. 6. A second load shift detection signal when the distance measured by the distance measuring means is equal to or larger than the first set value and smaller than a second set value set in advance. 6. The load shift detecting device according to claim 5, wherein the output of the load shift detecting device is output. 7. The apparatus according to claim 2, wherein each of the plurality of distance measuring means outputs a load shift detection signal when the distance measured is smaller than a preset individually set value. Load shift detector. 8. A distance measured by the plurality of distance measuring means,
Compare the set value corresponding to each of the plurality of distance measuring means stored in advance in the storage means, and if the distance measured by at least one distance measuring means is smaller than the corresponding set value,
3. The load shift detecting device according to claim 2, further comprising a determination unit that outputs a load shift detection signal.