JPH07106880B2 - Forklift unmanned transfer system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an unmanned transport system for directly picking up and transporting a transported product by a forklift truck.

[Conventional technology]

FIG. 8 shows a part of a conventional unmanned transportation system for unmanned transportation of a weight coil in which a steel plate is coiled. Reference numeral 1 is a guide wire laid on the floor of a taxiway, and 2 is the guide wire 1. It is a forklift vehicle for unmanned transportation that travels while moving, and has a fork 3 that is lifted and lowered by an elevator drive device (not shown). Reference numeral 4 is a pallet placed in one of the fixed points P _{0 in} the yard Zone P ₀ , and 5 is a weight coil placed on the pallet 4. Ps is a distance measurement reference point on the taxiway at a predetermined distance L ₀ from the fixed point.

When the forklift truck 2 receives the destination designation, the guideline 1
When the vehicle body reference position 2a travels on the taxiway toward the fixed point P ₀ and the vehicle body reference position 2a passes the distance measurement reference point Ps, the measurement of the traveling distance Lx started from this Ps is started, and the traveling distance Lx is the main control. After traveling until reaching the command distance L ₀ written in the memory 6A of the device 6 and inserting the forks 3 controlled up and down to the floor level of the fork insertion holes 4a of the pallet 4 into the fork insertion holes 4a, After moving the forks 3 up and down and confirming that "there is a load", the vehicle starts traveling to the next designated point. Conventionally, as shown in FIG. 10, this "in-load" is detected by attaching an in-load detection sensor 7 (eddy current sensor or the like) to the peripheral surface of the fork 3.

In this way, in a system that lifts and conveys a conveyed product with a fork, if there is a misalignment between the fork and the fork insertion hole on the conveyed product, the fork and the conveyed product will be damaged. Using the standardized pallet 4,
Fork lift control targeting the pallet 4 placed on the specified zone is performed to convey the conveyed object together with the pallet to ensure safety and reliability.

[Problems to be Solved by the Invention]

However, since a large weight coil with a weight of 10 tons to 25 tons is usually positioned and managed separately by a coil holder 8 which also functions as a stopper, as shown in FIG. When transporting coils unattended, the weight coil must be directly picked up and transported by a forklift truck, not through a pallet. Then
Since the fork insertion position (height) and the fork insertion amount are different, there is a problem that the above-mentioned conventional transfer system cannot be applied.

The present invention has been made to solve the above problem, and an object of the present invention is to provide an unmanned transfer system capable of directly picking up and transferring an object to be conveyed by a forklift truck.

[Means for Solving the Problems]

In order to achieve the above object, the present invention calculates the vertical position of a fork insertion portion of a conveyed product from the conveyed product shape data in the invention of claim 1, and in the invention of claim 5, the end surface of the conveyed product is detected by a sensor. The upper and lower positions of the fork insertion portion are detected by scanning, and in the invention of claim 3, the distance measurement reference point is given not by the set value but by the detection timing of the end of the fork insertion portion. Further, in claim 2, the fork insertion amount appropriate value is calculated from the shape data of the conveyed product, and the fixed point stop position of the forklift vehicle is corrected by the calculated value. In addition, according to the fourth aspect, there is provided a loading position monitoring device including a distance measuring sensor that measures the distance between the conveyed items.

[Action]

In the present invention, the vertical position of the fork insertion portion of the conveyed object is detected for each conveyed object by calculation or using a sensor,
Since the fork is controlled to this vertical position and the forklift vehicle stop position at the pickup fixed point is determined for each conveyed object by calculation or using a sensor, the conveyed object can be directly picked up.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1 and FIG. 2, 10 is a forklift truck for unmanned transportation, which has a ram fork 12 which is engaged with a mast 11 so as to be able to move up and down and which is controlled to move up and down by a lifting drive device 14. After traveling to the fixed point P ₀ designated by the guide line 1 of the above, the ram fork 12 is inserted into the coil hole 13a which is the fork insertion portion of the weight coil (for example, 10 ton to 15 ton) 13, and then the ram fork 12 Is lifted by a predetermined height, and after confirming "in-load" by the method described above, the vehicle starts traveling to the next designated point.

In the memory 6A of the main controller 6 of the forklift truck 10, the shape data Data I (coil outer diameter D, coil inner diameter d, coil width w) of the weight coil 13 and the data Data II of the coil stand 8 are stored.
(Height h) is given, and the fork insertion position H and the appropriate fork insertion amount value W are calculated. This shape data Data
I is, for example, read from the data storage device 16 storing the specification data given to the weight coil 13 through the line terminal device 17 of the rolling line and wirelessly transmitted via the central control station 18 of the transfer system. For forklift truck 10
Is transmitted to the main controller 6. Data Data II (height h
Are stored in advance in the memory 6A in association with the fixed point P ₀ . The arithmetic processing unit 6B of the main controller 6 uses the Data I and Data I
Coil hole 1 from I to fork insertion position (height) H
3a center height H and fork insertion amount optimum value (depth) W
And are calculated. The appropriate amount W of the fork insertion amount is for giving a position where the fork lift truck 10 can appropriately lift and transport the weight coil 13 without losing the balance of the center of gravity during the lifted load. FIG. 3 shows a fork insertion state. The calculated value H is given to the lifting drive device 14 that controls the lifting and lowering of the ram fork 12, and the calculated value W is given to the traveling control device 15 in order to correct the set distance L ₀ . This corrected value is ΔL ₀ . Normally, the coil stand 8 functions as a stopper, and the weight coil 13 is placed on the floor, so that h = 0. In this configuration, the command distance from the distance measurement reference point Ps to the fixed point P ₀ is the weight coil.
Only [Delta] L ₀ minutes suit 13 coil width of the modified, "L ₀ + delta
L ₀ ”, so the ram fork 12 is a heavy coil at the tip.
There is no need to lift with 13 hooked.

The coil insertion position H of the ram fork 12 is a heavy coil.
Since the ram forks 12 are controlled to move up and down to the calculated fork insertion position H for each 13, the misalignment between the coil holes 13a and the ram forks 12 is prevented, and the ram forks 12 are placed on the coil end surface when the coil holes of the ram forks 12 are inserted. Collisions are prevented.

In addition, in the above-mentioned embodiment, the case where the transported object is the heavy weight coil placed in the yard in a loose manner is explained. However, in the case of the light weight coil and being stacked on the rack as shown in FIG. 4, the rack levels F1, F2, F3 and rack number N for each rack level
By giving the addresses of o.1 to No.3, it is possible to realize the direct pickup and conveyance of the light weight coils C1, C2, C3 ... Having different shapes.

In the embodiment of FIG. 1, the fork insertion position H is calculated from Data I, but as shown in FIG.
You may make it detect directly using 20.

In FIGS. 5 (a) and 5 (b), 20 is a fork position check sensor, and this sensor 20 is an ultrasonic object detection sensor. As shown in FIG. 5 (a), the base of the lamb fork 12 is shown. May be directly attached to the screw, or as shown in FIG. 5 (b), for example, a screw 21 and a motor
It may be supported by a lifting device having the encoder 22 and the encoder 23. Reference numeral 24 is a guide, and 25 is a recess for accommodating the lifting device.
The ultrasonic object detection sensor 20 sends an ultrasonic wave forward in the longitudinal direction of the fork and detects the presence or absence of an object based on the presence or absence of reception of a reflected wave from the front. The elevation position of the ultrasonic object detection sensor is detected by a position detection device using an encoder 23.

In this configuration, the forklift truck 10 stops when it travels the predetermined set distance Lp (<L ₀ ) toward the fixed point P ₀ after passing the distance measurement reference point Ps, where the ultrasonic object The detection sensor 20 is moved up and down. By this elevating operation, the ultrasonic object detection sensor 20 scans the coil end surface of the weight coil 13 in the up-down direction, and scans the coil hole 13a for a signal of "Yes" while scanning the coil end surface in the coil diameter direction. The signal of "nothing" is generated while it is being held. Both of these signals are sent to the main controller 6 in correspondence with the position signals of the position detecting device, and the main controller 6 uses these signals to determine the coil hole.
The height H'from the floor surface of the hole center of 13a is detected by calculation. This detected value H'may be used to check the vertical position of the ram fork 12, or may be used as the target height of the ram fork 12, that is, the fork insertion position H. When it is used for check, the main controller 6 compares the detected value H ′ with the fork insertion position H calculated from Data I to determine whether the ram fork 12 is misaligned with the coil hole 13a and the size thereof. It is determined whether or not the deviation amount is outside the allowable range, and if it is within the allowable range, a deviation detection signal is generated and the forklift vehicle 10 thereafter.
Have software that interrupts the operation of.

In the above description, the forklift truck 10 is temporarily stopped and the ultrasonic object detection sensor 20 is moved up and down to detect the height H '. However, the ultrasonic object detection sensor 20 is moved up and down at a high speed. If the ascending / descending operation is performed while traveling, it is possible to reduce the positional deviation at the fixed point stop position.

Since the sensor 20 of the fork position detection device of this embodiment is an ultrasonic object detection sensor, it is less susceptible to noise than an optical device, and the detection accuracy depends on the material of the weight coil 13 that is the detection target. Therefore, the misalignment detection can be performed with high reliability.

By the way, in the above-described embodiment, the fork insertion amount proper value W is calculated, and the fixed point stop position of the forklift vehicle 10 is corrected so that the weight coil 13 is supported at the proper position on the ram fork 12. In reality, it is difficult to accurately stop the automatic guided vehicle at the designated position, and the positional deviation easily occurs when the automatic guided vehicle is stopped. In the forklift truck 10, when the stop position is displaced, the weight coil on the ram fork 12
The position of 13 also deviates from the proper position. Cargo detection sensor 7
Detects only whether or not the ram fork 12 has been inserted into the coil hole 13a, and does not determine whether the position on the fork, that is, the posture, is good or bad when picked up. For this reason, the forklift truck 10 is a lamb fork 12
Even if the tip end of the weight coil 13 ends in the coil hole 13a of the weight coil 13, it is determined to be "loaded" and the weight coil 13 is picked up and transported. It is dangerous.

The embodiment of the invention shown in FIG. 6 is a forklift truck provided with a load monitoring device for preventing such unstable traveling, and is housed in a recess 26 provided at a predetermined height on the front surface of the mast 11. It has the ultrasonic distance measuring sensor 27. The ultrasonic distance measuring sensor 27 is attached to a position where ultrasonic waves are transmitted forward in the longitudinal direction of the fork and a reflected wave from the weight coil 13 can be received.

In this configuration, when the forklift truck 10 travels to the above-mentioned fixed point P ₀ and stops, the ultrasonic distance measuring sensor 27 sends out ultrasonic waves and the distance to the end face of the weight coil 13 (distance l between coils) is increased. Start measurement. If the distance l between the coils is transmitted from the main control unit 6 to the central control station 18 and displayed on the display screen, the ram walk
The position of the weight coil 13 on 12 can be checked.

Further, the main controller 6 compares this inter-coil distance 1 with the limit value of the allowable range, and the inter-coil distance 1 shows the maximum limit value lm.
When it exceeds the minimum limit value ls, that is,
When the weight coil 13 is picked up near the tip of the ram fork 12, on the contrary, when the weight coil 13 is picked up at a position near the mast that collides with the mast, it has a function of generating a loading attitude abnormality signal. The weight coil 13 under the condition that this loading attitude abnormal signal is not generated.
If the pickup operation and the in-carrying traveling are allowed, it is possible to reliably prevent the unstable traveling as described above.

Further, in the conventional forlift truck, if the presence detection sensor 7 fails and the presence of the presence is not confirmed, it is not possible to pick up the conveyed object, and the unmanned vehicle operation system stops. If the distance measuring sensor 27 is provided,
"Available" depending on whether or not the reflected wave from the weight coil 13 is received
Since it is possible to determine the presence of the vehicle, it is possible to detect the presence of the vehicle twice, and even if the presence detection sensor 7 fails, the unmanned vehicle operation system does not go down.

As mentioned above, the weight coil 13 directly on the ram fork 12
When picking up, at all times so that fork insertion amount becomes a proper value, must be changed according to a fixed point stop position of forklifts vehicle 10 to the shape of the weight coil 13, the invention of FIG. 1, a fixed point P ₀ The specified distance L ₀ from the distance measurement reference point Ps on the taxiway is corrected according to the coil width w, but the distance measurement reference point Ps is changed according to the shape of the weight coil 13. The case where the end face detection timing of the weight coil 13 is used as the distance measurement reference point will be described with reference to FIG.

In FIG. 7, 30 is an end face detection sensor. The end face detection sensor 30 is, for example, an eddy current sensor, and is attached to a recess 31 formed on the peripheral surface of the tip end portion (position Ls from the tip end) of the ram fork 12 with the detection surface facing outward in the radial direction. Has been done.

In this configuration, the forklift truck 10 travels on the guideway by being guided by the guideline, travels to the vicinity of the fixed point P ₀ , and the ram fork 12 controlled to move up and down to the fork insertion position H is the coil of the weight coil 13. When entering the hole 13a for the length Ls, the end face detection sensor 30 outputs. When the traveling control device 15 of the forklift truck 10 receives this output, it starts measuring the traveling distance, and this measured value is the coil width w of the Data I.
The forklift truck 10 is stopped when the fork insertion amount proper value W'calculated on the basis of the above is reached.

In this configuration, even if the coil width w of the weight coil 13 changes, the distance measurement reference point Ps is changed according to the coil width w, and this distance measurement reference point Ps is the weight coil 13 in the zone of the fixed point P ₀ . Since it is very close, it is possible to substantially eliminate the positional deviation of the fixed point stop position of the forklift truck 10, and reliably prevent the collision with the weight coil 13 on the coil stand 8,
The weight coil 13 can be picked up in a stable posture.

In addition, in each of the above-mentioned embodiments, the case where the transported object is the coil has been described, but each invention can be carried out to transport a transported object that can be transported by a forklift truck having a ram fork or a side fork and obtain the same effect. You can

〔The invention's effect〕

As described above, the present invention obtains the vertical position of the fork insertion portion of the conveyed object for each conveyed object and controls the elevation of the fork to this vertical position, and also determines the stop position at the pickup fixed point for each conveyed object. It is possible to realize the direct pick-up transfer of the transfer object, and increase the flexibility of the transfer system.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing a data transmission system in the above embodiment,
FIG. 3 is a diagram showing a state of picked-up goods of the above embodiment, FIG. 4 is a diagram showing an example of a picked-up object to which the above embodiment is applied, and FIGS. 5 to 7 are views of other embodiments of the invention. The figure which shows the principal part, Figure 8 is the block diagram of the former conveying system, 9th
FIG. 10 is a view showing a table for a conveyed object, and FIG. 10 is a view showing a fork having a presence detection sensor. 1 ... Guidance line, 6 ... Main control unit, 7 ... In-vehicle detection sensor, 10 ... Forklift truck, 11 ... Mast, 12 ... Ramfork, 20 ... Object detection sensor, 27 ... Distance measurement Sensor, 30 ... Edge detection sensor.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 61-7199 (JP, A) Actual development S55-168000 (JP, U) JP 61-56159 (JP, B2)

Claims (5)

[Claims] 1. A plurality of fixed points connected by a taxiway and a forklift truck that is driven unmanned on the taxiway, and the forklift truck is another fixed point to which a conveyed object picked up in a designated fixed point zone is designated. In an unmanned transportation system for transporting to a zone, the forklift truck is given shape data of the transported object on the fixed point zone, calculates the vertical position of the fork insertion portion of the transported object from this shape data, and forks to this vertical position. A forklift unmanned transfer system that controls the lift of the forklift to directly pick up the load. 2. A proper value of the fork insertion amount is calculated from the shape data of the conveyed product together with the vertical position of the fork insertion portion of the conveyed product, and the fixed point stop position of the forklift truck is corrected by the proper value of the fork insertion amount. An unmanned transfer system for a forklift mounted on claim 1. 3. A forklift truck has a non-contact type end face detection device for detecting an insertion distance of a fork inserted into a fork insertion portion of a conveyed product near a tip of the fork, and the forklift truck travels to convey the fork. After the insertion into the object insertion site, if the measured value of the insertion distance of the fork detected by the non-contact type end face detection device and the fork insertion amount proper value of the fork insertion site calculated from the shape data of the conveyed product match, The unmanned forklift transfer system according to claim 2, wherein the traveling of the forklift truck is stopped. 4. A plurality of fixed points connected by a taxiway and a forklift truck that is driven unmanned on this taxiway, and the forklift truck is another fixed point to which a conveyed object picked up in a designated fixed point zone is designated. An unmanned forklift transport system for transporting to a zone, having a loading position monitoring device, and the loading position monitoring device comprising a distance measuring sensor for measuring a distance between a base part on which the fork is engaged and an end surface of the transported object. A forklift unmanned transport system featuring. 5. The forklift truck has a non-contact sensor that scans an end surface of a conveyed object, which is supported so as to be vertically movable and has a fork insertion portion of the conveyed object opened, and the non-contact sensor is provided near a base of the fork. An unmanned forklift transfer system according to any one of claims 1 to 3, wherein the forklift automatic transfer system is attached and detects the actual fork insertion position from the output of the non-contact sensor and the ascending / descending position.