JP3578331B2 - Cargo handling vehicle - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cargo handling vehicle such as a forklift.
[0002]
[Prior art]
Some forklifts as general cargo handling vehicles have a configuration as shown in FIG. 3 and are called counterbalance type. In this forklift, a fork 21 which is a carrier on which a load is placed and a mast 22 which is a support for guiding the fork 21 to move up and down are disposed at a front position, and at a rear position. The vehicle has a vehicle body 24 on which a counter weight 23 is provided. At this time, a hydraulic cylinder 25 is provided upright along the mast 22 which supports the fork 21 so as to be able to move up and down. The fork 21 is moved up and down by an elevating device (not shown) using the hydraulic cylinder 25 as an actuator. It is to be made.
[0003]
Further, a running motor 26 is provided inside the vehicle body 24, and the running body 26 itself, that is, the forklift is moved forward and backward along the front-rear direction by a running device (not shown) using the running motor 26 as an actuator, and Is to be turned. Although not shown, various operation levers are arranged on the driver's seat panel 27 of the vehicle body 24. A brake used when the operator operates the traveling device is provided at the foot of the driver's seat. And the accelerator is arranged. Further, a controller 28 using a microcomputer is provided inside the driver's seat panel 27. The controller 28 controls the operations of the elevating device, the traveling device, and the like, as well as the cooperative operation thereof. Is to be controlled.
[0004]
[Problems to be solved by the invention]
By the way, by using this kind of forklift, the loading operation and the unloading operation on the rack shelf 30 after the fork 21 is raised are to be executed. After placing the palletized luggage 31 on the fork 21 inserted into the rack shelf 30 with the forward movement of the vehicle body 24, the fork 21 is racked with the backward movement of the vehicle body 24. The lowering operation is performed after the reciprocating operation is performed to the outside of the shelf 30.
[0005]
However, since a lift bracket (not shown) attached to the base end of the fork 21 and a backrest 29 are interposed between the operator sitting on the vehicle body 24 and the fork 21, It is difficult to visually confirm the retreat operation of the fork 21. Further, since the rack shelf 30 is usually installed in a dim warehouse, it is also difficult to visually recognize that the fork 21 has reached the outside of the rack shelf 30. Since the fork 21 is brought into contact with the rack shelf 30 due to the lowering operation of the fork 21, the load collapses, and the load 31 may drop.
[0006]
The present invention has been made in view of such inconvenience, and an object of the present invention is to provide a cargo handling vehicle configured to effectively prevent a fork during a descending operation from contacting a rack shelf.
[0007]
[Means for Solving the Problems]
Cargo handling vehicle according to claim 1 of the present invention, a loading platform which baggage is placed, a lifting device for vertical movement of the loading platform, and a vehicle body to which the loading platform and the lifting device are disposed, distribution to the vehicle body It is set to a cargo handling vehicle comprising a running device for advancing and retracting operation of the vehicle body itself, and a vehicle body operation start means for starting the retracting operation of the vehicle body, the vehicle body and retraction by the vehicle body operation start means A moving distance measuring means for measuring the retreat distance , and a lowering operation of the carrier until the retreat distance of the vehicle body measured by the moving distance measuring means exceeds a set distance which is set by adding the total length of the carrier and a margin distance. prohibited and, and an operation control means for stopping the backward movement of the vehicle body with at the time when the retreat distance of the vehicle body exceeds the set distance, and a control execution instruction means for instructing the control execution by said operation control means And characterized in that it Bei.
[0008]
Cargo handling vehicle according to claim 2 of the present invention are those according to claim 1, wherein the control execution instructing means, a vehicle body in which the loading platform is raised operating to over the predetermined height has started to retreat operation is characterized by having at is an indication of the control execution by the operation control means.
[0009]
A cargo handling vehicle according to a third aspect of the present invention is the vehicle according to the first or second aspect, further comprising a notification unit or an alarm unit that notifies a state of control execution by the operation control unit. And
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, it is assumed that a cargo handling vehicle is a forklift. However, the cargo handling vehicle is not limited to only a forklift, and a cargo bed on which a load is placed, an elevating device for elevating the cargo bed, a vehicle body on which the loading platform and the elevating device are arranged, and Needless to say, a cargo handling vehicle other than a forklift may be used as long as it is a cargo handling vehicle provided with a traveling device disposed on the vehicle main body to move the vehicle main body itself.
[0011]
FIG. 1 is a block diagram showing a main part of a control system provided in the forklift according to the present embodiment, and FIG. 2 is a flowchart showing the control operation. It should be noted that the forklift according to the present embodiment is of a counterbalance type, and its overall structure is basically not different from the conventional embodiment shown in FIG. Will be described with reference to FIG.
[0012]
As shown in FIGS. 1 and 3, the forklift according to the present embodiment has a fork 21 serving as a carrier on which palletized luggage 31 is placed and a mast serving as a support for guiding the fork 21 to move up and down. 22 is disposed at a front position, and a vehicle body 24 having a counterweight 23 disposed at a rear position. A hydraulic cylinder 25 is provided upright along a mast 22 that supports the fork 21 so as to be able to move up and down. The hydraulic cylinder 25 is used as an actuator, and the elevating device 1 disposed inside the vehicle body 24, The fork 21 is to be moved up and down while being guided by the mast 22 as the elevating device 1 of the system is operated. Note that the height position of the fork 21 that has moved up is detected by using the lift detecting means 2 such as a reel-type potentiometer or a magnet sensor.
[0013]
A traveling motor 26 that can rotate forward and reverse is disposed inside the vehicle body 24. Depending on the electric traveling device 3 that uses the traveling motor 26 as an actuator, the vehicle body 24 itself, that is, the forklift itself is used. The reciprocating operation is performed along the front-rear direction, and the revolving operation is performed. The forward distance S1 and the retreat distance S2 of the vehicle body 24 are calculated using an up-down type measuring instrument that counts up the forward distance S1 of the vehicle body 24 and counts down the retreat distance S2, or a rotary encoder. It is measured by using the configured moving distance measuring means 4. The forward distance S1 of the vehicle body 24 is the stop position of the vehicle body 24 stopped just before the fork 21 is inserted into the rack shelf 30, and the retreat distance S2 is the load of the vehicle body 24 after the fork 21 is inserted into the rack shelf 30. The measurement is to be performed with the stop position of the vehicle main body 24 stopped with the 31 mounted thereon as the origin.
[0014]
Further, the driver's seat panel 27 provided in the forklift according to the present embodiment has a plurality of operation levers, that is, various operation levers that are manually operated when operating the elevating device 1 and the traveling device 3, and a liquid crystal display. A notification means 5 and an alarm means 6 such as a buzzer and a buzzer are arranged. The brake and accelerator used when the operator drives the traveling device 3, that is, the forcible stop of the traveling operation of the vehicle body 24 by the traveling device 3 is provided at the foot position of the driver's seat panel 27. An accelerator that functions as a brake and a speed adjusting unit that adjusts the operation speed of the forward operation and the backward operation performed by the vehicle body 24, and also functions as the vehicle body operation start unit 7 that starts the forward operation and the backward operation of the vehicle body 24. And are arranged.
[0015]
A switch functioning as control execution instructing means 8 for instructing execution of control for inhibiting the fork 21 from descending is disposed on the driver's seat panel 27. The ON signal, that is, an ON signal indicating an instruction to execute control for inhibiting the fork 21 from descending, is to be input to the controller 9 described later. When the ON signal output from the control execution instruction means 8 and the ON signal output when the accelerator serving as the vehicle body operation starting means 7 is depressed are input to the controller 9, the moving distance The measuring means 4 starts measuring the forward distance S1 and the reverse distance S2 of the vehicle body 24.
[0016]
Furthermore, in this case, inside the driver's seat panel 27, a controller 9 configured by using a microcomputer, that is, a controller for comprehensively controlling the operation of each device and the linked operation of various devices, etc. The controller 9 has a configuration including a memory unit 10 such as a ROM or a RAM that stores various data, and an arithmetic processing unit 11 including a CPU. The memory unit 10 that constitutes the controller 9 has a margin A measured beforehand, that is, the tip of the fork 21 and the rack shelf 30 when the fork 21 has completely moved out of the rack shelf 30. The set distance [L + A] set by adding the margin distance A to be secured to the outer surface of the fork 21 and the total length L of the fork 21 itself is stored in advance as data.
[0017]
On the other hand, in this case, the arithmetic processing unit 11 sets the retreat distance S2 of the vehicle main body 24 measured by the moving distance measuring means 4 by adding the set distance [L + A], that is, the total length L of the fork 21 and the allowance distance A. Until the set distance [L + A] is exceeded, the lowering operation of the fork 21 is prohibited. At the time when the retreat distance S2 of the vehicle body 24 exceeds the set distance [L + A], the retreat operation of the vehicle body 24 is prohibited. It functions as operation control means for stopping. Therefore, as shown in FIG. 1, various kinds of operation signals and detection signals are sent to the controller 9 from the lift detecting means 2, the moving distance measuring means 4, the vehicle body operation starting means 7 as an accelerator, and the control execution instruction means 8. A signal is input, and a signal for instructing these operations is output from the controller 9 to each of the elevating device 1, the traveling device 3, the notification unit 5, and the alarm unit 6.
[0018]
Next, a control operation at the time of unloading work performed by the forklift according to the present embodiment will be described based on the flowchart shown in FIG. Here, only the control operation at the time of the loading operation by the forklift is described, but the control operation at the time of the loading operation is basically the same as that at the time of the loading operation, and the description is omitted.
[0019]
First, the operator at the time of the unloading operation moves the vehicle body 24 close to the front of the rack shelf 30 where the unloading operation is to be performed, then moves the vehicle body 24 forward, and then moves the fork 21 to the rack. Insert it into the shelf 30. Then, the operator who places the load 31 on the fork 21 by slightly raising the fork 21 releases the brake forcibly stopping the operation of the traveling device 3 (step 1), and then moves the fork 21 down. The control execution instructing means 8 for instructing the execution of the control for inhibiting the operation, that is, the control execution instructing means 8 disposed on the driver's seat panel 27 as a switch is turned on (step 2). The height position of the fork 21 that has been raised when the fork 21 is inserted into the rack shelf 30 is detected by the lift detecting means 2.
[0020]
Subsequently, when the operator steps on the accelerator in order to make the vehicle body 24 move backward, an ON signal is output from the vehicle-body operation start means 7 which is the stepped-on accelerator (step 3). The ON signal from the vehicle body operation start means 7 and the ON signal from the control execution instruction means 8 are input. Then, the arithmetic processing unit 11 of the controller 9 to which the ON signal is input shifts to control for inhibiting the lowering operation of the fork 21 (step 4), and the arithmetic processing unit 11 moves backward with respect to the traveling device 3. A signal instructing the operation is output.
[0021]
Then, the vehicle body 24 is caused to move backward by the traveling device 3 instructed to move backward, and the fork 21 is caused to move backward together with the vehicle body 24 (step 5). Therefore, the moving distance measuring means 4 starts measuring the retreat distance S2 of the vehicle body 24, and the arithmetic processing unit 11 of the controller 9 measures the moving distance measuring means 4 while prohibiting the fork 21 from descending. It is determined whether or not the retreat distance S2 of the vehicle body 24 exceeds the set distance [L + A] set by adding the total length L of the fork 21 and the allowance distance A (step 6).
[0022]
When the arithmetic processing unit 11 determines that the retreat distance S2 of the vehicle main body 24 has exceeded the set distance [L + A], the arithmetic processing unit 11 causes the traveling device 3 to stop the retreat operation of the vehicle main body 24. The instruction signal is output, and the retreat operation of the fork 21 is stopped together with the retreat operation of the vehicle body 24 (step 7). That is, the arithmetic processing unit 11 of the controller 9 also functions as an operation control unit that automatically stops the retreat operation of the vehicle main body 24 when the retreat distance S2 of the vehicle main body 24 exceeds the set distance [L + A]. I have. Further, in the arithmetic processing unit 11, which has determined that the retreat distance S2 of the vehicle body 24 has exceeded the set distance [L + A], the control for inhibiting the fork 21 from descending is released (step 8). Allows the fork 21 to be lowered by manual operation of the lift lever.
[0023]
By the way, in the control operation according to the present embodiment, the control execution instructing means 8 is turned on by manual operation. However, the control execution instructing means 8 is not limited to being manually operated. May be automatically operated by using the lift detecting means 2 for detecting that is at a height position equal to or higher than a predetermined height. That is, when the vehicle main body 24 starts the retreating operation in a state where the fork 21 is moving up to the predetermined height or higher, it is determined that this is the unloading operation, and as described in the present embodiment. It is also possible to automatically execute various controls.
[0024]
Although a detailed description is omitted in the present embodiment, when the prohibition of the lowering operation of the fork 21 is released, the notifying unit 5 is used to notify the operator of the prohibition of the lowering operation. During the execution of the control for inhibiting the operation, it is desirable that the alarm unit 6 issues an alarm to the operator when the operator attempts to lower the fork 21 by a manual operation. When the configuration is adopted, the advantage that the operator is less likely to make erroneous determination is ensured.
[0025]
【The invention's effect】
As described above, in the cargo handling vehicle according to the present invention, the control for inhibiting the lowering operation of the loading platform is performed until the retreat distance of the vehicle main body exceeds the set distance that is set by adding the total length of the loading platform and the allowance distance. Therefore, during the loading operation and the unloading operation, the lowering operation of the loading platform is not started until the loading platform reaches the outside of the rack shelf and reaches a safe position. For this reason, it is unlikely that the loading platform that has started the lowering operation will come into contact with the rack shelves, and it is possible to reliably and effectively prevent the occurrence of load collapse.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a main part of a control system provided in a forklift according to the present embodiment.
FIG. 2 is a flowchart showing the control operation.
FIG. 3 is a side view showing the overall structure of a forklift according to the present embodiment and a conventional form.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Elevating device 3 Traveling device 4 Moving distance measuring means 5 Reporting means 6 Warning means 7 Accelerator (body operation starting means)
8 control execution instructing means 9 controller 11 arithmetic processing unit (operation control means)
21 Fork (packing bed)
24 Vehicle body 31 Luggage S2 Backward distance L of vehicle body L Overall length A of fork (packing bed) Extra distance

Claims (3)

A loading platform luggage is placed, a lifting device for vertical movement of the loading platform, the loading platform and the lifting device and the vehicle body is disposed is traveling device for advancing and retracting operation of the vehicle body itself is disposed on the vehicle body A cargo handling vehicle comprising:
A vehicle operation start means for starting the retracting operation of the vehicle body, a moving distance measuring means for measuring the reverse distance of the vehicle main body retracted operated by the vehicle body operation start means, the vehicle body as measured by the moving distance measuring means Until the retreat distance exceeds the set distance that is set by adding the total length of the luggage and the spare distance, the lowering operation of the luggage carrier is prohibited, and when the retreat distance of the vehicle body exceeds the set distance, the vehicle body retreats. cargo handling vehicle, wherein an operation control means for stopping the operation, in that it comprises a control execution instruction means for instructing the control execution by the operation control means. The control execution instructing means, characterized in that the loading platform is for instructing the control execution by the operation control means with at the time when the vehicle body has risen operates to over the predetermined height has started to retreat operation A cargo handling vehicle according to claim 1. The cargo handling vehicle according to claim 1 or 2, further comprising a notification unit or an alarm unit that notifies a state of control execution by the operation control unit.

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