JP3669902B2 - Cargo handling vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cargo handling vehicle such as a forklift.
[0002]
[Prior art]
Among general forklifts as a cargo handling vehicle, there is a so-called counter balance type configured as shown in FIG. In this forklift, a fork 21 that is a loading platform on which a load is placed and a mast 22 that is a support column that guides the lifting and lowering operation of the fork 21 are disposed at the front position, and at the rear position. A vehicle body 24 having a counterweight 23 is provided. At this time, a hydraulic cylinder 25 is erected along a mast 22 that supports the fork 21 so as to be movable up and down, and a lifting device (not shown) disposed in the vehicle body 24 using the hydraulic cylinder 25 as an actuator. As a result, the fork 21 is moved up and down.
[0003]
Furthermore, the vehicle main body 24 includes a travel motor 26. Depending on a travel device (not shown) using the travel motor 26 as an actuator, the vehicle main body 24 itself, that is, the forklift itself is moved forward and backward along the front-rear direction. And is supposed to be turned. Furthermore, a controller 28 configured by using a microcomputer is provided inside a driver's seat panel 27 disposed in the vehicle body 24. Depending on the controller 28, a lifting device, a traveling device, and the like are provided. The operations of the individual devices as described above and the operations linked with each other are generally controlled.
[0004]
[Problems to be solved by the invention]
By the way, by using this type of forklift, the loading and unloading operations on the rack shelf (not shown) after the fork 21 is lifted are performed. In the picking work, after placing the pallet load on the fork 21 inserted into the rack shelf with the forward movement of the vehicle body 24, the fork 21 is moved with the backward movement of the vehicle body 24. The lowering operation is performed after the retreating operation to the outside of the rack shelf.
[0005]
However, a lift bracket (not shown) or a backrest 29 attached to the base end of the fork 21 is interposed between the operator seated on the vehicle body 24 and the fork 21. It is difficult to confirm the backward movement of the fork 21 by visual observation. In addition, since the rack shelf is usually installed in a dim warehouse, it is also difficult to visually confirm that the fork 21 has run out of the rack shelf. Since the lowering operation was performed, the fork 21 was brought into contact with the rack shelf, and the load collapse occurred.
[0006]
The present invention has been made in view of such inconveniences, and an object of the present invention is to provide a cargo handling vehicle configured to effectively prevent a fork during a lowering operation from coming into contact with a rack shelf.
[0007]
[Means for Solving the Problems]
A cargo handling vehicle according to a first aspect of the present invention includes a loading platform on which a load is placed, a lifting device that moves the loading platform up and down along the column, a loading platform and a column arranged at a front side position, and the lifting device. And a traveling device that is disposed on the vehicle main body and moves the vehicle main body itself back and forth, and measures the forward distance of the vehicle main body that starts the forward movement after the lifting operation of the loading platform. In addition, the moving distance measuring means for measuring the backward distance of the vehicle body that started the backward movement after the completion of the forward movement, the measurement execution instructing means for instructing the execution of the measurement operation of the moving distance measuring means, and the backward movement started. And an operation control means for prohibiting the lowering operation of the loading platform until the backward distance of the vehicle body becomes equal to or longer than the forward distance.
[0008]
The cargo handling vehicle according to claim 2 of the present invention is provided with lifting height detecting means for detecting the height position of the loading platform in addition to the configuration according to claim 1, and the operation control means has a preset reference. It is characterized in that the loading platform is allowed to move up and down until the loading platform at a height exceeding the position exceeds a preset allowable vertical range.
[0009]
The cargo handling vehicle according to a third aspect of the present invention is the cargo handling vehicle according to the first or second aspect, wherein the operation control means performs the backward movement operation of the vehicle main body when the backward distance of the vehicle main body becomes equal to or greater than the forward distance. It is characterized by the fact that it stops.
[0010]
A cargo handling vehicle according to a fourth aspect of the present invention is the cargo handling vehicle according to any one of the first to third aspects, wherein the operation control means is configured such that when the backward distance of the vehicle body becomes equal to or greater than the forward distance, It is characterized in that the lowering operation of the is started.
[0011]
A cargo handling vehicle according to a fifth aspect of the present invention is the cargo handling vehicle according to any one of the first to fourth aspects, further comprising control release means for releasing the prohibition control of the descending operation by the operation control means. Features.
[0012]
A cargo handling vehicle according to a sixth aspect of the present invention is the cargo handling vehicle according to any one of the first to fifth aspects, and includes a reporting means or a warning means for notifying the operating state of the motion control means to the outside. It is characterized by.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, the cargo handling vehicle is a forklift. However, the cargo handling vehicle is not limited to a forklift, and a loading platform on which a load is placed, a lifting device that moves the loading platform up and down along the column, a loading platform and a column are disposed at the front side position. In addition, the vehicle may be other than a forklift as long as it is a cargo handling vehicle including a vehicle main body in which an elevating device is disposed and a traveling device that is disposed in the vehicle main body and moves the vehicle main body back and forth. Of course.
[0014]
FIG. 1 is a block diagram showing a main part of a control system provided in the forklift according to the present embodiment, FIG. 2 is a flowchart showing a pre-control process, and FIG. 3 is a flowchart showing a post-control process. . Note that the forklift according to the present embodiment is a counter balance type, and the overall structure thereof is basically not different from the conventional form shown in FIG. Will be described with reference to FIG.
[0015]
As shown in FIGS. 1 and 4, the forklift according to the present embodiment includes a fork 21 that is a loading platform on which a pallet-loaded cargo is placed, and a mast that is a column that guides the lifting operation of the fork 21. 22 is disposed at a front position, and a vehicle body 24 having a counterweight 23 is disposed at a rear position. A hydraulic cylinder 25 is erected along a mast 22 that supports the fork 21 so as to be movable up and down, and the lifting device 1 disposed inside the vehicle body 24 using the hydraulic cylinder 25 as an actuator, that is, hydraulic pressure is provided. The fork 21 moves up and down along the mast 22 as the system lifting apparatus 1 is operated.
[0016]
It is to be noted that the start of the fork 21 is detected by the start-up detection means 2, which is a detection sensor such as a limit switch disposed at a predetermined position of the mast 22, while the height of the fork 21 that has moved up is high. The position is detected by using well-known lift detection means 3 such as a reel type potentiometer or a magnet sensor.
[0017]
In addition, a traveling motor 26 is disposed inside the vehicle body 24, and depending on the electric traveling device 4 using the traveling motor 26 as an actuator, the vehicle body 24 itself, that is, the forklift itself extends along the front-rear direction. Advancing and retreating operation and a turning operation are performed. Further, the forward distance S1 and the backward distance S2 of the vehicle main body 24 at this time are the moving distance measuring means such as an up-down type measuring instrument for counting up the backward distance S2 while up-counting the forward distance S1 of the vehicle main body 24. It is measurable by 5.
[0018]
That is, in the present embodiment, based on the input of an ON signal from the measurement execution instruction means 6 such as a switch arranged on the driver's seat panel 27, that is, an ON signal indicating the measurement execution instruction, the movement distance measurement is performed. The means 5 measures the forward distance S1 of the vehicle main body 24 that has started the forward movement after the raising operation of the fork 21, and measures the backward distance S2 of the vehicle main body 24 that has started the backward movement after the forward movement ends at this time. Is supposed to do. Note that the moving distance measuring device 5 here is not limited to an up / down type measuring instrument that counts the number of rotations of the tire, for example, and may be configured using a rotary encoder or the like. It is.
[0019]
Further, the driver's seat panel 27 is provided with notifying means 7 and alarm means 8 such as a liquid crystal display and a buzzer, together with various operation levers used when manually operating the lifting device 1 and the like. Inside the driver's seat panel 27, the controller 9, which is configured by using a microcomputer, that is, the operation of each device and the operation of various devices linked to each other is controlled in an integrated manner. A controller 9 is provided that realizes operation control while prohibiting the lowering operation. Here, each of the reporting means 7 and the warning means 8 serves to notify the operation state of the controller 9 to the outside, specifically, to the operator.
[0020]
The controller 9 is composed of a memory unit 10 composed of a ROM or RAM that stores various data, and an arithmetic processing unit 11 composed of a CPU. The data of the height position used as the reference | standard which should prohibit the descending operation | movement of the fork | toe 21 at the time of the time or a cargo pick-up operation, ie, the data of the reference position H1, is memorize | stored. Note that the reference position H1 at this time is the height of the rack shelf on which the load is loaded or the height position of the rack shelf on which the load is to be taken out. It is the height position that should be reached.
[0021]
In the forklift according to the present embodiment, a vertical allowable range h1 in which the ascending and descending operations of the fork 21 at the height position H2 exceeding the reference position H1 is allowed is set in advance. Data relating to h1 is also stored in the memory unit 10. That is, when loading and unloading work with the fork 21, it is common to move the fork 21 up and down over a certain height range, and the actual height position H2 of the fork 21 exceeds the reference position H1. As long as the fork 21 is moved up and down over a certain height range, there is no inconvenience. However, if the up and down movement range h2 of the fork 21 is too large, it may be possible to hinder the loading operation. For this reason, the up and down allowable range h1 in which the fork 21 can be lowered is set in advance. The vertical movement range h2 of the fork 21 is restricted by setting the vertical allowable range h1.
[0022]
Further, the arithmetic processing unit 11 constituting the controller 9 determines whether or not the forward movement operation of the vehicle main body 24 is started after the raising operation of the fork 21 and whether or not the ON signal is output from the measurement execution instruction unit 6. The fork 21 is lowered until the determination is made and the reverse distance S2 of the vehicle body 24 measured by the movement distance measurement means 5 in a state where the ON signal from the measurement execution instructing means 6 is input becomes equal to or greater than the advance distance S1. It functions as an operation control means for prohibiting the operation. The arithmetic processing unit 11 considers the actual situation such as the cargo picking work, and the vertical movement range h2 of the fork 21 at the height position H2 that exceeds the reference position H1 exceeds the preset vertical allowable range h1. Until then, control for allowing the fork 21 to move up and down is also executed.
[0023]
Therefore, as shown in FIG. 1, various operation signals and detection signals are input to the controller 9 from each of the rising start detection means 2, the elevation detection means 3, the movement distance measurement means 5, and the measurement execution instruction means 6. In addition, an instruction signal is output from the controller 9 to each of the lifting device 1, the traveling device 4, the notification unit 7, and the alarm unit 8. In the present embodiment, data related to the allowable vertical range h1 in which the fork 21 is allowed to descend is stored in the memory unit 10 of the controller 9 until the vertical movement range h2 exceeds the vertical allowable range h1. Although control for allowing the fork 21 to move up and down is performed by the arithmetic processing unit 11, data related to the upper and lower allowable range h <b> 1 is not stored in the memory unit 10, and the arithmetic processing unit 11 Of course, even a configuration in which the control that allows the lowering operation of the fork 21 is not executed is included in the scope of application of the present invention.
[0024]
Next, based on the flowcharts shown in FIG. 2 and FIG. 3, the control at the time of the loading operation performed by the forklift according to the present embodiment will be described. Although only the control during the loading operation by the forklift is described here, the control during the loading operation is basically the same as that during the loading operation, and the description thereof will be omitted.
[0025]
First, the operator at the time of loading operation starts the operation of the lifting device 1 by manually operating the lift lever after the vehicle body 24 is brought close to the front of the rack shelf to be loaded. In addition, the hydraulic cylinder 25 is moved forward with the operation of the lifting device 1. Then, the fork 21 starts the ascending operation while being guided by the mast 22 (step 1), and it is detected by the ascending start detecting means 2 that the fork 21 has started the ascending operation. The actual height position H2 of the fork 21 is detected by the lift height detection means 3 (step 2).
[0026]
Eventually, when the actual height position H2 of the fork 21 exceeds the reference position H1 (step 3), the operator then manually turns on the measurement execution instructing means 6 (step 4). 4 causes the vehicle body 24 to move forward (step 5). As the vehicle body 24 moves forward, the fork 21 is inserted into a rack shelf in which pallet-loaded luggage is stored. In this case, the measurement execution instruction means 6 is turned on. Since the vehicle body 24 has been operated and the vehicle body 24 has started to move forward after the fork 21 has been lifted, the travel distance measuring means 5 measures the advance distance S1 of the vehicle body 24 (step 6). . Note that it is not necessarily necessary to turn on the measurement execution instructing means 6 in Step 3, and it goes without saying that the ON operation of the measurement execution instructing means 6 may be performed at a time prior to Step 3.
[0027]
Furthermore, the fork 21 inserted into the rack shelf lifts the pallet-loaded luggage while being raised and lowered, and the luggage stored in the rack shelf is placed on the fork 21 ( Step 7). By the way, the height position H2 of the fork 21 which is executing such ascending and descending operations is also detected by the lift height detecting means 3, and the fork 21 calculated based on the respective height positions H2 of the upper and lower sides. As long as the vertical movement range h2 does not exceed the preset vertical allowable range h1, that is, as long as h2 ≦ h1, the arithmetic processing unit 11 of the controller 9 allows the fork 21 to move up and down.
[0028]
After that, the fork 21 on which the load is placed is moved back out of the rack shelf as the traveling device 4 is driven to move the vehicle body 24 backward (step 8). In other words, since the vehicle body 24 has started to move backward while the actual height position H2 of the fork 21 exceeds the reference position H1, the control processing unit 11 of the controller 9 prohibits the fork 21 from being lowered. Is executed (step 9). And since the vehicle main body 24 has started the reverse operation after the completion of the forward movement, the reverse distance S2 of the vehicle main body 24 is measured by the movement distance measuring means 5 as the fork 21 moves backward ( Step 10), control for prohibiting the lowering operation of the fork 21 is executed by the arithmetic processing unit 11 until the backward distance S2 of the vehicle body 24 becomes equal to or longer than the forward distance S1 (step 11).
[0029]
That is, while the fork 21 is moving backward, the arithmetic processing unit 11 of the controller 9 starts that the vehicle main body 24 starts moving backward while the height position H2 of the fork 21 exceeds the reference position H1. Based on this, it is determined whether or not the reverse distance S2 of the vehicle body 24 is equal to or greater than the forward distance S1 (step 11), and unless the reverse distance S2 is equal to or greater than the forward distance S1, that is, as long as S2 <S1. The control for prohibiting the lowering operation of the fork 21 is executed (step 9). The lowering operation of the fork 21 is continued until the backward distance S2 of the vehicle body 24 is equal to or greater than the forward distance S1 (S2 ≧ S1), and the backward distance S2 of the vehicle body 24 is equal to or greater than the forward distance S1. When the arithmetic processing unit 11 determines that the fork 21 has become, the control for prohibiting the lowering operation of the fork 21 is released (step 12).
[0030]
Accordingly, after this point, the lift lever 1 is manually operated to resume the operation of the lifting device 1 and then the fork 21 is moved downward from the reference position H1 while the hydraulic cylinder 25 is retracted. Is possible. It is not necessarily necessary to manually operate the lift lever when the fork 21 is lowered. When the backward distance S2 of the vehicle main body 24 exceeds the forward distance S1, the downward movement of the fork 21 is automatically started. The function to be performed may be given to the arithmetic processing unit 11 which is an operation control means.
[0031]
By the way, in the present embodiment, the operation control for prohibiting the lowering operation of the fork 21 is released when the arithmetic processing unit 11 of the controller 9 determines that the backward distance S2 of the vehicle body 24 is equal to or longer than the forward distance S1. However, it is needless to say that the arithmetic processing unit 11 that has made this determination may simultaneously perform operation control for stopping the backward movement of the vehicle body 24. In the case where the ascending operation and the descending operation of the fork 21 inserted into the rack shelf are not executed at step 7 at all, or when the backward movement operation of the vehicle body 24 is not executed at step 8 at all, the normal unloading is performed. Since it is considered that there is no work or a failure has occurred, it is practical to stop the execution of the control for prohibiting the lowering operation of the fork 21 after a predetermined time has elapsed.
[0032]
Although detailed explanation is omitted here, the reporting means 7 and the warning means 8 inform the operator that the control state for prohibiting the lowering operation of the fork 21 has been started or the operating state that the fork 21 is moving backward. A configuration that appropriately notifies the user may be employed, and when such a configuration is employed, an advantage that an operator's misjudgment hardly occurs is ensured. It should be noted that the operation control for prohibiting the lowering operation of the fork 21 is not necessary in all the loading operations performed using the forklift, and the driver's seat panel is not necessary when the lowering operation of the fork 21 is not required. Even if a control canceling means (not shown) such as a switch disposed in 27 is used, the control unit 11 of the controller 9 cancels the forbidden control of the lowering operation of the fork 21. Of course it is good.
[0033]
【The invention's effect】
As described above, in the cargo handling vehicle according to the present invention, the forward movement is started after the lifting operation of the loading platform, and the backward movement distance of the vehicle main body that has started the backward movement after the completion of the forward movement is equal to or greater than the forward movement distance. The operation control for prohibiting the lowering operation of the cargo bed is executed. As a result, the fork descending operation is prohibited until the fork at the time of loading and unloading work is completely out of the rack shelf. As a result, the fork that has started descending comes into contact with the rack shelf. This is not possible, and the effect of reliably and effectively preventing the occurrence of cargo collapse is obtained.
[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 an embodiment.
FIG. 2 is a flowchart showing a pre-process of control.
FIG. 3 is a flowchart showing a subsequent process of control.
FIG. 4 is a side view showing the overall structure of a forklift according to the present embodiment and a conventional embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Lifting apparatus 2 Ascent start detection means 3 Lift height detection means 4 Traveling apparatus 5 Movement distance measurement means 6 Measurement execution instruction means 7 Notification means 8 Alarm means 9 Controller 10 Memory part 11 Calculation processing part (operation control means)
21 Fork
24 Vehicle body S1 Forward distance S2 Reverse distance

Claims (6)

A loading platform on which a load is placed, a lifting device that moves the loading platform up and down along the column, a vehicle body in which the loading platform and the column are disposed at the front side position, and the lifting device is disposed, and the vehicle body And a traveling device that moves the vehicle body itself forward and backward, and is a cargo handling vehicle that is operated by an operator , and a measurement execution instruction means that instructs measurement execution of the forward distance and the backward distance of the vehicle main body, When the measurement execution instruction is issued by the measurement execution instructing means, the forward distance of the vehicle body that has started the forward operation after the lift operation of the loading platform is measured, and the backward movement of the vehicle body that has started the reverse operation after the completion of the forward operation distance and travel distance measuring means for measuring, until the retreat distance measured by the distance traveled measurement means is the forward distance or more, and includes an operation control means for inhibiting the loading platform of the lowering operation Cargo handling vehicle according to claim Rukoto. The height detecting means for detecting the height position of the loading platform is provided, and the operation control means is configured to operate the loading platform until the loading platform at a height position exceeding a preset reference position exceeds a preset vertical allowable range. The cargo handling vehicle according to claim 1, wherein the lifting operation and the lowering operation of the vehicle are allowed. The cargo handling vehicle according to claim 1 or 2, wherein the operation control means stops the backward movement of the vehicle body when the backward distance of the vehicle body becomes equal to or greater than the forward distance. The cargo handling vehicle according to any one of claims 1 to 3, wherein the operation control means starts the descent operation of the loading platform when the backward distance of the vehicle body becomes equal to or greater than the forward distance. . The cargo handling vehicle according to any one of claims 1 to 4, further comprising a control canceling unit that cancels the prohibition control of the descending operation by the operation control unit. The cargo handling vehicle according to any one of claims 1 to 5, further comprising reporting means or warning means for notifying the operation state of the operation control means to the outside.

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