JP2004277073A - Forklift - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tilting automatic stopping device suitable for a forklift with a push-pull device or a pusher device. <P>SOLUTION: This forklift is furnished with a function to automatically stop tilting motion when a tilting angle of a fork 9d becomes a previously set angle, and a change-over switch 32 free to switch on and off the function to automatically stop tilting motion when the tilting angle of the fork 9d becomes a previously set angle and free to switch on and off a synchronous moving function of the push-pull device 9 or the pusher device, and the change-over switch 32 has a change-over function to switch on the tilting automatic stopping function by operation to switch on the synchronous moving function and to switch off the tilting automatic stopping function by operation to switch off the synchronous moving function. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a forklift provided with a push-pull device or a pusher device.
[0002]
[Prior art]
As a material handling device of a forklift, there is a push-pull device or a pusher device. Hereinafter, taking the push-pull device as an example, in any case of pulling the load on the fork or pushing the load from the fork, the fork is tilted forward by the tilt operation and the tip of the fork is attached to the ground. Work in the state. As a result, a step between the fork and the ground is eliminated, and smooth loading and unloading is performed.
[0003]
However, conventionally, the tilt operation of the fork was manually performed by operating the tilt lever by an operator, so that adjustment was troublesome, and there was a risk that the tilt angle was not accurate and the load collapsed. Focusing only on the tilt angle accuracy in a normal forklift other than a forklift with a push-pull device, there is a technique for automatically performing a tilt operation. Patent Documents 1 and 2 below stop the tilt operation at a predetermined tilt position. The technology is shown.
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 9-156895 [Patent Document 2]
JP-A-5-278998 [0005]
[Problems to be solved by the invention]
However, in the forklift work, as described in the above-mentioned literature, there are occasions where an operator wants to perform a manual operation by operating a tilt lever. Therefore, a dedicated automatic stop / release for switching between automatic and manual operation is required. Switches are often provided. Therefore, the operator has to press the dedicated automatic stop / cancel switch each time.
[0006]
A forklift equipped with a push-pull device has a synchronous switch for performing a synchronous operation for moving the vehicle body forward or backward in synchronization with a pull-in or push-out operation of a load. For this reason, if the automatic stop / release switch for tilt is applied to a forklift with a push-pull device as it is, the operator needs to press the automatic stop / release switch for tilt in addition to the synchronous switch, which complicates the operation. I could be.
[0007]
Accordingly, an object of the present invention is to provide a technology that can add a technology for automatically performing a tilt operation to a forklift equipped with a push-pull device or a pusher device, and in which case the operation does not become complicated.
[0008]
In order to solve the above problem, the present invention relates to a forklift including a push-pull device or a pusher device having a synchronous operation function of moving a vehicle forward and backward in synchronization with a rearward movement of a face plate, and a fork tilt function. Can switch on / off a function of automatically stopping the tilt operation when the tilt angle of the fork reaches a preset angle, and a synchronous operation function of the push-pull device or the pusher device, and And a switch capable of switching on / off a function of automatically stopping the tilt operation when the tilt angle becomes a preset angle. The switch is an operation for turning on the synchronous operation function. Turn on the tilt automatic stop function and turn off the synchronous operation function with Characterized in that it has a switching function to turn off the automatic stop function of the serial tilt.
[0009]
According to the present invention, the on / off switching of the synchronous operation function and the on / off switching of the automatic tilt function can be simultaneously performed by operating the changeover switch. Thus, it is not necessary to switch on / off the synchronous operation function and on / off of the automatic tilt function by separately provided switches or the like, and each switch can be turned on / off by one switch. It can be carried out. In addition, in the case of performing the synchronous operation, the conventional operation of the switch only for the synchronous operation does not require any new operation for switching the newly added automatic tilt function on / off. The automatic tilt operation can be added to the push-pull or pusher operation by exactly the same operation as the conventional one.
[0010]
Since the pusher device does not have the load pull-in mechanism in the push-pull device, the synchronous operation is performed only when the load is pushed out. Fork tilt is a forklift in which a fork is attached to a tiltable mast, for example, in a counter type forklift, the fork is tilted by the tilt operation of a mast device, and in a reach type forklift, the fork attached to the mast is directly tilted. Is what you do. In the forklift with a push-pull device or a pusher device, the tilt angle set in advance refers to a tilt angle of a forward tilt particularly suitable for pulling in or pushing out a load, but the tilt angle is not limited to this and can be freely selected as appropriate. It is.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 shows a counter-type forklift F, which is provided with a cargo handling device at a front portion of a vehicle body 14. The cargo handling device includes a mast 5 capable of tilt operation, a lift bracket 7 supported to be able to move up and down along the mast 5, and a push-pull device 9 attached to the lift bracket 7.
[0012]
The mast 5 includes a tilt cylinder 11 for enabling a tilt operation, and the mast 5 is tilted forward or backward by expansion and contraction of the tilt cylinder 11, whereby the fork 9d is tilted forward or backward. A tilt lever 18 for tilting the mast 5 is provided in the driver's seat of the vehicle body 14, and the tilt cylinder 11 expands and contracts in accordance with the tilt direction and the tilt amount of the tilt lever 18.
[0013]
The push-pull device 9 includes a face plate 9a that can move forward and backward in the front-rear direction, and a gripper 9b and a grip plate 9c that can sandwich an edge of a sheet-shaped pallet below the face plate 9a.
[0014]
The face plate 9a can be moved forward and backward by a pantograph mechanism 9e. It is the push-pull cylinder 9f that operates the pantograph mechanism 9e. In order to operate the face plate 9a, a push-pull lever 19 is provided in the driver's seat. The face plate 9a moves forward by tilting the push-pull lever 19 forward, and retreats by tilting backward.
[0015]
The gripper 9b attached to the face plate 9a can move up and down by a cylinder (not shown) attached to the face plate 9a, and sandwiches the end of the sheet pallet 7 with the grip plate 9c.
[0016]
The gripper 9b advances and retreats at the same time as the face plate 9a advances and retreats by operating the push-pull lever 19. When the push-pull lever 19 is tilted backward to retreat the face plate 9a, the gripper 9b advances downward to form a sheet. Pinch the edge of the pallet. Accordingly, when the face plate 9a retreats, the load is dragged in a state of being placed on the sheet-like pallet and retreats on the fork 9d. When the face plate 9a is moved forward by tilting the push-pull lever 19 forward, the face plate 9a is retracted upward to release the end of the sheet-shaped pallet. Therefore, with the advance of the face plate 9a, the load is pushed out on the sheet pallet and moves forward on the fork 9d. When the synchronous operation function of the push-pull device is used, the vehicle body 14 moves forward and backward in synchronization with the rearward movement of the face plate 9a, so that the load does not move on the road surface.
[0017]
Next, referring to the block diagram of FIG. 1, the present invention includes a tilt angle detecting means 30, a tilt operation detecting means 31, a changeover switch 32, a control means 33, and a tilt driving means 34.
[0018]
The tilt operation detecting means 31 is a means for detecting the operation direction and the operation amount of the tilt lever 18 operated by the operator in the driver's seat. For example, it includes a limit switch for detecting the forward tilt of the tilt lever 18 for detecting the operation direction, a limit switch for detecting the backward tilt, and an encoder for detecting how much the tilt lever 18 has tilted from the neutral position. Note that one potentiometer may be used as the tilt operation detecting means 31.
[0019]
The control unit 33 includes a central processing unit (CPU) and a storage device, and includes a tilt control unit 33a and a synchronization control unit 33b. The tilt control means 33a is a control means for tilting the mast 5 in response to the movement of the tilt lever 18, and when a detection value of the operation direction and the operation amount of the tilt lever 18 is input, this detection is performed. Calculate and output the output value corresponding to the value. This output value is input to the tilt drive unit 34.
[0020]
The tilt drive unit 34 is a hydraulic motor that sends pressure oil to the tilt cylinder 11, a proportional solenoid valve that adjusts the flow rate of the pressure oil, and the like, and is a hydraulic device that is controlled by a command signal from the tilt control unit 33a. . By driving the tilt driving means 34, pressure oil is delivered to the tilt cylinder 11, and the mast 5, that is, the fork 9d performs a tilt operation.
[0021]
The tilt angle detecting means 30 is means for detecting the tilt angle of the mast 5, that is, the tilt angle of the fork 9d. For example, it comprises a potentiometer 10a attached to the mast 5, and a wire 10b extending from the potentiometer 10a and having one end fixed to the vehicle body 14. The wire 10b can be unwound and wound, and the tilt angle of the mast 5 is detected based on the unwind length of the wire 10b. The tilt angle detected by the tilt angle detecting means 1 is input to the control means 33.
[0022]
A synchronization switch is provided at the front of the driver's seat to turn on / off the synchronization control means 33b of the push-pull device. The synchronization control means 33b is a control means for synchronizing the face plate 9a with the traveling speed of the vehicle body 14. When the synchronous control unit 33b is turned on by the synchronous switch, the synchronous control unit 33b enters a synchronous operation standby state. In this state, when the vehicle body 14 moves forward and the face plate 9a is retracted, a synchronous operation at the time of loading the load is performed, and when the vehicle body 14 moves backward and the face plate 9a is advanced, the synchronous operation at the time of pushing the load is performed.
[0023]
The synchronous operation between the face plate 9a and the vehicle body 14 refers to an operation in which the forward / backward speed of the face plate 9a and the forward / backward speed of the vehicle body 14 are the same, and the moving directions are opposite to each other. Specifically, when the face plate 9a moves backward at a predetermined speed, the vehicle body 14 moves forward at the same speed as the face plate 9a. When the face plate 9a advances at a predetermined speed, the vehicle body 14 moves the same as the face plate 9a. It refers to the action of retreating at speed. By this synchronous operation, the load can be loaded and unloaded on the fork without moving with respect to the ground. The synchronous operation requires a detecting means for detecting the moving distance or moving speed of the face plate 9a and the moving distance or moving speed of the vehicle body 14, but is omitted in FIG. 2 because it is a well-known technique.
[0024]
In the present invention, the synchronous switch is the changeover switch 32 according to the first aspect. This changeover switch is a switch for switching on / off of the synchronization control means 33b, and is also a switch for turning on / off the tilt control means 33a for stopping the tilt angle at an arbitrary preset angle. That is, the changeover switch 32 has a switching function of turning on the automatic tilt stop function by turning on the synchronous operation function and turning off the automatic tilt stop function by turning off the synchronous operation function. Have. Specifically, the changeover switch 32 turns on the tilt control means 33a by turning on the synchronization control means 33b by the changeover switch 32, and turns off the tilt control means 33a by turning off the synchronization control means 33b by the changeover switch 32. Has the function of performing
The function of stopping the tilt angle at a predetermined angle, that is, the function of automatically stopping the tilt, is achieved by the changeover switch 32, the tilt angle detecting means 30, the tilt operation detecting means 31, the tilt control means 33a, and the tilt driving means 34. When the tilt control means 33a is turned on by the changeover switch 32, the automatic tilt stop function enters a standby state. When the tilt lever 18 is operated in this state, the tilt lever 18 automatically stops at a preset tilt angle. The preset tilt angle is a tilt angle used when the push-pull device 9 is operated, and is an angle inclined forward by a predetermined angle. By setting the forward tilt angle to be an angle at which the loading and unloading of the load can be performed satisfactorily, the push-pull operation without load collapse can be performed.
[0026]
Next, a specific operation method will be described. Here, an operation of pushing out the load placed on the fork 9d by moving the face plate 9a forward will be described as an example. First, the operator presses the changeover switch 32. As a result, the synchronous operation function is turned on, and the tilt automatic stop function is also in the standby state. In this state, the operator tilts the tilt lever 18 forward. As a result, the tilt cylinder 11 is driven, and the fork 9d is tilted forward. The tilt control is performed by the tilt control unit 33a as described above, and when a predetermined tilt angle is reached, the tilt operation is automatically stopped.
[0027]
Next, the operator tilts the push-pull lever 19 forward. The synchronous control means 33b performs a synchronous operation in which the vehicle body moves backward in synchronization with the forward movement of the face plate 9a. That is, the load is pushed out of the fork 9d without changing its position. Since the fork 9d is maintained at the optimum tilt angle by the tilt control means 33a, the unloading can be smoothly performed without collapse of the load.
[0028]
As described above, when the changeover switch 32 is turned on when using the push-pull device, the tilt operation can be stopped at a predetermined tilt angle, and the operator can perform the synchronous operation and the automatic tilt stop operation only by the same switch operation as before. It can be performed.
[0029]
【The invention's effect】
As described above, according to the present invention, the on / off switching of the synchronous operation function and the on / off switching of the automatic tilt function can be simultaneously performed by operating the changeover switch. Thus, it is not necessary to switch on / off the synchronous operation function and on / off of the automatic tilt function by separately provided switches or the like, and each switch can be turned on / off by one switch. It can be carried out. In addition, in the case of performing the synchronous operation, the conventional operation of the switch only for the synchronous operation does not require any special operation for switching the automatically added automatic tilt function on / off. An automatic tilt operation can be added to a push-pull or pusher operation by the same operation as in the related art.
[Brief description of the drawings]
FIG. 1 is a side view of a forklift of the present invention.
FIG. 2 is a control block diagram of the present invention.
[Explanation of symbols]
9 Push-pull device 9d Fork 9a Face plate 11 Tilt cylinder 18 Tilt lever 30 Tilt angle detecting means 31 Tilt operation detecting means 32 Switching switch 33 Control means 33a Tilt control means 33b Synchronous control means 34 Proportional solenoid valve

Claims (2)

In a forklift equipped with a push-pull device or a pusher device having a synchronous operation function of moving the vehicle back and forth in synchronization with the backward movement of the face plate, and a fork tilt function,
The forklift has a function of automatically stopping a tilt operation when a tilt angle of the fork reaches a preset angle,
Switching on / off of the synchronous operation function of the push-pull device or pusher device, and switching on / off of a function of automatically stopping the tilt operation when the tilt angle of the fork reaches a preset angle And a possible changeover switch,
The change-over switch is a switch that turns on the tilt automatic stop function by an operation of turning on the synchronous operation function and turns off the tilt automatic stop function by an operation of turning off the synchronous operation function. A forklift having a function. In a forklift including a synchronous control means for controlling the forward and backward movement of the vehicle body in synchronization with the backward movement of the face plate provided in the push-pull device or the pusher device, and a means for tilting the fork by operating a tilt lever,
The forklift reads a detection value from a tilt operation detection unit that detects an operation amount of a tilt lever and a tilt angle detection unit that detects a tilt angle of a fork, and when the tilt angle becomes a preset angle, the tilt drive unit detects Tilt control means for stopping driving,
A changeover switch capable of switching on / off of the synchronization control means and capable of switching on / off of the tilt control means,
The changeover switch has a function of turning on the tilt control means by turning on the synchronization control means by the changeover switch and turning off the tilt control means by turning off the synchronization control means by the changeover switch. A forklift characterized by the following.

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