JP2004189450A - Pallet locking device of forklift - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pallet locking device capable of solving a problem of forgetting the locking by automatically locking a pallet, sufficiently adaptable to various kinds of pallets of different girder heights, and reliably lockable. <P>SOLUTION: The pallet locking device 21 comprises a lock lever 25 to lock a pallet 24 in cooperation with a fork 2, a cylinder to vertically turn the lock lever, and a transmission mechanism 54 to connect the cylinder 30 to the lock lever 25. A lock checking sensor 62 is disposed at a predetermined position of the transmission mechanism 54, which detects that the lock lever 25 is abutted on a lower deck board 24b of the pallet 24, and the pallet 24 is placed on a shelf or the like. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pallet lock device for locking a pallet inserted into a fork in a forklift.
[0002]
[Prior art]
In an order picking type forklift, which is a type of forklift, a fork and a driver's cab are integrally moved up and down along a mast. In such order picking type forklifts, after inserting a fork into a pallet and transporting it to a predetermined place, the pallet is raised to a predetermined height, and an operator is transferred onto the pallet to load and unload a load. .
[0003]
When carrying out cargo handling work at high altitudes with the cab raised in this way, simply supporting the pallet with a fork will cause the pallet to become unstable, causing the luggage to swing on the pallet and stabilize. It is difficult to carry out cargo handling work. Therefore, in order to prevent the pallet from swinging, a lock lever that presses and locks the pallet inserted into the fork is provided, and the pallet is fixed by operating the lock lever with a manual lever or a foot pedal. Pallet lock devices have been proposed in the following patent documents.
[0004]
[Patent Document 1]
JP-A-11-228085 [Patent Document 2]
JP 2001-316095 A [Patent Document 3]
JP 2002-12397 A [Patent Document 4]
JP 10-291790 A
[Problems to be solved by the invention]
However, in a configuration in which the operator operates a manual lever or a foot pedal that locks each time in order to prevent the pallet from swinging, the locking operation may be forgotten. Not enough. For this reason, the inventor of the present application detects the pallet locking operation, which has been performed by the operator, by the sensor that the pallet has been inserted into the fork, and controls the lock lever to rotate up and down based on the detection output. Thus, an attempt was made to automatically lock the pallet.
[0006]
However, since there are various types of pallets having different beam heights, it is difficult to reliably control the operation of the lock lever for various types of pallets, and the pallets cannot be smoothly locked. There was found.
[0007]
Therefore, the present invention solves the problem of forgetting to lock by automatically locking the pallets, and can sufficiently cope with various pallets having different digit heights as described above, and can securely lock the pallets. It is intended to provide a device.
[0008]
[Means for Solving the Problems]
To achieve the above object, the present invention is configured as follows.
[0009]
The invention according to claim 1 includes a lock lever attached to a base end of a fork and for pressing a lower deck board of a pallet, a cylinder for rotating a tip end of the lock lever up and down, and a cylinder. A transmission mechanism for transmitting a force to the lock lever via an elastic body, and a sensor for detecting a change in the length of the elastic body caused by the lock lever being pushed up from the lower deck board, When the output of the sensor reaches a predetermined value, control means is provided for controlling to stop the operation of the cylinder.
[0010]
According to the above invention, a lock lever for pressing the lower deck board, a cylinder for rotating the tip of the lock lever up and down, and a transmission for transmitting a force between the cylinder and the lock lever via an elastic body. By providing a mechanism and a lock confirmation sensor for detecting a change in the length of the elastic body, the pallet can be locked automatically. Furthermore, a sensor that detects a change in expansion and contraction of the elastic body can cope with various types of pallets having different girder heights and can reliably lock the pallets.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
[0012]
FIG. 1 is a side view showing a lock mechanism of a pallet lock device according to an embodiment of the present invention, FIG. 2 is a side view showing a main structure of the lock mechanism, and FIG. 3 is a view showing a main structure of the lock mechanism. FIG. 4 is a block diagram showing a configuration of a lock mechanism control system of the pallet lock device. FIG. 6 is an overall configuration diagram of an order picking type forklift according to the embodiment.
[0013]
In the forklift shown in FIG. 6, a cab 3 including a pair of forks 2 is provided so as to be able to move up and down along a mast 4. An operation panel 9 provided on the driver's cab 3 includes an elevating operation unit 10, an accelerator lever 11, instruments, a steering handle 12, and the like.
[0014]
1 and 7, the forklift 1 is provided with a pallet lock device 21. The pallet lock device 21 includes a lock mechanism 52 that mechanically locks the pallet 24 in cooperation with the fork 2 and a lock mechanism controller 23 that includes a microcomputer or the like that controls the operation of the lock mechanism 52. Prepare.
[0015]
The lock mechanism 52 includes a pair of lock levers 25 protruding from the pedestal 13 of the driver's cab 3 along the fork 2. Projecting upward. The base end of the lock lever 25 is fixed to a bracket 26, and the bracket 26 is supported by a support shaft 27 so as to be rotatable up and down.
[0016]
On the other hand, a cylinder 30 is disposed in the pedestal 13 of the cab 3 along the longitudinal direction of the vehicle body, and only at the rear end of the cylinder 30 is a contraction detection sensor 32 for detecting contraction of the cylinder 30 provided. It is arranged. Further, a transmission mechanism 54 for connecting the cylinder 30 and the lock lever 25 constituting the lock mechanism 52 is provided between the cylinder 30 and the lock lever 25.
[0017]
In the transmission mechanism 54, one end of a link member 55 is rotatably connected to the distal end of the rod of the cylinder 30 via the support shaft 34, and the other end of the link member 55 is fixed to the pedestal 13. The support shaft 37 is rotatably supported up and down. One end of a shaft body 56 that moves forward and backward in conjunction with the cylinder 30 is connected to a substantially central portion of the link member 55 by a support shaft 39 so as to be vertically rotatable. Further, as shown in FIGS. 2 and 3, a connecting block 57 having a U-shape in plan view is provided at the other end of the shaft body 56. That is, the shaft body 56 is inserted through the base end portion 57a of the connecting block 57 so as to be able to advance and retreat, and a fastener 58 such as a lock nut is fixed to the inserted front end portion. The portion serves as a stopper that does not come off from the base end portion 57a of the connection block 57.
[0018]
A coil spring 59, which is an elastic body, is attached between the base end portion 57a of the connection block 57 and the spring receiver 60 integrally fixed to the shaft body 56 so as to be fitted on the shaft body 56. The base end 57a of the connection block 57 is pressed and urged toward the fastener 58 at the distal end of the shaft body 56 by the coil spring 59. Further, the connection block 57 supports the connection plate 40 via a support shaft 41 so as to be rotatable up and down. The connection plate 40 is connected to the bracket 26 to which the lock lever 25 is attached.
[0019]
Further, a lock confirmation sensor 62 composed of a potentiometer or the like is mounted on the outer surface of the connection block 57 via a bracket 63, while a distal end portion of the shaft body 56 through which a base end portion 57a of the connection block 57 is inserted is provided. A detection plate 65 for transmitting the movement of the distal end position of the shaft body 56 to the lock confirmation sensor 62 is provided.
[0020]
That is, the detection plate 65 is fixedly supported at one end by a fastener 58 fixed to the distal end of the shaft body 56, and is fitted to the rotatable detection bar 62 a of the lock confirmation sensor 62 at the other end. ing. Then, in accordance with the first and second two rotation angle positions X and Y of the detection bar 62a, the lock confirmation sensor 62 detects the respective rotation angle positions X and Y by a change in resistance or the like. It has become.
[0021]
The lock confirmation sensor 62 is not limited to a potentiometer, but may be a limit switch, a magnetic sensor, or the like.
[0022]
Further, as shown in FIG. 5, the pallet lock device 21 includes a magnet 44 attached to the back of the bracket 26 to which the lock lever 25 is fixed, and a pallet detection sensor 45 attached to the pedestal 13.
[0023]
The pallet detection sensor 45 detects that the fork 2 has been inserted into the spar of the pallet 24. The pallet detection sensor 45 is ON when the lock lever 25 is in a horizontal state. It has a function of turning off when 25 is in an inclined state.
[0024]
Then, as shown in FIG. 4, the output of the pallet detection sensor 45 is input to the lock mechanism control unit 23 together with the outputs of the above-described contraction detection sensor 32 and lock confirmation sensor 62.
[0025]
Next, the lock operation and the unlock operation of the pallet 24 by the pallet lock device 21 will be described. The lock mechanism of the pallet lock device will be described with reference to FIG.
[0026]
First, when the cylinder 30 is retracted, the shaft body 56 is drawn toward the link member 55, so that the lock lever 25 is in a horizontal state as shown in FIG. At this time, the pallet detection sensor 45 is on because it faces the magnet 44.
[0027]
When the fork 2 is inserted into the spar of the pallet 24 from this state, as shown in FIG. 5B, the tip of the lock lever 25 contacts the upper deck board 24a of the pallet 24, and the insertion amount of the fork 2 , The lock lever 25 gradually inclines downward.
[0028]
When the magnet 44 is displaced from the position facing the pallet detection sensor 45 with the rotation of the lock lever 25, the output from the pallet detection sensor 45 is turned off. Turns the motor 31 forward to extend the rod of the cylinder 30.
[0029]
When the rod of the cylinder 30 is extended, the connection block 57 is pushed by the link member 55 via the coil spring 59 externally fitted to the shaft body 56, so that the bracket 26 and the lock lever 25 are turned downward via the connection plate 40. Move.
[0030]
Then, as shown in FIG. 5C, when the lock lever 25 abuts on the lower deck board 24b of the pallet 24, the downward rotation of the lock lever 25 is prevented by the lower deck board 24b of the pallet 24.
[0031]
As a result, the connection block 57 connected to the lock lever 25 via the connection plate 40 and the support shaft 41 stops moving forward despite being pushed by the link member 55 and the coil spring 59.
[0032]
When the cylinder 30 continues to be extended as it is, as shown in FIG. 3B, only the shaft body 56 moves forward while retracting the coil spring 59 while the connecting block 57 remains stopped at the lock position, The distal end portion of the shaft body 56 projects from the base end portion 57a of the connection block 57 toward the lock lever 25 side.
[0033]
When the detection plate 65 attached to the front end of the shaft body 56 rotates the detection bar 62a of the lock confirmation sensor 62 to the first rotation angle position X by the advance of the front end of the shaft body 56, Since the lock confirmation sensor 62 detects the first angular position X, the lock mechanism control unit 53 stops the forward rotation of the motor 31 in response thereto.
[0034]
Therefore, the upper deck board 24a and the lower deck board 24b in the spar of the pallet 24 are pushed and expanded by the lock lever 25 and the fork 2 having an increased separation distance, and the pallet 24 is in the locked state. Become.
[0035]
Thus, after the cylinder 30 is extended and the lock lever 25 contacts the lower deck board 24b of the pallet 24, the cylinder 30 is extended until the first rotation angle position X is detected by the lock confirmation sensor 62. Therefore, it is possible to reliably lock various types of pallets 24 having different heights.
[0036]
Subsequently, after the pallet 24 is locked, cargo handling operations such as transportation and loading / unloading of the luggage are performed. Then, as shown in FIG. When the pallet 24 is placed on the pallet 47, the fork 2 is lowered away from the upper deck board 24 a of the pallet 24, and accordingly, the support shaft 27 of the lock lever 25 supported by the pedestal 13 of the cab 3 is also moved. It descends with the fork 2. Then, the lock lever 25 pivots upward, and the connecting plate 57 is moved backward by the connecting plate 40 while retracting the coil spring 59, so that as shown in FIG. The portion further advances from the base end portion 57a of the connection block 57 toward the lock lever 25 side.
[0037]
As a result, the detection plate 65 supported by the distal end of the shaft body 56 rotates the detection bar 62a of the lock confirmation sensor 62 to the second rotation angle position Y. The angular position Y is detected. In response, the lock mechanism control unit 23 reversely rotates the motor 31 to retract the rod of the cylinder 30.
[0038]
Then, as the rod of the cylinder 30 is retracted, the shaft body 56 is drawn toward the link member 55, so that the bracket 26 and the lock lever 25 are rotated upward, and as a result, as shown in FIG. As shown, the lock lever 25 returns to the horizontal state. Then, since the contraction of the cylinder 30 is detected by the contraction detection sensor 32, the lock mechanism control unit 23 stops the motor 31 in response thereto.
[0039]
In the above-described embodiment, the order picking type forklift has been described as an example.However, the present invention is applicable to other counterbalance type or reach type forklifts for the purpose of preventing load collapse due to pallet swing. Can also be applied
Further, in the above-described embodiment, the case where the cylinder 30 is driven by electric power is described. However, the driving method of the cylinder 30 is not limited to electric power, and may be a hydraulic type or the like.
[0041]
【The invention's effect】
A pallet lock device according to the present invention includes a lock lever for pressing a lower deck board, a cylinder for rotating the tip of the lock lever up and down, and a force between the cylinder and the lock lever via an elastic body. By providing a transmission mechanism for transmitting and a sensor for detecting a change in the length of the elastic body, the pallet can be automatically locked, so that the pallet can be locked without forgetting to be locked. The pallet can be locked and swinging of the pallet can be reliably prevented. Further, a sensor that detects a change in expansion and contraction of the elastic body can cope with various types of pallets having different beam heights, so that the pallets can be reliably locked.
[Brief description of the drawings]
FIG. 1 is a side view showing a lock mechanism in a pallet lock device of a forklift according to an embodiment of the present invention.
FIG. 2 is a side view showing a main part of the lock mechanism of FIG. 1;
FIG. 3 is a plan view showing a main part of a lock mechanism of FIG. 1;
FIG. 4 is a block diagram showing a configuration of a lock mechanism control system of the pallet lock device according to the embodiment of the present invention.
FIG. 5 is an explanatory view showing a pallet locking operation and a pallet unlocking operation by the pallet locking device according to the embodiment of the present invention.
FIG. 6 is a perspective view showing the overall configuration of an order picking type forklift.
[Explanation of symbols]
1 Forklift 21 Pallet lock device 23 Lock mechanism control unit 24 Pallet 25 Lock lever 30 Cylinder 32 Retraction detection sensor 45 Pallet detection sensor 52 Lock mechanism unit 54 Transmission mechanism 56 Shaft 57 Connection block 62 Lock confirmation sensor 65 Detection plate (detected object) )

Claims (1)

A lock lever attached to the base end of the fork and pressing the lower deck board of the pallet; a cylinder for rotating the tip of the lock lever up and down; and an elastic body from the cylinder to the lock lever. And a sensor that detects a change in expansion and contraction of the length of the elastic body caused by the lock lever being pushed up from the lower deck board, and the output of the sensor is set to a predetermined value. A pallet lock device for a forklift, comprising control means for controlling the operation of the cylinder to be stopped when the pallet reaches.

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