JP3827293B2 - Forklift pallet lock device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pallet locking device for a forklift that locks a pallet lifted by a fork so that it is not accidentally displaced on the pallet during transportation.
[0002]
[Prior art]
FIG. 18 shows an example of a conventional forklift. This includes a vehicle body 1 having a drive tire 1a and a caster tire 1b, and a straddle leg 1A with a pair of left and right road wheels 1c protruding forward from the front lower end of the vehicle body 1, and a pair of left and right outer masts 2 By engaging the wheel 3 provided at the lower end with a guide groove 4 formed on the inner surface of each straddle leg 1A, each outer mast 2 is formed to be movable in the front-rear directions a and b. A lift bracket 6 is arranged to be movable up and down on a pair of left and right inner masts 5 engaged so as to be movable up and down, and a lift cylinder 7 for raising and lowering both the inner mast 5 and the lift bracket 6 is arranged along the masts 2 and 5. The pivot frame 9 is rotatably supported by the lift bracket 6 via the support shaft 8, and a pair of left and right forks 10 disposed on the front surface of the pivot frame 9 is provided in front. A tilt device 11, which is supported by the support shaft 8 so as to be able to rotate and tilts both forks 10 in the vertical directions c and d via a tilt bar 9 a installed on the rotation frame 9, is attached to the lift bracket 6. Is provided.
[0003]
In the above configuration, when carrying out the cargo handling work, the fork 10 is lowered (see the two-dot chain line in FIG. 18), and the masts 2 and 5 are moved forward a to move the tip of the fork 10 in a horizontal state. The load W is lifted through the pallet P by inserting it into the hole Pa of the pallet P (see the dashed line in FIG. 18) and raising the fork 10. Thereafter, the tilt device 11 is driven to tilt the fork 10 upward c, so that the load W is tilted toward the backrest 9b of the rotating frame 9 and the vehicle body 1 is moved to bring the load W to a predetermined position. It is designed to be transported.
[0004]
[Problems to be solved by the invention]
In the above-described conventional configuration, when the fork 10 lifts and transports the load W via the pallet P, the transport operation is performed in a place where condensation is likely to occur on the pallet P, such as in a freezer, or a composition with a small friction coefficient. When the resin pallet P is used, the pallet P may slide on the fork 10 and shift its position, resulting in load collapse.
[0005]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described conventional drawbacks, and an object of the present invention is to provide a pallet locking device for a forklift that locks a pallet lifted by a fork so as not to be displaced unexpectedly.
[0006]
[Means for Solving the Problems]
To achieve the above object, as a first invention, in a forklift having a mast erected on a vehicle body, a lift bracket that is raised and lowered along the mast, and a fork supported by the lift bracket, A forklift pallet locking device is provided, wherein the lift bracket is provided with locking means for locking a pallet that is operated by hydraulic pressure and inserted into the fork.
[0007]
According to the first aspect of the present invention, the locking means for locking the pallet inserted into the fork is provided in the lift bracket. Therefore, the locking means can be provided at an appropriate position near the fork, and the lift bracket. Always moves up and down along the mast together with the fork, so that the relative positional relationship between the locking means and the fork does not change, and therefore a pallet locking device that can securely perform the pallet locking operation can be realized. . In addition, the locking means is not operated by an operator's manual operation such as lever operation or pedal operation, but is operated by electricity or hydraulic pressure, so this is installed on a lift bracket far from the driver's seat. It became possible to operate it reliably.
[0008]
Also As the first invention The lock means comprises a lock bar that presses the pallet inserted into the fork and a drive mechanism for operating the lock bar, and the drive mechanism is disposed below the lift bracket. A pallet locking device for a forklift is provided.
[0009]
this 1st invention According to the above, since the drive mechanism for operating the lock bar is disposed below the lift bracket, the position of the drive mechanism approaches the fork, and therefore the lock bar and the drive press the pallet inserted into the fork. The mechanical connection with the mechanism can be easily configured. The lock bar may be singular or plural, and may be rod-shaped or bowl-shaped. The rod shape is convenient for press contact with the pallet, and the hook shape is convenient for engaging with the unevenness or hole of the pallet. The drive mechanism means a motor, a solenoid, a cylinder, and an accessory device that are mechanically operated by electricity or hydraulic pressure, and does not mean a lever that is manually operated by an operator, a wire connected thereto, or the like. . this 1st invention In this case, the drive mechanism is disposed below the lift bracket means that the drive mechanism is not disposed at the top or the center of the lift bracket but at a position closer to the lower side thereof. Therefore, it is also included that it is disposed lower than the lower end of the lift bracket.
[0010]
Also As a second invention, in the first invention, A forklift pallet locking device is provided, wherein the drive mechanism includes a hydraulic or electric cylinder device.
[0011]
this Second invention According to this, in operating the lock bar, the drive mechanism can be configured relatively simply. Particularly in a forklift having a structure in which the fork tilts with respect to the lift bracket, a hydraulic tilt cylinder for tilting the fork is often provided in the vicinity of the fork. Since the hydraulic cylinder for driving the lock bar can be configured by using this, the drive mechanism can be configured very easily.
[0012]
Also As a third invention, in the first or second invention, A forklift pallet locking device is provided in which both the fork and the lock bar are adjustable in the lateral direction of the vehicle body.
[0013]
this Third invention According to the above, forks can be securely inserted into pallets of different sizes and various pallets with different hole positions, and the pallet pressing lock bar can be adjusted freely to interfere with the pallets. Can be avoided, and a stable pallet locking action can be achieved by setting the optimum position.
[0014]
Also As a fourth invention, in the above first to third inventions The lock bar is disposed between the forks and is inserted into the hole of the pallet together with the fork, and is moved up and down by the drive mechanism to press the lower deck board of the pallet from the inside of the pallet. A forklift pallet locking device is provided.
[0015]
this 4th invention According to the present invention, in a pallet having deck boards on both the upper and lower sides, the pallet is securely pressed by pressing the upper deck board of the pallet from below with a fork and the lower deck board of the pallet from above with a lock bar. Can be slippery. In this case, since the lock bar is inserted into the hole of the pallet, there is no obstacle to placing the load on the pallet, and the load can be loaded up to the full pallet.
[0016]
Also As a fifth invention, in the first to fourth inventions described above, A forklift pallet locking device is provided, wherein the drive mechanism is operated by a switch provided in a driver seat of the forklift.
[0017]
this 5th invention According to the above, since the drive mechanism is operated by electricity or hydraulic pressure and a switch for operating the drive mechanism is provided in the driver's seat of the forklift, the operator can arbitrarily perform the pallet locking operation. In this case, as a matter of course, an electric wiring is appropriately provided between the driving mechanism and the switch in the case of an electric type, and a hose for supplying pressure oil in the case of a hydraulic type.
[0018]
As a sixth invention, in the above first to fourth inventions A pallet locking device for a forklift, wherein a lift height detection sensor for detecting that the fork has reached a predetermined lift height is provided, and the drive mechanism is operated according to an output of the lift height sensor. I will provide a.
[0019]
this 6th invention According to the above, when the fork is inserted into the pallet and lifted up to a predetermined height, the lift detection sensor is turned on and an operation signal is output to the drive mechanism, and the lock bar locks the pallet. Therefore, the pallet is automatically locked without the operator performing a switch operation or the like. Forklifts run and turn with the pallet lifted, so by setting the height at which the lift detection sensor is turned ON appropriately, the pallet is always locked during running and turning. Slip of the pallet on the fork is reliably prevented. The lift detection sensor can be composed of a limit switch or the like, which is fixed to either the mast or the lift bracket, and the dog that contacts the limit switch and turns it on is fixed to the other side. Just keep it. The height at which the above-described lift height detection sensor is turned on can be freely set by appropriately determining the heights of these limit switches and dogs.
[0020]
Also As a seventh invention, in the above first to fourth inventions A forklift pallet locking device is provided, wherein a vehicle speed detection sensor for detecting that the forklift has reached a predetermined vehicle speed is provided, and the drive mechanism is operated in accordance with an output of the vehicle speed detection sensor. To do.
[0021]
this 7th invention According to the above, when the pallet reaches a vehicle speed at which the pallet slips on the fork, the vehicle speed detection sensor is turned on and an operation signal is output to the drive mechanism, whereby the pallet is automatically locked. The vehicle speed detection sensor can be easily configured by providing a rotation speed detection sensor on a traveling wheel of a forklift or a driving motor.
[0022]
Also As an eighth invention, in the above first to fourth inventions A pallet for a forklift characterized in that a tilt angle detection sensor for detecting that the fork has reached a predetermined tilt angle is provided, and the drive mechanism operates in accordance with the output of the tilt angle detection sensor. A locking device is provided.
[0023]
this Eighth invention According to the above, after the fork is inserted into the pallet, the tilt angle detection sensor is turned on and the drive is performed at a stage where the fork tip side is tilted by a predetermined angle so as to turn upward by a tilt device provided on the forklift. An actuation signal is output to the mechanism, which automatically locks the pallet. Forklifts normally run and turn with the pallet tilted as described above. By setting the angle at which the tilt angle detection sensor is turned on appropriately, the pallet is always locked during running and turning. Therefore, the slip of the pallet on the fork is surely prevented. The tilt angle detection sensor is provided between the vehicle body and the mast when the mast is tilted with respect to the vehicle body, and with the lift bracket and the fork when the fork is tilted with respect to the lift bracket. Between each of them can be easily configured by providing an appropriate sensor or switch.
[0024]
Also As a ninth invention, in the above first to fourth inventions A forklift pallet locking device is provided, characterized in that a turning state detection sensor for detecting the turning state of the vehicle body is provided, and the drive mechanism operates in accordance with the output of the turning state detection sensor.
[0025]
this Ninth invention Therefore, when the pallet is most slippery on the fork, that is, when the vehicle body is turning, the turning state detection sensor is turned on and an operation signal is output to the drive mechanism, so that the pallet is automatically locked. Slip of the pallet above is reliably prevented. The turning state detection sensor must operate the drive mechanism when turning the vehicle body.To determine the turning state that produces this output, the steering wheel angle, vehicle speed, vehicle body acceleration, Various elements such as an acting centrifugal force may be detected and used, or these elements may be combined to be judged comprehensively by a computer.
[0026]
Also As a tenth invention, in the first to fourth inventions described above, The forklift is a reach type forklift in which the mast is supported so as to be movable in the front-rear direction of the vehicle body, and is provided with a reach sensor for detecting the back-and-forth movement of the mast, and the drive mechanism outputs the reach sensor A pallet locking device for a forklift is provided which operates according to the above.
[0027]
this 10th invention When the forklift is a reach-type forklift that is supported so that the mast can move in the longitudinal direction of the vehicle body, the reach sensor detects the forward and backward movement of the mast and outputs an operation signal to the drive mechanism. Will automatically lock the pallet. Reach-type forklifts normally run and turn with the mast pulled toward the vehicle body, that is, with the reach in, so whether or not the vehicle is in a state where it can run and turn by providing the reach sensor. Therefore, the phenomenon that the pallet slips on the fork can be prevented. Since the reach sensor only needs to detect the position movement of the mast in the front-rear direction, it can be easily configured by providing a sensor for detecting the front-rear position of the mast or a member moving integrally with the mast at an appropriate position. can do.
[0028]
Also As an eleventh invention, in the first to tenth inventions, A forklift pallet locking device is provided, wherein a surface of the lock bar contacting the pallet is subjected to a treatment for increasing a frictional force against the pallet.
[0029]
this Eleventh invention According to this, the frictional engagement force between the lock bar and the pallet is increased, and the slippage of the pallet on the fork can be further effectively suppressed. Here, the process for increasing the frictional force refers to a process such as forming irregularities on the lock bar or sticking rubber or a flexible resin.
[0030]
Also As a twelfth invention, in the first to eleventh inventions, A forklift pallet locking device is provided, wherein the lock bar includes an elastic member.
[0031]
this 12th invention Accordingly, since the lock bar includes the elastic member, the pallet can be pressed using the elastic force of the elastic member, and the pallet can be locked with an appropriate force.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a pallet locking device for a reach-type forklift according to a first embodiment of the present invention. Locking means R for locking a pallet P inserted into a fork 10 is provided on a lift bracket 6. Yes. Since the configuration other than the above is substantially the same as the configuration shown in FIG.
[0033]
As shown in FIGS. 2 to 5, the locking means R includes a pair of left and right suspension plates 14 suspended between the forks 10 so as to be pivotable in the vertical directions c and d between the forks 10. It has a drive mechanism 12 composed of a hydraulic or electric cylinder device such as a hydraulic cylinder or an electric cylinder fixed to the lower part of the rear surface of the suspension plate 14, and a lock bar 13. The lock bar 13 has a longitudinal direction a, a bar body 13a made of a square steel material extending to b, and a rising portion 13b extending upward from the base end of the bar body 13a. When the piston rod 12a is in the contracted state, the bar main body 13a is substantially horizontal and its lower surface 13A is positioned flush with or slightly above the lower surface 10a of the fork 10. .
[0034]
In FIGS. 2 and 4, reference numeral 17 denotes a support beam installed on the upper end of the lift bracket 6, and the support shaft 8 is rotatably supported by bearings 18 fixed to both ends and the center of the support beam 17. Reference numeral 19 denotes a positioning pin that engages with the upper end recess of each fork 10 and each suspension plate 14 through a through hole 20 provided in the support beam 17. Reference numerals 21a and 21b are guide rollers rotatably provided on both side surfaces of the lift bracket 6. The guide rollers 21a and 21b are in contact with the inner side surface and the bottom surface of each inner mast 5 to support the lift bracket 6 so as to be movable up and down.
[0035]
As shown in FIG. 6, a tumbler switch 22 for extending and retracting the drive mechanism 12 is provided in the driver's seat 1B of the vehicle body 1, and the switch 22 is rotated from the neutral position O to the front and rear e and f. Thus, the piston rod 12a of the drive mechanism 12 is extended or contracted, and the operator can operate the switch 22 from the driver's seat 1B to arbitrarily lock the pallet P. In this case, it is assumed that an electric wiring is provided between the driving mechanism 12 and the switch 22 when the driving mechanism is an electric type, and a hydraulic oil supply hose or the like is provided when the driving mechanism is a hydraulic type.
[0036]
In the above configuration, when carrying out the cargo handling operation, the fork 10 is lowered (see the two-dot chain line in FIG. 1), and the masts 2 and 5 are moved forward a to move the tip of the fork 10 in a horizontal state. It inserts in the hole Pa of the pallet P (refer the dashed-dotted line of FIG. 1). In this case, since the tip of the fork 10 and the lock bar 13 are at substantially the same horizontal level, the fork 10 and the lock bar 13 can be easily inserted into the hole Pa of the pallet P (see FIG. 4).
[0037]
Next, the fork 10 is lifted to lift the load W through the pallet P, and the tilt device 11 is driven to tilt the fork 10 upward c so that the load W is moved to the backrest 9b side of the rotating frame 9. Tilt to. At substantially the same time, the switch 22 is operated to drive the drive mechanism 12, thereby extending the piston rod 12a. As a result, the lock bar 13 is pressed against the lower deck board P2 of the pallet P to lock the pallet P (see FIG. 5). Subsequently, by traveling the vehicle body 1, the load W is conveyed to a predetermined position.
[0038]
According to the above configuration, the locking means R for locking the pallet P inserted into the fork 10 is provided in the lift bracket 6, so that the locking means R can be provided at an appropriate position in the vicinity of the fork 10, Since the lift bracket 6 always moves up and down along the masts 2 and 5 together with the fork 10, the relative positional relationship between the locking means R and the fork 10 does not change, and therefore the locking operation of the pallet P is surely performed. Can be realized. Further, since the locking means R is not operated by manual operation of the operator such as lever operation or pedal operation, but is operated by the switch 22, it is ensured that it is far from the lift bracket 6 from the driver seat 1B. It became possible to operate.
[0039]
Further, the drive mechanism 12 for operating the lock bar 13 is disposed below the lift bracket 6, and therefore the position of the drive mechanism 12 approaches the fork 10, and thus the pallet P inserted into the fork 10. It is possible to easily configure the mechanical connection between the lock bar 13 that presses and the drive mechanism 12.
[0040]
When the lock bar 13 is operated, the drive mechanism 12 may be electric or hydraulic as described above, but a hydraulic tilt device 11 for tilting the fork 10 is already provided in the vicinity of the fork 10. In this case, a hydraulic cylinder for driving the lock bar can be configured by using the pressure oil for the tilt device 11.
[0041]
Further, by pressing the upper deck board P1 of the pallet P from below with the fork 10 and the lower deck board P2 of the pallet P from above with the lock bar 13 (see FIG. 5), the pallet P can be securely attached. Can be slippery. In this way, since the lock bar 13 is inserted into the hole Pa of the pallet P, there is nothing in the way of placing the load W on the pallet P, and the load W is loaded until the pallet P is full. can do.
[0042]
As shown in FIG. 2, a plurality of through holes 20 are provided in the support beam 17 of the lift bracket 6 at a predetermined interval k, and the positioning pins 19 are inserted into the forks 10 through the appropriate through holes 20. By engaging with the upper end recesses of the respective suspension plates 14, the distance α between the lock bars 13 and the distance β between the forks 10 can be adjusted along the left-right direction of the vehicle body.
[0043]
In this way, the fork 10 can be surely inserted into the pallets P having different sizes and various pallets P having different positions of the holes Pa, and the lock bar 13 for pressing the pallet can be freely positioned. By adjusting, interference with the pallet P can be avoided, and by setting the optimum position, a stable pallet locking action can be always achieved.
[0044]
As shown in FIG. 7, an anti-slip recess (or projection) 23 is formed on the lower surface 13A of the bar main body 13a of the lock bar 13, or as shown in FIG. It is preferable to attach a friction mat 24 having a large friction coefficient such as a simple resin.
[0045]
In this way, the frictional engagement force between the lock bar 13 and the pallet P is increased, and the slip of the pallet P on the fork 10 can be further effectively suppressed.
[0046]
9 to 12 show a pallet locking device according to a second embodiment of the present invention, in which a cylindrical protruding portion 25a is projected from the end surface of the rising portion 13b of each lock bar 13, By fitting the annular ring 25b to the protrusion 25a through the base end of the bar main body 13a made of a coil spring (elastic member), the base end of the bar main body 13a made of the coil spring is integrated with the rising portion 13b. It is connected. Since the configuration other than the above is substantially the same as that of the first embodiment shown in FIGS. 1 to 4, the same parts are denoted by the same reference numerals and the description thereof is omitted.
[0047]
According to the second embodiment described above, as shown in FIG. 12, when the tilt device 11 is driven and the fork 10 is tilted upward c, each drive mechanism 12 is driven to extend the piston rod 12a. Thus, the lower deck board P2 of the pallet P can be pressed by using the elastic force of the coil spring bar body 13a of each lock bar 13, and the pallet can be locked with an appropriate force.
[0048]
In the first embodiment, the drive mechanism 12 is operated by the switch 22, but the present invention is not limited to this, and the elevation detection sensor 27 shown in FIG. 13 may be used instead of the switch 22. . The lift height detection sensor 27 includes a magnetic sensor body 27a fixed to one outer mast 2, and a magnet 27b fixed to the lift bracket 6 (or the tilt bar 9a) in the lowest position facing the sensor body 27a. When the fork 10 is lowered, the magnet 27b is opposed to the sensor body 27a (see the solid line in FIG. 13B), and the fork 10 is inserted into the hole Pa of the pallet P from this state. Thereafter, when the lift bracket 6 and the tilt bar 9a are raised and the pallet P is lifted by the fork 10, the magnet 27b moves upward and is separated from the sensor body 27a, and the CPU is based on the output from the sensor body 27a due to the separation. The drive mechanism 12 is actuated by a control unit (not shown) comprising the piston rod 12 A is extended. As a result, the lock bar 13 is pressed against the lower deck board P2 of the pallet P to lock the pallet P (see FIG. 5).
[0049]
In this way, when the fork 10 is inserted into the pallet P and lifted up to a predetermined height, the lift height detection sensor 27 is turned on and an operation signal is output to the drive mechanism 12, and the lock bar 13 causes the pallet P to move. Lock it. Therefore, the pallet P is automatically locked without the operator performing a switch operation or the like.
[0050]
In place of the switch 22, a vehicle speed detection sensor 28 shown in FIG. 14 may be used. The vehicle speed detection sensor 28 is a sensor main body 28a composed of a proximity switch or the like provided on the upper surface of the drive motor 29 so as to face the rotary plate 30 such as a disc brake plate fixed to the rotary shaft 29a of the drive motor 29 that drives the drive tire 1a. And a gear 28b fixed to the rotary shaft 29a so as to face the sensor main body 28a, and when the vehicle body 1 travels for cargo handling work, the rotation pulse of the drive motor 29 is read by the sensor main body 28a, and the sensor A vehicle speed is detected by a control unit (not shown) composed of a CPU based on the output from the main body 28a. When the detected vehicle speed reaches a certain level or more, the drive mechanism 12 is activated to extend the piston rod 12a. As a result, the lock bar 13 is pressed against the lower deck board P2 of the pallet P to lock the pallet P (see FIG. 5).
[0051]
According to the above configuration, when the pallet P reaches a vehicle speed at which the pallet P slips on the fork 10, the vehicle speed detection sensor 28 is turned on and an operation signal is output to the drive mechanism 12. Is locked. The vehicle speed detection sensor 28 can be easily configured by providing a rotation speed detection sensor in the drive tire (traveling wheel) 1a of the forklift or the drive motor 29 for driving.
[0052]
Further, a tilt angle detection sensor 31 shown in FIG. The tilt angle detection sensor 31 includes a magnetic sensor main body 31a fixed to the lift bracket 6 and a magnet 31b fixed to a protruding plate 32 protruding from the tilt bar 9a so as to face the sensor main body 31a. Is tilted downward d or leveled, the magnet 31b is close to the sensor body 31a (see the solid line in FIG. 15A). From this state, the fork 10 is moved by the tilt device 11 via the tilt bar 9a. When tilted upward c, the magnet 31b also moves upward c and is separated from the sensor main body 31a (see the solid line in FIG. 15B), and a control unit (CPU) based on the output from the sensor main body 31a due to the separation. The drive mechanism 12 is actuated by (not shown) to extend the piston rod 12a. As a result, the lock bar 13 is pressed against the lower deck board P2 of the pallet P to lock the pallet P (see FIG. 5).
[0053]
According to the above configuration, after the fork 10 is inserted into the pallet P, the tilt angle is adjusted when the tilt device 11 provided on the forklift is tilted by a predetermined angle so that the rear side of the vehicle body, that is, the front end side of the fork 10 is raised. The detection sensor 31 is turned on and an operation signal is output to the drive mechanism 12, whereby the pallet P is automatically locked.
[0054]
Further, instead of the switch 22, a turning state detection sensor 33 shown in FIG. 16 may be used. The turning state detection sensor 33 includes a sensor main body 33a including a proximity switch that is fixed to the vehicle body 1 in close proximity to the large gear 35 fixed to the support frame 34 of the drive tire 1a, and a large gear that faces the sensor main body 33a. When the drive tire 1a is moved straight along the front-rear directions a and b, the magnet 33b is engaged with the large gear 35 and the small gear 36 interlocked with the handle. Is opposed to the sensor body 33a (see the solid line in FIG. 16 (b)). From this state, the vehicle body 1 is moved forward a, and the fork 10 is inserted into the hole Pa of the pallet P. The lift bracket 6 and the tilt bar 9a is raised and the pallet P is lifted by the fork 10, then the vehicle body 1 is moved backward b and the handle is turned to the right or left. When the direction of the drive tire 1a is switched to the left or right by rotating the large gear 35 via the small gear 36, the magnet 33b is separated from the sensor body 27a (see FIG. 16 (b) phantom line), The drive mechanism 12 is actuated by a controller (not shown) composed of a CPU based on the output from the sensor body 33a due to the separation, and the piston rod 12a is extended. As a result, the lock bar 13 is pressed against the lower deck board P2 of the pallet P to lock the pallet P (see FIG. 5).
[0055]
According to the above configuration, the pallet P is in the most slippery state on the fork 10, that is, when the vehicle body 1 is turning, the turning state detection sensor 33 is turned on and an operation signal is output to the drive mechanism 12, thereby automatically palletizing. Since P is locked, slipping of the pallet P on the fork 10 is reliably prevented.
[0056]
Instead of the switch 22, a reach sensor 37 shown in FIG. The reach sensor 37 includes a magnetic sensor body 37a fixed to one outer mast 2 (or straddle leg 1A), and a magnet 37b fixed to the straddle leg 1A (or outer mast 2) opposite to the sensor body 37a. The masts 2 and 5 are moved forward a while the fork 10 is lowered, and the fork 10 is inserted into the hole Pa of the pallet P, whereby the magnet 37b is separated from the sensor body 37a. Based on the output from 37a, the drive mechanism 12 is actuated by a control unit (not shown) comprising a CPU, and the piston rod 12a is extended. As a result, the lock bar 13 is pressed against the lower deck board P2 of the pallet P to lock the pallet P (see FIG. 5).
[0057]
According to the above configuration, when the forklift is a reach type forklift in which the masts 2 and 5 are supported so as to be movable in the longitudinal directions a and b of the vehicle body 1, the reach sensor 37 detects the longitudinal movement of the masts 2 and 5. Then, an operation signal is output to the drive mechanism 12, and the pallet P is automatically locked thereby.
[0058]
In the first and second embodiments, the case where two lock bars 13 are provided has been described as an example. However, only one lock bar 13 or three or more lock bars 13 may be provided. Although a rod-shaped body is shown as the main body 13a, it may be a bowl-shaped body. In the case of a rod shape, it is convenient to press contact with the pallet P, and in the case of a bowl shape, it is convenient to engage with the unevenness or hole of the pallet P. Furthermore, the reach type forklift has been described as an example, but the present invention is not limited to this, and can be applied to various forklifts.
[0059]
【The invention's effect】
According to the first invention, since the lift bracket is provided with the lock means for locking the pallet inserted into the fork, the lock means can be provided at an appropriate position near the fork. Since it always moves up and down along the mast together with the fork, the relative positional relationship between the locking means and the fork is not changed, and therefore a pallet locking device capable of reliably performing the pallet locking operation can be realized. In addition, the locking means is not operated by an operator's manual operation such as lever operation or pedal operation, but is operated by electricity or hydraulic pressure, so this is installed on a lift bracket far from the driver's seat. It became possible to operate it reliably.
[0060]
The first invention According to the above, since the drive mechanism for operating the lock bar is disposed below the lift bracket, the position of the drive mechanism approaches the fork, and therefore the lock bar and the drive press the pallet inserted into the fork. The mechanical connection with the mechanism can be easily configured.
[0061]
Second invention According to this, in operating the lock bar, the drive mechanism can be configured relatively simply. When a hydraulic tilt cylinder for tilting the fork is provided in the vicinity of the fork, a hydraulic cylinder for driving the lock bar can be configured using the pressure oil for the tilt cylinder. The drive mechanism can be configured very easily.
[0062]
Third invention According to the above, forks can be securely inserted into pallets of different sizes and various pallets with different hole positions, and the pallet pressing lock bar can be adjusted freely to interfere with the pallets. Can be avoided, and a stable pallet locking action can be achieved by setting the optimum position.
[0063]
4th invention According to the present invention, in a pallet having deck boards on both the upper and lower sides, the pallet is securely pressed by pressing the upper deck board of the pallet from below with a fork and the lower deck board of the pallet from above with a lock bar. Can be slippery. In this case, since the lock bar is inserted into the hole of the pallet, there is no obstacle to placing the load on the pallet, and the load can be loaded up to the full pallet.
[0064]
5th invention Since the switch for operating the drive mechanism is provided in the driver's seat of the forklift, the operator can arbitrarily perform the pallet locking operation.
[0065]
6th invention According to the above, when the fork is inserted into the pallet and lifted up to a predetermined height, the lift detection sensor is turned on and an operation signal is output to the drive mechanism, and the lock bar locks the pallet. Therefore, the pallet is automatically locked without the operator performing a switch operation or the like.
[0066]
7th invention According to the above, when the pallet reaches a vehicle speed at which the pallet slips on the fork, the vehicle speed detection sensor is turned on and an operation signal is output to the drive mechanism, whereby the pallet is automatically locked.
[0067]
Eighth invention According to the above, after the fork is inserted into the pallet, the tilt angle detection sensor is turned on when the tilt device provided on the forklift is tilted by a predetermined angle so that the rear side of the vehicle body, that is, the front end side of the fork is raised. The operation signal is output to the drive mechanism, and the pallet is automatically locked.
[0068]
Ninth invention Accordingly, when the vehicle body turns, the turning state detection sensor is turned on and an operation signal is output to the drive mechanism, so that the pallet is automatically locked, so that the pallet slipping on the fork is reliably prevented. The
[0069]
10th invention According to the above, when the forklift is a reach type forklift, the reach sensor detects the back and forth movement of the mast and outputs an operation signal to the drive mechanism, whereby the pallet is automatically locked.
[0070]
Eleventh invention According to this, the frictional engagement force between the lock bar and the pallet is increased, and the slippage of the pallet on the fork can be further effectively suppressed. .
[0071]
12th invention Accordingly, since the lock bar includes the elastic member, the pallet can be pressed using the elastic force of the elastic member, and the pallet can be locked with an appropriate force.
[Brief description of the drawings]
FIG. 1 is a side view showing a pallet lock device for a reach-type forklift according to a first embodiment of the present invention.
FIG. 2 is a front view of the same.
FIG. 3 is a perspective view of the main part.
4 is an AA arrow view of FIG. 2;
FIG. 5 is a longitudinal sectional view of the main part in a tilted state of the fork.
FIG. 6 is a perspective view of the reach-type forklift.
FIG. 7 is a partially cutaway side view showing an example of deformation of the lock bar.
FIG. 8 is a partially cutaway side view showing another example of deformation of the lock bar.
FIG. 9 is a perspective view of a main part showing a pallet locking device of a reach-type forklift according to a second embodiment of the present invention.
10 is a BB arrow view of FIG. 9;
FIG. 11 is a view taken along the line CC in FIG.
FIG. 12 is a longitudinal sectional view of the main part in a tilted state of the fork.
FIGS. 13A and 13B are a horizontal cross-sectional view and a vertical cross-sectional view of a main part showing a lift detection sensor, respectively.
FIGS. 14A and 14B are a rear view and a perspective view of a main part showing a vehicle speed detection sensor, respectively.
FIGS. 15A and 15B are longitudinal sectional views of a main part showing a tilt angle detection sensor before and after tilting.
FIGS. 16A and 16B are a rear view and a perspective view of a main part showing a turning state detection sensor, respectively.
FIGS. 17A and 17B are a front view and a side view of a main part showing a reach sensor, respectively.
FIG. 18 is a side view showing a conventional example.
[Explanation of symbols]
1 body
2,5 mast
6 Lift bracket
10 forks
11 Tilt device
13 Lock bar
23 recess
24 Friction mat
27 Lifting height detection sensor
28 Vehicle speed detection sensor
31 Tilt angle detection sensor
33 Turning state detection sensor
37 Reach Sensor
R lock means
a, b front-back direction
P palette
Pa Pallet hole
P1 Pallet upper deck board
P2 Pallet lower deck board

Claims (12)

A forklift having a mast erected on a vehicle body, a lift bracket that is moved up and down along the mast, and a fork supported by the lift bracket, locks a pallet that is operated by electricity or hydraulic pressure and inserted into the fork. The lift bracket includes a lock bar that presses the pallet inserted into the fork, and a drive mechanism for operating the lock bar, and the drive mechanism is located below the lift bracket. pallet locking device of a forklift, characterized in that disposed on. The pallet locking device for a forklift according to claim 1 , wherein the driving mechanism includes a hydraulic or electric cylinder device. The pallet locking device for a forklift according to claim 1 or 2 , wherein the position of both the fork and the lock bar can be adjusted in the left-right direction of the vehicle body. The lock bar is disposed between the forks and is inserted into a hole of the pallet together with the fork, and is moved up and down by the drive mechanism to press the lower deck board of the pallet from the inside of the pallet. A pallet locking device for a forklift according to claim 1 . The pallet locking device for a forklift according to any one of claims 1 to 4 , wherein the drive mechanism is operated by a switch provided in a driver seat of the forklift. Provided with a fork height detecting sensor for detecting that the fork has reached a predetermined lifting height, according to claim 1 to 4 wherein the drive mechanism is characterized in that to operate in accordance with the output of該揚height sensor A pallet locking device for a forklift described in 1. With forklift provided vehicle speed detection sensor for detecting that has reached a predetermined vehicle speed, the driving mechanism according to claim 1 to 4, characterized in that to operate in accordance with the output of the vehicle speed sensor Forklift pallet locking device. Provided with a tilt angle detecting sensor for detecting that the fork has reached a predetermined tilt angle, claim 1 wherein the drive mechanism is characterized in that to operate in accordance with the output of the tilt angle detecting sensor 4. A pallet locking device for a forklift according to item 4 . The forklift according to any one of claims 1 to 4 , wherein a turning state detection sensor for detecting a turning state of the vehicle body is provided, and the drive mechanism is operated according to an output of the turning state detection sensor. Pallet lock device. The forklift is a reach type forklift in which the mast is supported so as to be movable in the longitudinal direction of the vehicle body, and is provided with a reach sensor for detecting the forward and backward movement of the mast, and the drive mechanism is connected to the output of the reach sensor. The pallet locking device for a forklift according to any one of claims 1 to 4 , wherein the pallet locking device is actuated accordingly. The pallet locking device for a forklift according to any one of claims 1 to 10 , wherein a surface of the lock bar that contacts the pallet is subjected to a treatment for increasing a frictional force against the pallet. The pallet lock device for a forklift according to any one of claims 1 to 11 , wherein the lock bar includes an elastic member.

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