JPS6019113Y2 - Lift height limiting device for forklift trucks - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a lifting height limiting device for a forklift truck that can arbitrarily limit the lifting height.

Conventionally, when carrying out cargo handling work in warehouses, station premises, etc., where beams, overhead wires, etc. are appropriately routed, if a forklift is driven with a high lift height of the fork, the top of the inner mast or the top of the load may be exposed to the beams or overhead wires. The forklift truck could get caught in the forklift, damage the forklift, overhead wires, etc., or cause the forklift itself to fall, so the driver had to drive with extreme caution, resulting in a significant inefficiency in cargo handling operations.

This invention limits the lifting height of the fork to prevent the fork from rising more than necessary during cargo handling work in areas where there are obstacles such as beams and overhead wires, making it possible to carry out cargo handling work in areas where there are no obstacles. The object of the present invention is to provide a device that can remove the limitation on the lifting height of the fork, thereby solving the above-mentioned drawbacks.

Hereinafter, embodiments of the present invention will be described based on the drawings.

In FIG. 1, '2' is a pair of left and right outer masts that are pivotally supported on the front part of the vehicle body frame 1 so as to be tiltable forward and backward, and 3 is an inner mast that is attached to the inside of the outer mast 2 so that it can be raised and lowered.
4 is a lift bracket mounted inside the inner mast 3 so as to be movable up and down; 5 is a fork secured to a finger bar 6 fixed to the front surface of the lift bracket 4; 7 is a fork mounted inside the vehicle body frame 1; IIJ controls the vertical movement of 5, and 8 moves the spool of the control valve 7.
This is a lift lever that switches the oil path of the forklift, and is constructed and operates in the same way as a conventional forklift.

The main components of the present invention will be described below.

Reference numeral 9 in the figure denotes a bracket fastened to the rear surface of the rear flange 2A at the upper part of the outer mast 2 with bolts 10, and a proximity switch 11 is fixed to the bracket 9.

Reference numeral 12 denotes a bracket fastened to the rear surface of the rear flange 3A at the bottom of the inner mast 3 with bolts 13, and a vertically long holding bracket 14 is fixed to the bracket 12.

Reference numeral 15 denotes a movable plate to which a permanent magnet 16 is fixed, and the movable plate 15 is configured to be movable within a channel 14A formed in the holding bracket 14.

Reference numeral 17 denotes a butterfly bolt for restraining the movement of the moving plate 15, which is screwed in in a direction perpendicular to the moving direction of the moving plate 15, and whose tip (not shown) is attached to the holding bracket 14. The movement of the movable plate 15 is restrained by contact with the movable plate 15.

A bracket 18 is fixed to the upper part of the control valve 7, and rotatably supports the base end side of the lift lever 8 via a pin 19.

A connecting plate 20 connects the rear end of the lift lever 8 and the upper end of the valve spool 7A that switches the oil passage of the control valve 7 via pins 21 and 22.

Reference numeral 8A denotes a protrusion formed in the rotating part near the pin 19 that is the center of rotation of the lift lever 8, and the protrusion 8A has a rivet member with a spherical receiving part 23A formed at the tip. 2
Further, a disk-shaped suction plate 24 is connected to the spherical portion 23A so as to be able to swing α0.

On the other hand, when the lift lever 8 is operated, the holding bracket 25 of the electromagnetic magnet that attracts and holds the suction plate 24 is located within the rotation range of the lift lever 8, especially within the rotation range of the suction plate 24. The bolt 27 is fastened and fixed to an elongated hole 26A drilled in the front-rear direction of 26 so as to be movable in the front-rear direction.

Inside the holding bracket 25, an iron core 28 is fastened with bolts 29, and an insulating plate 30A and an insulating bushing 30
An electromagnetic coil 31 is wound around the iron core 28 via B.

Furthermore, 32 is a starter switch provided in the driver's seat, 33 is a changeover switch, 34 is an electric control device installed inside the vehicle body 1, and this electric control device 34, the proximity switch 11, the electromagnetic coil 31, The starter switch 32 and the changeover switch 33 are connected to the wiring 35.
36. 37. 38.

FIG. 5 is an electric circuit diagram of the device of the present invention, and as shown in the figure, the A contact 3 of the starter switch 32 is connected to the battery B.
2A, A contact 33A of fuse F1' changeover switch 33
1 B contact 11B of proximity switch 11 and electromagnetic coil 3
1 are connected in series.

Next, the operation of the device of the present invention configured as described above will be explained.

Now, when the starter switch 32 and the changeover switch 33 are turned ON from the state shown in the first figure, the electromagnetic coil 31 is excited, and in this state, when the lift lever 8 is operated to the upward side, the lift lever 8 moves the attraction plate 2 It is attracted and held by an electromagnetic magnet via the .

With the lift lever 8 being attracted and held in the upward direction, the fork 5 moves up inside the inner mast 3, and the inner mast 3 moves up inside the outer mast 2, and the permanent magnet 16 attached to the rear surface of the inner mast 3 moves up inside the outer mast 3. 2
When approaching the proximity switch 11 attached to the rear surface of the
Proximity switch 11 operates and its b contact 11B turns OFF
As a result, the excitation of the electromagnetic coil 31 is released.

When the electromagnetic coil 31 is de-energized, the spool 7A of the control valve 7 is always biased toward the neutral side, as in the conventional one, so the lift lever 8 returns to the neutral position, and the fork 5 and inner mast 3 The rise stops.

As described above, in the device of the present invention, the raising of the fork 5 and the inner mast 3 can be automatically stopped by operating the proximity switch 11. Therefore, by vertically adjusting the position of the permanent magnet 16 within the holding bracket 14, the fork 5 can be stopped. The lift height can be set to any position.

In this embodiment, the position of the permanent magnet 16 is adjusted using the wing bolt 17, but it is also possible to use a structure as shown in FIGS. 6 and 7.

That is, as shown in FIG. 6, an appropriate number of retaining holes 39 are formed in the vertical direction of the retaining bracket 14', and an engaging portion 15A having a spring action is formed on the movable plate 15. The coupling portion may be configured to engage with the engagement hole 39, and further, as shown in FIG. 7, an engagement hole 40 for directly engaging the permanent magnet may be bored in the holding bracket 14''. At the same time, a locking groove 16A is formed in the permanent magnet 16',
The locking groove 16A may be configured to lock into the engagement hole 40.

If configured as shown in Figures 6 and 7, the permanent magnet 16.1
6' can be adjusted more easily.

As described above, the device of the present invention attaches the suction target plate 24 to the lift lever 8, and when the lift lever 8 is operated to the upward side, the lift lever 8 is suction-held via the suction target plate 24. An electromagnetic magnet is fixed to the vehicle body, and a proximity switch 11 is attached to the upper rear surface of the outer mast 2. By attaching a vertically long holding bracket 14 to the rear surface of the inner mast 3 and fixing the permanent magnet 16 to the holding bracket 14 so that it can move up and down, the top of the inner mast 3 or the top surface of the load on the fork 5 comes into contact with obstacles such as overhead wires. This eliminates the possibility of cutting the overhead wires or overturning the forklift truck, and also allows the driver to carry out cargo handling operations with peace of mind even in areas where there are obstacles such as overhead wires.

In addition, when moving the forklift truck to a location where fork lift height restrictions are not required, selector switch 3
3 can be easily released by simply turning OFF the lift height of the fork, and the lift height of the forklift itself can be easily restored.

Furthermore, while the lift lever is attracted and held by the electromagnetic magnet, the driver can operate other operating levers, further improving work efficiency. It also has the effect that there is no breakdown and maintenance is extremely easy.

Note that the proximity switch 11 and permanent magnet 16 in the device of the present invention can be installed between members that move relative to each other when the fork 5 moves up and down, and are not limited to the configuration of the embodiment.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, Fig. 1 is a schematic side view of a forklift truck equipped with the device of the present invention, Fig. 2 is a plan view showing the mounting part of the proximity switch, and Fig. 3 is the mounting part of the electromagnetic magnet. Fig. 4 is a perspective view showing the permanent magnet mounting part, Fig. 5 is an electric circuit diagram, Figs. 6 and 7 show the permanent magnet mounting part, and Fig. 4 shows the mounting part of the permanent magnet. It is a perspective view showing an example of this. 1... Vehicle body, 2... Outer mast, 3
...Inner mast, 4.Lift bracket, 5.Fork, 6.Finger par 7.Control valve, 8.
... Lift lever, 11 ... Proximity switch, 14 ... Holding bracket, 16 ...
... Permanent magnet, 24 ... Attracted plate,
31... Electromagnetic coil.

Claims (1)

[Scope of utility model registration request] An outer mast that is attached to the front of the vehicle body so that it can be tilted forward and backward,
An inner mast that moves up and down within the outer mast, a lift bracket that moves up and down inside the inner mast, a fork that is secured to the front surface of the lift bracket via a finger bar, and a control valve that controls the up and down operation of the fork. In a forklift truck equipped with a lift lever for switching the oil path of the control valve, when a suction plate is attached to the lift lever and the lift lever is operated to the upward side, the suction plate A magnet for attracting and holding the lift lever is fixed to the vehicle body through a magnet, a proximity switch is attached to the upper rear surface of the outer mast, and a permanent magnet is attached to the rear surface of the inner mast to move it up and down via a vertically long holding bracket. possible to fix and furthermore,
A lift height limiting device for a forklift truck, comprising an electric control device disposed within the vehicle body to de-energize the electromagnetic magnet when the proximity switch is activated.