JPH09183600A - Fork position indicating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fork position display device which can grasp the height of the fork and can make horizontal alignment easily and accurately without requiring skillfulness of an operator even if there is no wall surface etc., in the neighborhood of cargo and which can be embodied in a simple structure and manufactured at a low cost. SOLUTION: The first to third irradiation regions of blue, red, violet 28-30 are formed by the light source 25 of a lamp house 18 and the first and second colored lenses 26 and 27, and when a fork 16 lies horizontal, the tail of an optical fiber 20 is positioned within the third irradiation region 30 and a light spot of violet 33 is formed on the cargo 31. When the fork 16 tilts ahead, the tail 22 of the fiber 20 lies within the first irradiation region 28, and a light spot of blue 34 is formed; and when the fork 16 tilts back, the tail 22 lies within the second irradiation region 29, and a light spot of red 35 is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fork position display device for displaying the position of the tip of a fork in a forklift.

[0002]

2. Description of the Related Art In a forklift truck, it is necessary for the driver to be skilled in grasping the height and tilt angle of the fork and inserting the fork into a hole in a pallet or the like. When doing so, positioning the fork was difficult. Therefore, in Japanese Utility Model Laid-Open No. 49-68455, as shown in FIG. 5, the light irradiation devices 2 are provided on the outer sides of the left and right forks 1, respectively.
Irradiates a plane fan-shaped light beam 3 in parallel with the upper surface of the fork 1, and raises the height of the fork 1 in an irradiation area 5 on the front wall surface 4.
Devices are disclosed which each attempt to indicate the tilt angle of the fork 1 in an illuminated area 7 on the side wall 6.

[0003]

However, in order to grasp the tilt angle of the fork 1, it is necessary to have a wall surface or the like on the side of the fork 1, and a wall surface near the pallet 8 and the load 9 in a large warehouse or the like. I could not know the tilt angle when there was no such thing. Further, even if the wall surface 6 exists on the side, it is necessary to visually determine the angle of the irradiation area 7 with respect to the horizontal plane, and it is difficult to accurately level the fork 1 horizontally.

A device for detecting the lift position or tilt angle of a fork using an optical sensor or a tilt angle detection sensor is disclosed in Japanese Utility Model Application Laid-Open No. 63-11499 and No. 63-14000. Proposed in the gazette. According to these devices, the height and the tilt angle of the fork can be accurately detected without any visual inspection by the driver. However, these devices are for automatically controlling an unmanned forklift and require a complicated system using a sensor, a controller, a solenoid valve, and the like. Further, JP-A-5-24798 discloses a device in which a small CCD camera is installed on the fork and the front of the fork can be confirmed by a monitor.
Since the CCD camera and monitor are used, the manufacturing cost of the device is high.

The present invention has been made in order to solve such a problem, and even if there is no wall surface in the vicinity of the load, the driver can easily and accurately grasp the height of the fork without requiring skill. An object of the present invention is to provide a fork position display device that can be leveled and can be manufactured at a low cost with a simple structure.

[0006]

A fork position display device according to the present invention is a device mounted on a forklift to display the position of a fork. The fork position display device is provided in a portion where the fork does not tilt even when tilted, and has an irradiation angle. Light source means for forming a plurality of irradiation areas of different colors according to
An optical fiber having one end located in a plurality of irradiation areas by the light source means, the other end fixed to the fork, and the light from the light source means incident on one end emitted from the other end to the front of the fork, and attached to the fork Along with the tilting motion of the fork, the other end of the optical fiber is provided with fixing means for fixing the optical fiber so that the other end of the optical fiber moves within a plurality of irradiation areas by the light source means.

The light source means includes a first irradiation area having a first color, a second irradiation area having a second color, and first and second
A third irradiation area having a third color and located between the two irradiation areas of the optical fiber such that one end of the optical fiber is positioned in the central third irradiation area when the fork is horizontal. If is fixed, the fork can be leveled extremely easily. The light source means can be composed of a light source and first and second colored lenses having first and second colors arranged adjacent to each other in front of the light source.
In this case, only the light transmitted through the first colored lens is
The second irradiation area is formed only from the light that has passed through the second colored lens, and the lights that have respectively passed through the first and second colored lenses overlap each other. An irradiation area is formed.

When the present invention is applied to a reach type forklift, the light source means is attached to the lift bracket, and when it is applied to the counter type forklift, the light source means is attached to the frame of the forklift.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Embodiment 1 FIG. FIG. 1 shows the structure of a fork position display device according to a first embodiment of the present invention applied to a reach type forklift. In FIG. 1, one lift bracket 11
Only one is shown, but a pair of left and right lift brackets 1
Between two horizontal shafts 12 and 13 parallel to each other
Is stretched. A bracket 14 is movably provided along the shafts 12 and 13, and a light shielding box 15 is fixed to one end of the bracket 14. The other end of the bracket 14 has a shape in which it is bifurcated from each other in the horizontal direction.
The back of the is loosely pinched from both sides. Therefore, even if the fork 16 tilts in the vertical direction, the bracket 14
Does not move, but fork 1 to change fork width
When 6 is moved horizontally, the bracket 14 is also configured to move horizontally along with the forks 16 along the shafts 12 and 13.

In order to clarify the internal structure, the light-blocking box 15 is shown in a largely broken state in FIG. 1, but in reality, the light-blocking box 15 is formed with an opening 17 formed on the side surface facing the fork 16. It has a closed box shape except for. A lamp house 18 forming a light source means is arranged in an upper part of the light shielding box 15 so as to face downward.

A single groove 19 is formed along the length of the bottom of the fork 16, and the front half of the optical fiber 20 is embedded in the groove 19. The second half of the optical fiber 20 has a bracket 21 attached to the fork 16.
Fixed to and extended linearly behind the fork 16,
The rear end 22 of the optical fiber 20 passes through the opening 17, is bent upward at a right angle in the light shielding box 15, and faces the lamp house 18. The opening 17 of the light shielding box 15 has a size that does not hinder the movement of the bracket 21 and the optical fiber 20 accompanying the tilting motion of the fork 16. The bracket 21 also forms the fixing means of the present invention. On the other hand, a condenser lens 24 for preventing diffusion of light is connected to the front end portion 23 of the optical fiber 20. The condenser lens 24 is directed toward the front of the fork 16 in the groove 19 at the tip of the fork 16 and emits the light propagating in the optical fiber 20 in parallel with the upper surface of the fork 16.

As shown in FIG. 2, the lamp house 18 includes a light source 25 and first and second colored lenses arranged in front of the light source 25 and adjacent to each other in the length direction of the fork 16. 26 and 27. The first and second colored lenses 26 and 27 have a blue color (first color) and a red color (second color), respectively, so that only the light transmitted through the first colored lens 26 The first irradiation area 28 of blue, the second irradiation area 29 of red consisting only of light transmitted through the second colored lens 27, and the colored lenses 2 of both
A purple third irradiation area 30 is formed in which the lights transmitted through 6 and 27 overlap each other. First to third irradiation area 2
FIG. 3 shows how 8 to 30 are formed.

Since such three irradiation areas 28 to 30 having different colors are continuously formed, the fork 1
The rear end portion 22 of the optical fiber 20 accompanying the tilting operation of
Is moved, the rear end portion 22 causes the first to third irradiation areas 28 to
Depending on which one of 30 the light is located, blue, red, or violet light is incident on the optical fiber 20.
That is, when the rear end portion 22 is located in the first irradiation area 28, blue light is emitted, when it is located in the second irradiation area 29, red light is emitted, and when it is located in the third irradiation area 30, purple light is emitted. Respectively enter the optical fiber 20 from the rear end portion 22. In addition,
The positional relationship between the bracket 21 and the lamp house 18 is set so that the rear end portion 22 of the optical fiber 20 is located in the third irradiation area 30 when the fork 16 is in the horizontal state.

Next, the operation of the fork position display device according to the first embodiment will be described. First, the light from the light source 25 of the lamp house 18 is emitted from the first and second colored lenses 2
6 and 27 are irradiated toward the first and third irradiation areas 2 in the light shielding box 15 by these lenses 26 and 27.
8-30 are formed. Here, natural light and indoor light are substantially blocked by the light shielding box 15 and are prevented from entering the rear end portion 22 of the optical fiber 20 as a disturbance.

The light from the lamp house 18 is emitted from the rear end 22.
Is incident on the optical fiber 20, propagates in the optical fiber 20, and is projected to the front of the fork 16 from the condenser lens 24 connected to the front end portion 23. Therefore, when the load 31 and the like exist in front of the fork 16 as shown in FIG. 1, the light spot 32 is formed on the load 31 by the light projected from the condenser lens 24. At this time, if the fork 16 is horizontal, the rear end portion 22 of the optical fiber 20 is in the third irradiation area 30.
Since it is located inside, a purple light spot 33 is formed as shown in FIG. When the fork 16 tilts forward and the tip of the fork 16 descends, the rear end 22 of the optical fiber 20 is located in the first irradiation area 28, and thus a blue light spot 34 is formed. Conversely, fork 16
When the rear end portion 22 of the optical fiber 20 is tilted backward and the tip portion of the fork 16 rises, the rear end portion 22 of the optical fiber 20 is positioned in the second irradiation area 29, so that a red light spot 35 is formed.

Since a light spot of a color corresponding to the inclination of the fork 16 is formed on the load 31 in this way, the driver grasps the height of the fork 16 from the position of the light spot and at the same time, detects the fork from the color of the light spot. It is possible to intuitively grasp the degree of inclination of 16. Therefore, the tilt lever (not shown) is operated to adjust the tilt angle of the fork 16 so that the light spot formed on the load 31 becomes purple, and then the lift lever (not shown) is operated so that the purple light spot 33 is formed. If the height of the fork 16 is adjusted so as to enter the hole 37 of the pallet 36, even if the driver is not an expert, the fork 16 can be easily inserted into the hole 37 of the pallet 36 without hitting the load 31. Is possible.

Embodiment 2 FIG. FIG. 4 shows a counter-type forklift truck including the fork position display device according to the second embodiment. In the counter-type forklift, the entire mast 41 is tilted by the cylinder 42. Therefore, when the lamp house is attached to the horizontal shaft provided on the lift bracket as in the first embodiment, the lamp house is tilted together with the fork, and the fork of the fork is lifted. It becomes impossible to form light spots of different colors depending on the tilt angle.

Therefore, as shown in FIG. 4, the lamp house 18 may be fixed to the frame 43 of the forklift. In this case, one end of the optical fiber 20 is attached to the bracket 45 fixed to the outer mast 44, and the one end of the optical fiber 20 moves within the irradiation area formed by the lamp house 18 as the mast 41 tilts. To do. Although omitted in FIG. 4, the first embodiment
Similarly, the lamp house 18 and one end of the optical fiber 20 are surrounded by a light shielding box. The optical fiber 20 is
Similar to a hydraulic pipe (not shown), after being rewound by a pulley 47 arranged above the inner mast 46, it reaches a fork 49 via a lift bracket 48, and is connected to the condenser lens 24 at the tip of the fork 49. Has been done.

When the fork 49 is tilted together with the mast 41, one end of the optical fiber 20 moves within the first to third irradiation areas formed by the lamp house 18 and having different colors, and the fork 49 is colored in accordance with the inclination of the fork 49. A light spot will be formed on the load in front of the fork 49. In this way, even with a counter-type forklift, the driver can easily grasp the position of the fork 49 and perform leveling.

In the lamp house 18 used in the first and second embodiments, two colored lenses 26 and 27 are arranged to form three irradiation areas 28 to 30 having different colors, but the colors are different. The irradiation area can be formed by adjoining three filters. Further, it is also possible to form four or more irradiation areas having different colors in the same manner and to change the color more finely according to the tilt angle of the fork.

The fork position display device of the present invention is effective even if it is provided for only one of the pair of left and right forks, but if similar fork position display devices are provided for both forks, the cargo handling work is further facilitated. It will be easier to do.

In the first embodiment shown in FIG. 1, the fork 1 is used.
Although the groove 19 was formed in the bottom portion of the optical fiber 6 and the optical fiber 20 was embedded in the groove 19, the optical fiber was added to the side surface of the fork.
Alternatively, a groove may be formed on the side surface and the optical fiber may be embedded therein. In this case, in order to reduce the risk of the optical fiber and the condenser lens colliding with the pallet or the like during the cargo handling work, it is preferable to provide the optical fiber on the inner side surfaces of the pair of left and right forks.

In the first and second embodiments, the condenser lens 24 is fixed to the tips of the forks 16 and 49.
It can also be attached to the base of the fork.

Furthermore, the present invention can be applied not only to the fork but also to other attachments to display the height and inclination of the attachment.

As described above, according to the present invention,
The position and color of the spot light emitted from the optical fiber allows the driver to easily and intuitively grasp the positional relationship between the fork, the pallet, the load, etc., and does not require any skill to perform complicated operations. It is possible to insert the fork into a pallet or the like without any trouble. Further, since light is emitted from the tip of the fork toward the front of the fork, the height and tilt angle of the fork can be grasped even if there is no wall surface near the pallet or the like. Further, the fork position display device of the present invention has a simple structure composed of a light source means such as a lamp house and an optical fiber, and does not require a sensor, a controller, a solenoid valve or the like as in the conventional case, and Since no CCD camera or monitor is required, the existing forklift can be manufactured at a low cost with only a slight modification.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing the structure of a fork position display device according to a first embodiment of the present invention applied to a reach type forklift.

FIG. 2 is a perspective view showing the operation of the first embodiment.

FIG. 3 is a side view showing the operation of the first embodiment.

FIG. 4 is a side view showing a counter type forklift including a fork position display device according to a second embodiment.

FIG. 5 is a perspective view showing the principle of a conventional fork position display device.

[Explanation of symbols]

 11,48 Lift bracket 12,13 Shaft 14,21,45 Bracket 15 Shading box 16,49 Fork 17 Opening 18 Lamp house 19 Groove 20 Optical fiber 22 Rear end 23 Front end 24 Condenser lens 25 Light source 26 First Colored lens 27 Second colored lens 28 First irradiation area 29 Second irradiation area 30 Third irradiation area 32-35 Light spot 41 Mast 42 Cylinder 43 Frame 44 Outer mast 46 Inner mast 47 Pulley

Claims (5)

[Claims] 1. A device for displaying the position of a fork mounted on a forklift, the fork being provided in a portion that does not tilt even when tilted, and forming a plurality of irradiation areas of different colors according to the irradiation angle. A light source means, an optical fiber having one end located in a plurality of irradiation areas by the light source means, the other end fixed to a fork, and the light from the light source means incident on one end emitted from the other end to the front of the fork And a fixing means for fixing the optical fiber so that the other end of the optical fiber is attached to the fork and moves with the other end of the optical fiber in a plurality of irradiation areas by the light source means in accordance with the tilt operation of the fork. Fork position display device. 2. The light source means has a first color having a first color.
A second exposure area having a second color, and a third exposure area having a third color and located between the first and second exposure areas.
And the fixing means fixes the optical fiber so that one end of the optical fiber is located in the third irradiation area when the fork is horizontal. Fork position display device. 3. The light source means includes a light source and first and second colored lenses having first and second colors, which are arranged in front of the light source and adjacent to each other. The first irradiation area is formed only from the light transmitted through the colored lens, and the second irradiation area is formed only from the light transmitted through the second colored lens.
3. The fork position display device according to claim 2, wherein the third irradiation area is formed by overlapping the lights respectively transmitted through the first and second colored lenses with each other. . 4. The fork position display device according to claim 1, wherein the light source means is attached to a lift bracket of a reach type forklift. 5. The fork position display device according to claim 1, wherein the light source means is attached to a frame of a counter type forklift.