KR102018765B1 - Device for detecting position of fork for forklift truck - Google Patents

Abstract

The present invention relates to a forklift fork position detecting device for detecting the position of a fork mounted on a forklift. The forklift fork position detecting device includes: a light radiating part installed in the bottom of a fork to be elevated in cooperation with the fork, and radiating straight light towards a lift target; a reflection plate installed beside the lift target, and in which a regular reflection surface regularly reflecting the light radiated from the light radiating part at a predetermined angle and a diffused reflection surface diffusedly reflecting the light radiated from the light radiating part are placed alternately; a light receiving part elevated in cooperation with the fork, and receiving the light reflected from the regular reflection surface; and a control part calculating the relative distance to the lift target and height of the fork from the output of the light receiving part. According to the present invention, the light radiating part and light receiving part, which are elevated in cooperation with the fork, are installed, the reflection plate, in which the regular reflection surface and diffused reflection surface are plated alternately, is installed beside the lift target, the straight light radiated from the light radiating part is diffusedly reflected from the diffused reflection surface to be easily seen by a driver, and the relative distance to the lift target and height of the fork are calculated from a detection value, which is obtained as the light receiving part receives the light regularly reflected from the regular reflection surface, to automatically warn a driver, manipulate a brake, or control a forklift′s posture when reaching a dangerous position, thereby preventing accidents.

Description

FORKLIFT FORK POSITION DETECTION DEVICE {DEVICE FOR DETECTING POSITION OF FORK FOR FORKLIFT TRUCK}

The present invention relates to a device for detecting a fork position of a forklift, and more particularly, a blind spot that makes it easy for the driver to visually recognize the height of the fork and the relative distance to the lift object, while at the same time it is difficult to easily identify the position of the fork. A forklift fork position detection device for automatically detecting the position of the fork in the zone.

In general, forklifts are equipment for unloading, loading and transporting cargo in factories, ports, and airports. The forklift runs by power like a normal heavy duty vehicle. In front of the forklift is installed a mast for performing a tilting operation by the hydraulic force, the fork for lifting is installed on the mast so as to be lifted. The operator lifts and lowers the fork to lift and lower the weight and transports it with the weight up.

Typically, heavy weights are loaded on pallets and forks are inserted into grooves formed in the pallets to lift the heavy weights. By the way, when the pallet is at a high position, a blind spot is formed, for example, in which the height of the fork is difficult to visually identify near the driver's eye level. The driver has a problem that it is difficult for the driver to accurately control the height of the fork and the relative distance to the lift object, and a safety accident occurs such that heavy weight falls or the forklift rolls over due to the wrong position of the fork.

As a device for measuring or detecting a fork height of a conventional forklift, Korean Patent Application Publication No. 20-1999-009593, Korean Utility Model Publication No. 20-1999-002536, and Korean Patent Registration No. 10-0797011 have been disclosed.

Republic of Korea Utility Model No. 20-1999-009593 "Fork lift position detection device for forklift truck" is installed by installing the upper limit switch and the lower limit switch on the mast of the highest point and the lowest point where the fork can be positioned, the fork is the best Be alert when you reach the point and trough. Although the preceding document is suitable for the use of detecting deviation of the fork's operating range, there is a limitation that the height of the fork cannot be detected in a blind spot where the driver cannot easily identify the height of the fork.

Republic of Korea Utility Model No. 20-1999-002536 "Forklift height detection device of the forklift" is connected to the pot by connecting the potentiometer through the reduction gear train on one end of the chain sheave of the mast, and converts the analog signal output from the potentiometer to a digital signal The digital signal is converted into a video signal and displayed on the driver's seat. However, the process of converting the signal is complicated, and it is difficult to trust the display image by converting the mechanical motion into a video signal, and it is difficult to concentrate on the operation of the forklift and the operation of the fork because the driver must watch the display. There is a high risk of generating.

Republic of Korea Patent No. 10-0797011 "fork position detection device of the forklift and the speed control method using the same" is a fork position corresponding to the oil level by detecting a change in the fluid height in the fluid tank for generating a hydraulic force for fork movement Detect. Similar to the method of detecting a mechanical motion, the prior document has a problem that the conversion process of the signal is complicated, the driver is difficult to trust the fork height, and it is difficult for the driver to visually recognize the current height of the fork.

Korean Utility Model Model No. 20-1999-009593 Korean Utility Model Model No. 20-1999-002536 Republic of Korea Patent No. 10-0797011

The present invention is provided with a light emitting unit and a light receiving unit which is lifted in conjunction with the fork, and by installing a reflecting plate in which the regular reflection surface and the diffuse reflection surface is alternately arranged on the side of the lift object, the height of the fork is located near the driver's eye level Forklift fork position detection devices, which allow the driver to easily recognize the height of the fork and the relative distance to the lift object, while automatically detecting the position of the fork to alert the driver or to operate the brakes. The purpose is to provide.

Further, the present invention forms a plurality of light receiving surfaces on the light receiving side and detects the relative distance between the lift object and the fork according to the position of the surface receiving the light reflected by the reflection plate provided on the lift object side, Accordingly, there is another purpose to warn the driver or to operate the brake.

In addition, the present invention has another object that the driver can easily recognize the position of the object to be lifted at any angle by disposing different installation angles of the diffuse reflection surface formed on the reflecting plate.

In the forklift fork position detection apparatus according to an embodiment of the present invention, a forklift fork position detection device for detecting the position of the fork mounted on the forklift, is installed on the lower end of the fork is lifted in conjunction with the fork, lift A light emitter for emitting light straight toward the object; A reflection plate installed on the side of the object to be lifted, the reflecting plate alternately reflecting light reflected from the light emitting unit at a predetermined angle, and a diffuse reflecting surface scattering the light emitted from the light emitting unit; A light receiving unit which is lifted in conjunction with the fork and receives light reflected from the specular reflection surface; And a controller configured to calculate a height of the fork and a relative distance from the object to be lifted from the output of the light receiver.

In the forklift fork position detecting apparatus according to another embodiment of the present invention, the control unit outputs a warning signal when the height of the fork or the relative distance to the lift object reaches a predetermined reference value, and generates a warning sound according to the warning signal. At least one of a warning buzzer for outputting a warning light, a warning light that is turned on according to the warning signal, a brake driving unit for stopping the operation of the fork according to the warning signal, and a posture control unit for controlling the posture of the fork according to the warning signal. Include.

In the forklift fork position detection apparatus according to another embodiment of the present invention, the light receiving portion is a plurality of light receiving surface having an inclined surface toward the reflecting plate is arranged in a vertical direction, the control unit is the position of the light receiving surface receiving the reflected light The distance between the lift object and the fork or the insertion depth of the fork is calculated.

In the forklift fork position detecting apparatus according to still another embodiment of the present invention, the plurality of diffuse reflection surfaces formed on the reflecting plate are arranged to have different installation angles.

In the forklift fork position detection apparatus according to another embodiment of the present invention, the light emitting portion is a laser pointer for emitting a straight fan-shaped light toward the reflecting plate.

According to the forklift fork position detection device of the present invention, the forklift position detection device is provided with a light emitting unit and a light receiving unit which is elevated in conjunction with the fork, the reflection object is provided with a reflector plate is alternately arranged with a regular reflection surface and a diffuse reflection surface, the radiation from the light emission unit The linearly diffused light is diffusely diffused on the diffuse reflection surface and can be easily recognized by the driver. The specular reflection is performed on the specular reflection surface to calculate the height of the fork and the relative distance to the lift target from the detection value received by the light receiving unit to reach a dangerous position. In this case, there is an effect of preventing a safety accident by automatically warning a driver or performing a brake operation or posture control.

Further, according to the present invention, there is an effect that can accurately calculate the relative distance to the lift target according to the position of the light receiving surface to arrange a plurality of light receiving surfaces in the vertical direction on the light receiving side.

Further, according to the present invention, by disposing different installation angles of the diffuse reflection surface formed on the reflecting plate, there is an effect that the driver can easily visually recognize the position of the lift object from any angle.

1 is a view showing an application example of the forklift fork position detection apparatus according to the present invention,
Figure 2 is a perspective view illustrating the configuration of a reflector in the present invention,
3 is a view illustrating a configuration of an optical receiver in the present invention, and
Figure 4 is a block diagram illustrating a forklift fork position detection apparatus according to the present invention.

Hereinafter, with reference to the accompanying drawings will be described a specific embodiment according to the present invention. However, this is not intended to limit the present invention to the specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

The same reference numerals are used for parts having similar configurations and operations throughout the specification. And the drawings attached to the present invention is for convenience of description, the shape and relative measures may be exaggerated or omitted.

In describing the embodiments in detail, overlapping descriptions or descriptions of obvious technology in the art are omitted. In addition, in the following description, when a portion "includes" another component, it means that the component can be further included in addition to the described component unless otherwise stated.

 In addition, the terms "~", "~", "~ module" described in the specification means a unit for processing at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. Can be. In addition, when a part is electrically connected to another part, this includes not only the case where it is directly connected, but also the case where it is connected through the other structure in the middle.

Terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be referred to as the first component, and similarly, the first component may also be referred to as the second component.

1 is a view showing an application example of the forklift fork position detection apparatus according to the present invention.

Referring to FIG. 1, a forklift 100 travels while a wheel installed at a lower portion rotates by power as is commonly known, and a mast 110 and a fork 120 operated by hydraulic force are installed in front of a driver's seat. . The mast 110 performs a tilting operation by the hydraulic force, and the fork 120 is installed to be liftable on the mast 110. The fork 120 is a means for performing an operation of lifting or lowering a lift object. Here, the lift object may include a pallet 410 into which the fork 120 is inserted and a heavy material loaded on the pallet 410. have.

Forklift fork position detection device of the present invention when the pallet 410 located near the driver's eye level, that is, the position of the fork when the blind spot is difficult for the driver to visually identify the position of the fork and the lift target We propose a device for accurately detecting. For example, as shown in FIG. 1, the forklift fork position detection device of the present invention may be usefully used when the pallet 410 is positioned on the loading pawl 400 and the heavy material is loaded on the pallet 410. Can be.

Referring to Figure 1, the forklift fork position detection device of the present invention is provided at the lower end of the fork 120 and includes a light emitting unit 210 and a light receiving unit 220 to be elevated in conjunction with the fork, the reflection object side of the reflecting plate 300 is installed.

Here, the lift object side may not be understood to mean only the lift object, but may be understood as a place where the lift object is located. For example, the reflector plate 300 may be installed in a transverse bar of the pallet 410 or the loading pawl 400. As another example, the reflector 300 may be installed on a heavy object to be lifted.

In addition, the light emitting unit 210 is linked up and down in all sections together with the fork 120, but the light receiving unit 220 may collide with the bottom surface when the fork 120 is lowered to the minimum height, so that the fork ( When 120 is raised above a certain height, it is preferable to be configured to move up and down. For example, when the fork 120 reaches a predetermined height while the fork 120 reaches a predetermined height, the light receiving unit 220 is accommodated in the free space between the forks 120 and appears when the fork 120 rises from the lowest point and reaches a predetermined height. And it may be configured to be elevated with the fork 120.

The light emitter 210 emits straight light toward the lift object. For example, the light emitter 210 is a laser pointer that emits straight fan-shaped light toward the reflector 300.

The reflector 300 reflects the light emitted from the light emitter 210, and the light receiver 220 receives the reflected light. For example, the light receiving unit 220 may be configured as a light detector for detecting the light receiving surface and the light received by the light receiving surface.

The controller 200 to be described below with reference to FIG. 4 calculates the height of the fork 120 and the relative distance from the lift object from the output of the light receiver 220. The control unit 200 may display the height of the fork 120 and the relative distance to the lift object through the display means according to the calculation result. In addition, a visual and / or audio warning signal may be output when the position of the fork 120 reaches a dangerous area.

2 is a perspective view illustrating the configuration of a reflecting plate in the present invention.

Referring to FIG. 2, the reflecting plate 300 is disposed to be inclined at a predetermined angle θ of the reflecting surface with respect to the vertical rear surface fixed to the mounting pole 400. Therefore, the light incident straightly is reflected in the downward oblique direction.

Specifically, the reflecting plate 300 is a specular reflecting surface 310 that specularly reflects the light emitted from the light emitting unit 210 at a predetermined angle, and a diffuse reflecting surface 320 which scatters and diffuses the light emitted from the light emitting unit 210. ) Are alternately arranged.

As shown in FIG. 2, the specular reflective surface 310 is disposed such that the first specular reflective surface 310a and the second specular reflective surface 310b are spaced apart from each other by a predetermined interval. However, the first specular reflecting surface 310a and the second specular reflecting surface 310b reflect light at the same reflecting angle as depicted by the dotted line.

The diffuse reflection surface 320 is disposed so that the first diffuse reflection surface 320a and the second diffuse reflection surface 320b are spaced apart from each other by a predetermined interval, and diffused by reflecting the incident light at various angles as described by the solid line. The light scattered by the diffuse reflection surface 320 may allow the driver of the forklift 100 to visually recognize the position of the lift object and the corresponding position of the fork.

In the example of FIG. 2, the specular reflection surface 310 and the diffuse reflection surface 320 are alternately arranged in two planes, but the number thereof may be further increased. In addition, the first diffuse reflection surface 320a and the second diffuse reflection surface 320b may be disposed to have different installation angles. This varies the light scattering direction, allowing the driver to easily see the position of the lift object at any angle.

3 is a diagram illustrating a configuration of an optical receiver in the present invention.

Referring to FIG. 3, the light receiver 220 may have a structure in which a plurality of light receiving surfaces 221, 222, 223, 224, and 225 having an inclined surface toward the reflecting plate 300 are arranged along a vertical direction. The first light receiving surface 221 at the uppermost end has the smallest light receiving area, and the light receiving area gradually increases toward the bottom, so that the fifth receiving surface 225 at the lowermost end may have the largest light receiving area.

The control unit 200 may calculate the distance between the lift object and the fork 120 or the insertion depth of the fork 120 according to the position of the light receiving surfaces 221 to 225 that have received the reflected light. For example, when the reflected light is received at the fifth light receiving surface 225, the fork 120 may be spaced apart from the lift object by a sufficient distance. As another example, when the reflected light is received from the first light receiving surface 221, the fork 120 may indicate a state in which the fork 120 is inserted into the lift object as much as possible. In this case, the controller 200 may generate a warning signal to call attention of the driver.

Figure 4 is a block diagram illustrating a forklift fork position detection apparatus according to the present invention.

Referring to FIG. 4, the controller 200 performs overall control of the illustrated components. The controller 200 controls the light output of the light emitter 210 and detects an output signal of the light receiver 220. In addition, a warning signal is output when the height of the fork 120 or the relative distance with the lift object reaches a predetermined reference value. Although not shown, the detection value of the light receiving unit 220 is calculated to convert the height of the fork 120 and the relative distance from the lift object into an actual value, and the converted actual value is converted into a display means (for example, an LCD or an OLED). Or the like).

The control unit 200 includes a microprocessor for controlling and signal processing of the components, and includes a read only memory (ROM) in which a control program is written and an analog circuit added to an input / output terminal of the microprocessor. Can be. In addition, the control unit 200 may include an input / output interface for transmitting an appropriate output signal to the warning buzzer 230, the warning lamp 240, the brake driving unit 250, the posture control unit 260, and the like.

The warning buzzer 230 outputs a warning sound according to the warning signal output from the controller 200. The warning lamp 240 is turned on according to the warning signal output from the controller 200. Therefore, the driver may recognize that the fork 120 has reached a dangerous position depending on whether the warning buzzer 230 or the warning lamp 240 is operated.

The brake driver 250 may be operated by a command of the controller 200 to stop the operation of the fork 120 despite the driver's manipulation. The posture control unit 260 may perform posture control such as raising / lowering the fork 120 or reversing the forklift by the command of the control unit 200. Therefore, even when the driver enters the force majeure of the fork 120 and difficult to accurately operate the fork 120 despite the warning signal output, it is possible to prevent a safety accident due to a poor position of the fork 120.

Preferably, the control unit 200 controls the output terminal devices by comparing the signal detected by the light receiving unit 220 with a predetermined threshold value, the first to operate the warning buzzer 230 and the warning light 240 The threshold and the second threshold for operating the brake driver 250 and the posture controller 260 may be set to different values. Thus, when the fork 120 enters a dangerous position, an audible / visual warning is primarily performed, and the driver nevertheless does not move out of the dangerous position by manipulating the fork 120 (eg, fork 120). The brakes or posture control can be used to prevent safety accidents by autonomous control.

Various modifications are possible in the invention disclosed above without departing from the basic idea. That is, the above embodiments should all be interpreted as illustrative and not restrictive. Therefore, the protection scope of the present invention should be determined according to the appended claims rather than the above-described embodiments, and if the components defined in the appended claims are replaced by equivalents, they should be regarded as belonging to the protection scope of the present invention.

100: forklift 110: mast
120: fork 200: control unit
210: light emitting unit 220: light receiving unit
221: first light receiving surface 222: second light receiving surface
223: third light receiving surface 224: fourth light receiving surface
225: fifth light receiving surface 230: warning buzzer
240: warning lights 250: brake drive unit
260: posture control unit 300: reflector
310: specular reflection 310a: first specular reflection
310b: second specular reflection surface 320: diffuse reflection surface
320a: first diffuse reflection surface 320b: second diffuse reflection surface
400: loading pole 410: pallet

Claims (5)

In the forklift fork position detection device for detecting the position of the fork mounted on the forklift,
A light emitting unit installed at a lower end of the fork and being lifted in conjunction with the fork and emitting straight light toward a lift object;
A reflection plate installed on the side of the object to be lifted, the reflecting plate alternately reflecting light reflected from the light emitting unit at a predetermined angle, and a diffuse reflecting surface scattering the light emitted from the light emitting unit;
A light receiving unit which is lifted in conjunction with the fork, receives light reflected from the specular reflecting surface, and a plurality of light receiving surfaces having an inclined surface toward the reflecting plate are arranged along a vertical direction; And
Compute the height of the fork and the relative distance between the lift object from the output of the light receiving unit, the distance between the lift object and the fork or the insertion depth of the fork according to the position of the light receiving surface receiving the reflected light from the light receiving unit Control to calculate
Forklift fork position detection device comprising a.
The method of claim 1,
The control unit outputs a warning signal when the height of the fork or the relative distance to the lift object reaches a predetermined reference value,
A warning buzzer for outputting a warning sound according to the warning signal, a warning light that is turned on according to the warning signal, a brake drive unit for stopping the operation of the fork according to the warning signal, and a posture for controlling the posture of the fork according to the warning signal Forklift fork position detection device further comprising at least one of the control unit.
delete The method according to claim 1 or 2,
And a plurality of diffuse reflection surfaces formed on the reflecting plate are arranged to have different installation angles.
The method according to claim 1 or 2,
The forklift fork position detection device, wherein the light emitter is a laser pointer that radiates straight fan-shaped light toward the reflector.

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