JPH08113156A - Forklift - Google Patents

Abstract

PURPOSE: To run a forklift depending on plural convertible running modes and inform to the people around the forklift that it has selected a specific running mode, by providing an alarm means to be operated when the selected running mode is a special mode. CONSTITUTION: A running mode converting means 10 receives a running mode signal Smm from a running mode selecting means 9, and it can be excited by communicating the switching member 10 of relay coils Xm1 to Xm4 corresponding the above signal so as to turn on the mode switch of a running control circuit. And after that, the running can be controlled by making the steering angle of a drive wheels as the standard, according to the converted running mode. A rotary lamp 11 as a warning means is connected in series to the switches Xms2 to Xms4 of a relay coil to carry out the specific modes of three relay coil Xm2 to Xm4, that is a parallel movement mode, a rotating mode at the position, and a lateral movement mode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forklift capable of traveling on the basis of a plurality of switchable traveling modes and capable of informing the surroundings that a specific traveling mode is selected.

[0002]

2. Description of the Related Art Conventionally, a so-called multifunctional forklift capable of performing parallel movements and turning on the spot by appropriately switching a plurality of driving modes according to a use environment is disclosed by the applicant of the present invention, for example, in Japanese Patent Laid-Open No. 5-116643. Have already been proposed in.

[0003] Such a forklift is basically provided with a pair of left and right roadwheels arranged in front of the vehicle body of the reach type forklift so as to be steerable. In addition, it includes a special mode such as a parallel movement mode, an in-situ turning mode, and a traverse mode, which are appropriately selected by a mode changeover switch or the like normally provided in the driver's seat.

[0004]

However, the above-mentioned new and special running mode is not yet well known as compared with the conventional normal mode. Therefore, it is difficult for not only the driver but also the worker around the forklift truck to predict in which direction the vehicle will travel, which requires skilled skill in the operation of the forklift truck and also makes the surrounding worker uneasy. There is a problem such as

The present invention has been devised in view of the above problems, and when a certain traveling mode is selected,
Provided is a forklift capable of solving the above-mentioned problems by preliminarily selecting a specific mode based on the use of an alarm means or a traveling direction informing means, and notifying a driver and surrounding people of the traveling direction. Is intended.

[0006]

According to a first aspect of the present invention, there is provided a road wheel which is steerably supported by each of the left and right straddle arms, a drive wheel which can be steered by a steering wheel and can be rotationally driven, and a drive wheel of the drive wheel. A steering angle detecting means for detecting a steering angle is provided, and the rotation axis of the road wheel is fixed to be unsteerable at a position along the width direction of the vehicle body and the direction of the vehicle body is changed by steering the drive wheel. A traveling mode switch for switching the traveling mode by an output signal of a traveling mode selecting means capable of selecting one traveling mode from a plurality of traveling modes including a normal mode that can be changed and a special mode that is a traveling mode other than the normal mode. Means for steering the left and right road wheels based on the selected traveling mode. A forklift, comprising a warning means that is activated when the selected traveling mode is a special mode.

According to a second aspect of the present invention, a road wheel steerably supported by each of the left and right straddle arms, a drive wheel that can be steered by a steering wheel and can be rotationally driven, and a steering wheel that detects a steering angle of the drive wheel. The drive system further includes an angle detection means and a rotation direction detection tool capable of detecting the rotation direction of the drive wheel, and the rotation axis of the road wheel is fixed to the steering wheel at a position along the width direction of the vehicle body so that it cannot be steered. A normal mode in which the direction of the vehicle body can be changed by steering the wheels, and a parallel movement mode in which the vehicle body can be moved without changing the direction by substantially matching the steering angles of the drive wheel and the left and right road wheels. Of a plurality of traveling modes including at least one of the traveling mode selecting means capable of selecting one traveling mode A forklift having a traveling mode switching means for switching the traveling mode according to the output signal, and steering the left and right road wheels based on the selected traveling mode, wherein the parallel movement mode is selected, A drive wheel orientation detecting means capable of detecting an orientation of the drive wheel with respect to a neutral position based on a detection signal of the steering angle detecting means of the drive wheel; and a drive wheel orientation signal output from the drive wheel orientation detecting means, A traveling direction discriminating means capable of discriminating a traveling direction of the forklift based on a rotational direction signal of the drive wheel outputted from the rotational direction detecting tool, and a traveling direction operated by the traveling direction signal outputted from the traveling direction discriminating means. The forklift is characterized by being provided with a notification means.

[0008]

According to the first aspect of the invention, if the selected traveling mode is the special mode, the alarm means is activated. Therefore, it is useful for informing the driver and surrounding workers that the forklift is traveling in the special mode in advance, and for calling attention.

As an example of the operation of the alarm means, various means appealing to the eyes and ears such as turning on and off of a rotating lamp, reproduction of a voice signal stored in advance, and generation of a buzzer sound can be preferably used.

According to the second aspect of the present invention, when the parallel movement mode is selected, the direction signal with respect to the neutral position of the drive wheel and the rotation direction signal of the drive wheel output from the rotation direction detector. The traveling direction discriminating means discriminates the traveling direction of the forklift on the basis of the traveling direction, and the traveling direction informing means is operated based on the traveling direction. Therefore, it is possible to notify the driver and surrounding workers of the direction in which the forklift is advancing, call attention, and improve the operability of the forklift for the driver.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a forklift 1 is a battery-type reach type forklift, and a road wheel 3 steerably supported by left and right straddle arms 2A projecting forward from a vehicle body 2.
And a drive wheel 5 that can be steered by the steering wheel 4 and can be rotationally driven, a steering angle detection unit 6 that detects a steering angle of the drive wheel 5, and a unit that can detect the rotation direction of the drive wheel 5. In the example, the accelerator device 7 is provided, and the head guard H is provided with a rotating light 11 as a warning means and a pair of left and right direction indicator lights 14A, 14B as a traveling direction informing means. The direction indicator light 14A is provided on the right side of the vehicle body and the direction indicator light 14B is provided on the left side of the vehicle body in plan view as shown in FIG. 2B.

A lift cylinder S is provided in front of the vehicle body 2.
By expanding and contracting the piston rod of (1), a fork (F) that can move up and down along the mast (M) is provided to enable various cargo handling operations.

The road wheel 3 is exemplified as being rotatably supported by a bracket 14 which can be turned around a vertical axis by an electric motor P1 arranged in the straddle arm. Also, the drive wheel 5
Is rotatably driven by an electric motor (not shown) and is connected to the handle 4 through a mechanical connecting means, so that the drive wheel 5 is rotated by rotating the handle 4.
Can be steered by turning left or right.

Further, the turning angle case 15 for supporting the drive wheel 5 is provided with a steering angle detecting means 6 which is a potentiometer in this embodiment so that the current steering angle of the drive wheel 5 can be detected as a voltage signal. Is configured.

In the present example, the accelerator device 7 is arranged on the upper surface of the driver's seat of the vehicle body 2 and has an operating lever 7A which can be tilted back and forth.
And a signal generator 7B that outputs a signal according to the tilting direction and tilting angle of the operating lever 7A. In this example, the signal generator 7B is generated by tilting the operating lever 7A forward.
B reverses the backward signal V by tilting the forward signal VF backward.
It is configured to output RR. That is, the drive wheel 5 is detected by detecting the direction of the operation lever 7A.
The rotation direction of is almost determined. Further, the tilting angle of the operating lever 7A is determined to be slow or slow depending on its magnitude.

As a means for detecting the rotation direction of the drive wheel 5, instead of the accelerator device 7, a means for directly detecting the rotation of the drive wheel 5 or a direction of a current flowing through an electric motor for driving the drive wheel 5 is used. It goes without saying that a detecting means capable of detecting such as can also be adopted.

Further, in this embodiment, the forklift 1 has a normal mode m as shown in FIGS. 2 (A) to 2 (D).
In addition to 1, a total of 4 including three special modes including a parallel movement mode m2, an in-situ turning mode m3, and a traverse mode m4.
The thing which can be driven based on one driving mode is illustrated.

In the normal mode m1, as shown in FIG. 2 (A), the rotation axes N of the left and right road wheels 3 are fixed so that they cannot be steered at positions along the width direction of the vehicle body. It realizes the same movement as a conventional reach type forklift that moves by changing the direction of the vehicle body, that is, the posture angle only by steering.

In the parallel movement mode m2, as shown in FIG. 2B, the steering angle θ of the drive wheel 5 steered by the steering wheel is detected, and the steering angle θ of the drive wheel 5 and the left and right roads are detected. By making the steering angles of the wheels 3 substantially coincide with each other, the forklift 1 can be moved without changing the direction of the vehicle body, that is, while keeping the posture angle constant, and the shortest travel and the travel in a narrow passage can be facilitated.

The in-situ turning mode m3 is controlled by steering so that the rotation axis N of the road wheel and the rotation axis D of the drive wheel intersect at a predetermined turning center point G1 as shown in FIG. 2 (C). The forklift 1 is turned around this turning center G with a small turning radius to facilitate turning in a narrow passage.

In the traverse mode m4, as shown in FIG. 2D, one of the left and right road wheels 3 (right in this example) is fixed at θ = 90 degrees, and the rotation axis of the fixed road wheel is fixed. The steering angle of the other road wheel 3 can be adjusted so that the rotation axis N coincides with the geometrical turning center point G2 determined by N and the rotation axis D of the drive wheel. It should be noted that one of the plurality of traveling modes is selected by the traveling mode selection means 9 according to the work environment.

As shown in FIGS. 1, 3 and 4, the traveling mode selection means 9 has four switches S1 to S1 arranged corresponding to each mode provided in the instrument panel portion which is easily operated by the driver.
By pressing any of the switches S1 to S4, one traveling mode signal Smn (n is an integer of 1 to 4 corresponding to the mode) from the plurality of traveling modes is transmitted to the traveling mode switching means 10. Can be output.

As shown in FIG. 4, the traveling mode switching means 10 receives a traveling mode signal Smn from the traveling mode selecting means 9 and a relay coil Xm corresponding to this signal.
It can be excited by turning on the switching units 10A of 1 to Xm4, and the mode switch (both not shown) of the traveling control circuit is turned on. After that, the traveling control can be performed based on the steering angle of the drive wheel according to the switched traveling mode.

In the present embodiment, the rotary lamp 11 as the alarm means has three relay coils Xm as shown in FIG.
2 to Xm4, that is, switches Cms2 to Xms4 of the relay coil for executing the special modes of the parallel movement mode, the in-situ turning mode and the traverse mode are connected in series.

Therefore, the revolving light 11 has the special mode m
When any one of 2 to m4 is selected, the relay coil is excited, and one of the switches Xms2 to Xms4 can be closed and energized to light. That is, the special modes m2 to m4 other than the normal mode m1 are selected to operate.

In this case, the rotating lamp 1 is operated only in the parallel movement mode m2 in which it is particularly difficult to predict the traveling direction of the forklift.
It may be configured to operate the rotary lamp 11 by selecting a special mode other than the normal mode m1.

The alarm means includes a rotating lamp 11 and an audio reproducer capable of reproducing an audio signal previously stored in an IC memory or the like. For example, "start running" or "run in special mode". Such as voice, melody horn, etc. to inform the driver and other workers around.
Helps to draw attention.

In this embodiment, the parallel movement mode m2
Is selected, the drive wheel orientation detection means 12 capable of detecting the orientation of the drive wheel 5 with respect to the neutral position based on the detection signal of the drive wheel steering angle detection means 6, and the drive wheel orientation detection means 12 It has a traveling direction discriminating means 13 capable of discriminating the traveling direction of the forklift 1 based on the drive wheel direction signal output from the vehicle and the forward / backward traveling signal output from the accelerator device 7.

The drive wheel direction detecting means 12 is, as shown in FIG. 6, a steering angle detecting means 6 of the drive wheel.
Of the output voltage VPS of the first comparator 16 and the second comparator 17 for comparing the output voltage VPS thereof with the reference voltages VL and VR, respectively.
The switching elements SW1 and SW2 are made conductive by the H-level outputs LS and RS of the comparators 16 and 17, and the relay coils X1 and X2 are excited by the conduction of the switching elements SW1 and SW2.

The drive wheel steering angle detecting means 6 composed of the potentiometer can output an output voltage VPS corresponding to the steering angle of the drive wheel 5 which is turned by rotating the steering wheel 4. In this embodiment, the drive wheel is left. The output voltage VPS is configured to increase as it turns around.

The first comparator 16 receives the output voltage VPS of the steering angle detecting means 6 at one terminal, and at the other terminal it can be considered that the drive wheel 5 is steered leftward rather than neutral. Input the threshold voltage VL of the potentiometer and set the output voltage VPS to the threshold voltage V
When it is larger than L, it outputs an H level signal LS for conducting the switching element SW1.

The second comparator 17 also inputs the output voltage VPS of the steering angle detecting means 6 which is divided into two parts, and the drive wheel 5 is steered to the right from the neutral position to the other terminal. The threshold voltage VR of the potentiometer, which can be regarded as, is input, and when the output voltage VPS becomes lower than the threshold voltage VR, an H-level signal RS that conducts the switching element SW2 is output.

The threshold voltages VL and VR are VL.
> VR, the drive wheel direction detection means 12 is
When VL>VPS> VR, this is processed as a dead zone.

With the above configuration, when the drive wheel 5 is steered to the left of the neutral position, the first comparator 16 outputs the H-level leftward signal LS, whereby the relay coil X1 When the drive wheel 5 is steered to the right of the neutral position, the second comparator 17 outputs the H-level rightward signal RS.
Is output, the relay coil X2 can be excited.

As shown in FIG. 7, the advancing direction discriminating means 13 advances the forward signal V of the signal generator 7B of the accelerator device 7.
A diode for preventing backflow from the terminal T1 to which F is input, and a switch X for the relay coil Xm2 in the parallel movement mode m2.
ms2 a contact, the drive wheel orientation detection means 1
It is grounded via the b contact of the switch Xs1 of the second relay coil X1, the switch Xs2 of the relay coil X2, and the relay coil X4.

Further, from the terminal T2 to which the backward signal VRR of the signal generator 7B of the accelerator device 7 is inputted, a diode for preventing backflow, a contact point of the switch Xs1A of the relay coil X1 of the drive wheel direction detecting means 12, and a relay coil X.
The second switch Xs2 and the relay coil X3 are grounded.

Further, the b contact of the switch Xms2 of the relay coil Xm2 in the parallel movement mode m2 is the terminal T.
2 and the switching device Xs2A.

The contact a of the switching device Xs1 is connected to the terminal T2.
Side switch Xs2 and relay coil X3, and the a contact of switch Xs1A is the switch Ts on the side of terminal T1.
And the relay coil X4, respectively.

Further, as shown in FIG. 8, the relay coil X4 has its switch Xs4 connected in series with the right direction supporting lamp 14A as the traveling direction informing means, and is excited by being excited to support this direction. The lamp 14A can be turned on. Similarly, the relay coil X3 has its switch Xs3.
Is connected in series with the direction support lamp 14B indicating leftward travel,
The direction support lamp 14B can be turned on by being excited.

Now, for example, the forward signal VF is output from the signal generator 7B of the accelerator device 7, and as shown in FIG. 2 (B), the drive wheel 5 has an angle θ greater than neutral.
Consider the parallel movement mode m2 when the steering wheel is steered to the left only.

When the parallel movement mode m2 is selected and switched, the switch Xms2 shown in FIG. 7 is switched to the contact a, and the drive wheel direction detection means 12 causes the first comparator 16 to go high. A level signal LS is output, the relay coil X1 is excited, and the switch Xs1 is switched to the a contact.

At this time, the forward signal VF is sent to the switch Xms2.
The relay coil X3 can be excited through the a contact of the above and the a contact of the switch Xs1 to turn on the direction support lamp 14B indicating the leftward travel. In other words, the traveling direction of the forklift that moves to the left can be known to outside people, drivers and the like.

Similarly, in the case of reverse travel, the forklift can travel to the right, while the reverse travel signal VRR is switched by the exciter of the relay coil X1.
The relay coil X4 can be excited through the a contact of 1A to turn on the directional support lamp 14A indicating the rightward travel. That is, it is possible to inform the outside of the traveling direction of the forklift. In addition, although the case where the drive wheel 5 is located on the left side of the neutral has been described, regarding the case of the right side,
The operation is the reverse of the above case.

In this example, the direction support lamps 14A and 14B which are turned on (or blink) are shown as the traveling direction informing means, but in addition to this, the "right direction" is provided by the audio output means which can be informed by the occurrence of an audio. The present invention can be modified into various modes such as reproducing a sound such as "Proceed to". A block diagram of the above embodiment is shown in FIG.

[0045]

As described above, according to the invention of claim 1,
If the selected traveling mode is the special mode, the alarm means is activated to notify the driver, surrounding workers, etc. in advance that the vehicle is traveling in the special mode, and call attention.

Further, according to the second aspect of the present invention, when the parallel movement mode is selected, the traveling direction informing means is operated so that the driver, the surrounding worker, and the like can move the forklift in the traveling direction. Not only can this be informed and attention given, but the operability of the driver can also be improved.

[Brief description of drawings]

FIG. 1 is a side view of a forklift showing an embodiment of the present invention.

FIG. 2A to FIG. 2D are conceptual diagrams for explaining each traveling mode of a forklift.

FIG. 3 is a plan view showing an embodiment of a traveling mode selection means.

FIG. 4 is a circuit diagram showing an embodiment of a traveling mode switching means.

FIG. 5 is a circuit diagram for activating alarm means.

FIG. 6 is a circuit diagram of drive wheel orientation detection means.

FIG. 7 is a circuit diagram of traveling direction determination means.

FIG. 8 is a circuit diagram for operating a traveling direction notifying unit.

FIG. 9 is a block diagram of the present embodiment.

[Explanation of symbols]

 1 Forklift 2 Car Body 2A Straddle Arm 3 Road Wheel 4 Handle 5 Drive Wheel 6 Steering Angle Detection Means 7 Accelerator 9 Driving Mode Selection Means 10 Driving Mode Switching Means 11 Warning Means 12 Drive Wheel Orientation Detecting Means 13 Moving Direction Discriminating Means 14A Direction Indicator light 14B Direction indicator light

Claims (2)

[Claims] 1. A road wheel steerably supported by each of the left and right straddle arms, a drive wheel that can be steered by a steering wheel and can be rotationally driven, and steering angle detection means for detecting a steering angle of the drive wheel. And a normal mode in which the rotation axis of the road wheel is fixed so that it cannot be steered at a position along the width direction of the vehicle body and the direction of the vehicle body can be changed by steering the drive wheel. A plurality of driving modes including a special mode which is a driving mode of the driving mode, and a driving mode switching means for switching the driving mode according to an output signal of the driving mode selecting means capable of selecting one driving mode. A forklift that steers the left and right road wheels based on Forklift driving mode, characterized in that a warning means activated when a special mode. 2. A road wheel steerably supported by each of the left and right straddle arms, a drive wheel which can be steered by a steering wheel and can be rotationally driven, and steering angle detection means for detecting a steering angle of the drive wheel. A rotation direction detection tool capable of detecting the rotation direction of the drive wheel, wherein the rotation axis of the road wheel is fixed to be unsteerable at a position along the vehicle body width direction, and the drive wheel is steered. A plurality of traveling modes including at least a normal mode in which the direction of the vehicle body can be changed by a vehicle and a parallel movement mode in which the vehicle body can be moved without changing the direction by substantially matching the steering angles of the drive wheel and the left and right road wheels. One of the driving modes can be selected from the driving modes by the output signal of the driving mode selection means. A forklift having a travel mode switching means for switching modes, which steers the left and right road wheels based on the selected travel mode, wherein the drive wheel of the forklift truck is operated when the parallel movement mode is selected. Based on a detection signal of the steering angle detection means, a drive wheel orientation detection means capable of detecting the orientation with respect to the neutral position of the drive wheel, a drive wheel orientation signal output from the drive wheel orientation detection means, and the rotation direction detection tool. A traveling direction discriminating means capable of discriminating a traveling direction of the forklift truck based on a rotation direction signal of the drive wheel outputted from the traveling direction discriminating means, and a traveling direction notifying means operated by the traveling direction signal outputted from the traveling direction discriminating means. A forklift characterized by being provided.