JP2599328Y2 - Omnidirectional forklift - Google Patents

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 switching between a plurality of driving modes, and an improved device for allowing a driver to easily select a desired driving mode.

[0002]

2. Description of the Related Art In recent years, as represented by Japanese Patent Application No. 3-306767 previously proposed by the present applicant, forklifts have been improved and various driving modes (hereinafter referred to as "driving modes" or simply "running modes") have been proposed. Mode ") has been proposed.

As shown in FIG. 6, the forklift 1 has a drive wheel 4 steered by a steering wheel 3 and left and right road wheels 5 and 6 steerable via steering motors 11 and 12 and a transmission 10. And potentiometers 13 and 1 that can detect the respective steering angles.
4, and a potentiometer 18 and the like capable of detecting the steering angle of the drive wheel are mounted. Although not shown, the drive wheel 4 is steered by obtaining an assist torque from a power steering motor as torque applied to the steering wheel.

The forklift 1 uses the steering angle of the drive wheel 4 as a command signal and steers the left and right road wheels based on the signal. The switches A, B and C of the traveling mode selection device 15 are operated. By doing so, it is possible to travel in a desired traveling mode.

For example, when the switch A is selected, an in-phase mode is set. As shown in FIG. 5A, the steering angle of the drive wheel 4 and the steering angle θ of the left and right road wheels 5 and 6 are set.
D, θL, and θR are all controlled to be equal, and the vehicle can travel without changing the attitude of the forklift.

When the switch B is selected, a spin turn mode is set, and as shown in FIG. 5B, the turning center point can be made coincident with the center of the body of the forklift at the maximum turning angle of the steering wheel.

Further, when the switch C is selected, a so-called anti-phase mode is set, and the control is performed so that the axis where the turning center is continuous can be located below the axis connecting the left and right road wheels, so that a small turn is achieved. .

Incidentally, in each of the above-mentioned running modes, there is a restriction due to the steering angle of the drive wheel 4. That is, the left and right steering ends of the drive wheel 4 are mechanically limited, and cannot be continuously steered by 360 degrees. Further, due to the calculation processing of the control device (not shown),
In order to execute a certain driving mode, the steering angle of the drive wheel 4 may need to be limited to a certain angle range.

As an example, as shown in FIG. 5C, in the reverse phase mode, the trajectory of the turning center point is not continuous. Therefore, when the steering angle of the drive wheel 4 is within the range α shown in FIG. The reverse phase mode is set so that it cannot be selected even if the switch C is pressed.

[0010]

However, the driver of the forklift 1 is always informed of the current direction of the drive wheel 4 and the limit angle of the steering angle of the drive wheel 4 in each driving mode. While it is difficult to make them familiar, there is a problem in that even if they are familiar, they require driving skills, are easily fatigued, and have poor workability.

The present invention has been devised in order to solve such a problem, and an object of the present invention is to provide a driving mode selection device capable of easily selecting a driving mode without concern for the steering angle of a drive wheel. To provide.

[0012]

According to the present invention, there is provided a mode selection switch capable of selecting and inputting a plurality of driving modes, and a means for storing a left and right limit steering angle of a drive wheel in the driving mode selected by the mode selection switch. Means for detecting the actual steering angle of the current drive wheel, and means for comparing the stored left and right limit steering angles of the drive wheel with the detected actual steering angle. When the detected actual steering angle is out of the range of the stored left-right limit steering angle, the steering wheel is rotated so that the detected actual steering angle falls within the stored left-right limit steering angle. The present invention has a configuration in which a steering display unit for instructing a power direction is provided to solve the above-described problem.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a block diagram of the present invention,
An operation display section 40, a potentiometer 18 capable of detecting an actual steering angle of the drive wheel 4, a CPU 27 for performing arithmetic processing based on these input signals, a limit steering angle of the drive wheel 4 in each traveling mode, and various processes It comprises a ROM 29 for storing procedures, and indicators 24 and 25 capable of displaying the direction in which the steering wheel should be steered.

The operation display unit 40 includes, as illustrated in FIG.
A mode selection switch 21 corresponding to each driving mode,
22 and 23, an illustration display section 33 on which an illustration of a steering wheel is drawn, and arrows 24 and 25 in the form of arrows surrounding the direction in which the steering wheel should be steered can be displayed by lighting. .

FIG. 2 illustrates a state in which the indicator 24 is lit, thereby indicating that the steering wheel should be turned counterclockwise. Note that the indicator portion is not limited to the arrow-shaped one shown in the present embodiment, but may be an LED or a liquid crystal display panel using character characters or the like.

The ROM 29 has a CPU 27 to be described later.
In addition to the processing procedure described above, a range of the steering angle of the drive wheel 4 that can execute each traveling mode, that is, a limit steering angle is stored.

In FIG. 1, reference numeral 28 denotes a RAM serving as a working memory, reference numerals 30 and 31 denote input / output interfaces, respectively, and reference numeral 32 denotes a lighting controller for the indicators 24 and 25.

[0018]

The operation of the present invention configured as described above will be described with reference to the flowchart shown in FIG.
For convenience of explanation, it is assumed in this example that the handle 3 and the drive wheel 4 rotate in the same direction.

First, when the driver of the forklift 1 turns on an arbitrary mode selection switch to switch the driving mode, it is determined whether or not the driving mode is the same as the currently selected driving mode (S1). The running mode is executed as it is.

When the selected traveling mode is different from the previous traveling mode (N in S1), the traveling of the forklift is stopped (S1).
2) The drive wheel limit steering angles θDR and θDL in the drive mode are read from the ROM 29 into the RAM 28 (S3). Here, θDR is, as schematically shown in FIG.
This is the rightmost angle of the limit steering angle, and θDL is the leftmost angle.

Next, the current actual steering angle θD of the drive wheel 4 is read into the RAM 28 (S4), and the actual steering angle θ is read.
D and the right end angle θDR of the limit steering angle (S
5).

As schematically shown in FIG. 4, when the actual steering angle θD of the drive wheel 4 is larger than the right end angle θDR of the limit steering angle (Y in S5), the traveling mode cannot be changed as it is. . Accordingly, in this case, a lighting instruction signal for the left indicator 24 is output, and
A turn-off instruction signal is output to the right indicator 25 (S11). As a result, the driver who looks at the operation display section 40 can turn the steering wheel 3 in the direction indicated by the indicator 24 to position the drive wheel 4 within the range of the limit steering angle.

Similarly, even if step S5 has been cleared, but in step S6 the actual steering angle θD is smaller than the left end angle θDL of the limit steering angle (Y in S6), the traveling mode can be changed. Therefore, a light-off instruction signal is output to the left indicator 24 and a light-on instruction signal is output to the right indicator 25 to increase θD (S12). When the driver who looks at the operation display unit rotates the steering wheel 3 in the direction indicated by the indicator 25, the drive wheel 4 can be positioned within the range of the limit steering angle.

It should be noted that, after steps S11 and S12, the procedure for releasing the restriction of the steering wheel steering range in the previously selected driving mode is included (S10) because of the limit steering in the previously selected driving mode. If the steering angle of the drive wheel is limited by the range of the angle, the steering wheel cannot be turned and the case where the transition to the next selected driving mode cannot be performed is taken.

When steps S5 and S6 are cleared, the steering angle of the drive wheel 4 can be located within the range of the limit steering angle, so that it is possible to shift to the selected driving mode. After restricting the steering range to the range of the selected limit steering angle so as not to go out of the range of the limit steering angle (S7), a turn-off instruction signal is output to all the indicators 24 and 25 (S7). S
8), the running stop is released (S9).

As a result, the forklift does not travel until the change of the traveling mode is completed, so it is safe, and the selected traveling mode is executed thereafter.

The means for limiting the end of the steering angle of the drive wheel is not shown, but it is possible to mechanically move the stopper, or to assist the power steering motor as the drive wheel approaches the limit steering angle. Various methods can be adopted such as reducing the torque and limiting the limit steering angle by generating an assist torque that is equal to the torque applied to the steering wheel in the final direction and that is in the opposite direction.

On the contrary, when the rotation directions of the steering wheel 3 and the drive wheel 4 are transmitted in the reverse direction, the lighting of the indicators 24 and 25 is opposite to that of the present embodiment. Just do it.

[0029]

[Effect of the Invention] The present invention adopts the above configuration,
The driver does not need to recognize the limit steering angle of the drive wheel at all, and the driving mode can be selected without the need for skilled driving skills, so that fatigue during driving can be reduced and workability can be improved. obtain.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a plan view of an operation display unit.

FIG. 3 is a flowchart illustrating a processing procedure of a CPU.

FIG. 4 is a schematic diagram for explaining a limit steering angle.

FIG. 5 is a schematic diagram for explaining a driving mode.

FIG. 6 is a plan view showing an embodiment of a forklift.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Forklift 3 Handle 4 Drive wheel 5 Load wheel 6 Load wheel 18 Potentiometer 21 Mode selection switch 22 Mode selection switch 23 Mode selection switch 24 Indicator 25 Indicator 27 CPU 40 Operation display part

Continuation of front page (56) References JP-A-53-114134 (JP, A) JP-A-1-197174 (JP, A) JP-A-2-169372 (JP, A) JP-A-61-67278 (JP) JP-A-62-146780 (JP, A) JP-A-62-181971 (JP, A) JP-A-4-34176 (JP, U) JP-A-2-32478 (JP, U) (58) Surveyed field (Int.Cl. ⁶ , DB name) B62D 7/14

Claims (1)

(57) [Scope of request for utility model registration] 1. A mode selection switch capable of selecting and inputting a plurality of driving modes, means for storing the left and right limit steering angles of the drive wheel in the driving mode selected by the mode selection switch, Means for detecting a steering angle, and means for comparing a stored left and right limit steering angle of the drive wheel with a detected actual steering angle,
In a forklift capable of traveling in all directions by switching to a plurality of traveling modes, the results of comparison by the comparing means are compared.
As a result, the detected actual steering angle is out of the range of the stored left and right limit steering angles.
When the detected actual steering angle falls within the stored left-right limit steering angle
An omnidirectional forklift comprising a steering indicator for indicating a direction in which a steering wheel should be turned .