JP3904441B2 - Cargo vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cargo handling vehicle, and more particularly, to a cargo handling vehicle including a steering handle that is mounted so as to be swingable in a horizontal direction, such as a low lift truck.
[0002]
[Prior art]
Conventionally, for example, a low lift truck as shown by reference numeral 1 in FIGS. 5 and 6 is known as a cargo handling vehicle.
The low lift truck 1 is provided at a lower portion of the vehicle body 2, a pair of left and right forks 3 that extend forward at a lower portion of the vehicle body 2 and is moved up and down by a predetermined distance. The steering wheel 4 for adjusting the traveling direction of the vehicle body 2, the front wheel 5 provided at the tip of the fork 3, and the upper portion of the vehicle body 2 are attached so as to be swingable in the horizontal direction, and the steering wheel In the state where the steering wheel 6 for adjusting the direction of the wheel 4 and the rear part of the vehicle body 2 are mounted so as to be rotatable between two positions in the vertical direction and the horizontal direction and are positioned in the horizontal direction, Step 7 for forming a space.
[0003]
As shown in FIGS. 6 and 7, the steering handle 6 is operated so as to swing from the neutral position to the left and right within a range of 90 ° with the position along the axial direction of the vehicle being neutral (straight-running state). Similarly, as shown in FIG. 7, the steering wheel 4 is also changed in its rolling direction within a range of 90 ° to the left and right from the neutral position, with the position along the axial direction of the vehicle being neutral. It is like that.
[0004]
Then, the steering handle 6 and the steering wheel 4 are shown in FIG. 8 when the operation amount of the steering handle 6 is θ and the direction change angle (cut angle) of the steering wheel 4 is φ. So that the relationship of θ = φ is maintained so that they are always equal.
That is, the operation amount of the steering handle 6 is set to be the turning angle of the steering wheel 4.
[0005]
[Problems to be solved by the invention]
By the way, in the low lift truck 1 mentioned above, the following improvements are left.
That is, since the operator can move to the side of the vehicle when not riding, the steering handle 6 is swung to the maximum left and right operating angles as indicated by θ1 in FIGS. Although the step 7 is set in a horizontal state and the vehicle is operated in the state of getting in the step 7, the range in which the steering handle 6 can be operated is shown in FIGS. Is limited as indicated by θ2.
Thus, when the operation range of the steering handle 6 is limited, the range of the turning angle of the steering wheel 4 that is turned in synchronization with the steering handle 6 is also the range of θ2 that is the operable range of the steering handle 6. As a result, the turning ability set in the low lift truck 1 cannot be fully utilized.
[0006]
The present invention has been made to solve such a conventional problem, and provides a cargo handling vehicle capable of extracting the turning ability of the cargo handling vehicle even in a specific driving state in the same manner as in a normal driving state. The purpose is to do.
[0007]
[Means for Solving the Problems]
In order to achieve the above-described object, the cargo handling vehicle of the present invention includes a vehicle body, a steering wheel provided on the vehicle body, a steering handle provided on the vehicle body so as to be rotatable in a horizontal direction, and the steering handle. A cargo handling vehicle comprising a steering mechanism that adjusts the direction of the steering wheel according to an operation amount, a step for riding provided in the vehicle body, and a step sensor provided in this step for detecting a riding state. The steering mechanism includes a control unit that sets a correlation between an operation amount of the steering wheel and a turning angle of the steering wheel, and the control unit is configured to control the operation amount of the steering wheel when not riding. Proportionally set the steering wheel turning angle, When the steering wheel operation amount exceeds a predetermined amount, the correlation between the steering wheel turning angle and the steering wheel operation amount is canceled, and the steering wheel is turned in a predetermined cutting mode. Further, the cutting mode is a control mode in which the cutting amount of the steering wheel is changed in a curved manner so as to be gentle between an initial stage and a vicinity of the maximum cutting angle. .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to FIGS. The present embodiment is applied to a low lift truck as in the conventional example shown in FIGS. 5 to 8. Since the main parts of the low lift truck are common, the common parts are denoted by the same reference numerals. To simplify the description.
[0009]
In the present embodiment, the vehicle body 2, the steering wheel 4 provided on the vehicle body 2, the steering handle 6 provided on the vehicle body 2 so as to be swingable in the horizontal direction, and the operation amount of the steering handle 6 are determined. A steering mechanism 10 (see FIG. 1) for adjusting the direction of the steering wheel 4, a step 7 for riding provided in the vehicle body 2, and a step sensor 11 provided in this step 7 for detecting the riding state; The steering mechanism 10 includes a control unit 12 that sets a correlation between an operation amount of the steering handle 6 and a turning angle of the steering wheel 4, and the control unit 12 is a non-loading vehicle. When riding, the steering wheel is proportional to the operation amount of the steering handle 6. And the correlation between the turning angle of the steering wheel 4 and the operation amount of the steering handle 6 is canceled when the operation amount of the steering handle 6 exceeds a predetermined amount when getting on. The steering wheel 4 is cut in a predetermined cutting mode.
[0010]
As shown in FIG. 1, the steering mechanism 10 includes a turning shaft 13 that rotatably supports the steering wheel 4, a bracket 14 that rotatably connects the turning shaft 13 to the vehicle body 2, and the bracket. 14, a speed reducer 15 connected to the steered shaft 13, a hydraulic motor 17 attached to the bracket 46 and meshed with the input gear 16 of the speed reducer 15, and the bracket 14 and is engaged with the input gear 16 to detect the turning angle φ of the steering wheel 4 and to detect the turning angle φ of the steering wheel 4 and the operation amount of the steering handle 6 ( The oil is driven by a potentiometer 19 that detects a swing angle) and an AC motor 20. It pressurizes the hydraulic oil stored in the tank 21 is constituted by a pump 22 supplies the hydraulic oil to the hydraulic motor 17.
[0011]
The potentiometer 18 detects the turning angle φ of the steering wheel 4 and sends it to the control unit 12, and the potentiometer 19 sends the operation amount θ of the steering handle 6 to the control unit 12. The step sensor 11 detects that the operator is on the step 7 in a state where the step 7 is rotated to a position along the horizontal direction, and sends the signal to the control unit 12. Further, the control unit 12 supplies a drive current to the AC motor 20 based on the upper side from the steering handle 6 so as to drive the AC motor 20 either forward or backward.
[0012]
Further, as shown in FIG. 2, the step 7 is rotatably mounted on a pivot shaft 23 fixed to the lower rear side of the vehicle body 2, and a torsion spring 24 mounted on the pivot shaft 23 It is always biased upward.
That is, the torsion spring 24 is attached to the pivot shaft 23 by fitting the coil portion and the pivot shaft 23, and one end of the torsion spring 24 is twisted at the maximum angle in the state where the step is performed. 8, and the other end is in contact with the rear end surface of the vehicle body 2.
Accordingly, the step 7 is urged toward the position along the vertical direction by the elasticity of the torsion spring 224, and the step 7 is held at the position along the vertical direction when not riding. ing.
[0013]
Further, a cam 25 is integrally attached to the step 7 on the same axis as the pivot shaft 23, and the step sensor 11 operated by the cam 25 is attached to the other end of the torsion spring 24. Yes.
The step sensor 11 is actuated by the cam 25 in a state in which the step 7 is rotated to the horizontal position, and outputs the detection signal of the step 7.
[0014]
Further, the step 7 is provided with an engagement arm 26 extending to the opposite side of the pivot shaft 23. This engagement arm 26 is moved into the vehicle body 2 by the rotation of the step 7 in the horizontal direction. By being moved and brought into contact with a stopper 27 provided in the vehicle body 2, the rotation of the step 7 is restrained and the step 7 is held in a horizontal state.
[0015]
The stopper 27 is attached to the vehicle body 2 so as to be movable up and down, and is fixed to a lower end of the locking rod 28, and a locking plate 29 with which the tip of the engaging arm 26 is brought into contact. A buffer spring 30 that is interposed between the locking plate 29 and the vehicle body 2 and biases the locking rod 28 and the locking plate 29 downward, and an upper end portion of the locking rod 28. And a locking nut 31 for preventing the locking rod 28 from moving downward, and a lock for preventing the locking nut 31 from moving. And a nut 32.
[0016]
Further, the control unit 12 is in a non-riding state where the step 7 is rotated to a position along the vertical direction (the position detection of the step 7 is performed by the step sensor 11 being OFF). The hydraulic motor 17 is driven so that the turning angle (steering angle) φ of the steering wheel 4 is equal to the operation angle θ of the steering handle 6, and a signal from the step sensor 11 is input. When the vehicle is getting on and the operation amount of the steering handle 6 exceeds a predetermined amount (for example, 45 °), the correlation between the turning angle φ of the steering wheel 4 and the operation amount θ of the steering handle 6 described above. The relationship is canceled and the turning angle φ of the steering wheel 4 is set to the operation amount of the steering handle 6. No changes, the program that causes cut at a predetermined cut mode is stored in advance.
[0017]
The cutting mode is a control mode in which the cutting amount of the steering wheel 4 is linearly changed to the maximum cutting angle (90 °) as shown by solid lines in FIGS. As shown by a chain line, the control mode is such that the curve changes so as to be gentle in the initial stage of cutting and in the vicinity of the maximum cutting angle.
[0018]
In the cargo handling vehicle 1 according to the present embodiment configured as described above, the information is detected by the potentiometer 19 when the operation amount of the steering handle 6 exceeds 45 ° particularly during operation in the riding state. At the same time, it is sent to the control unit 12.
In the control unit 12, a drive current is supplied to the AC motor 20, and the supply of hydraulic oil to the hydraulic motor 17 is continued regardless of the operation amount of the steering handle 6, thereby the steering wheel. 4 is cut to the maximum cutting angle (90 °).
[0019]
Thus, in the present embodiment, the steering wheel 4 can be cut to the maximum turning angle within the range in which the operator can operate the steering handle 6, and the turning ability can be fully utilized.
[0020]
Then, in the cutting control of the steering wheel 4 when the operation amount of the steering handle 6 exceeds a predetermined amount at the time of boarding, the change of the cutting amount is curved so as to be gentle between the initial stage of cutting and the vicinity of the maximum cutting angle. By changing to, stable steering operation can be performed.
[0021]
Note that the shapes, dimensions, and the like of the constituent members shown in the above embodiment are merely examples, and various changes can be made based on design requirements and the like.
[0022]
【The invention's effect】
As described above, according to the cargo handling vehicle according to claim 1 and claim 2 of the present invention, when the steering wheel is operated in the riding state, the steering wheel is operated with the maximum turning angle by the operation within the operable range. The turning ability can be fully utilized.
According to the cargo handling vehicle of claim 3 of the present invention, in the steering wheel cutting control when the operation amount of the steering wheel exceeds a predetermined amount during riding, the initial stage of cutting and the vicinity of the maximum cutting angle A stable steering operation can be performed by changing the change of the cutting amount in a curve so as to be gradual.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a steering mechanism according to an embodiment of the present invention.
FIG. 2 shows an embodiment of the present invention and is an enlarged longitudinal sectional view of a step attachment portion.
FIG. 3, showing an embodiment of the present invention, is a correlation diagram between a steering wheel operation amount and a wheel cutting angle indicating a control mode of a steering wheel cutting amount;
FIG. 4 shows an embodiment of the present invention and is a diagram showing temporal changes in the amount of cut of a steering wheel.
FIG. 5 is a side view showing an example of a low lift truck as a cargo handling vehicle.
FIG. 6 is a plan view showing an example of a low lift truck as a cargo handling vehicle.
FIG. 7 is a plan view showing a relative positional relationship during operation of a conventional steering wheel and steering wheel.
FIG. 8 is a correlation diagram between an operation amount of a steering wheel and a turning angle of a steering wheel in the related art.
[Explanation of symbols]
1 Low lift truck (loading vehicle)
2 Car body 3 Fork 4 Steering wheel 5 Front wheel 6 Steering handle 7 Step 10 Steering mechanism 11 Step sensor 12 Control unit 13 Steering shaft 14 Bracket 15 Reducer 16 Input gear 17 Hydraulic motor 18 Potentiometer 19 Potentiometer 20 AC motor 21 Oil tank 22 Pump 23 Pivot shaft 24 Torsion spring 25 Cam 26 Engagement arm 27 Stopper 28 Locking rod 29 Locking plate 30 Buffer spring 31 Retaining nut 32 Lock nut

Claims (1)

A vehicle body, a steering wheel provided on the vehicle body, a steering wheel provided on the vehicle body so as to be swingable in a horizontal direction, and a steering mechanism for adjusting the direction of the steering wheel according to an operation amount of the steering wheel A loading vehicle provided in the vehicle body and a step sensor provided in this step for detecting the riding state, wherein the steering mechanism includes an operation amount of the steering wheel and the step A control unit is provided for setting a correlation with the steering wheel turning angle, and the control unit sets the steering wheel turning angle in proportion to the operation amount of the steering wheel when not riding, The operation amount of the steering handle is predetermined. When exceeded, the steering angle of the steering wheel, to release the correlation between the operation amount of the steering wheel, the have been made so as to cut at a predetermined cut mode steering wheel, cut further the A cargo handling vehicle characterized in that the mode is a control mode in which the cutting amount of the steering wheel is changed in a curved manner so as to be gentle between an initial stage and a vicinity of a maximum turning angle .

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