JP3665241B2 - Forklift with side shift - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a forklift with a side shift such as a counterbalance type forklift or a reach type forklift capable of side shifting a fork.
[0002]
[Prior art]
Conventionally, an example of this type of forklift with side shift is shown in FIG. This is a counterbalance type forklift, in which a pair of left and right outer masts 2 are installed in a tiltable manner at the front portion of the vehicle body 1, and a pair of left and right inner masts 3 are fitted to both the outer masts 2 so as to be movable up and down. ing. Further, lift brackets 5 are arranged on both inner masts 3 via guide rollers 4 so as to be movable up and down, shift brackets 6 are arranged on the lift brackets 5 so as to be horizontally movable, and a pair of left and right forks 7 is arranged on the shift brackets 6. A shift cylinder 8 is provided between the lift bracket 5 and the shift bracket 6. When the shift cylinder 8 is extended and contracted, the shift bracket 6 and the fork 7 are side-shifted. The position in the left-right direction can be adjusted. Reference numeral 9 denotes a hydraulic unit provided in the vehicle body 1, and 10 denotes an operation unit including a steering handle 10 a, a lift switching lever 10 b, and a side shift switching lever 10 c.
[0003]
A lift cylinder 11 is erected along the masts 2 and 3, and a piston rod tip is connected to the inner mast 3 via a support shaft 12. A sprocket wheel 13 is rotatably fitted on the support shaft 12, One end of a chain (not shown) wound around the sprocket wheel 13 is connected to the lift bracket 5, and the other end of the chain is connected to the outer mast 2. The height position of the fork 7 can be adjusted by raising and lowering the inner mast 3 and the lift bracket 5. Reference numeral 14 denotes a battery.
[0004]
[Problems to be solved by the invention]
In the above conventional configuration, two relatively thick hydraulic hoses (not shown) connecting the shift cylinder 8 and the hydraulic unit 9 are hung between the inner masts 3 via the concentric reels with the sprocket wheel 13. Therefore, the visibility is hindered by both of the hydraulic hoses, which may hinder the visual handling operation. Further, since each hydraulic hose is forcibly bent with a small radius of curvature around the reel, oil leakage is less likely to occur and the life is short. Furthermore, each hydraulic hose is long and expensive to manufacture.
[0005]
Therefore, it is conceivable to attach an electric actuator to the lift bracket 5 and thereby shift the shift bracket 6 and the fork 7 side by side. However, since the electric actuator is large, the field of view also deteriorates, It is expensive and expensive to manufacture.
[0006]
An object of the present invention is to provide a forklift with a side shift that has good visibility, can maintain a long life, and is inexpensive to manufacture.
[0007]
[Means for Solving the Problems]
To achieve the above object, according to the present invention , a lift bracket is disposed on a mast on a vehicle body so as to be movable up and down, a shift bracket is disposed on the lift bracket so as to be horizontally movable, a fork is attached to the shift bracket, and the lift A shift cylinder is provided between the bracket and the shift bracket. In the forklift with side shift, in which the shift bracket and the fork are side-shifted by extending and contracting the shift cylinder, the hydraulic unit of the shift cylinder includes Mounted on the lift bracket, the shift cylinder is composed of a double rod cylinder, the hydraulic unit is composed of a bidirectional hydraulic pump with a motor, and the bidirectional hydraulic pump is directly connected to the double rod cylinder to provide a hydraulic circuit. Oil tongue It is characterized in that there as no sealed structure.
[0008]
According to the above configuration, the hydraulic unit is attached to the lift bracket and is close to the shift cylinder, and the hydraulic hose that connects the two is not hung between the inner masts as in the prior art. It is possible to easily carry out the cargo handling work visually. In addition, since the hydraulic hose is not forced to be bent as in the conventional case, oil leakage hardly occurs and the life can be kept long. Furthermore, the hydraulic hose can be shortened as much as it is not masted, and the production cost is low.
[0009]
Further , according to the above configuration, an oil tank is not required by directly connecting a hydraulic unit including a bidirectional hydraulic pump with a motor to a shift cylinder including both rod cylinders. Since no filter is required, the manufacturing cost can be reduced by downsizing the hydraulic unit.
[0010]
According to a second aspect of the present invention, in the first aspect of the present invention, the hydraulic unit is disposed in front of the mast.
[0011]
According to the above configuration, the hydraulic unit is hidden behind the mast, and the visual field is not obstructed by the hydraulic unit, so that the visual loading operation can be performed more easily.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
1 to 5 show a forklift with a side shift according to an embodiment of the present invention, and a receiving shelf 16 extending from the lift bracket 5 to the front of the right and left masts 2 and 3 is provided. The hydraulic unit 9 is disposed on the receiving shelf 16, and the hydraulic unit 9 and the shift cylinder 8 are directly connected by a hydraulic hose 17. Reference numeral 18 denotes a substantially U-shaped backrest fixed to the shift bracket 6, in which the hydraulic unit 9 is housed. In the configuration other than the above, the same parts as those in the conventional example shown in FIG.
[0013]
According to the above configuration, the hydraulic unit 9 is attached to the lift bracket 5 via the receiving shelf 16 and is brought close to the shift cylinder 8, and the hydraulic hose 17 connecting the both 8 and 9 is provided on both inner masts as in the prior art. Since it is not hung between three, the visual field is not obstructed by the hydraulic hose 17 and the cargo handling work by visual observation can be easily performed. Further, since the hydraulic hose 17 is not forcedly bent as in the conventional case, oil leakage hardly occurs and the life can be kept long. Further, since the hydraulic hose 17 is short, the production cost is low.
[0014]
Further, since the hydraulic hose 17 is hidden behind the right and left masts 2 and 3 on the right side and the visual field is not obstructed by the hydraulic unit 9, it is possible to carry out the cargo handling work visually.
[0015]
The shift cylinder 8 is composed of a double rod cylinder, the cylinder body 8a is fixed to the lift bracket 5, and both the piston rods 8b are formed on the upper side of the shift bracket 6 formed in a substantially square shape via a connector 19. It is connected to the crosspiece 6a.
[0016]
As shown in FIG. 6, the hydraulic unit 9 is composed of a bidirectional hydraulic pump 9b driven by a motor 9a, and an electric wire 20 connecting the motor 9a and the battery 14 is connected to a sprocket wheel 13 via a concentric reel 21. It is hung between both inner masts 3. In addition, since the said electric wire 20 is thin, a visual field is hardly disturbed.
[0017]
According to the above configuration, since the hydraulic unit 9 including the bidirectional hydraulic pump 9b with the motor 9a is directly connected to the shift cylinder 8 including both rod cylinders, an oil tank is not necessary and the hydraulic circuit has a sealed structure. Therefore, an oil filter is also unnecessary, and thereby the hydraulic unit 9 can be reduced in size and the manufacturing cost can be reduced.
[0018]
In FIG. 6, 22 is an overcurrent prevention circuit connected to the battery 14, and when the current value detected by the overcurrent detector exceeds a predetermined value, the circuit is cut off by operating the cutoff switch. As a result, the relief valve of the hydraulic circuit can be omitted, the hydraulic unit 9 can be downsized, and the manufacturing cost can be reduced. Reference numeral 23 denotes a change-over switch for turning on / off the motor 9a.
[0019]
In the above configuration, when performing a cargo handling operation, the lift cylinder 11 is extended and retracted by operating the lift switching lever 10b, so that the inner mast 3 and the lift bracket 5 are moved up and down, and the height position of the fork 7 is adjusted. Further, the shift switch 23 is turned on to operate the hydraulic unit 9, and the side shift switching lever 10c is operated to extend and retract the shift cylinder 8 interlocked with the lever 10c. 7 is side-shifted in the directions of arrows a and b to adjust the position of the fork 7 in the left-right direction, whereby the tip of the fork 7 can be quickly and easily positioned on a pallet, for example.
[0020]
【The invention's effect】
According to the first aspect of the present invention, the hydraulic unit is attached to the lift bracket and approached to the shift cylinder, and the hydraulic hose connecting the two is not hung between the inner masts as in the prior art. The visibility is not hindered by the hydraulic hose, and the cargo handling work can be easily performed visually. In addition, since the hydraulic hose is not forced to be bent as in the conventional case, oil leakage hardly occurs and the life can be kept long. Furthermore, the hydraulic hose can be shortened as much as it is not masted, and the production cost is low.
[0021]
According to the first aspect of the present invention, an oil tank is not required by directly connecting a hydraulic unit composed of a bidirectional hydraulic pump with a motor to a shift cylinder composed of a double rod cylinder, and the hydraulic circuit has a sealed structure. This eliminates the need for an oil filter, thereby reducing the size of the hydraulic unit and reducing the production cost.
[0022]
According to the second aspect of the present invention, the hydraulic unit is hidden behind the mast, and the visual field is not obstructed by the hydraulic unit, so that the cargo handling work by visual inspection can be performed more easily.
[Brief description of the drawings]
FIG. 1 is a side view showing a forklift with side shift according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of the main part.
FIG. 3 is a front view of the main part.
FIG. 4 is a partially cutaway plan view of the main part.
FIG. 5 is a perspective view of the main part.
FIG. 6 is a schematic explanatory diagram of the main part.
FIG. 7 is a side view showing a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vehicle body 2 Outer mast 3 Inner mast 5 Lift bracket 6 Shift bracket 7 Fork 8 Shift cylinder 9 Hydraulic unit 9a Motor 9b Bidirectional hydraulic pump 16 Receptacle

Claims (2)

A lift bracket is disposed on the mast on the vehicle body so as to be movable up and down, a shift bracket is disposed on the lift bracket so as to be horizontally movable, a fork is attached to the shift bracket, and a shift cylinder is disposed between the lift bracket and the shift bracket. In the forklift with a side shift, wherein the shift bracket and the fork are side-shifted by extending and contracting the shift cylinder, the hydraulic unit of the shift cylinder is attached to the lift bracket, and the shift bracket JP that with cylinder composed of a double rod cylinder, the hydraulic unit is composed of a bidirectional hydraulic pump with motor, is a hydraulic circuit connected directly to the bidirectional hydraulic pump to the double-rod cylinder, if not sealed structure of an oil tank Side shift with a forklift to.   The forklift with a side shift according to claim 1, wherein the hydraulic unit is disposed in front of the mast.

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