JP2001226094A - Hydraulic lift device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide fixed structure of a hydraulic lift cylinder, a reservoir, a hydraulic gear pump, and an electric motor with a small size, lightweight, simple external structure, and easy handling. SOLUTION: This hydraulic lift device is constituted in such a way that an oil passage base 19 is fixed to one end of the hydraulic lift cylinder 12, a piston 13 is allowed to go into and out of the other end of the hydraulic lift cylinder 12, and the reservoir 22 is fixed in a multiplex shape to the outer circumference of the hydraulic lift cylinder 12. In this device, the hydraulic gear pump 28 for driving the hydraulic lift cylinder 12 and the electric motor 29 for driving the hydraulic gear pump 28 are installed in the oil passage base 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic lift device which is mounted on a mast, for example, a lift truck for loading and unloading cargo which is mounted on a mast.

[0002]

Conventionally, there is a lift truck in which a hydraulic lift cylinder is erected between a pair of left and right masts, and a loading platform to be lifted by the hydraulic lift cylinder is mounted between the left and right masts so as to be able to move up and down. However, when the hydraulic lift cylinder is operated electrically, an electric motor, a hydraulic pump, and an oil tank are fixed to an oil passage base to constitute a hydraulic drive unit, and the hydraulic drive units are separately mounted on the hydraulic lift cylinder. Therefore, these mounting structures cannot be easily reduced in size or weight, and the oil passage base and the hydraulic lift cylinder need to be connected by hydraulic piping, which simplifies assembly work and reduces manufacturing costs. There is a problem that it cannot be performed.

[0003]

According to the present invention, an oil passage base is fixed to one end of a hydraulic lift cylinder, and a piston is moved in and out of the other end of the hydraulic lift cylinder. In a hydraulic lift device for fixing tanks in a multiplex form, a hydraulic gear pump for operating the hydraulic lift cylinder and an electric motor for driving the hydraulic gear pump are provided on the oil passage base. Provided on the same shaft core and fixed to the oil passage base, hydraulic gear pump and electric motor are connected and fixed to the oil passage base, and hydraulic lift cylinder and oil tank, hydraulic gear pump and electric motor are arranged on the oil passage base To easily reduce the size or weight of the mounting structure, and to install hydraulic piping such as hydraulic lift cylinders and hydraulic gear pumps. Omitted to simplify and easily performed to obtain a reduction in the manufacturing cost of the assembly operation is to obtain aim to facilitate and improve the simplicity and handling operations of the outer structure.

Further, an electric motor is provided in a multilayer form on a hydraulic gear pump fixed to the oil passage base, and the hydraulic gear pump and the electric motor are connected in the axial direction of the hydraulic lift cylinder, and the hydraulic motor is mounted on the same mounting surface of the oil passage base. The cylinder and the hydraulic gear pump are fixed, and the hydraulic lift cylinder and the hydraulic gear pump are installed on the flat surface of the oil passage base to support the oil tank and the electric motor in a compact manner. In addition, the mounting structure can be simplified easily.

In addition, a manually operated valve for retracting the piston of the hydraulic lift cylinder is provided on the oil passage base,
A switch for operating the electric motor to advance the piston of the hydraulic lift cylinder is provided. The lift of the bed mounted on the lift truck can be easily performed by the switch operation. Performs load operation, performs low-load operation that lowers the loading platform, etc., by manually controlling the valve of the operator, and can easily improve handling operability and reduce manufacturing costs. It is possible to easily extend the working time and the like.

Further, one end of the hydraulic lift cylinder and the oil passage base are screwed and fixed, and a cylinder head is screwed and fixed to the other end of the hydraulic lift cylinder. The hydraulic lift cylinder and oil tank can be easily attached to and detached from the oil passage base, and the working stroke of the piston is different by using the oil passage base to which the hydraulic gear pump and electric motor are fixed. The hydraulic cylinder can be easily mounted interchangeably and the specification of the hydraulic lift cylinder can be easily changed.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a side view of a lift truck, and FIG. 2 is a plan view of the lift truck.
And a pair of left and right masts (2) for loading and unloading the loading platform (1) and a pair of left and right leg frames (4) for supporting a pair of left and right front wheels (3) by hollow pipes made of aluminum alloy. A bogie frame (5) for forming the mast (2) to stand substantially vertically is formed by molding an aluminum alloy casting, and a pair of left and right rear wheels (6) are attached to the bogie frame (5). The mast (2) is provided behind the lower end.

A pair of left and right handle handles (7) are fixed to the rear surface of the upper end side of the mast (2), and the upper ends of the pair of left and right masts (2) are screwed and connected by an upper frame (8). (1) The front surface of the lifting frame (9) is fixed to the rear surface, and a pair of left and right guide rollers (10) made of synthetic resin are rotatably supported on both sides of the rear portion of the lifting frame (9). The guide roller (10) is rotatably fitted in the guide groove (11) to be formed, and the lifting frame (9) is mounted between the left and right masts (2) so as to be movable up and down by two sets of four left and right guide rollers (10). .

Furthermore, a single-acting hydraulic lift cylinder (12) is erected between the left and right masts (2) substantially at the center of the upper surface of the bogie frame (5), and the upper end of the piston (13) of the cylinder (12) is fixed. A pulley (15) is mounted on a pulley stand (14) via a pulley stand (14), and a load wire (16), one end of which is fixed to the luggage carrier (1), is stretched around the pulley (15) to extend and retract the piston (13). The pulley (15) is moved up and down to move the loading platform (1) and the lifting frame (9) up and down. Further, both ends of the beam frame (17) are fixed between the left and right masts (2), and the beam frame (1) is fixed.
7) At the upper end of the cylinder (13) and the load wire (1)
6) The other end is bolted and fixed. Further, a mast base (18) is integrally formed on the upper surface of the carriage frame (5),
The lower ends of the left and right masts (2) are fixed to the mast base (18), and the oil passage base (1) is mounted on the upper surface of the bogie frame (5).
Place 9).

As shown in FIGS. 3 to 5, the oil passage base (1)
9) The lower end of the lift cylinder (12) is detachably fixed to the upper surface side with screws (20), and the lift cylinder (12) is erected on the oil passage base (19). Insert the cylindrical oil tank (2
2) The lower end side is detachably fitted, and the lift cylinder (12) is inserted into the oil tank (22). The lower end of the cylinder head (23) is detachably fixed to the upper end of the lift cylinder (12) with a screw (24), and the fitting part (25) in the middle of the cylinder head (23) is connected to the upper end of the oil tank (22). The piston (13) is removably inserted into the lift cylinder (12) from the upper end side of the cylinder head (23). The lift cylinder (12) is short-circuited to the oil tank (22) through a pressure relief path (26) at the lower end of the piston (13) and a pressure relief port (27) of the cylinder head (23). Hydraulic advance is restricted to prevent falling off. Further, the oil passage base (19) is formed of an aluminum lightweight alloy to reduce the weight and simplify the drilling process.

Further, the hydraulic gear pump (38) is detachably bolted and fixed to the upper surface of the oil passage base (19), and the electric motor (2) is fixed to the upper surface of the hydraulic gear pump (28).
9) is bolted and fixed, and the hydraulic gear pump (28) is driven by the electric motor (29). The oil passage base (19) is inserted into the hole (30) on the upper surface of the bogie frame (5).
The protrusion (31) on the lower surface is detachably engaged and fixed, and the lower end of the lift cylinder (12) is detachably fixed to the upper surface side of the oil passage base (19) with the screw (20).
The lower end of the oil tank (22) is detachably fitted into a circular opening (21) formed on the upper surface, and the lift cylinder (12) and the oil tank (22) are erected and fixed to the oil passage base (19).

Further, as shown in FIGS. 6 to 8, a suction port (32) for supplying hydraulic oil from an oil tank (22) to a hydraulic gear pump (28), and a high pressure oil from the pump (28) to a lift cylinder (28). A discharge valve (33) to be sent out to the oil passage base (19) and a relief valve (34) for setting a maximum lifting operation load of the lift cylinder (12) are provided on the oil passage base (19) and formed on the oil passage base (19). The above-mentioned valves (33) and (34) are connected to the discharge port (35).
Is connected to the oil passage. In addition, a lift cylinder (12) which is opened and closed by operation of a pressure release lever (36), a pressure release valve (37) for lowering operation is provided in the oil path base (19), and a tank port (38) formed in the oil path base (19). (39) connects the suction port (32) and the valves (34) and (37) to the oil passage, and raises and lowers the frame (9) when lowering the lift cylinder (12) by opening the pressure release valve (37). A) A descent prevention valve (40) for setting the descending speed to be adjustable is provided in the oil passage base (19), and a discharge valve (33) and a pressure relief valve (37) are provided in the cylinder port (41) of the oil passage base (19). Is connected to an oil passage via a sudden drop prevention valve (40). Then, by turning on a lift switch (43) for connecting the battery (42) to the electric motor (29), oil in the oil tank (22) is pressure-fed from the hydraulic gear pump (28) to the lift cylinder (12), and the lift frame ( 9) While raising the pressure, releasing the pressure relief valve (37) by rotating the pressure relief lever (36), returning the oil of the lift cylinder (12) to the tank (22) and lowering the lifting frame (9). Thus, a lift truck for electric operation in which the lift cylinder (12) is electrically driven to rise using the hydraulic gear pump (28) is configured.

A power relay (44) is connected to the lift switch (43), and the battery (4) is connected to the electric motor (29) through the contact (45) of the relay (44).
At the same time, a control box (46) is attached to the back of the mast (2) below the handle (7), and a lift switch (43) is attached to the back of the box (46).
A power supply relay (44) is provided inside the box (46), and a wiring (47) for electrically connecting a contact (45) of the relay (44) and the electric motor (29) is provided on the back of the mast (2). Pass through the wiring cover (48). Also,
The battery (42) is provided inside the battery case (49) above the box (46). A battery case (49) is detachably fixed to the hook (50) of the mast (2), the battery case (49) is removed to charge the battery (42), and the control box (46) and the battery The front and rear width of the handle (7) is made larger than the front and rear width of the case (49) to prevent collision damage of the box (46) and the case (49).

As is apparent from the above, the oil passage base (19) is fixed to one end of the hydraulic lift cylinder (12), and the piston (13) is moved in and out of the other end of the hydraulic lift cylinder (12). Hydraulic lift cylinder (1
2) A hydraulic lift device for fixing an oil tank (22) to the outer periphery of the hydraulic lift cylinder (1).
A hydraulic gear pump (28) for operating the hydraulic pump (28) and an electric motor (29) for driving the hydraulic gear pump (28) are provided on the oil passage base (19).
2) and the oil tank (22) are provided on substantially the same axis and fixed to the oil passage base (19), and the hydraulic gear pump (28) and the electric motor (29) are connected in series to the oil passage base (19). Fix the hydraulic lift cylinder (12) and oil tank (2
2) and hydraulic gear pump (28) and electric motor (2)
9) is disposed on the oil passage base (19) to reduce the size or weight of the mounting structure, and to increase the hydraulic lift cylinder (1).
2) and omitting the hydraulic piping such as the hydraulic gear pump (28) to simplify the assembling work and reduce the manufacturing cost, and to simplify the external structure and improve handling operability.

An electric motor (29) is provided in a multilayer form on a hydraulic gear pump (28) fixed to the oil passage base (19), and the hydraulic gear pump (28) and the electric motor (29) are connected to the hydraulic lift cylinder (12). ), The hydraulic cylinder (12) and the hydraulic gear pump (28) are fixed to the same mounting surface of the oil passage base (19), and the hydraulic lift cylinder (1) is fixed to the flat surface of the oil passage base (19).
2) and a hydraulic gear pump (28).
2) and the electric motor (29) are compactly supported, and the assembling work for a lift truck and the like and the mounting structure are simplified with a small and lightweight structure.

A pressure relief valve (37), which is a manually operated valve for retracting the piston (13) of the hydraulic lift cylinder (12), is provided on the oil passage base (19), and the electric motor (29) is operated. Hydraulic lift cylinder (1
The lift switch (4) that advances the piston (13) of 2)
3) is provided, and the loading platform (1) mounted on the lift truck can be lifted by operating the lift switch (43);
The hydraulic lift cylinder (12) is electrically operated to perform a high-load operation by performing a high-load operation to save lifting work, and a low-load operation is performed by lowering the carrier (1) and the like by controlling a manually operated valve (37) of an operator. The electric control for the descending side is omitted, the handling operability is improved, and the electric parts for reciprocating the piston (13) are not required, so that the manufacturing cost is reduced, and both the advance and retreat of the piston (13) are electrically controlled. Battery (42) of the electric motor (29)
Reduce the power consumption and extend the continuous working time.

Further, one end of the hydraulic lift cylinder (12) and the oil passage base (19) are screwed and fixed, and a cylinder head (23) is screwed to the other end of the hydraulic lift cylinder (12). The oil tank (22) is fixed between the oil passage base (19) and the cylinder head (23), and the hydraulic lift cylinder (12) and the oil tank (2) are fixed.
2) is detachably fixed to the oil passage base (19), and the working stroke of the piston (13) is different by using the oil passage base (19) to which the hydraulic gear pump (28) and the electric motor (29) are fixed. The hydraulic cylinder (12) is interchangeably mounted, and specifications such as a stroke change of the hydraulic lift cylinder (12) can be changed using the oil passage base (19).

FIG. 9 shows a modification of the above-mentioned FIG. 2. In FIG. 2, the oil passage base (19) is provided on the bogie frame (5) in the front-rear direction. ) Is placed on the top of the bogie frame (5) sideways, and the gear pump (2) is placed between one mast (2) and the lift cylinder (12).
8) and the electric motor (29) are arranged, and the gear pump (28) and the electric motor (29) are connected to the bogie frame (5).
Control box (46) on the upper surface of the bogie frame (5) between the other mast (2) and the lift cylinder (12).
The battery (42) is provided inside the box (46) so as to be able to be taken out, and a foot pedal (51) for operating an up switch (43) is attached to the box (46). The lifting switch (43) is turned on by the stepping operation of the pedal to raise the bed (1), and the operator grips the handle (7) with his / her hand while pressing the pedal (5).
1) can be operated, and a heavy battery (42) is provided at a low position to lower the center of gravity of the lift truck, thereby preventing the lift truck from tipping over.

FIG. 10 shows a modification of FIG. 2, in which a power supply relay (44) is attached adjacent to the electric motor (29), and the power supply relay (44) is attached to the left and right mast bases (18) of the base frame (5). A rear cover (52) that also serves as a rear bumper frame is fixed, and an oil passage base (19), a hydraulic gear pump (28) and an electric motor (29) on the upper surface are
The rear side of the power relay (44) is surrounded by a rear cover (52) to prevent collision damage and to prevent the rear cover (5).
A battery case (49) is provided in the surrounding of (2) to store the battery (42) to prevent the battery from tipping over or the battery (42).
For protection.

[0020]

As is apparent from the above embodiments, the present invention has an oil passage base (19) fixed to one end of a hydraulic lift cylinder (12) and a piston (19) mounted to the other end of the hydraulic lift cylinder (12). 13) A hydraulic gear pump (28) for operating the hydraulic lift cylinder (12) in a hydraulic lift apparatus for moving the hydraulic lift cylinder (12) in and out of the hydraulic lift cylinder (12).
And an electric motor (2) for driving a hydraulic gear pump (28).
9) is provided on the oil passage base (19). The hydraulic lift cylinder (12) and the oil tank (22) are provided on substantially the same axis and fixed to the oil passage base (19). (28) and the electric motor (29) are connected to each other and fixed to the oil passage base (19).
2) and oil tank (22) and hydraulic gear pump (28)
In addition, the electric motor (29) is disposed on the oil passage base (19) so that the mounting structure can be easily reduced in size or weight, and the hydraulic pressure of the hydraulic lift cylinder (12) and the hydraulic gear pump (28) can be reduced. By omitting piping, simplification of assembly work and reduction of manufacturing cost can be easily performed, and simplification of external structure and improvement of handling operability can be easily achieved.

An electric motor (29) is provided in a multilayer form on a hydraulic gear pump (28) fixed to the oil passage base (19), and the hydraulic gear pump (28) and the electric motor (29) are connected to the hydraulic lift cylinder (12). ), The hydraulic cylinder (12) and the hydraulic gear pump (28) are fixed on the same mounting surface of the oil passage base (19), and the hydraulic lift is mounted on the flat surface of the oil passage base (19). The cylinder (12) and the hydraulic gear pump (28) are provided to support the oil tank (22) and the electric motor (29) compactly, and the compact and lightweight structure facilitates assembly work on lift trucks and simplification of the mounting structure. It can be aimed at.

A manually operated valve (37) for retracting the piston (13) of the hydraulic lift cylinder (12) is provided on the oil passage base (19), and the electric motor (29) is provided.
A switch (43) is provided for causing the piston (13) of the hydraulic lift cylinder (12) to advance by operating the lift truck. The lift of the bed (1) attached to the lift truck is easily performed by operating the switch (43). The hydraulic lift cylinder (12) can be electrically operated to perform a high-load operation by raising the hydraulic lift cylinder (12).
A low-load operation of lowering the bed (1) or the like is performed by control, so that handling operability can be improved and manufacturing cost can be easily reduced, and continuous operation can be performed by reducing the power consumption of the battery (42) of the electric motor (29). It is possible to easily extend the working time and the like.

Further, one end of the hydraulic lift cylinder (12) and the oil passage base (19) are screwed and fixed, and a cylinder head (23) is screwed to the other end of the hydraulic lift cylinder (12). The hydraulic lift cylinder (12) and the oil tank (22) are fixed by holding the oil tank (22) between the oil passage base (19) and the cylinder head (23). ) Can be easily attached and detached,
Piston (13) serving also as oil passage base (19) to which hydraulic gear pump (28) and electric motor (29) are fixed
Hydraulic cylinders (12) having different working strokes can be easily and interchangeably mounted, and specifications of the hydraulic lift cylinder (12) can be easily changed.

[Brief description of the drawings]

FIG. 1 is a side view of a lift truck.

FIG. 2 is an enlarged explanatory view of the same plane.

FIG. 3 is an exploded view of the lift cylinder.

FIG. 4 is an explanatory view of mounting a hydraulic gear pump.

FIG. 5 is an enlarged view of FIG.

FIG. 6 is a plan view of an oil passage base for electric operation.

FIG. 7 is an explanatory plan view of the same.

FIG. 8 is a hydraulic circuit diagram for electric operation.

FIG. 9 is an explanatory view showing a modification of FIG. 2;

FIG. 10 is an explanatory view showing a modification of FIG. 2;

[Explanation of symbols]

 (12) Hydraulic lift cylinder (13) Piston (19) Oil passage base (22) Oil tank (23) Cylinder head (28) Hydraulic gear pump (29) Electric motor (37) Depressurizing valve (manually operated valve) (43) Lift switch

Claims (4)

[Claims] 1. A hydraulic lift device in which an oil passage base is fixed to one end of a hydraulic lift cylinder, a piston moves in and out of the other end of the hydraulic lift cylinder, and an oil tank is fixed in a multiplex form on the outer periphery of the hydraulic lift cylinder. A hydraulic gear pump that operates the hydraulic lift cylinder;
A hydraulic lift device, wherein an electric motor for driving a hydraulic gear pump is provided on the oil passage base. 2. A multi-layered electric motor is provided on a hydraulic gear pump fixed to an oil passage base, and the hydraulic gear pump and the electric motor are connected in the axial direction of the hydraulic lift cylinder. The hydraulic lift device according to claim 1, wherein the cylinder and the hydraulic gear pump are fixed. 3. A hydraulic valve according to claim 1, further comprising a manually operated valve for retracting the piston of the hydraulic lift cylinder, and a switch for operating the electric motor to advance the piston of the hydraulic lift cylinder. 2. The hydraulic lift device according to 1. 4. An oil passage base is screwed and fixed to one end of a hydraulic lift cylinder, and a cylinder head is screwed and fixed to another end of the hydraulic lift cylinder. 2. The hydraulic lift device according to claim 1, wherein an oil tank is sandwiched and fixed to the hydraulic lift device.