JPH10236313A - Working vehicle for loading and unloading - Google Patents

Abstract

PROBLEM TO BE SOLVED: To preclude oil leakage only through replacement of a valve case in a fit hole provided in a hydraulic base even in case a valve seat on the valve case is deformed due to wear, etc., which may bring about occurrence of oil leak. SOLUTION: A working vehicle for loading and unloading comprises a hydraulically elevating/sinking cylinder to support a loading table with possibility of elevating and sinking, a hydraulic pump to driven the cylinder, and an elevating, sinking, and stopping valve case 45 furnished with an oil tank and changes over the connection between the elevating/sinking cylinder and the pump and oil tank, wherein the hydraulic base 10 for fixing the cylinder rigidity is provided with a fit hole 47 in which the valve case 45 is inserted fast removably.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cargo handling vehicle such as a hand lift truck for carrying loads loaded on pallets.

[0002]

Conventionally, a fork-type carrier having a front wheel at the front end, a hydraulic lifting cylinder supporting a rear wheel at a lower portion and supporting the rear end of the carrier, and a lifting cylinder A plunger-type hydraulic pump for driving the pump. Then there was a hand lift truck that carried the luggage. In the related art, an oil passage connecting the elevating cylinder, a hydraulic pump, and an oil tank is formed on a hydraulic base that integrally fixes an elevating cylinder, and a valve seat is formed in the oil passage, and the elevating and lowering is performed. Since the pressure ball and the suction ball for switching the connection between the cylinder, the hydraulic pump and the oil tank were inserted into the oil passage via the valve seat, when the valve seat was deformed by the contact of the pressure ball and the suction ball, the jig was removed. It was necessary to shape the valve seat to prevent oil leakage, and it was necessary for a specialized technician having special technology to perform repair using a special jig.

[0003]

SUMMARY OF THE INVENTION Accordingly, the present invention relates to a loading / unloading vehicle having a hydraulic lifting cylinder for supporting a loading platform so as to be able to lift and lower, a hydraulic pump for driving the lifting cylinder, and an oil tank. A valve case for raising, lowering and stopping operation for switching connection between a hydraulic pump and an oil tank is provided, and a fitting hole for detachably inserting and fixing the valve case is formed in a hydraulic base for integrally fixing the lift cylinder. By forming a valve seat inside the valve case and inserting a pressure ball and a suction ball for switching the connection between the lifting cylinder, the hydraulic pump and the oil tank into the valve case, the valve seat of the valve case is worn. Even if oil leakage occurs due to deformation, etc., oil leakage can be prevented simply by attaching and removing the valve case to the fitting hole of the hydraulic base and replacing it. , Obtained will repair in a short time by a simple technique than the conventional use location, in which the like improve handling operability obtain aim easily.

[0004]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 is a sectional view of a hydraulic base, FIG. 2 is a side view of a hand lift truck, FIG. 3 is a side view of an elevating cylinder unit, and FIG. 4 is a plan view of the hydraulic base.
Is a bifurcated fork-type carrier having front running wheels (2) and (2) attached to the front end so as to protrude downward, and (3) supports the rear running wheels (4) and (4) at a lower portion. A jack device for supporting and lowering the rear end of the loading platform (1), (5) a hydraulic lifting cylinder for mounting rear wheels (4) and (4) at a lower end via an axle (6), and (7) a loading platform (1). (1) a ram piston for bringing the hemispherical tip (9) into contact with the chevron support (8);
Reference numeral 0) denotes a hydraulic base integrally fixed to the middle of the cylinder (5), and (11) is provided on the outer side of the cylinder (5) below the base (10) so as to be freely rotatable horizontally and above the piston (7). A bearing plate for connecting the arm (12) and the rod (13) for projecting the front wheel (2) in proportion to the movement; and (14) an oil tank fixedly mounted on an outer peripheral side of the cylinder (5) on the upper surface of the base (10) , (15) are plunger type hydraulic pumps for sending pressure oil to the cylinder (5), (1)
6) is a handle base bracket fixed above the back of the tank (14), and (17) is the bracket (1).
6) a handle base for supporting a pressure roll (20), which is supported by a rotation fulcrum pin (18) via a rotation fulcrum pin (18) and abuts against a plunger piston (19) of the pump (15); And a pumping handle for raising and lowering operation and pushing and pulling operation in which a loop-shaped grip portion (22) is provided and a base end is connected and fixed to the handle base (17).

[0005] Further, as shown in FIG.
0) is provided with a hydraulic pressure switching valve (23) and an overload prevention valve (24). And, via the ball-shaped suction ball (25) of the switching valve (23), the tank port (26)
Is connected to a pump port (27), and the pump port (27) is connected to a cylinder port (29) via a pressure ball (28) of the valve (23), respectively. A back pressure spring (31) and a throttle spool (32) are provided in a back pressure chamber between the plugs (30) to be sealed, and the back pressure of the pressure ball (28) is set to substantially the same value as the oil pressure of the cylinder (5). When the hydraulic pump (15) is operated, hydraulic oil in the tank (14) is sucked through the suction ball (25), and the pressure ball (28) is opened against the back pressure spring (31) to open the cylinder ( 5) The pressure oil is sent to 5) to lift the loading platform (1).

Further, a push rod (34) for depressurizing is provided in the switching valve (23), and the push rod (34) is pushed in against the return spring (35).
Only the suction ball (25) is kept open and the hydraulic pump (15)
The switching valve (23) is switched to a neutral operation state in order to perform idle operation, and is moved by a push-pull operation and a horizontal rotation operation of the handle (21). On the other hand, by further pushing the push rod (34), the suction ball (25) is brought into contact with the pressure ball (28), and the pressure ball (28) and the throttle spool (28) are pressed against the back pressure spring (31). 32) is opened, the cylinder port (29) is connected to the tank port (26), and the pressure oil of the cylinder (5) is discharged at a desired flow pressure by the throttle action of the pressure ball (28) and the throttle spool (32). It is configured to return to the tank (14) and lower the loading platform (1).

Further, the pumping handle (21)
A cap (36) is fixed to the upper end, and the cap (3
The base end of the hydraulic operation switching lever (37) is inserted into the internal space of (6), and the pin (3) fixed to the cap (36) is inserted.
8), the base end of the lever (37) is rotatably supported, and a suspension rod (39) is loosely inserted into the internal space of the handle (21), and the rod (39) is inserted into the lever (37). Hook the upper hook. One end of an L-shaped hydraulic operating arm (40) is brought into contact with the outer end of the push rod (34) projecting from the side of the base (10), and the middle of the arm (40) is pinned to the flange of the base (10). (41), and the other end of the arm (40) is extended on the upper surface of the base (10) between the oil tank (14) and the hydraulic pump (15). A suspension bolt (42) is fixed to the end so as to be adjustable in length. The lower end of the rod (39) and the upper end of the bolt (42) are connected by a chain (43).
3) A handle base bracket (16) for allowing the handle (21) to bend freely in the swinging direction of the handle (21) and for inserting the inner ends of the left and right pivot pins (18) and (18).
A chain guide pin (44) is installed on the rear side of the bearing part of
When the handle (21) is swung and rotated about the rotation fulcrum pins (18) and (18), the chain (43)
The middle is brought into contact with the guide pin (44) to make the chain (4
3) is bent, and the chain (43) is moved by the hydraulic pump (1).
5) to prevent contact with the rotation fulcrum pin (1).
8) The axis of (18) is substantially aligned with the bent portion of the chain (43), and the chain (43) is bent with the valve (23) and the arm (40) stationary at a fixed position, and the handle is The hydraulic pump (15) can be operated by swinging (21).

Further, as shown in FIGS. 1, 5 to 7,
The suction ball (25), the pressure ball (28), and the throttle provided with a valve case (45) for raising, lowering, and stopping operations, and switching connection of a lifting cylinder (5), a hydraulic pump (15), and an oil tank (14). The spool (32) and the back pressure spring (31) are inserted into the valve case (45) via the plug (30), and the return spring (35) is inserted into the end of the valve case (45) opposite to the plug (30). ), The end of the push rod (34) is inserted, and the end of the push rod (34) is arranged to face the suction ball (25). ) Forming a throttle passage (46) between the inner peripheral surfaces;
The pressure oil of the lifting cylinder (5) is returned to the oil tank (14) through the throttle passage (46), and the valve case (4) is
The back pressure spring (31), the throttle spool (32) and the pressure ball (2) are removed by attaching and detaching the plug (30) to be screwed to 5).
8) and the suction ball (25) are moved into and out of the valve case (45), and the valve case (45) is detachably screwed and fixed to the fitting hole (47) of the hydraulic base (10). 28) or when the valve seat portion of the valve case (45) with which the suction ball (25) abuts is worn and deformed, the valve case (45) is detached and replaced, and the pressure ball (28) or the suction ball (25) valve seat portion is replaced. It is configured to repair oil leaks at

As is apparent from the above description, a hydraulic lifting cylinder (5) for supporting the loading platform (1) so as to be able to move up and down, a hydraulic pump (15) for driving the lifting cylinder (5), and an oil tank (14). The lifting / lowering cylinder (5), the hydraulic pump (15), and the oil tank (1)
The valve case (45) is provided with a valve base (45) for ascending, descending and stopping operation for switching the connection of 4), and the valve case (45) is detachably attached to a hydraulic base (10) for integrally fixing the lifting cylinder (5). Insertion hole (4
7), a valve seat is formed inside the valve case (45), and a pressure ball (28) and a suction ball () for switching the connection of the lifting cylinder (5), the hydraulic pump (15) and the oil tank (14). 25) into the valve case (45),
Even if the valve seat of the valve case (45) is deformed due to abrasion or the like and oil leakage occurs, it is only necessary to attach and detach the valve case (45) to the fitting hole (47) of the hydraulic base (10) and replace it. It is designed to prevent oil leaks, perform repairs in a shorter time with simpler techniques than before, and improve handling operability at the place of use.

The present embodiment is constructed as described above. When a load loaded on a pallet (not shown) or the like is mounted on the loading platform (1), the switching state shown in FIG. , Pumping handle for push-pull operation (2
When the pumping operation is performed by swinging 1) about the fulcrum pin (18), the tank (14) is moved through the suction ball (25).
Hydraulic oil is sucked into the hydraulic pump (15),
8) and the hydraulic pump (1) via the throttle spool (32).
The pressure oil of 5) is sent to the cylinder (5) by pressure, and the ram piston (7) protrudes to raise the carrier (1).

When the loading platform (1) is moved to an appropriate height while being moved, as shown in FIG. 1, the operation of the switching lever (37) causes the push rod (34) via the operating arm (40). , The suction ball valve (25) is opened and supported, and the valve (23) is switched to the neutral operation state, the hydraulic pump (15) operates idle even if the handle (21) is tilted, and the ram piston ( 7) and the loading platform (1) are fixedly supported at a constant height, and in this state, the handle (21) is pushed and pulled to carry the load, and the handle (21) is tilted around the fulcrum pin (18). When performing the lifting / lowering operation and the push / pull operation, the middle of the chain (43) connecting the suspension rod (39) and the bolt (42) abuts on the guide pin (44), and is placed on the axis of the fulcrum pin (18). The middle part of the chain (43) The song, the fulcrum pin (1
8) Regardless of the displacement of the handle (21) about the center,
The operation arm (40) and the push rod (34) are kept stationary at a fixed position.

Further, when lowering the luggage loaded on the pallet or the like by lowering the luggage carrier (1), as shown in FIG. 7, the switching lever (37) is pulled up and operated via the suspension rod (39) or the like. The arm (40) is displaced, the push rod (34) is pushed in, the suction ball (25) comes into contact with the pressure ball (28), the pressure ball (28) and the throttle spool (32) are opened, and the throttle spool is opened. (32) Throttle passage (4)
Due to the throttle action of 6), the pressure oil of the cylinder (5) is supplied to the tank (14) at a flow rate proportional to the operation of the lever (37).
The ram piston (7) is retracted at a desired speed to lower the carrier (1), and the pallet on the carrier (1) is lowered.

Further, the pressure ball (2
8) and the valve case (4) with which the suction ball (25) abuts.
When the valve seat of (5) is worn and deformed, oil leakage occurs at the pressure ball (28) and the suction ball (25), and the pressure oil of the lifting cylinder (5) comes out, the hydraulic base (10) )
The valve case (45) is detached and replaced with a new one, and the valve case (45) is replaced with an unused valve case (45) to repair an oil leak.

[0014]

As is apparent from the above embodiments, the present invention is directed to a hydraulic lifting cylinder (5) for supporting the loading platform (1) so as to be able to move up and down, and a hydraulic pump (15) for driving the lifting cylinder (5). , A lifting / lowering cylinder (5) and a hydraulic pump (1).
A hydraulic base (1) that includes a valve case (45) for raising, lowering, and stopping operation for switching the connection between the oil tank (14) and the oil tank (14), and integrally fixing the lifting cylinder (5).
0), an insertion hole (47) for detachably inserting and fixing the valve case (45) is formed. A valve seat is formed inside the valve case (45), and the lifting cylinder (5) and By inserting the pressure ball (28) and the suction ball (25) for switching the connection between the hydraulic pump (15) and the oil tank (14) into the valve case (45), the valve seat of the valve case (45) is worn. Even if oil leakage occurs due to deformation due to the insertion hole (4) of the hydraulic base (10),
Oil leakage can be prevented simply by removing and replacing the valve case (45) in 7), repair can be performed in a shorter time with a simpler technique than before, and handling operability can be improved easily. It can be aimed at.

[Brief description of the drawings]

FIG. 1 is a sectional view of a hydraulic base.

FIG. 2 is a side view of the hand lift truck.

FIG. 3 is a side view of a lifting cylinder unit.

FIG. 4 is a plan view of a hydraulic base.

FIG. 5 is an exploded view of the valve case.

FIG. 6 is an explanatory diagram of switching in FIG. 1;

FIG. 7 is an explanatory view of the same.

[Explanation of symbols]

 (1) Loading bed (5) Lift cylinder (10) Hydraulic base (14) Oil tank (15) Hydraulic pump (45) Valve case (47) Fitting hole

Claims (1)

[Claims] 1. A hydraulic lifting cylinder for supporting a loading platform so as to be movable up and down, a hydraulic pump for driving the lifting cylinder,
A loading / unloading work vehicle having an oil tank, comprising a valve case for raising, lowering, and stopping operation for switching the connection between the lifting cylinder, a hydraulic pump, and an oil tank; and a hydraulic base for integrally fixing the lifting cylinder, wherein the valve case is provided. A loading and unloading work vehicle, wherein a fitting hole for detachably inserting and fixing the inside is formed.