JP3224212B2 - Receiving bed actuator for cargo handling vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for operating a receiving pallet in a cargo handling vehicle, and more particularly to a lifting / lowering body provided on a vehicle body and capable of moving up and down between a predetermined upper limit position and a lower limit position. A movable lifting cylinder, a loading table pivotally supported by the lifting body so as to be able to turn up and down between an upright position and an upside down position with respect to the lifting body; And a single-acting undulating cylinder capable of forcibly rotating the load receiving table operating device.

[0002]

2. Description of the Related Art A loading cradle operating device having the above-mentioned structure is conventionally known as described in, for example, Japanese Patent Publication No. 5-131131.

[0003]

In such a conventional device,
In order to sequentially operate the lifting and lowering operation of the load receiving table and the raising and lowering operation of the lifting and lowering body, the selective supply of the hydraulic oil to the above-mentioned lifting and lowering cylinder and the lifting and lowering cylinder is performed through the switching valve means. In addition, the configuration of an electric circuit for controlling the same becomes complicated, the cost increases, the handling operation tends to be complicated, and the working time tends to be long.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a device for operating a receiving pallet in a cargo-handling vehicle, which can solve the above-mentioned problem of the conventional device and has a simple structure and easy handling. The purpose is.

[0005]

In order to achieve the above object, an object of the present invention is to provide an elevating member provided on a vehicle body and capable of elevating between a predetermined upper limit position and a lower limit position, and driving the elevating member up and down. A single-acting lifting cylinder, a loading table pivotally supported by the lifting body so as to be able to turn up and down between an upright position and an upside down position with respect to the lifting body, and a loading table A lifting / lowering cylinder of a cargo-handling vehicle, comprising a single-acting raising / lowering cylinder capable of forcibly rotating the lifting / lowering cylinder toward a rising side; a common hydraulic supply source in which the lifting / lowering cylinder and the lifting / lowering cylinder are connected in parallel; A first opening / closing valve interposed in a first return oil passage extending from the hydraulic cylinder to the oil tank side, and a second opening / closing valve interposed in a second return oil passage extending from the hoisting cylinder to the oil tank side. The working oil pressure is the undulating cylinder It is characterized by being set to be smaller than the operating pressure.

[0006] In this feature, the "operating oil pressure of a cylinder" means a minimum necessary oil pressure to be supplied to the cylinder in order to always effectively operate the cylinder under normal use conditions. In setting the operating oil pressure of the lifting cylinder to be lower than the operating oil pressure of the hoisting cylinder, at least one of various mechanical factors that determine the magnitude of the operating oil pressure, for example, the lifting cylinder The mechanical configuration of the lifting cylinder, the mechanical configuration of the lifting body drive system that transmits driving force from the lifting cylinder to the lifting body, and the mechanical configuration of the loading tray drive system that transmits driving force from the lifting cylinder to the loading platform. Be considered. More specifically, for example, the piston diameter of the lifting cylinder (and thus the effective pressure receiving area) is relatively large, or conversely, the piston diameter of the undulating cylinder (and therefore the effective pressure receiving area) is relatively small, or To increase the total pressure receiving area by increasing the number of used cylinders, or to reduce the overall pressure receiving area by decreasing the number of undulating cylinders relatively, or to reduce the moment exerted by the lifting cylinder on the elevating body. Various methods, such as making the effective length of the arm relatively long, or conversely, making the effective length of the arm of the moment exerted by the undulating cylinder on the loading table relatively short, or combining these technical means as appropriate Can be considered.

According to the above-mentioned feature of the first aspect of the present invention,
When hydraulic oil is simultaneously supplied from a common hydraulic supply source to the lifting cylinder and the up-and-down cylinder when the lifting body is at the lower limit position and the loading tray is at the down position, Based on the difference (ie, the operating hydraulic pressure of the former cylinder was made smaller than that of the latter cylinder), first, the lifting cylinder was operated to raise the lifting body to the upper limit position, and then the loading tray was moved to the standing position. It can be turned up to the storage state. In addition, if the first or second on-off valve is opened and closed appropriately from this storage state, the lowering operation of the lifting / lowering body and the falling-down operation of the loading table can be appropriately performed. The lowering operation of the body and the falling operation of the load receiving table are performed at the same time, and the state quickly shifts from the stored state to the downwardly expanded state.

According to a second aspect of the present invention, in addition to the features of the first aspect of the invention, a detecting means for detecting that the elevating body has risen to an upper limit position, and the detecting means based on the detecting operation of the detecting means. Control means for stopping supply of hydraulic pressure from the hydraulic supply source to each of the cylinders. According to this feature, when the lifting / lowering body reaches the upper limit position during the supply of the hydraulic pressure to each cylinder, the supply of the hydraulic pressure can be automatically stopped based on the detection operation of the detecting means that detects this. Can be reliably stopped when the lifting / lowering body is at the upper limit position and the loading cradle is in the upwardly-deployed state at the prone position.

The invention according to claim 3 further includes, in addition to the features of the invention described in each of the above claims, control means having an up / down / up / down changeover switch and an up / down changeover switch. When the up / down switch is switched to the up / down position and the up / down switch is switched to the down position from the retracted state where the up / down body is in the upright position and the upper limit position, both the first and second on-off valves are opened. And when the up / down switch is switched to the up / down side and the up / down switch is switched to the lower side from the retracted state, only the second on-off valve is opened. I do. According to this feature, when the up / down switch is switched to the up / down side and the up / down switch is switched to the down side from the retracted state, both the first and second on-off valves are opened. When the lowering operation and the lowering operation of the loading cradle are performed in parallel and the lowering operation of the loading / unloading cradle is performed in parallel, Since only the two on-off valves are opened, the loading cradle moves up and down while the lifting body is held at the upper limit position, and is in the upwardly deployed state.

The invention according to claim 4 further includes, in addition to the features of the invention described in each of the above claims, control means having a lifting / lowering changeover switch and an up / down changeover switch. When the lifting / lowering switch is switched to the raising / lowering side and the upper / lower switching switch is switched to the upper side from the downwardly deployed state where the lifting / lowering body is at the lowering position and the lifting / lowering body is at the lower limit position, the receiving tray supplies the hydraulic pressure to each cylinder. The lifting / lowering switch is switched to the raising / lowering side, and the upper / lower switching switch is switched to the upper side from the lower deployed state, and the lifting / lowering body supplies the hydraulic pressure from the hydraulic supply source to each cylinder. The apparatus is characterized in that the operation is performed until the upper limit position is reached. According to this feature, when the up / down / up / down switch is switched to the up / down side and the up / down switch is switched to the upper side from the lower deployed state, hydraulic pressure supply to each cylinder is continued until the load receiving platform reaches the upright position. Therefore, the lifting operation of the elevating body and the erecting operation of the loading table are sequentially and accurately performed in this order, and the elevating / lowering switch is located on the elevating side and the up / down switching switch is located on the upper side from the lower deployed state. When the switching is performed, the supply of hydraulic pressure from the hydraulic supply source to each cylinder is stopped when the lifting / lowering body reaches the upper limit position, so that the load receiving table is stopped and held in the upwardly deployed state.

According to a fifth aspect of the present invention, in addition to the features of the first to third aspects of the present invention, a backflow of hydraulic oil from each of the cylinders to a hydraulic supply source and a flow of hydraulic oil between the two cylinders are provided. And a valve means for preventing the above. According to this feature, each cylinder is reliably held at the operation position at the time when the supply of the hydraulic pressure to them is stopped, so that the rest position of the loading table can be stabilized, and the lowering operation of the lifting / lowering body can be performed. And the loading / unloading operation of the receiving table can be performed independently of each other.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below based on embodiments of the present invention illustrated in the accompanying drawings.

1 to 9 show a first embodiment of the present invention. FIG. 1 is a side view of a main part of a cargo handling vehicle, and FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 3, FIG. 3 is an enlarged longitudinal sectional view of a main part of the receiving table (sectional view taken along line 3-3 in FIG. 2), FIG. 4 is a sectional view taken along line 4-4 in FIG. 2, FIG. FIG.
FIG. 7 is a side view showing the loading tray in a downwardly-deployed state, FIG. 7 is a perspective view schematically showing main parts of an operation mechanism of the loading tray, FIG. 8 is a hydraulic circuit diagram, FIG. 9 is an electric circuit diagram, and FIG. 11 shows a second embodiment of the present invention. FIG. 10 is a plan view corresponding to FIG. 5, FIG. 11 is a hydraulic circuit diagram, and FIG.
2 and 13 show a third embodiment of the present invention.
Is a sectional view corresponding to FIG. 4, and FIG. 13 is a hydraulic circuit diagram.

First, a first embodiment of the present invention will be described with reference to FIGS. The body B of the cargo handling vehicle has a body frame F,
A cargo box 1 mounted on the body frame F and capable of storing luggage is provided. An opening 1a serving as a luggage doorway is provided at the rear of the luggage box 1, and the opening 1a is arbitrarily opened and closed. An open / close gate (not shown) is provided.

At the rear of the vehicle body B, there is provided a flat rectangular receiving tray G which is used when loading and unloading the cargo into the packing box 1 through the opening 1a. The loading tray G changes from a storage state X standing upright along the rear surface of the packing box 1 to an upper developing state Y expanding rearward at substantially the same height as the packing surface 1b of the packing box 1 as shown in FIG. Then, it can be operated in a range extending downwardly at a height substantially equal to the ground and extending rearward. Next, the structure of the loading tray operating device will be specifically described.

At the lower rear end of the vehicle body frame F, a mounting frame 3 consisting essentially of a rectangular rigid frame is fixedly mounted. At the lower front end of the mounting frame 3, a horizontal rotating shaft extending in the left-right direction is provided. 4 is rotatably supported through. Its rotating shaft 4
The base end of the compression link 5 is fixed to both left and right ends of the mounting frame 3, and the base end of the tension link 6 is pivotally connected to the front part of the mounting frame 3 above the rotation shaft 4 so as to be swingable. You. The two links 5 and 6 extend rearward and upward, respectively, and are vertically connected to the frame-shaped lifting / lowering body L at a pivot connection 2 respectively.
The lifting body L, the links 5, 6, the rotating shaft 4, and the mounting frame 4 cooperate to move the lifting body L between the predetermined upper limit position U and the first lower limit position D '. The parallel link mechanism Li is configured to move up and down while maintaining a constant posture between them. The upper limit position U is regulated by stopper means (not shown) provided at an appropriate position between the lifting body L and the vehicle body B. The first lower limit position D 'is such that the lifting body L comes into contact with the ground. It is regulated by that.

An arm 4a is provided on the outer periphery of the center of the rotation shaft 4.
The arm 4a and the central rear end of the mounting frame 3 are provided with both ends of a single-acting first hydraulic cylinder C _L as a lifting / lowering cylinder interposed therebetween and extending in the front-rear direction. Pivot connections 23 and 24 are provided respectively. When the first hydraulic cylinder _CL is extended, the rotating shaft 4
1 (the compression link 5) can be forcibly rotated in the counterclockwise direction in FIG. 1 to drive the lifting body L from its lower limit position (a second lower limit position D described later) to an upper limit position U.

The left and right elevating bodies L are rotatably supported at the base end of a load receiving table G coaxially with a pivotal connection portion between the left and right lifting elements L and the pulling link 6. G is vertically rotatable between a standing position V that stands substantially vertically with respect to the elevating body L and a falling position H that falls substantially horizontally. Note that the standing position V and the lying position H are regulated by stopper means (not shown) provided at appropriate positions between the load receiving table G and the elevating body L.

On the back side of the receiving tray G,
Both ends are pivotally connected to the end wall and the middle part of the elevating body L, respectively.
25, 26 undulations extending substantially along the back of the cradle
Single acting second hydraulic cylinder C as cylinder_GIs arranged
This cylinder C _GBarrel and piston rod
Between the cylinder C_GSurround it and keep it
A coil return spring 7 biasing in the time contraction direction is interposed.
Thus, against the urging force of the spring 7, the cylinder C_GExtend
When activated, the loading tray G is forced to the upright side for the lifting body L
Can be rotated.

By the way the compression link 5 includes a first link 5 ₁ fixed to the rotation shaft 4 in the illustrated example, the first link 5
₁ and which is more structure to the second link 5 ₂ pivotally connected between lift L, the first and second link 5 _1, 5 Between _2, the first link 5 ₁ of the second link 5 ₂ stopper means S ₁ for preventing a downward refraction is provided for. If the compression link 5 is configured to be able to bend only upward as described above, when the lifting / lowering body L is lowered to the first lower limit position D 'by its own weight of the load receiving table G or the like and its lower end is grounded, the compression link 5 Is slightly bent upward due to the weight moment of the loading tray G (therefore, the parallel link configuration of the parallel link mechanism Li is broken), and the lifting body L is slightly tilted to the second lower limit position D, and the loading tray G is moved. Slightly tilt backward and downward from the horizontal posture. Thus, the level difference between the loading tray G and the ground is reduced, and the loading and unloading of the load between the receiving tray G and the ground can be performed smoothly.

As described above, in the present embodiment, the loading tray G is slightly inclined in the downwardly expanded state Z, but in the present invention, the compression link 5 is not a bending link as shown in the illustrated example, but one rigid body. It is also possible to configure only with the link, and in this case, the loading tray G is maintained in a horizontal posture without being inclined even in the downwardly expanded state Z.

A normally-closed upper limit between the elevating body L and the vehicle body B (in the illustrated example, between the upper end of the tension link 6 and the vehicle body frame F) only when the elevating body L reaches the upper limit position U. A switch LS is provided, and the upper limit switch LS constitutes a detection unit of the present invention for detecting that the elevating body L has risen to the upper limit position U.

[0023] FIG. 8, the first and second hydraulic cylinder C _L, the hydraulic circuit CH actuate C _G is also in FIG. 9, the electrical circuit CE as control means for controlling the hydraulic circuit CH One example is described.

The hydraulic circuit CH includes an oil tank T and this tank
Driven by motor M to pump up oil in T
Pump P as a hydraulic supply source to be used, and this pump
Branched bifurcated from the discharge side of P (and therefore connected in parallel)
First and second hydraulic cylinders C _L, C_GEach in the hydraulic chamber
First and second supply oil passages L communicating with each other₁, L_TwoAnd the
1st and 2nd hydraulic cylinder C_L, C_GFrom the hydraulic chamber of the first
And the second supply oil passage L₁, L_TwoThrough a part of (or without
) First and second return oil passages L extending toward the oil tank T side_Three,
L_FourAnd the first and second return oil passages L_Three, L_FourIn the middle of
First and second on-off valves V interposed respectively₁, V_TwoAnd
Have.

In the illustrated example, each of the on-off valves V ₁ and V ₂ is provided with a corresponding hydraulic cylinder C _L , C
_Although a check valve function for preventing the flow of hydraulic oil from _G to the oil tank T side is provided, a simple shutoff function may be provided instead of such a check valve function. In the illustrated example, the first and second return oil passages L ₃ , L ₄ are connected to the oil tank T via a common variable throttle valve V ₀ by joining their downstream sides. The downstream side of L ₃ and L ₄ may be individually connected to the oil tank T.

Between the hydraulic pump P and the first and second supply oil passages L ₁ and L ₂ , a relief valve V _L for setting an upper limit (for example, 140 kgf / cm ² ) of the output hydraulic pressure of the pump P is provided.
Branches are relief circuit L ₅ having. The stop 10 of the buffer is provided also a second hydraulic cylinder C _G between the second supply oil passage L _2.

Further, the first and second check valves allow only the flow of the hydraulic oil from the hydraulic pump P to the respective cylinders C _L and C _{G in} the first and second supply oil passages L ₁ and L _2. Vc ₁ , V
c ₂ is interposed, respectively, these check valves Vc _1, Vc ₂
Cooperate with each other, the blocking each cylinder C _L, and back flow of hydraulic fluid from C _G hydraulic supply source to the (hydraulic pump P) side, the two cylinders C _L, and a circulation of hydraulic oil between C _G mutually This constitutes a valve means.

In this embodiment, in particular, the operating oil pressure (for example, 9.6 kgf / cm ² ) of the first hydraulic cylinder C _L is set to the second hydraulic cylinder CL.
In order to reduce than the operating pressure (66Kgf / cm ² at Fushimi lying state, for example, receiving platform G) of the hydraulic cylinder C _G, first
The piston diameter of the hydraulic cylinder C _L (for example, 95 mm)
Is made larger than the piston diameter of the hydraulic cylinder C _G (e.g. 45 mm), it is made larger than the pressure receiving area of the former to the latter.

In the electric circuit CE, a driving circuit 13 for the motor M is provided between a pair of power supply lines 11 and 12,
The switch circuit 14 is interposed in parallel. In the drive circuit 13, a motor M and a normally open relay contact r are connected in series with each other. Also the switch circuit 14, a key switch S _k for arbitrarily closing the該路, and "upper" position and a "lower" arbitrarily switching operation possible upper and Shitagiri換switch S _UD to the position "lift "and the position and the" undulations "arbitrarily switching operation possible lifting-relief changeover switch S _LG in position are connected in series, the upper and Shitagiri換switch S _UD, when it is switched to the" upper " and upper contact t _U which is closed only has a lower contact t _D which is closed only when it is switched to "lower", the lift-relief changeover switch S _LG, it is shown in FIG. 9 (a) The first and third contacts t ₁ , which are closed only when switched to the “elevation” side as shown by,
and t _3, and a just closed is the second and fourth contacts t _2, t ₄ when switched to "undulation" side as shown in FIG. 9 (b). The switches S _k , S _UD , and S _LG are installed at appropriate places (not shown) of the vehicle body B so that an operator can easily operate the switches at any time.

The upper contact t of the upper and Shitagiri換switch S _UD
U can be selectively connected to the first and second contacts t ₁ and t ₂ , and the lower contact t _D of the switch _SUD is the third contact t 3
It can be selectively connected to the fourth contacts t ₃ and t ₄ .
The upper limit switch LS and the relay R are connected in series to the first contact t ₁ , and the upper limit switch LS is directly connected to the relay R without the upper limit switch LS connected to the second contact t _2. The first and second contacts t ₃ are connected to the third contact t ₃ .
Is connected to the opening and closing valve V _1, the solenoids SOL ₁ of V _2, SOL _2, wherein the fourth junction t _4, the second on-off valve V ₂
It is connected to the solenoid SOL ₂ only.

Next, the operation of the above embodiment will be described. When unloading the stored luggage in the packing box 1 from the storage state X of the receiving tray G, only the receiving tray G is rotated downward to the lying position H while the lifting / lowering body L is held at the upper limit position U. Table G in packing box 1
In this state Y, the cargo is moved from the inside of the cargo box 1 to the cargo receiving table G in the upwardly unfolded state Y substantially flush with the loading surface 1b. Next, the lifting / lowering body L is rotated downward to the second lower limit position D to bring the load receiving table G to the lower deployed state Z, and the load is moved from the load receiving table G to the ground side. When loading the luggage into the packing box 1 from the ground side, the procedure is reversed.

Next, a specific method for controlling the loading tray G and the elevating body L as described above will be described. In this case when moving the receiving platform G of lower extension state Z to the upper deployed state Y, the lifting-relief changeover switch S _LG toward "lifting", switches respectively upper and Shitagiri換switch S _UD to "upper". As a result, the upper contact t _U and the first contact t ₁ are closed to energize the relay R, and the closing of the relay contact r activates the motor M to drive the hydraulic pump P. , the second hydraulic cylinder C _L, at the same time hydraulic fluid is supplied to the C _G. In this case, both cylinders C _L and C _G
The hydraulic pressure of the magnitude of the difference (i.e. to the working oil pressure of the first cylinder C _L as described above was set smaller than that of the second hydraulic cylinder C _G), a first hydraulic cylinder relatively lightly operated C Only _L first extends (ie the second
To raise the lifting body L from the lower limit position D to the upper limit position U without operating the hydraulic cylinder _CG at all)
Rises while being kept in the horizontal posture (the lying position H).

When the lifting body L reaches the upper limit position U,
The upper limit switch LS is opened and the power supply to the relay R is stopped.
Drive of the motor M, and hence the hydraulic pump P, is stopped
And each cylinder C_L, C_GHydraulic supply to
You. Incidentally, even if the supply of the hydraulic pressure is stopped, the first hydraulic
Da C_LThe hydraulic oil inside is the first check valve Vc₁And the first on-off valve V
₁The loading cradle G has its own weight
Or the weight of the luggage or the weight of the luggage. Move the receiving table G in the lower deployed state Z to the stored state X
In this case, the lifting / lowering switch S_LGThe "undulating" side
And up / down switch S_UDSwitch to "upper"
I can. Thereby, the upper contact t_UAnd the second contact t_TwoIs closed
And the relay R is energized without going through the upper limit switch LS
The hydraulic pump P is driven by the operation of the motor M.
From the pump P to the first and second hydraulic cylinders C._L, C
_GAnd the operating oil is supplied simultaneously. In this case, both cylinders
C_L, C _GDue to the difference in the operating hydraulic pressure
Hydraulic cylinder C which operates relatively lightly_LGrowth
Prior to the operation, the lifting body L is moved from the lower limit position D to the upper limit position U.
To raise. Then, the lifting body L reaches the upper limit position U.
And the second hydraulic cylinder C_GDue to an increase in hydraulic pressure supplied to
2 hydraulic cylinder C_GBegins to extend and falls down on loading tray G
Rotate upward from position H to standing position V.

[0034] Thus the receiving platform G reaches a retracted state X, the key switch S _k open the or any of the above-Shitagiri換switch S _UD contacts t _U, by switching to the neutral position t _D also does not close, the motor The energization of M is stopped, and the supply of hydraulic pressure to each of the cylinders C _L and C _G is stopped. At that time, each hydraulic oil in each of the hydraulic cylinders C _L and C _G
The second check valves Vc ₁ , VC ₂ and the first and second on-off valves V ₁ ,
Since the confined respectively by V _2, receiving platform G
Is held in the stored state X against its own weight. In this case when moving the receiving platform G of a storage state X to the upper deployed state Y is the lift-relief changeover switch S _LG in "relief" side switches respectively upper and Shitagiri換switch S _UD to the "lower". Thus, since the second solenoid SOL ₂ only energized lower contact t _D and the fourth contact point t ₄ is closed is made, only the second on-off valve V ₂ is opened. As a result, due to the own weight of the load receiving table G and the like, the load receiving table G is rotated downward from the standing position V to the lying down position H to be in the upper deployed state Y. In this case, hydraulic oil in the first hydraulic cylinder C _L is first check valve Vc
₁ and the first on-off valve V ₁
The elevating body L does not descend while being held at the upper limit position U. In this case when moving the receiving platform G of a storage state X to a lower deployed state Z is a lift-relief changeover switch S _LG to "lift" position, switches respectively upper and Shitagiri換switch S _UD to the "lower" position . As a result, the lower contact t _D and the third contact t
₃ is closed to energize both solenoids SOL ₁ and SOL ₂ , so that both the first and second on-off valves V ₁ and V ₂ are opened. As a result, the lifting operation of the elevating body L from the upper limit position U and the loading
Is performed at the same time in parallel with the falling-down operation from the upright position V, and the receiving table G reaches the downwardly unfolded state Z in a short time.

In the above or above, in the upwardly deployed state Y
When moving the held receiving tray G to the storage state X once
In the same manner as above, the lifting / lowering switch S_LGTo
Up / down switch S_UDTo the upper side.
What is necessary is just to switch each. Also above or in
The loading tray G once held in the upper unfolded state Y is unfolded downward
When moving to the state Z, as described above,
・ Undulation switch S _LGSwitch to the “elevating” side
Switch S_UDCan be switched to "lower"
Good.

FIGS. 10 and 11 show a second embodiment of the present invention. In this embodiment, the piston diameters of the cylinders C _L and C _G are the same (for example, 45 mm). In particular, the number of the first hydraulic cylinders C _L used as the elevating cylinders is
By then more than that of the second hydraulic cylinder C _G as derricking cylinder larger than total pressure receiving area of the total pressure receiving area of the latter in the former, the working oil pressure of the former cylinder C _L (e.g. 20 Kgf / cm ²⁾ the, 66Kgf / cm hydraulic pressure of the latter cylinder C _G (e.g. in Fushimi lying state of receiving platform G
² ) It is configured to be smaller than that. That is, in this embodiment, the pair of first hydraulic cylinders C _L , C _L arranged side by side on the left and right sides are attached to the pair of left and right arms 4 a protruding from the outer periphery of the rotating shaft 4 and the mounting frame 3. The two cylinders C _L , C _L are interposed in parallel between the rotating shaft 4 and the mounting frame 3 by pivotally connecting the end portions 23 and 24 respectively.

The other structure is basically the same as that of the first embodiment.
The same reference numerals as those of the embodiment are used. In this embodiment, the same operation and effect as in the previous embodiment are achieved.

FIGS. 12 and 13 show a third embodiment of the present invention.
Is shown. In this embodiment, each cylinder C_L, C_Gof
Piston diameter is the same (for example, 45mm)
First hydraulic cylinder C as cylinder_LExtends to the elevating body L
The effective length of the arm of the moment to be lost (for example, the arm 4a
Length) is much longer than that of the previous embodiment,
Cylinder C_LOperating hydraulic pressure (for example, 10 kgf / cm^Two)
With the latter cylinder C _GOperating hydraulic pressure (for example,
66Kgf / cm when lying down^Two) Smaller than
Make up.

The other structure is basically the same as that of the first embodiment, and the same functional parts are denoted by the same reference numerals as those of the first embodiment. In this embodiment, the same operation and effect as in the previous embodiment are achieved.

Although the first to third embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various embodiments are possible within the scope of the present invention. For example, in the above-described embodiment, the receiving tray G is a gate dedicated to loading and unloading cargo, which is installed separately from the gate that opens and closes the opening of the packing box. It may be also used as a gate for opening and closing the opening of the box. In the above-described embodiment, the parallel link mechanism Li is used to raise and lower the elevating body L in the vehicle body B in a fixed posture. However, instead of this, the elevating body is moved along a vertical rail fixed to the vehicle body. It may be moved up and down vertically or may be moved up and down via a non-parallel link mechanism.

Further in the above embodiment has been shown as coupled to only that one of the lift L of the second hydraulic cylinder C _G as derricking cylinder installed only on one of left and right sides of the receiving platform G, the present invention in the second hydraulic cylinder C _G provided pair on the left and right sides of the receiving platform G, the pair of lift L,
L may be respectively connected.

[0042] In still above embodiment, the second hydraulic cylinder C _G as derricking cylinder is provided between the receiving platform G and lift L, in the present invention, receiving platform G and rotating the cylinder C _G It may be provided between the shafts 4 (for example, Japanese Patent Publication No. 5-6113).
No. 1).

[0043]

As described above, according to the invention of each claim,
When the lifting body is in the upper limit position and the storage tray is in the standing position in the storage state where the lifting body is at the upper limit position and the loading tray is in the upright position, the lifting body is lifted and lowered from the downwardly deployed state in which the lifting body is at the lower limit position and the loading tray is in the lying position Only by simultaneously supplying hydraulic oil to the cylinder and the up-and-down cylinder, both cylinders can be sequentially operated without special use of the switching valve means, and the first or second on-off valve is appropriately opened and closed depending on the stored state. By this, it is possible to appropriately perform the lowering operation of the elevating body and the falling operation of the loading table, and especially if both open / close valves are simultaneously opened, the lowering operation of the lifting body and the falling operation of the loading table are performed simultaneously. It is possible to quickly shift from the storage state to the downwardly expanded state. As a result, while the hydraulic circuit and its control system are simplified in structure, sequential operation or simultaneous operation of the loading table and the lifting / lowering body can be performed accurately, which can contribute to cost reduction and handling operation. It is extremely simple and has good workability, and the work time can be reduced as much as possible.

According to the second aspect of the present invention, when the lifting / lowering body reaches the upper limit position when the hydraulic pressure is supplied to each cylinder,
Since the supply of hydraulic pressure to each cylinder can be automatically stopped based on the detection operation of the detection means that has detected this,
When the lowering of the receiving tray in the expanded state, the receiving tray can be reliably stopped in the upwardly expanded state as required.

According to the third aspect of the present invention, the first and second opening / closing switches are respectively provided when the up / down / up / down switch is switched to the up / down side and the up / down switch is switched to the down side from the storage state of the receiving table. Since both valves are opened, the lowering operation of the lifting / lowering body and the falling operation of the loading table can be performed quickly in parallel, and the work efficiency can be improved.
When the up / down switch is switched to the up / down side and the up / down switch is switched to the down side from the retracted state, only the second on-off valve is opened. While holding at the upper limit position, the loading table can be moved down and down, and can be simply and accurately placed in the upper deployed state. Moreover, such two control modes on the descending side can be easily selected by a simple switch operation, and the workability is good.

According to the fourth aspect of the present invention, when the lifting / lowering switch is switched to the up / down side and the up / down switch is switched to the upper side from the downwardly deployed state of the receiving table, hydraulic pressure is supplied to each cylinder. Is performed until the load receiving platform reaches the upright position, so that the lifting operation of the elevating body and the raising operation of the load receiving platform can be sequentially and accurately performed in this order. When the switch is set to the up / down position and the up / down switch is set to the upper position, the hydraulic supply from the hydraulic supply to each cylinder is stopped when the lifting / lowering body reaches the upper limit position. The stop can be easily and accurately maintained in the upwardly deployed state. In addition, such two control modes on the ascending side can be easily selected by a simple switch operation, and the workability is good.

According to the fifth aspect of the present invention, there is provided the valve means for preventing the backflow of the hydraulic oil from each cylinder to the hydraulic supply source and the flow of the hydraulic oil between the two cylinders. Each cylinder is securely held at the operating position at the time when the supply of hydraulic pressure to them is stopped, so that the rest position of the loading tray can be stabilized, and the lowering operation of the lifting / lowering body and the falling operation of the loading tray can be performed. Can be accurately and independently performed without being affected by each other.

[Brief description of the drawings]

FIG. 1 is a side view of a main part of a cargo handling vehicle, showing a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is an enlarged longitudinal sectional view of a main part of the loading tray (a sectional view taken along line 3-3 in FIG. 2);

FIG. 4 is a sectional view taken along line 4-4 in FIG. 2;

FIG. 5 is a plan view of FIG.

FIG. 6 is a side view showing the receiving tray in a lower deployed state.

FIG. 7 is a perspective view schematically showing a main part of an operation mechanism of the loading tray.

FIG. 8 is a hydraulic circuit diagram of the first embodiment.

FIG. 9 is an electric circuit diagram of the first embodiment, particularly showing (a)
Shows a case switching the lift-relief changeover switch S _LG toward "lift", also (b) shows the case where switching to the "undulation" side respectively

FIG. 10 is a plan view showing a second embodiment and corresponding to FIG. 5;

FIG. 11 is a hydraulic circuit diagram of a second embodiment.

FIG. 12 is a sectional view corresponding to FIG. 4, showing a third embodiment;

FIG. 13 is a hydraulic circuit diagram of a third embodiment.

[Explanation of symbols]

B · · · · · · vehicle C _L · · · · · first hydraulic cylinder C _G · · · · · relief electrical circuit as a second hydraulic cylinder CE · · · · · control means as a cylinder as a lifting cylinder D: the second lower limit position as the lower limit position G: the loading tray H: the falling down position L: the elevating body LS: detection Upper limit switch L ₁ , L ₂ , first and second supply oil passages L ₃ , L ₄ , first and second return oil passages P hydraulic pump T as a hydraulic supply source ... Oil tank U ... Upper limit position V ... Standing position V ₁ , V ₂ ··· First and second on-off valves Vc ₁ , Vc ₂ ··· As valve means The first and second non-return valves X: stored state Y: upwardly expanded state Z: downwardly expanded state

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-108869 (JP, A) JP-A-5-310073 (JP, A) JP-A 8-268141 (JP, A) JP-A-7-108 137571 (JP, A) JP-A-63-22740 (JP, A) JP-A-5-42296 (JP, U) JP-A-62-145841 (JP, U) JP-A 9-220964 (JP, U) Tokiko Hei 5-61131 (JP, B2) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60P 1/44

Claims (5)

(57) [Claims] An elevator (L) provided on a vehicle body (B) and capable of moving up and down between a predetermined upper limit position (U) and a lower limit position (D), and a single lifter (L) capable of driving the elevator (L) up and down. The lifting / lowering body (L) can be rotated up and down between a movable lifting / lowering cylinder (C _L ) and an upright position (V) and a falling down position (H) with respect to the lifting / lowering body (L). ) Is provided with a load receiving platform (G) supported by a shaft (8), and a single-acting undulating cylinder (C _G ) capable of forcibly rotating the load receiving platform (G) to the upright side. in receiving platform actuator, the lifting cylinder (C _L) and derricking cylinder (C _G) common hydraulic supply source is connected in parallel with (P), extending to the oil tank (T) side from the lifting cylinder (C _L) the first return oil passage (L ₃₎ first on-off valve interposed between (V _1), derricking cylinder (C _G) oil tanks from (T) side Extending second return oil passage (L ₄₎ to the second on-off valve interposed (V ₂₎ at least provided with, working oil pressure of the lifting cylinder (C _L) is derricking cylinder (C
_G ) An operating device for a receiving pallet in a cargo handling vehicle, wherein the operating pressure is set to be smaller than the operating hydraulic pressure of _G ). 2. A detecting means (LS) for detecting that the elevating body (L) has risen to an upper limit position (U), and the hydraulic pressure source (P) based on a detecting operation of the detecting means (LS). And a control means (CE) capable of stopping supply of hydraulic pressure to each of the cylinders (C _L , C _G ) from the vehicle. 3. An up / down switch (S)_LG)and
Up / Down switch (S_UD) Having control means (CE)
The control means (CE) includes a receiving stand (G) standing up.
Position (V) and lifting body (L) at upper limit position (U)
Up / down / up / down switch from a certain storage state (X)
(S_LG) Is on the up / down side and the up / down switch (S_UD) Is below
First and second on-off valves when switched to the respective side
(V₁, V_Two) Are both opened and the storage
(X) from the up / down switch (S _LG) Is the undulating side
And an up / down switch (S_UD) Switches to the lower side
When it is obtained, the second on-off valve (V_TwoOnly)
3. The method according to claim 1, wherein
Receiving bed actuating device in a loading vehicle. 4. A control means (CE) having an up / down switch (S _LG ) and an up / down switch (S _UD ).
The control means (CE) is provided with a switchover mechanism for raising and lowering and raising / lowering from a lower deployed state (Z) in which the receiving table (G) is at the falling position (H) and the lifting / lowering body (L) is at the lower limit position (D). When the switch (S _LG ) is moved up and down and the up / down switch (S _UD ) is moved upward, each cylinder (CL, C _L)
G ) is supplied until the receiving table (G) reaches the standing position (V), and the hydraulic pressure is raised and lowered from the lower deployed state (Z).
Undulating changeover switch (S _LG) is vertically shifting each cylinder from the hydraulic supply source (P) when the upper and Shitagiri換switch (S _UD) is switched respectively to the upper (C _L, C _G) a hydraulic pressure supply to 4. The apparatus according to claim 1, wherein said lifting member is moved until said lifting member reaches an upper limit position.
A loading tray actuating device in a cargo handling vehicle according to claim 1. 5. A reverse flow of hydraulic oil from each of the cylinders (C _L , C _G ) to a hydraulic supply source (P),
_L, C _G), characterized in that it comprises a valve means for preventing (Vc _1, Vc ₂₎ a flow of hydraulic fluid therebetween, the consignee in the handling vehicle according to claim 1, 2, 3 or 4 Table actuator.