JPH0446780B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a cargo handling vehicle, and more particularly to a cargo handling control device that can maintain the attitude of a removable container when loading and unloading the container onto a vehicle body. It is.

[Conventional technology]

Some vehicles that transport containers are equipped with a cargo handling device that loads, unloads, or reloads containers onto the vehicle body. In order to handle a container with this device, it is necessary to support the container, and support shafts are protruded from the left and right sides of the container. In order to receive the support shaft, the cargo handling device is provided with a lift arm having a support portion formed therein.
It is supported on the vehicle body so that it can rotate forward and backward using a lift cylinder operated by hydraulic pressure.

An example of this type of lift arm is
Although it is stated in Publication No. 3170, in any case, the container is supported by the lift arm only through a pair of left and right support shafts, and the mounting position of the support shafts is above the center of gravity of the container. The container is designed to prevent the container from tilting undesirably during cargo handling operations.

[Problem to be solved by the invention]

In the above-mentioned lift arm that rotates back and forth to load and unload a container, the arm main body is bifurcated, the base of which forms a support part for the container, and the support shaft is mounted on the support part. As a result, the support shaft can rotate and slide on the support part while the lift arm rotates back and forth, and the attitude of the container is maintained.

By the way, if there is an uneven storage position or weight distribution of cargo or contents within the container, the container will be supported in an inclined position from the beginning. If cargo is handled in such a position, the container will swing and become unstable, which may cause the contents to collapse, or in the case of a container without a lid or ceiling, the cargo may fall or fly out. Problems such as this occur.

In order to improve this, when the lift arm rotates back and forth, a part of the supported container may be auxiliary supported to prevent the container attitude from changing. To achieve this, a structure is adopted in which an auxiliary arm that rotates forward and backward is installed on the vehicle body, and the structure is linked to the forward and backward rotation of the lift arm via a container. However, since it is necessary to be able to independently rotate the auxiliary arm back and forth when the lift arm is not working in conjunction with the cargo handling operation, a cylinder dedicated to the auxiliary arm is also provided.

With such a configuration, when supporting a container, the operation of one cylinder has an adverse effect, such as inhibiting the operation of the other cylinder having a different stroke amount and stroke speed. Therefore, when the auxiliary arm is to be moved in synchronization with the forward and backward rotation of the lift arm, the auxiliary cylinder must be enabled to follow the lift cylinder, or when the auxiliary arm does not need to be synchronized with the lift arm, It would be desirable to have a control system that could selectively switch the auxiliary cylinders so that they could be operated independently of the lift cylinders.

The present invention has been made in view of the above-mentioned demands, and its purpose is to achieve interlocking operation between an auxiliary arm for maintaining the posture of a container during cargo handling and a lift arm that supports the container and rotates back and forth, and the independence of the auxiliary arm. A control device that enables operation and prevents unreasonable loads from being applied to the auxiliary cylinder when the lift arm and auxiliary arm operate simultaneously, making it possible to load and unload containers while maintaining the container's posture during cargo handling. An object of the present invention is to provide a cargo handling vehicle equipped with the following.

[Means to solve the problem]

The present invention provides a vehicle body with a lift arm that supports a removable container and performs loading/unloading operations, and an auxiliary arm that maintains the attitude of the container. It is applied to a cargo handling vehicle in which the vehicle body is equipped with auxiliary cylinders that rotate the vehicle forward and backward, and these cylinders can be operated independently.

Its characteristics are as shown in Figure 1.
A support portion 10 formed on the lift arm 5 to support the support shaft 9 of the container 3, a support shaft 7 that supports the lift arm 5 so as to be rotatable forward and backward, and an auxiliary arm 6.
The auxiliary arm 6 can be integrated with or separated from the container 3 at a fourth position determined by forming a parallelogram with vertices at the first to third positions of the support shaft 8 that supports the support arm 8 so as to be rotatable back and forth. A locking/disengaging member 12 is attached to the auxiliary arm 6.

In order to simultaneously rotate the lift arm 5 and the auxiliary arm 6 back and forth, arm forward and backward rotation control means 56 (see FIG. 7a) is provided which issues a command to extend and retract the lift cylinder 14 and the auxiliary cylinder 15.

The container 3 is supported by the lift arm 5, and the auxiliary arm 6 and the container 3 are connected by the engaging/disengaging member 12.
are integrated and the attitude of the container 3 is maintained constant, the lift cylinder 14 and the auxiliary cylinder 15 extend and contract in response to a command from the arm forward/backward rotation control means 56, thereby moving the lift arm 5.
and the auxiliary arm 6 are simultaneously rotated forward and backward to remove the container 5.
When displacing the auxiliary cylinder 15 , a pressure switching section 34 ( A pressure control means 57 (see FIG. 7c) is provided for instructing the auxiliary cylinder 15 to reduce the pressure of the hydraulic oil supplied to the auxiliary cylinder 15 by switching the pressure (see FIG. 6).

[Effect]

When loading the container 3 on the ground onto the vehicle body 4, the lift arm 5 and the auxiliary arm 6 independently extend the lift cylinder 14 and the auxiliary cylinder 15, which operate simultaneously upon receiving a signal from the arm forward and backward rotation control means 56. It is rotated backwards by operation.

When both arms 5 and 6 are rotated backwards and the lift arm 5 is engaged so as to support the container 3, and the auxiliary arm 6 is integrated with the container 3 via the engaging/disengaging member 12, the lift arm 5 and Auxiliary arm 6
and the container 3 are integrally rolled forward.

At that time, the operation of the auxiliary cylinder 15 is often not synchronized with the lift cylinder 14, and the reduction operation of the lift cylinder 15 causes the auxiliary cylinder 14 to
In order to reduce the pressure so that the operation of the auxiliary cylinder 14 is not inhibited, that is, so that excessive hydraulic pressure that would impair the contraction operation of the auxiliary cylinder 14 does not act on the auxiliary cylinder 14, the pressure is controlled so as to switch the pressure switching section 34 provided in the hydraulic circuit. A switching command is issued from means 57.

As a result, the auxiliary cylinder 15 is brought into a state in which it can be contracted, following the container 3 that is displaced mainly by the forward rotation of the lift arm 5, and the auxiliary arm 6 is rotated forward, following the forward rotation of the lift arm 5 via the container 3. . Container 3 has both arms 5 and 6 and car body 4
Since the container 3 forms a parallelogram link body, the attitude of the container 3 is maintained and it is loaded onto the vehicle body 4.

When unloading the loaded container 3, the pressure control means 57 allows the auxiliary cylinder 15 to extend to follow the displacement of the container 3.
While maintaining this posture, the lift arm 5 and the auxiliary arm 6 are rotated backwards by a strong extension action of the lift cylinder 14 and a weak extension action of the auxiliary cylinder 15, and the container 3 is unloaded from the vehicle body 4.

〔Effect of the invention〕

The present invention includes arm forward and backward rotation control means that issues a command to simultaneously rotate the lift arm and the auxiliary arm forward and backward, and a pressure control means that allows the auxiliary cylinder to operate in accordance with the displacement of the container. When the lift arm is supporting the container, the pressure control means can put the auxiliary cylinder into a low load state where it can be driven, while when the lift arm is not supporting the container, the auxiliary cylinder can be put into a state where it can be operated independently. can. Therefore, when the auxiliary cylinder is under low load, the lift arm and the auxiliary arm are rotated forward and backward in synchronized motion.
It is possible to prevent an unreasonable load from being applied to the auxiliary cylinder, maintain the support posture during container loading and unloading, and realize stable and smooth loading and unloading without shaking.

〔Example〕

The present invention will be described in detail below based on examples thereof.

FIG. 1 shows an example of a cargo handling vehicle 1, in which a container 3, which can be freely attached to and detached from a cargo handling device 2, can be loaded and unloaded onto a vehicle body 4. On the vehicle body 4, a pair of left and right lift arms 5, 5 (see Fig. 2) that support and unload the container 3, and an auxiliary arm 6 that maintains the attitude of the container 3 are attached to a support shaft 7, respectively. It is supported so that it can rotate forward and backward around 8.

The distal end side of the main body of the lift arm 5 is bifurcated, and the base of the lift arm 5 forms a support portion 10 that engages with a support shaft 9 extending to the left and right of the container 3 to support the container 3. The support shaft 9 is attached above the center of gravity of the container 3, and is mounted on the support part 10 during cargo handling operation.

Note that while the lift arms 5, 5 are rotating back and forth, the support shafts 9, 9 are in sliding contact with the support parts 10, 10, so that the attitude of the container 3 is not affected by the back and forth rotation of the lift arms 5. It's getting old.
Incidentally, the upper end of the fork is extended to a position where it does not interfere with the container 3, and a connecting shaft 11 is attached in order to integrate the left and right lift arms 5, 5 and increase rigidity.

The above-mentioned auxiliary arm 6 is bent in a dogleg shape, and a locking/disengaging member 12 consisting of an insertion pin attached to the tip of the arm 6 is attached to a bracket 13 attached to the upper front end of the container 3 (described later). hole 22
It is now possible to insert it into the In addition, when this auxiliary arm 6 is provided on the left and right sides of the vehicle body 4, it may be in a straight shape, and in short, it can be connected to a part of the container 3 to maintain the attitude of the container without interfering with the container 3 being loaded or unloaded. It's fine as long as it's possible.

Incidentally, the respective mounting positions are selected in advance so that the lines connecting the support shafts 7 and 8, the support portion 10, and the insertion pin 12 form a parallelogram.
That is, although the insertion pin 12 as the above-described engaging/disengaging member 12 is provided at the tip of the auxiliary arm 6,
These include a support part 10 formed on the lift arm 5 to support the support shaft 9 of the container 3, a support shaft 7 that supports the lift arm 5 so that it can rotate forward and backward, and a support shaft that supports the auxiliary arm 6 so that it can rotate forward and backward. The fourth position is determined by forming a parallelogram with vertices at the first to third positions of 8. Then, in the fourth position, the auxiliary arm 6 can be integrated with the container 3 or separated.

The above two types of arms 5 and 6 are adapted to be rotated forward and backward by the expansion and contraction operations of hydraulic cylinders 14 and 15 that are swingably mounted on the vehicle body 4. The tip of each piston rod is attached to both arms 5, 6 via pins 16, 17, and when the piston rod is extended, the lift arm 5 and the auxiliary arm 6 are rotated backward to the imaginary line position. In addition, vehicle body 4
There are outriggers 18 on the left and right sides of the rear of the vehicle, which prevent the vehicle body 4 from going into a head-up position due to the weight of the container 3 being loaded and unloaded by the cargo handling device 2.

The mechanism for connecting the auxiliary arm 6 and the container 3 with the insertion pin 12 is as shown in FIG.
9 and a dogleg-shaped link 20, and when the link 20 swings about a fulcrum 21 attached to the auxiliary arm 6, the insertion pin 12 moves in and out of the hole 22 of the bracket 13.

Such a cargo handling device is also capable of standing the container 3 loaded on the vehicle body 4 upright and unloading only the stored items to the rear of the vehicle body, as shown in FIG. Therefore, the left and right lift arms 5,
5 is provided with a dump pin 23 for tilting the container 3, and as shown in FIG.
A side hole 24 into which the container 3 is inserted is formed in the abdomen of the container 3.

This dump pin 23 is connected to the support shaft 9 of the container 3.
The container 3 is tilted in cooperation with the support section 10 on which the dump pin 23 is loaded.
is inserted into the side hole 24, the auxiliary arm 6
The aforementioned insertion pin 12 is pulled out from the hole 22 of the bracket 13 of the container 3. The mechanism for inserting and removing the dump pin 23 consists of a cylinder 25 and a dogleg-shaped link 26. When the link 26 swings around a fulcrum 27 attached to the lift arm 5, the dump pin 23 is inserted into the side hole. Coming and going on the 24th.

Each arm and link in the cargo handling device 2 described above is equipped with a limit switch for detecting their respective positions and conditions. First, the first
As shown in the figure, limit switches LS1 and LS2 are provided on the left and right sides, respectively, for detecting that the lift arms 5, 5 are in the forward rotation position by contact between the arms. Regarding the auxiliary arm 6,
A limit switch LS3 detects that it is in the forward rotation position by the contact of its arm, and a limit switch LS4 detects that it is in the rear rotation position.
They are installed at the front and center of the loading platform, respectively.

At the tip of the auxiliary arm 6, as shown in FIG.
There is a limit switch LS6 that detects when 2 is completely removed. As shown in FIG. 5, the lift arm 5 includes left and right limit switches LS7 and LS8 that detect whether the dump pin 23 is inserted into the side hole 24, and a limit switch that detects that the dump pin 23 has completely come out.
There are LS9 and LS10.

As shown in FIG. 1, limit switches LS11 and LS12 detect that the hydraulic jack (not shown) that extends the outrigger 18 to the ground to support the vehicle body 4 has been extended, and limit switches LS13 and LS14 that detect that it has contracted. There is. In addition, when the container 3 is tilted as shown in Fig. 4 to unload the contents, a limit switch is installed to detect the container tilting limit by the movement of the lift arm 5.
LS15 (see Figure 1) is also provided.

Hydraulic cylinders and hydraulic jacks, which switch the functional position of the solenoid valve based on detection signals from a large number of limit switches and operate each arm, link, etc., are incorporated into a circuit as shown in Figure 6. There is. The lift cylinders 14, 14 that rotate the lift arm 5 back and forth are solenoids.
It is connected to a solenoid valve 31 that is switched by the excitation of SOL1 and SOL2, and forms a hydraulic circuit independent from other hydraulic cylinders. The auxiliary cylinder 15 that rotates the auxiliary arm 6 back and forth is a solenoid.
It is connected to a solenoid valve 32 that is switched by the excitation of SOL3 and SOL4. These two hydraulic circuits constitute an arm forward/backward rotation drive unit 33, and arm forward/backward rotation control means 56 (see FIG. 7a), which will be described later.
Each cylinder 14, 14, 15 receives a signal from
is expanded or contracted.

The hydraulic circuit that operates the auxiliary cylinder 15 includes:
While the container 3 is supported by the lift arm 5 and the auxiliary arm 6 and the container 3 are integrated by the above-mentioned engaging/disengaging member 12 and the attitude of the container 3 is maintained constant, the lift cylinder 14 and the auxiliary cylinder 15 are When the lift arm 5 and the auxiliary arm 6 are simultaneously rotated forward and backward to displace the container 5 due to the telescopic operation of the A pressure switching section 34 is provided to enable expansion and contraction.

This consists of a relief valve 35 with a high pressure setting, a relief valve 36 with a low pressure setting, and a solenoid valve 37, and the relief valve 35, the solenoid valve 37, and the relief valve 36 are arranged in the order of the hydraulic oil supply oil path 38. Therefore, when the solenoid valve 37 is in the closed position 37b, the operating pressure is regulated to the high set pressure of the relief valve 35, and when the solenoid valve 37 is in the open position 37a, the operating pressure is regulated to the low set pressure of the relief valve 36. are becoming regulated.

When the lift arm 5 and the auxiliary arm 6 work together to load and unload the container 3, the solenoid SOL
5 is excited to the open position 37a, and the hydraulic pressure flowing through the supply oil path 38 is lowered. In that case, although hydraulic oil is supplied to the auxiliary cylinder 15, the hydraulic oil does not actively expand or contract.
The lift cylinder 14 expands and contracts as the lift cylinder 14 expands and contracts, and during this time only the hydraulic oil is replenished into the piston chamber, so that no unreasonable load is applied to the auxiliary cylinder 15. Note that the supply oil passage 38 may be set to atmospheric pressure when the electromagnetic valve 37 takes the open position 37a without providing the relief valve 36.

The cylinder 19 for the insertion pin 12 is connected to the supply oil passage 38 via a solenoid valve 39 that is switched by the excitation of solenoids SOL6 and SOL7.
The cylinders 25, 25 for the dump pin 23 are
It is connected to the supply oil path 38 via a solenoid valve 40 that is switched by the excitation of solenoids SOL8 and SOL9. Hydraulic jacks 41, 41 for outrigger 18 are also equipped with solenoid SOL10 and
It expands and contracts using hydraulic oil supplied through a solenoid valve 42 that is switched by the excitation of the SOL 11.

The excitation and demagnetization of the solenoid that switches the functional position of each solenoid valve in such a hydraulic circuit is carried out by the seventh
This is performed by control circuits as shown in FIGS. 7a to 7c.

Although this circuit is shown as a relay circuit for ease of understanding, it goes without saying that a microcomputer using a digital IC or the like can be used. To explain the circuit configuration in order, the operation mode selection circuit 51, the container attachment/detachment circuit 52, and the traveling circuit 5.
3. There is a dump circuit 54 and a solenoid excitation circuit 55 that excites the solenoid of the electromagnetic valve by energizing the respective circuits.

The container attachment/detachment circuit 52 includes arm forward/backward rotation control means 56, and the solenoid excitation circuit 55 includes pressure control means 57. Each circuit consists of a normally open contact or a normally closed contact that is connected or disconnected by the operation of each of the limit switches described above, a relay coil that is energized by these operations, a normally open contact that is connected by the excitation of the relay coil, and the like.

The arm forward and backward rotation control means 56 extends and retracts the lift cylinder 14 and the auxiliary cylinder 15 in order to simultaneously rotate the lift arm 5 and the auxiliary arm 6 forward and backward, regardless of whether the cargo handling device 2 supports the container 3 or not. It emits a signal to activate it.

On the other hand, the pressure control means 57 simultaneously rotates the lift arm 5 and the auxiliary arm 6 back and forth while the container 3 is supported by the lift arm 5 and the attitude of the container 3 is maintained constant by the auxiliary arm 6. When the container 5 is displaced, the movement of the auxiliary cylinder 15 is commanded so that it can expand and contract following the displacement of the container 3 mainly due to the forward and backward rotation of the lift arm 5.

As a result, the arm forward/backward rotation drive unit 33 of the hydraulic circuit described above is operated in response to a signal from the arm forward/backward rotation control means 56, thereby causing the lift cylinder 14 and the auxiliary cylinder 15 to extend and contract, and to control the pressure. In response to a signal from the means 57, the pressure switching unit 34 is switched so that the pressure of the hydraulic oil supplied to the auxiliary cylinder 15 is reduced to a low pressure or to atmospheric pressure.

Therefore, as mentioned above, the lift arm 5
and the auxiliary arm 6 are simultaneously rotated forward and backward to remove the container 5.
When displacing the auxiliary cylinder 15, the engaging/disengaging member 1
The container 3 can be expanded and contracted by following the movement of the container 3 via the container 2. The container attachment/detachment circuit 52 includes a means 58 for controlling expansion and contraction of the hydraulic jack 41, a means 59 for controlling the insertion and removal of the insertion pin, and a means 60 for controlling the independent forward and backward rotation of the auxiliary arm 6.

The container attachment/detachment circuit 52 includes push buttons PB1, PB2 for the operator to command forward and backward rotation of the lift arms 5, 5, push buttons PB3, PB4 for commanding the extension and retraction of the outrigger 18 by the hydraulic jack 41, Push buttons PB5 and PB6 for commanding insertion and removal of the insertion pin 12 and push buttons PB7 and PB8 for commanding forward and backward rotation of the auxiliary arm 6 are provided, and these push buttons are separately placed together at a position that is easy for the operator to operate. Ru. On the other hand, the dump circuit 54 includes push buttons PB9 and PB10 for instructing the insertion and removal of the dump pin 23, which are installed on an operation panel or the like together with the other push buttons described above.

The cargo handling operation by the cargo handling device configured as above, the control circuit, the hydraulic actuator operated by the cargo handling device, and the like will be explained in order below.

(1) As shown in Fig. 8a, there are no containers 3 loaded on the vehicle body 4, and the containers 3 on the ground at a container yard or the like are loaded by a series of operations shown in Figs. 8a to 8d. Let's talk about the case.

The lift arms 5, 5 and the auxiliary arm 6 are rotating forward on the vehicle body 4, and the lift cylinder 14 and the auxiliary cylinder 15 are in a contracted state. Since each arm 5, 5, 6 is in a forward rolling position, the limit switches LS1, LS2, and LS3 are in the on state, and the corresponding normally open contacts S1, S2, and S3 in the relay circuit are connected.
Therefore, when the operator sets the selection switch 61 in the selection circuit 51 to contact n1, the relay coil R1
is excited, and the normally open contact T1 of the container attachment/detachment circuit 52 is connected.

If the dump pin 23 enters inside the lift arm 5, it will get in the way when supporting the container 3 on the ground, so the dump pin 23 is retracted. That is, if at least one dump pin 23 enters even though the container 3 is not supported by the lift arm 5, the limit switches LS9 and LS shown in FIG.
10 is turned off, and the normally closed contact s9 or s10 of the solenoid excitation circuit 55 maintains the connection.

By connecting the contacts T1, S1, and S2, the relay coil R4 is energized, thereby connecting the normally open contact T4 of the solenoid excitation circuit 55. Via the connected contact s9 or s10, the solenoid SOL9 is energized and the solenoid valve 40 shown in FIG. 6 is switched from the neutral to the functional position 40a. The cylinder 25 in the extended state
is contracted by the hydraulic fluid discharged from the hydraulic pump 62, and the dump pin 23 is retracted. When completely evacuated, link 26 will switch to limit switch LS.
9, Turn on LS10, normally closed contacts s9, s1
0 returns to cut-off state.

Since the solenoid SOL9 is demagnetized, the solenoid valve 40 returns to neutral, the contraction of the cylinder 25 is stopped, and the dump pin 23 is held at the retracted position. In that state, the limit switch LS
9, LS10 is on, and the normally open contacts S9 and S10 of the arm forward and backward rotation control means 56 are connected.

Therefore, when the operator presses the push button PB1, the relay coil R5 is energized, and the solenoid SOL1 is energized by the connection of the normally open contact T5.
The solenoid valve 31 is switched to the functional position 31a,
The lift cylinder 14 is extended by hydraulic oil from the hydraulic pump 63, and the lift arm 5 is rotated backward about the support shaft 7. Since the auxiliary arm 6 is also rotating forward, the limit switch LS4 is off, and the relay coil R6 is energized by the connection of the normally closed contact s4. Normally open contact T6 connects and solenoid
SOL3 is energized and solenoid valve 32 is in functional position 3.
Switched to 2b.

The auxiliary cylinder 15 is extended by the hydraulic oil from the hydraulic pump 62, and the auxiliary arm 5 is rotated backward about the support shaft 8. As long as the push button PB1 is kept pressed, both arms 5 and 6 move backward, but when the auxiliary arm 6 moves backward by a predetermined amount, the limit switch LS4 is turned on. As a result, the normally closed contact s4 is cut off, the relay coil R6 is de-energized, the solenoid valve 32 returns to neutral, and the backward rotation of the auxiliary arm 6 is stopped.

On the other hand, to stop the backward rotation of the lift arm 5, push button PB1 to cut off the current to relay coil R5.
All you have to do is let go. In addition, the push button PB1
is turned off when the support part 10 of the lift arm 5 reaches a position where it can support the support shaft 9 of the container 3 on the ground.

In this state, the vehicle body 4 is moved backward until the support shaft 9 fits into the support part 10 of the lift arm 5 as shown in FIG. 8b. At this time, since the auxiliary arm 6 is not necessarily rotated backwards to the extent that the insertion pin 12 attached to the auxiliary arm 6 fits into the hole 22 of the bracket 13 of the container 3, the operator must independently control the forward and backward rotation. Push button PB7 of means 60 or
Press PB8 to finely adjust the backward rotation position of auxiliary arm 6.

When push button PB7 is pressed, relay coil R1
3, the normally open contact T13 is connected, the solenoid SOL3 is energized, and the auxiliary cylinder 15 is extended as in the case described above. push button
When PB7 is released, the auxiliary arm 6 stops at that position. On the other hand, if the auxiliary arm 6 is rotated too far backward, it is rotated forward to return to the position corresponding to the hole 22. At that time, push button PB8 is pressed, and relay coil R14 is energized to normally open contact T1.
4 is connected. Since the limit switch LS3 of the auxiliary arm 6 is not turned on, the normally closed contact s3 is in a connected state, and the solenoid SOL4 is energized.

The solenoid valve 32 is switched to the functional position 32a, the auxiliary cylinder 15 is retracted, and the auxiliary arm 6 is rotated forward. When the insertion pin 12 attached to the auxiliary arm 6 is adjusted to match the hole 22 of the bracket 13 in this way, the push button PB5 of the ejection/extraction control means 59 is pressed, and the insertion pin 12 is inserted into the auxiliary arm 6. is integrated into container 3.

That is, relay coil R11 is energized and normally open contact T11 is connected. And since the insertion pin 12 has come out, limit switch LS
5 is off, the normally closed contact s5 is in the connected state, the solenoid SOL6 is energized, and the solenoid valve 39 is switched to the functional position 39b.

Cylinder 19 with hydraulic oil from hydraulic pump 62
is extended, and the insertion pin 12 is fitted into the hole 22 of the bracket 13 via the link 20.
Limit switch LS by rotating link 20
5 turns on, the normally closed contact s5 is in a cutoff state, the solenoid SOL6 is demagnetized, and the cylinder 19 stops expanding.

Next, in order to prevent the vehicle body 4 from lifting its head when supporting the container 3, the operator extends the outriggers 18 as shown in FIG. 8c. When the push button PB3 of the expansion/contraction control means 58 is kept pressed, the relay coil R9 is energized during that time. If the left and right hydraulic jacks 41 are not fully extended, at least limit switch LS11 or LS
12 is never on, the normally closed contact s11 or s12 is in a connected state. Therefore, the solenoid SOL10 is energized, the solenoid valve 42 is switched to the functional position 42b, and the hydraulic jack 41 is extended.

When the left and right outriggers 18 extend to the extent that they support the ground, the limit switch LS11 or
LS12 turns on and normally closed contact s11 or s
12 is in a cut-off state. Solenoid SOL10
is demagnetized, the solenoid valve 42 returns to neutral, and the extension of the hydraulic jack 41 is stopped.

When the container 3 is ready to be loaded onto the vehicle body 4 in this manner, the operator presses the push button PB2 of the arm forward/backward rotation control means 56 to rotate the lift arm 5 and the auxiliary arm 6 forward. Since the dump pin 23 has been removed from the side hole 24 of the container 3 as described above, the limit switch LS9,
LS10 is in the on state, normally open contacts S9,
S10 is connected and safety lamp PL1 lights up. The operator sees the light on and confirms that the container 3 can be loaded onto the vehicle body 4 while maintaining its posture without being dumped.

As mentioned above, the insertion pin 12 is inserted into the bracket 1.
The limit switch LS is inserted into the hole 22 of 3.
5 is in the on state, the normally open contact S5 of the pressure control means 57 is connected, and the solenoid valve 37 assumes the functional position 37a by energizing the solenoid SOL5. As a result, the discharge pressure of the hydraulic oil discharged from the hydraulic pump 62 is regulated by the relief valve 36 which is set to a low pressure, and the auxiliary cylinder 15 is brought into a state in which it operates with an extremely low hydraulic pressure of, for example, about 10 kg/cm ² .

This pressure is sufficient to operate the auxiliary cylinder 15 on which no load is applied, or to replenish hydraulic oil to the piston chamber on the side where negative pressure is applied when the piston rod is forcibly pushed or pulled by an external force. be. Therefore, the auxiliary cylinder 15 is placed in a driven state and is in a state where it can operate following the lift cylinder 14 which is operating with a strong force.

When push button PB2 is pressed in this state, relay coils R7 and R8 are energized, and normally open contacts T7 and T8 of solenoid excitation circuit 55 are brought into a connected state. Since the auxiliary arm 6 is not rotating forward, the limit switch LS3 is off, the normally closed contact s3 is connected, and the solenoid SOL4 is energized.

On the other hand, since the lift arm 5 is not rotating forward, limit switches LS1 and LS2 are off, normally closed contacts s1 and s2 are connected, and solenoid SOL2
is excited. Therefore, the solenoid valve 32 assumes the functional position 32a, and the solenoid valve 31 assumes the functional position 31.
Take a. Hydraulic oil is supplied to the lift cylinder 14 and the auxiliary cylinder 15 so that both are contracted.

By the way, since the auxiliary cylinder 15 is generally smaller than the lift cylinder 14, the stroke amount and stroke speed are often not the same. Therefore, if the auxiliary cylinder 15 is kept in the driven state as described above, as shown in FIG. 6, the auxiliary cylinder 15 is moved. That is, the auxiliary cylinder 15 does not actively operate, but mainly operates as the lift cylinder 14.
The stroke is caused by the movement of the container 3, which is displaced at .

In addition, since low-pressure hydraulic oil is supplied during this time, it prevents the generation of negative pressure within the auxiliary cylinder 15. Therefore, both cylinders 14,1
Modulation of the operation of the auxiliary cylinder 15 and generation of excessive hydraulic pressure, which would otherwise occur if the cylinder 5 were actively operated, are avoided. Since the container 3 constitutes a parallelogram link body with the lift arm 5, the vehicle body 4, and the auxiliary arm 6, the container 3 is loaded on the vehicle body 4 while maintaining its original horizontal support attitude.

When the lift arm 5 is completely rotated forward as shown in Fig. 8d, limit switches LS1 and LS2 are activated.
is turned on, and the normally closed contacts s1 and s2 are in the cutoff state. Further, when the auxiliary arm 6 is also completely rotated forward, the limit switch LS3 is turned on, and the normally closed contact s3 is cut off. As a result, even if the operator continues to press pushbutton PB2, the solenoid
SOL2 and SOL4 are demagnetized, and the solenoid valves 31,
32 is in the neutral position and both cylinders 14 and 15
The reduction operation of is stopped.

(2) Next, as shown in Fig. 8d, the container 3 is attached to the vehicle body 4.
This section describes the case where a vehicle is loaded with cargo and transported from a container yard to a destination.

The lift arm 5 and the auxiliary arm 6 are rotating forward on the vehicle body 4, and the lift cylinder 14 and the auxiliary cylinder 15 are in a contracted state, so the limit switches LS1, LS2, and LS3 are on, and the traveling circuit 53 is constantly turned on. Open contacts S1, S2, S3
is in a connected state.

Therefore, when the operator switches the selection switch 61 in the selection circuit 51 to the contact n2, the relay coil R2 is excited and the normally open contact T2 of the traveling circuit 53 is connected. As a result, relay coil R15 is energized and normally open contact T15 is connected. Since the dump pin 23 has been removed as described above, the limit switches LS7 and LS8 are off, the normally closed contacts s7 and s8 are connected, and the solenoid SOL8 is demagnetized. Solenoid valve 40
assumes the functional position 40a, the cylinder 25 is extended and the dump pin 23 is inserted into the side hole 24 of the container 3.
be fitted into.

In addition, link 26 is limit switch LS7,
When LS8 is turned on, the normally closed contacts s7 and s8 are turned off, and the cylinder 25 stops expanding. Therefore, the container 3 is restrained on the vehicle body 4 by the support portion 10, the insertion pin, and the dump pin 23.

At the same time as this operation, relay coil R16
is also energized and the normally open contact T16 is connected. Since the outrigger 18 is extended, the limit switches LS13 and LS14 are in the OFF state, and the normally closed contacts s13 and s14 are connected. As a result, the solenoid SOL11 is energized and the solenoid valve 42 assumes the functional position 42a. Hydraulic jack 4
1 is contracted and the outrigger 18 is retracted. Limit switch LS1 when evacuated to storage position
3, LS14 turns on, normally closed contact s13,
s14 is in a cutoff state. And solenoid valve 42
returns to the neutral position, and the contraction of the hydraulic jack 41 is stopped.

In this way, the limit switch LS13,
LS14 and limit switch LS mentioned above
7. When LS8 turns on, normally open contact S13,
S14, S7, and S8 are connected, and safety lamp PL2 lights up. By checking that the light is on, the driver can prevent the vehicle from starting in an unstable state.

(3) A case will be described in which the container 3 on the vehicle body 4 is placed in a substantially vertical position as shown in Fig. 4, and only the contents are to be unloaded.

An operator switches the selection switch 61 in the selection circuit 51 to contact n3. Relay coil R
3 is energized and the normally open contact T3 of the dump circuit 54
is connected, and immediately relay coils R17 and R1
8 is energized. Since the insertion pin 12 is fitted into the hole 22 of the bracket 13, the limit switch LS6 is in the OFF state and the normally closed contact s6 is connected. As a result, solenoid SOL7
is energized and the solenoid valve 39 assumes the functional position 39a. The cylinder 19 contracts and the insertion pin 12 comes out of the hole 22. When it is completely removed, the limit switch LS6 is turned on, the normally closed contact s6 is cut off, and the contraction of the cylinder 19 is stopped.

Incidentally, since the limit switch LS5 is turned off, the normally open contact S5 of the pressure control means 57 is in a cutoff state. The solenoid SOL5 is demagnetized, the solenoid valve 37 assumes the closed position 37b, and the hydraulic oil in the supply oil path 38 becomes high pressure regulated by the relief valve 35. In parallel with this operation, the normally open contact T18 is also connected, so the solenoid SOL10 is energized, and the outrigger 18
is displayed.

Since the lift arm 5 is rotating forward, limit switches LS1 and LS2 are turned on.
Even if the dump pin 23 is not fitted into the side hole 24 of the container 3, the relay coil R19 is energized by the connection of the normally open contacts S1 and S2, and the solenoid SOL8 is energized by the connection of the normally open contact T19, and the cylinder 25 extends, and the dump pin 23 is fitted into the side hole 24. Since the insertion pin 12 is completely retracted, the limit switch LS6 is turned on, the normally open contact S6 is connected, and the outrigger 18
The limit switch LS is overhanging.
11, LS12 is turned on and normally open contacts S11, S
12 is also connected, and since the dump pin 23 is fitted, limit switches LS7 and LS8 are turned on, and normally open contacts S7 and S8 are also connected.

When the operator presses the push button PB9 to command dump-up, the relay coil R20 is energized via the normally closed contact s15, which maintains the connected state until the container tilting limit. When the normally open contact T20 is connected, the solenoid SOL1 is energized and the lift cylinder 14 is extended. Auxiliary cylinder 1
The solenoid valve 32 that operates the arm 5 remains in the neutral position, and the auxiliary arm 6 does not move from the forward rotation position.

The lift arm 5 rotates backward around the support shaft 7, but at this time, the support portion 10 of the container 3 is supported by the dump pin 23, so the supporting posture of the container 3 changes until it stands upright as shown in Fig. 4. tilted. When the lift arm 5 moves backward to the container tilting limit, the limit switch LS15 is turned on, the normally closed contact s15 is cut off, and the extension operation of the lift cylinder 14 is stopped even if the push button PB9 is kept pressed.

When the contents are unloaded, the operator presses the button
Press PB10 to command dump down. Relay coil R21 is energized and normally open contact T21
is connected, the solenoid SOL2 is energized, and the lift cylinder 14 is operated to contract. The lift arm 5 rotates forward around the support shaft 7, and the container 3 is returned to its original position. When the lift arm 5 turns on the limit switches LS1 and LS2, the normally closed contacts s1 and s2 are cut off and the solenoid
SOL2 is demagnetized and the reduction operation of the lift cylinder 14 is stopped.

(4) Finally, we will discuss the case where the container 3 is loaded on the vehicle body 4 as shown in Fig. 8 d, and the container is unloaded onto the ground via Fig. 8 c and as shown in Fig. 8 b.

Since the lift arm 5 and the auxiliary arm 6 are in a forward rolling position, limit switches LS1 and LS are activated.
2 and LS3 are on, normally open contacts S1,
S2 and S3 are in a connected state. When the operator switches the selection switch 61 in the selection circuit 51 to the contact n1, the relay coil R1 is excited,
The normally open contact T1 of the container attachment/detachment circuit 52 is connected. The dump pin 23 is connected to the side hole 24 of the container 3.
When the dump pin 23 is fitted into the container 3, the container 3 is tilted and the dump pin 23 is retracted.

In that state, limit switch LS9,
LS10 is on, and the normally open contacts S9 and S10 of the arm forward and backward rotation control means 56 are connected. In order to maintain the posture of the container 3, insert the insertion pin 1.
2 is inserted into the hole 22 of the bracket 13. The limit switch LS5 is turned on, the normally open contact S5 of the pressure control means 57 is connected, and the solenoid valve 37 is moved to the open position 37 by energizing the solenoid SOL5.
Take a. As a result, the discharge pressure of the hydraulic oil discharged from the hydraulic pump 62 is regulated by the relief valve 36 which is set to a low pressure, and the auxiliary cylinder 15 is operated with extremely low hydraulic pressure.

When push button PB1 is pressed in this state, relay coil R5 is energized and lift cylinder 1
4 extends and rotates the lift arm 5 backward.
Limit switch LS4 by forward rotation of auxiliary arm 6
is off, relay coil R6 is also energized by the connection of normally closed contact s4, and hydraulic oil is supplied to the auxiliary cylinder 15 that follows the operation of the lift cylinder 14, preventing excessive hydraulic pressure from acting on the auxiliary cylinder 15. is avoided.

The procedure for lowering the container 3 to the ground after the outriggers 18 are extended is almost the same as the operation described in (1). The operation of removing the insertion pin 12 connecting the container 3 lowered to the ground and the auxiliary arm 6 is performed by the removal/removal control means 59.
Press push button PB6, and relay coil R1
This is done by energizing the solenoid SOL7 through the normally open contact T12, which is connected when energization of No. 2 is applied, and contracting the cylinder 19.

Finally, rotate the lift arm 5 and the auxiliary arm 6 forward, and push the button PB of the extension control means 58.
When 4 is pressed, the relay coil R10 is energized, the solenoid SOL11 is energized by the connection of the normally open contact T10, the hydraulic jack 41 is contracted, the outrigger 18 is retracted, and the vehicle body 4 can be moved.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the configuration of a cargo handling device in a cargo handling vehicle of the present invention, FIG. 2 is a plan view of an example of the cargo handling vehicle,
Fig. 3 is a diagram of the connection mechanism between the auxiliary arm and the container using the insertion pin, Fig. 4 is an explanatory diagram of the operation when dumping the container, Fig. 5 is a diagram of the mechanism for inserting and removing the dump pin, and Fig. 6 is the operation of the hydraulic actuator. Figures 7a to 7c are relay circuit diagrams including arm forward and backward rotation control means and pressure control means, and Figure 8a is a forward rotation state diagram of the cargo handling device when no containers are loaded. b is an operation explanatory diagram showing a state in which a container on the ground begins to be loaded or a state in which a container is unloaded onto the ground; 8c is an operational state diagram in which the container is being loaded and unloaded while maintaining it horizontally;
FIG. 8d is an operational explanatory diagram showing a state in which containers are loaded on the vehicle body 4. 3... Container, 4... Vehicle body, 5... Lift arm, 6... Auxiliary arm, 7, 8... Support shaft, 9...
...Support shaft, 10... Support part, 12... Engagement/disengagement member (insertion pin), 14... Lift cylinder, 15...
Auxiliary cylinder, 34...Pressure switching unit, 56...Arm forward and backward rotation control means, 57...Pressure control means.

Claims (1)

[Scope of Claims] 1. A lift arm that supports a removable container and performs loading/unloading operations, and an auxiliary arm that maintains the attitude of the container are provided on the vehicle body, a lift cylinder that rotates the lift arm back and forth, and a lift cylinder that rotates the lift arm back and forth; In a cargo handling vehicle in which the vehicle body is equipped with an auxiliary cylinder that rotates the auxiliary arm back and forth, and these cylinders can be operated independently, the lift arm is formed to support the support shaft of the container. a support part that supports the lift arm so as to be rotatable back and forth, a support shaft that supports the auxiliary arm so that it can rotate back and forth, and a support shaft that supports the auxiliary arm so that it can rotate back and forth; In order to integrate or separate the auxiliary arm from the container at the fourth position, a locking/disengaging member provided on the auxiliary arm, and a lift cylinder for simultaneously rotating the lift arm and the auxiliary arm back and forth. and arm forward and backward rotation control means for issuing a command to extend and retract the auxiliary cylinder; and the container is supported by a lift arm, and the auxiliary arm and the container are integrated by the engaging and disengaging member to maintain a constant posture of the container. in a state in which the lift arm and the auxiliary arm are simultaneously rotated back and forth to displace the container by receiving a command from the arm forward and backward rotation control means, by telescopic operation of the lift cylinder and the auxiliary cylinder, In order to enable the movement of the auxiliary cylinder to expand and contract following the container which is displaced mainly by the forward and backward rotation of the lift arm, a pressure switching section interposed in the hydraulic circuit of the auxiliary cylinder is switched to operate the supply to the auxiliary cylinder. A cargo handling vehicle, comprising: pressure control means for instructing to reduce the pressure of oil;