JPH0543038Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a work machine control device for a forklift truck equipped with a rotatable fork.

[Conventional technology]

Conventionally, as shown in Fig. 8, there is a forklift truck in which a turret head c is provided on a mast b erected on a self-propelled vehicle body a so as to be movable vertically and horizontally, and a fork d is attached to the turret head c so as to be rotatable. Truck implements are known.

In addition, as a control device for the above-mentioned work machine, for example, Jikosho
The one described in Japanese Patent No. 60-19120 is known.

In the above-mentioned publication, a lateral position detector for detecting the lateral position of the turret head c is provided on a carriage e that supports the turret head c in a lateral movement, and a load supporting plate f is provided on the turret head c.
A rotation detector is provided to detect the rotational position of the work machine, and the drive source is sequentially controlled based on the signals detected by these detectors, thereby controlling the working machine.

[Problem that the invention attempts to solve]

In the above-mentioned conventional control device, the lateral movement operation and the turning movement operation are divided into six stages and operated sequentially, and one set of self-holding relay circuits is provided for each stage, so a large number of detectors and There were problems such as the need for relays, which made the circuit complex and expensive.

This invention was made for the purpose of improving the above-mentioned conventional problems.

[Means and actions for solving problems]

A turret head 7 is provided on a mast which is installed upright on a self-propelled vehicle body so as to be able to move vertically and freely shift, and a fork is provided on this turret head so as to be able to freely turn. A limit switch and at least one limit switch for detecting the turning position of the fork are provided, and the position signals detected by these limit switches are input to a control circuit, and the control circuit is used for a shift turning operation for switching between shift movement and turning movement. It consists of a switching circuit, a self-holding circuit for this circuit, a closing circuit for turning on the self-holding circuit, and a release circuit for releasing the self-holding circuit, and by controlling the shift actuator and the turning actuator by the output of the control circuit, the fork A work equipment control device for a forklift truck that allows cargo handling work to be carried out while automatically controlling the shifting and turning of the forklift truck.

〔Example〕

An embodiment of this invention will be described in detail with reference to the drawings.

In the figure, reference numeral 1 denotes a vehicle body that can move freely on wheels 2, and a mast 2 is erected at the front of the vehicle body 1.

An elevating carriage 4 that is movable up and down by a lift cylinder (not shown) is attached to the mast 3, and a guide rail 5 is installed in the front part of the elevating carriage 4 in the horizontal direction on the upper and lower surfaces. These guide rails 5 and rollers 6
The rear part of the turret head 7 is supported via.

The turret head 7 is provided with a shift actuator 8 consisting of a hydraulic motor or an electric motor, and the shift actuator 8 moves the turret head 7 along the guide rail 5.
is shiftable in a direction perpendicular to the traveling direction of the vehicle body 1, and a pivot shaft 9 is provided in the front part of the turret head 7 in a vertical direction. The pivot shaft 9 can be pivoted by a pivot actuator 10, which is a hydraulic motor or an electric motor, provided in the turret head 7, and the lower end of the pivot shaft 9 projects below the turret head 7. , a finger board 13 supporting the fork 12 is disposed on the lower end side of the pivot shaft 9.
A bracket 14 protruding from the rear surface of the fork 12 is fixedly attached to the fork 12, and as the pivot shaft 9 rotates, the fork 12 can pivot around the pivot shaft 9 within the range shown by the imaginary line in FIG.

On the other hand, at the base end of the turret head 7, there is a
One limit switch LS1 is installed, and one limit switch LS2 is installed on the tip side.

The limit switch LS1 above is the lift carrier 4.
The lateral position of the turret head 7 can be detected by being operated by a plurality of cams 15 provided on the side. , for example, by five cams 16, so that the turning position of the fork 12 can be detected.

Detection signals detected by these limit switches LS1 and LS2 are input to a control device 17 mounted on the vehicle body 1.

As shown in FIG. 4, the control device 17 has a shift operation switch 18 and a swing operation switch 19. When the shift operation switch 18 is turned on, the shift solenoid 20 is excited and the shift actuator 8 rotates. When the turret head 7 is shifted and the swing operation switch 19 is turned on, the swing solenoid 21 is energized, the swing actuator 10 is rotated, and the fork 12 is turned.

In addition, the rotation operation switch 19 and the rotation solenoid 2
A manual/automatic changeover switch 22 is interposed between 0 and 0, and when the switch 22 is turned to the automatic side, the control circuit 23 operates as follows.

The control circuit 23 is a shift rotation switching circuit 23.
₁ , and a self-holding circuit 23 that switches this circuit.
₂ , a circuit ₂₃₃ for turning on the self-holding circuit ₂₃₂ , and a circuit ₂₃₄ for releasing the self-holding of the self-holding circuit ₂₃₂ .

When the manual/automatic changeover switch 22 is now turned to the automatic side, as shown in Figure 3, the limit switch LS2 starts operating with the limit switch LS2 on and the limit switch LS1 off.
Limit switches LS1 and LS2 are turned on alternately as follows: LS1 on → limit switch LS2 on → limit switch LS1 on → limit switch LS2 on.

Shift rotation limit switch LS1 at this time
The LS2 may run on the cams 15, 16 and operate, or may remain on the cams 15, 16 and stop shifting or turning, or the LS2 may ride on the cams 15, 16 and move further. 15,
In some cases, the shift or turning operation may stop in a state where it deviates from 16. Therefore, the limit switch
In either case of LS1 or LS2, it is necessary to reliably repeat the sequence of holding → release → holding → release of relay XB of self-holding circuit ₂₃₂ in a regulated manner.

The circuit that achieves this operation is the self-holding closing circuit 2.
3 ₃ and a self-hold release circuit 23 ₄ .

The self-holding closing circuit ₂₃₃ is a circuit that sends a holding signal Y to the relay coil XB line 24 only at the moment when the limit switch LS1 is switched from inactive to active. Furthermore, the RC circuit in the circuit diagram is for delaying the operation of relay coil XC by T seconds.

Figure 5 shows the time chart. t ₂ in the chart indicates the operating speed of the relay itself. As you can see from this time chart, Reitsu Switch LS1
At the moment when the switch changes from non-operating to operating, signal Y turns on for T+t ₂ seconds, and then limit switch LS1
The signal Y remains off regardless of whether it is inactive or remains active. This signal Y causes relay XB to self-hold and the operation changes from shift to turn.

Next, the self-hold release circuit 23 ₄ that releases the self-held state will be described.
3 ₄ is a circuit that disconnects the self-holding line 25 of the relay coil XB only at the moment when the limit switch LS2 switches from non-operating to operating. Figure 6 shows the time chart. In the figure, _t1 indicates the time when the contact of limit switch LS2 changes from normally open to normally closed.
Further, t ₂ indicates the operating time of relay XA.

As shown in this time chart, at the moment when limit switch LS2 switches from inoperable to actuated, signal W is turned off for the shorter of t ₁ or t ₂ , and then the switch remains in either the inoperable or actuated state. The signal W remains on even if the temperature changes. This signal W causes relay XB to release its self-holding state and switch its operation from turning to shifting.

A time chart of the above series of operations is shown in FIG. 7.

That is, by repeating the above operations, it becomes possible to automatically perform cargo handling work in narrow passages and the like.

In the above embodiment, the shift is performed in 5 steps and the rotation is performed in 4 steps, but the cams 15, 1
By increasing the number of 6, the number of steps can be further increased.

Furthermore, in the above embodiment, the limit switch LS1,
The number of cams 15 and 16 may be increased relative to LS2, or the number of limit switches LS1 and LS2 may be increased by using one cam 15 and 16 each.

[Effect of idea]

As detailed above, when carrying out cargo handling work in narrow aisles, by selecting automatic, the shifting and turning movements of the forks are automatically controlled, making the work easier. This makes cargo handling work more efficient and reduces driver fatigue.

Furthermore, since the circuit can be configured with a smaller number of relays and limit switches than in conventional circuits, reliability is improved and the device itself can be provided at low cost.

[Brief explanation of the drawing]

The drawings show one embodiment of this invention; Fig. 1 is a plan view of the forklift truck, Fig. 2 is a side view of the same, Fig. 3 is an explanatory diagram showing the arrangement of the limit switch, and Fig. 4 is an illustration of the device. The circuit diagram, FIGS. 5 through 7 are timing charts showing the operation, and FIG. 8 is a conventional explanatory diagram. 1 is the vehicle body, 3 is the mast, 7 is the turret head, 13 is the fork, LS1, LS2 are the limit switches, 23 is the control circuit, 23 ₁ is the shift turning switching circuit, 23 ₂ is the self-holding circuit, 23 ₃ is the self-holding closing circuit, 23 ₄ is a self-hold release circuit.

Claims (1)

[Scope of utility model registration request] A turret head 7 is provided on a mast 3 erected on a self-propelled vehicle body 1 so as to be movable up and down and freely shiftable, and a fork is provided on the turret head 7 so as to be freely pivotable, and the shift position of the turret head 7 is detected. at least one limit switch LS1 and at least one limit switch for detecting the pivot position of the fork;
LS2 is provided, and these limit switches LS1 and LS
A shift rotation switching circuit 2 inputs the position signal detected by 2 to the control circuit 23, and switches the control circuit 23 between shift movement and rotation movement.
3 ₁ , a self-holding circuit 23 ₂ of this circuit 23 ₁ , a closing circuit 23 ₃ that closes the self-holding circuit 23 ₂ , and a release circuit 23 ₄ that releases the self-holding circuit 23 2, and the shift actuator is controlled by the output of the control circuit 23. 8 and a swing actuator 10.