JPS6241040Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a work range regulating device that is attached to an aerial work vehicle or the like.

For aerial work vehicles with telescoping booms or retractable booms, moving the boom outside of a certain range may cause the vehicle to fall over or be damaged, so a certain range of work has been determined. The boom operation is then stopped by detecting the limit position of the working range, but in this case, the boom operation suddenly stops without prior notice to the worker, and the worker is forced to stop due to inertia. It caused a shock and also had a negative impact on the aerial work vehicle.

The present invention was made in consideration of such circumstances, and activates an alarm and a timer at a certain distance before the limit of the working range, and changes the setting time of the timer according to the operating speed of the boom,
The object of the present invention is to provide a working range regulating device which prevents shock to the worker or vehicle body by stopping the operation of the boom after the time set by a timer.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of an aerial work vehicle equipped with a working range regulating device according to the present invention, in which a turntable 4 is provided on a frame 1 supported by four outriggers 3. A work platform 7 on which a worker rides is balancedly supported at the tip of a telescopic boom 6 which is pivotally mounted 11 to the telescopic boom 6. The telescopic boom 6 swings in a vertical plane by a raised cylinder 5 provided between the turntable 4 and the telescopic boom 6. Reference numeral 8 indicates a boom extension/contraction length detection device, and reference numeral 9 indicates a boom elevation angle detection device.

Figure 2 is a work range diagram. When the hoisting angle of the telescopic boom 6 is in range a, there is no restriction on the boom's telescopic length, and when the hoisting angle of the boom is in range b, the boom's hoisting angle is in range b. The length of extension and contraction is regulated to be less than l ₂ , and when the boom angle is within range C, the length of extension and contraction of the boom is regulated to be less than l ₁ .

FIG. 3 shows a hydraulic circuit diagram, in which the directional control valve 15,
16 and 17, the luffing cylinder 5, the boom telescopic cylinder 20 and the turntable drive motor 18
are respectively controlled, and the circuit of the undulation cylinder 5 and the circuit of the telescopic cylinder 20 are respectively provided with an electromagnetic switching valve 25 and an electromagnetic switching valve 24, which are actuation stop devices, and both the electromagnetic switching valves 24, 25 are controlled by the solenoid 2.
4' and 25', the extension operation of the telescopic cylinder 20 and the elevating and lowering operation of the undulating cylinder 5 are stopped.

22 and 23 are holding valves, 14 is a pump, and 13 is a reservoir.

FIG. 4 shows an electrical circuit diagram, in which the limit switches 9' and 9'' of the boom hoisting angle detection device 9 constitute a parallel circuit, and the limit switch of the boom extension/contraction length detection device 8 is connected to the circuit of each limit switch 9' and 9''. 8' and 8'' are connected in series, respectively, and both circuits are connected to an alarm 27 and an on-delay type timer 28. The contact 30 of the timer 28 is connected to the solenoid 2 of the electromagnetic switching valve 24, 25.
4' and 25'.

FIG. 5 shows a block diagram in which a boom position detection device 32 detects the position of the boom, and when the boom reaches a certain position set before the limit position of the working range, an alarm 34 and a timer 35 are activated. The timer 35 changes the set time according to the boom operating speed detected by the boom operating speed detection device 33 that detects the boom's hoisting speed and extension/contraction speed.
The stopping position of the boom stopped by 6 is made constant regardless of the operating speed of the boom.

Next, the effect will be explained. When the hoisting angle of the boom 6 is within the range a', the limit switches 9' and 9'' of the boom hoisting angle detection device 9 are both turned OFF, and the alarm 27 and timer 28 are activated regardless of the extension/retraction length of the boom. No. When the boom hoisting angle is in range b', the limit switch 9' of the boom hoisting angle detection device 9 is turned on, and when the boom extension/retraction length reaches l ₂ ', the boom extension/retraction length detection device 8 is turned ON. The limit switch 8' is turned on, and the alarm 27 and timer 28 are activated.Then, after the set time of the timer 28, the contact 30 is turned on, the solenoids 24' and 25' are energized, and the solenoid switching valve 2
4 and 25 are switched and the boom extension operation is stopped. When the boom hoisting angle is within range C', the limit switch 9'' of the boom hoisting angle detection device 9 is turned ON, and when the boom extension length reaches ₁ ', the limit switch 8 of the boom extension/contraction length detection device 8 is turned on. ” turns on, alarm 27 and timer 2
8 is activated, and the boom extension operation is stopped after the time set by the timer 28.

When changing the hoisting angle while keeping the boom extension length constant, if the boom extension length exceeds _l2 ' and the boom hoisting angle is lowered beyond range a', the alarm 27 and timer 28 will be activated. is activated, and when the boom extension/retraction length exceeds l ₁ ', the alarm 27 and timer 28 are activated when the boom's luffing angle is lowered beyond range b'.

When the boom extension/retraction length is ₁ ' or less, limit switches 8' and 8'' of the boom extension/retraction length detection device 8 are both turned off, and the alarm 27 and timer 28 are not activated regardless of the boom angle.

The setting time of the timer 28 depends on the boom operating speed.If the boom operating speed is fast, the setting time will be short; if the boom operating speed is slow, the setting time will be long, and the boom stop position will be within the working range. The boom always stops at a fixed position without coming off.

As described above, according to the present invention, the alarm and timer are activated before the limit position of the boom working range, the timer setting time is changed by the signal from the boom operation speed detection device, and the timer setting time is By later stopping the activation of the boom toward the limit position, you can simply set one position where the alarm and timer operate before the limit position of the working range, and the alarm activation position and boom operation stop can be set. It is possible to obtain the same effect as when two positions are set.

[Brief explanation of the drawing]

Fig. 1 is a side view of the aerial work vehicle, Fig. 2 is a working range diagram, Fig. 3 is a hydraulic circuit diagram, Fig. 4 is an electrical circuit diagram, and Fig. 5 is a block diagram. 8...Boom telescopic length detection device, 9...Boom elevation angle detection device, 24, 25...Solenoid switching valve,
24', 25'... Solenoid, 27... Alarm,
28...Timer, 30...Contact, 33...Boom operation speed detection device.

Claims (1)

[Scope of utility model registration request] An alarm that operates before the limit position of the working range of the boom, a boom operating speed detector that detects the operating speed of the boom, and a boom operating speed detector that operates simultaneously with the alarm and determines the set time by a signal from the boom operating speed detector. A working range regulating device for an aerial work vehicle, etc., comprising a timer that changes the time, and a boom operation stop device that operates after the set time of the timer and stops the boom from moving toward the limit position. .