JPS6214079Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a safety device for a work vehicle having a boom, such as a crane vehicle or an aerial work vehicle.

Work vehicles with booms, especially aerial work vehicles with a work platform at the end of the boom, have poor visibility of the underside of the boom or the work platform from above the work platform. There was a risk of damaging the electric wires or the aerial work vehicle by operating the device without knowing that it would come into contact with obstacles such as electric wires.

The present invention was developed in view of the above circumstances, and includes an overturning moment calculator that detects the operating state and calculates the overturning moment, an overturning moment detector that detects the overturning moment that is actually acting, and a overturning moment detector that detects the overturning moment that is actually acting. By providing a comparator that compares the detected overturning moment with the detected overturning moment, and an alarm or a work vehicle operation stop device that operates when the detected overturning moment becomes smaller than the calculated overturning moment. The purpose of the present invention is to provide a safety device for a work vehicle having a boom that can prevent accidents such as damage to electric wires or other obstacles or damage to the aerial work vehicle due to contact between the boom or the underside of the work platform and obstacles such as electric wires. It is something to do.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an aerial work vehicle, in which a telescopic boom 3 is pivotally supported on a swivel base 2 provided on a vehicle body 1.
The telescopic boom 3 is extended and contracted by a built-in telescopic cylinder (not shown) and raised and lowered by a undulation cylinder 5, and a workbench 4 is held in equilibrium at the tip of the telescopic boom 3. The rotating base 2 is divided into upper and lower parts 2' and 2'', and the rear end side is connected by a horizontal axis, and the overturning moment is detected by the overturning moment detector 6 by the compressive force acting on the front end side. 7 is A detector 8 detects the up-and-down angle of the telescopic boom 3, a boom length detector 8, and a load detector 9 for the workbench 4.

FIG. 2 shows a block diagram of the safety device, in which a luffing angle detector 7, a boom length detector 8 and a load detector 9 are connected to an overturning moment calculator 10,
The overturning moment calculator 10 calculates a theoretical overturning moment according to the operating state. The overturning moment calculator 10 and the overturning moment detector 6 are connected to a comparator 11, and the comparator 11 compares the calculated overturning moment and the detected overturning moment, and the detected overturning moment is greater than the calculated overturning moment. output when the overturning moment becomes smaller, or when the overturning moment becomes less than a certain percentage of the calculated overturning moment. The comparator 11 is connected to an alarm 12, and the alarm 12 sounds an alarm or stops the operation of the work vehicle based on the output from the comparator 11.

With the above configuration, if the bottom surface of the boom or the bottom surface of the work platform comes into contact with an obstacle such as a power line while the boom is operated and the bottom surface of the work platform comes into contact with an obstacle such as a power line, the boom or work platform will be supported by the obstacle. The overturning moment acting on the work vehicle is smaller than the overturning moment theoretically calculated from the boom hoisting angle, boom extension/retraction length, and workbench load. Therefore, the overturning moment detected by the overturning moment detector 6 is smaller than the overturning moment calculated by the overturning moment calculator 10, the comparator 11 outputs an output, the alarm 12 is activated, and an alarm is issued. It sounds to notify the worker of contact with an obstacle, and also stops the operation of the aerial work vehicle to prevent damage to the aerial work vehicle or obstacles such as power lines.

In addition, although the Example showed the aerial work vehicle, it is clear that it can implement similarly also in a crane vehicle.

As described above, the present invention has a boom that prevents accidents when electric wires, etc. come into contact with the bottom surface of the boom or the bottom surface of the workbench, which can be easily implemented especially in a work vehicle equipped with a moment limiter. A safety device for a working vehicle is provided, and the present invention has a great effect on improving the safety of a working vehicle with a boom.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a side view of the aerial work vehicle, and FIG. 2 is a block diagram of the safety device. 6... Falling moment detector, 10... Falling moment calculator, 11... Comparator, 12... Alarm.

Claims (1)

[Scope of utility model registration request] an overturning moment calculator that calculates the overturning moment that should be applied by detecting the lifting load or the load of the workbench, the extension/contraction length and the heave angle of the boom;
An overturning moment detector that detects the actually acting overturning moment, a comparator that compares the calculated overturning moment and the detected overturning moment, and a comparator that compares the overturning moment that is calculated and the overturning moment that is detected, and the overturning moment that is detected is smaller than the calculated overturning moment. 1. A safety device for a working vehicle having a boom, characterized in that it is equipped with an alarm or a device for stopping the operation of the working vehicle, which is activated when the vehicle is activated.