JPH0372500B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an overturn prevention device for a working vehicle in which a working machine such as a crane or a lift device for boarding a worker is mounted on the vehicle.

(Prior Art) When working with this type of work vehicle, it is necessary to take care to prevent it from falling over. This fall is caused by the grounding point of the overturning side (the side that is about to overturn) of the work vehicle, that is, the wheel on the overturning side in the case of a vehicle without an outrigger device, or the outrigger in the case of a vehicle with an outrigger device. The ground contact point is the overturning fulcrum, and the overturning moment generated around this overturning fulcrum exceeds the counter-overturning moment (the remainder of the weight of the work vehicle and the distance from the overturning fulcrum to the center of gravity of the work vehicle). Conventional measures to prevent overturning of work vehicles have been to either increase the weight of the work vehicle or to extend the grounding point of the outrigger device as far as possible to the outside of the overturning side of the work vehicle. The amount of protrusion of the outrigger was increased to allow the vehicle to touch the ground, or both were increased.

(Problem to be solved by the invention) However, increasing the weight of the work vehicle
Because it reduces the running performance of work vehicles,
Furthermore, there is a limit to increasing the amount of overhang of the outrigger device due to mechanical constraints.

The present invention is based on the conventional approach to preventing overturning of work vehicles, that is, consideration of increasing the anti-overturning moment generated around the overturning fulcrum, which increases the weight of the work vehicle and moves the ground contact point on the overturning side of the work vehicle to the outside of the vehicle. Focusing on the fact that the above-mentioned limits were reached due to relying solely on An object of the present invention is to provide a novel overturn prevention device for a work vehicle that can dramatically increase the overturn prevention function without moving the ground contact point on the overturning side of the work vehicle to the outside of the vehicle.

(Problems to be Solved by the Invention) A fall prevention device for a work vehicle according to the present invention is a fall prevention device for a work vehicle that has a work machine such as a crane or a lift device for boarding a worker mounted on the vehicle. , a grounding part that protrudes from the side of the vehicle and can be grounded is provided, and a vacuum suction part is attached to surround the grounding part, and the anti-overturning moment of the work vehicle is increased by the suction force of this vacuum suction part to the ground. This is to prevent the work vehicle from falling over.

(Function) The fall prevention device for a work vehicle configured as described above is provided with a vacuum suction part that surrounds the grounding part that protrudes to the side of the vehicle and can touch the ground, and the work vehicle is prevented by the suction force of this vacuum suction part to the ground. Since the anti-overturning moment of the vehicle is increased, under normal working conditions, the weight of the work vehicle can be supported by the ground contact part, and a large overturning moment acts on the work vehicle, causing the ground contact part to support the weight of the work vehicle. In a state where the work vehicle is about to rise, the anti-overturning moment can be increased by the suction force of the vacuum suction portion to the ground, thereby preventing the work vehicle from overturning.

Furthermore, since the vacuum suction part is attached surrounding the grounding part, there is no need to separately attach the grounding part and the vacuum suction part, and a compact arrangement can be achieved.

(Example) Hereinafter, an example in which the overturn prevention device for a work vehicle of the present invention is implemented in a work vehicle having a crane mounted on the vehicle will be described in detail based on the drawings.

(First Embodiment) In FIG. 1, A is a working vehicle on which a crane 2 serving as a working machine is rotatably mounted. The crane 2 has a swivel base 3 rotatably mounted on a vehicle 1 and a boom 4 disposed on the swivel base 3 so as to be freely adjustable in elevation. After suspending the load, turn the swivel platform 3, raise and lower the boom 4,
The cargo block 5 is hoisted up and lowered to move the cargo to a desired location. 6 is a pair of left and right front wheels installed on both sides of the front of work vehicle A; 7
are a pair of left and right rear wheels provided on both rear sides of work vehicle A. The work vehicle A travels on the ground B and performs crane work at the work site using a crane 2 as a work machine. Between the pair of left and right front wheels 6 and the pair of left and right rear wheels 7 of the vehicle 1 of the work vehicle A, a vacuum suction part 8 configured to be able to suction to the ground B can be extended to the side of the vehicle 1 via a coupling device 9. It is located in The vacuum suction section 8 and the connecting device 9 constitute the fall prevention device according to the present invention. As shown in FIG. 2, the suction portion 8 includes a grounding portion 21 attached to the lower end of the coupling device 9, a suction substrate 10 attached surrounding this grounding portion 21, and an outer edge of the suction substrate 10. When the suction part 8, which is provided to extend outward and downward, is pressed against the ground B, the suction substrate 10 comes into contact with the ground.
It is composed of a flexible seal member 11 that defines a space C below which is isolated from the outside.

The coupling device 9 includes an overhanging device 17 consisting of an outer tube 15 installed horizontally on the vehicle 1 between the front wheels 6 and the rear wheels 7, and an inner tube 16 telescopically fitted into the outer tube 15.
and a double-acting hydraulic cylinder 20, in which the cylinder 19 is suspended and fixed to the tip of the inner cylinder of the extending device 17 with its piston rod 18 facing downward.
It consists of

Next, the effect will be explained. When the work vehicle A is traveling, the suction part 8 of the stabilizing device drives the double-acting hydraulic cylinder 20 in the coupling device 9 to contract, and also drives the inner cylinder 16 of the extending device 17 in the coupling device 9 to contract, so that (indicated by the two-dot chain line in FIG. 2). When performing crane work using the crane 2 at a work site, the inner cylinder 16 of the extending device 17 is driven to extend, and the double-acting hydraulic cylinder 20 is also driven to extend,
Together with the grounding part 21, the suction part 8 is brought into pressure contact with the ground on the side of the vehicle 1. At this time, first, the outer edge of the seal member 11 of the suction part 8 contacts the ground, and a space C isolated from the outside is formed below the suction part 8. From this state, when the double-acting hydraulic cylinder 20 is further extended and driven to press the suction part 8, the volume in the space C decreases and the internal pressure in the space C increases, and this increased pressure is pushed outward and downward at the outer edge of the suction substrate 10. The extending seal member 11 is pushed open, and as a result, the gas inside the space C leaks to the outside. Once the gas in the space C has leaked to the outside, when the suction section 8 is subsequently lifted upward, a negative pressure is generated in the space C, and this negative pressure resists the force that lifts the suction section 8 upward. In the case of this embodiment, the negative pressure generated in the space C of the suction section 8 is 1/2 to 7/10 of the atmospheric pressure, so the suction area of the suction section 8 is set to 4900 cm ² (the width of the suction section and When the vertical width is 70 cm), the adsorption force F
is F≒1/2 (Kg/cm ² )・4900 (cm ² ) ~ 3/10 (Kg/cm
² ) ・4900 (cm ² ) ≒2.45 tons to 1.47 tons. The suction force F of the suction portion 8 is transmitted to the vehicle 1 via the coupling device 9, and acts to prevent the vehicle A from lifting up when it falls. Now, to explain the case where work vehicle A rotates its crane boom 4 to the side of vehicle 1 and to the opposite side to where the suction part 8 is located, the following steps are taken to prevent work vehicle A from overturning. The relationship between anti-overturning moment M _R and overturning moment M _W is as follows: Lifting load by crane 2; _W Weight of work vehicle A; W
Horizontal distance between the line connecting the grounding points of the front and rear wheels 6 and 7 and the lifting load W; L _W Vehicle 1 on the side facing the boom 4 which is the tipping fulcrum
Horizontal distance between the line connecting the grounding points of the longitudinal axles 6 and 7 of the vehicle A and the center of gravity of the weight _WV of the vehicle A; Vehicle 1 on the side toward which the boom 4, which is the fulcrum of L _V's overturning, is facing
The distance between the line connecting the grounding points of the front and rear wheels 6 and 7 and the center of the double-acting hydraulic cylinder 20 of the coupling device 9;
If the adsorption force of the L _S adsorption section 8 is F, then M _W =W·L _W <M _R =W _V ·L _V +F·L _S.

Here, it is clear that the suction force F of the suction part 8 greatly contributes to preventing the work vehicle A from falling to the side opposite to where the suction part 8 is arranged via the coupling device 9. be. In the above equation, the term F· _LS in the anti-overturning moment M _R is a factor newly introduced by the overturn prevention device of the present invention.

Further, since the suction part 8 is provided to surround the grounding part 21, when the boom 4 is rotated to the suction part 8 side for crane work, the grounding part 21 touches the ground and the work vehicle A Since it supports the weight of
The grounding portion 21 and the coupling device 9 function as an outrigger device to increase the anti-overturning moment of the work vehicle A and prevent the work vehicle A from overturning.

Furthermore, in this embodiment, a fall prevention device consisting of a suction part 8 and a coupling device 9 is provided on one side of the vehicle, but a similar fall prevention device is provided on the other side of the vehicle 1 so that it can be connected to both sides of the work vehicle A. Of course, it is also possible to prevent the person from falling over. Furthermore, it goes without saying that similar overturn prevention devices may be provided at left and right positions of the vehicle 1 behind the rear wheels 7 to prevent the work vehicle A from overturning in any direction.

Furthermore, in the above embodiment, the line connecting the front and rear wheels 6 and 7 of the vehicle 1 on the side toward which the boom 4 is facing serves as the overturning fulcrum; When a possible outrigger device is provided, the grounding point of this outrigger device becomes the tipping point of the work vehicle, so the counter-overturning moment generated due to the suction force of the suction part 8 increases, and the tipping prevention device according to the present invention increases accordingly. It is something that can enhance the functions of.

(Second Embodiment) In the first embodiment, the suction portion 8 of the fall prevention device according to the present invention, which is composed of the suction portion 8 and the connecting device 9, is connected to the suction substrate 10 provided surrounding the grounding portion 21. At the outer edge of this suction substrate, when the suction part 8 is pressed against the ground surface B, which extends outward and downward,
The flexible seal member 11 defines an externally isolated space C below the suction substrate 10 in contact with the suction substrate 10, and by pressing the suction part 8 to the ground, the gas in the space C is removed from the seal member 11. The suction part 8 is made to leak from between the space C and the ground B, and the suction part 8 is made to adsorb to the ground, but by venting the gas in the space C of the suction part 8 with a vacuum pump, the suction part 8 is forced to If it is made to stick to the ground, the suction part 8 can be made to stick to the ground more reliably. In this case as well, the suction section 8 is connected to the vehicle 1 via the coupling device 9 as in the first embodiment, so in this embodiment, only the configuration of the suction section 8 will be described. This will be explained based on FIGS. 3 and 4.

In FIG. 3, the suction section 8 is composed of a suction substrate 10 and a seal member 11, similar to that described in the first embodiment. Reference numeral 22 designates an air vent opening on the upper surface of the suction substrate 10, and 23 represents a flexible air venting hose having one end connected to the air venting port and the other end connected to the vacuum pump 24. Vacuum pump 24
is installed at a suitable location in the vehicle and is driven by electricity or hydraulic pressure. In the case of this embodiment, the suction unit 8 is grounded to form a space C isolated from the outside under the suction substrate 10, and then
4 is activated to remove the gas in the space C, thereby causing the suction part 8 to adsorb to the ground. At this time, the atmospheric pressure in space C is less than 1/10 of the atmospheric pressure, so if the adsorption area is the same, the adsorption force will be the first
This is several times the suction force of the suction unit 8 in the embodiment.

The suction section 8 shown in FIG. 3 is provided with a flexible seal member 11 extending outward and downward at the outer edge of the suction substrate 10, but the gas in the space C of the suction section 8 is In this embodiment, in which air is removed by a vacuum pump and the suction part 8 is forcibly adsorbed to the ground, the seal member of the suction part 8 does not necessarily have to be as shown in FIG.
1 may be of any type as long as it defines a space C isolated from the outside below the suction substrate 10 when the suction portion 8 is pressed against the ground.

For example, the seal member 11 may be a steel plate seal member extending downward around the outer edge of the suction substrate 10, as shown in FIG. In this case, when the suction portion 8 is pressed against the ground, the sealing member 11 digs into the ground to define a space C below the suction substrate 10 that is isolated from the outside. The one provided with such a seal member 11 is
This is particularly effective when the ground is soft.

Each of the above embodiments was carried out on a work vehicle equipped with a crane as a work machine, but it was also applied to a work vehicle equipped with other work machines, such as a lift device for boarding a worker, on the vehicle for so-called high-place work. Of course, it can also be applied to work vehicles called cars.

Further, in the overturn prevention device for a working vehicle according to the present invention, the negative pressure generated in the space C when the suction portion 8 is suctioned to the ground varies over time depending on the sealing performance of the seal member 11. , and its sealing performance changes depending on the type of ground, ie, the ground is concrete, mortar, asphalt, soil, sand, etc. Therefore, the pressure in the space C is detected as an electric signal by a pneumatic-electrical converter, and based on this detected signal value, the suction force of the suction part 8 and the anti-overturning moment generated in the work vehicle due to the suction force are calculated. From a safety standpoint, it is desirable to perform calculations and use the calculation results to vary the limit value of the safety device of the crane or lift device for boarding workers.

(Effects) Although the overturn prevention device for work vehicles constructed as described above has an extremely simple and compact structure, it has a suction section that surrounds the grounding section that supports the weight of the vehicle and vacuum-sucks the ground. This has the excellent effect of increasing the anti-overturning moment of the work vehicle without increasing the weight of the vehicle and moving the ground contact point on the overturning side of the work vehicle to the outside of the vehicle, which would adversely affect the running performance of the work vehicle. It is something.

[Brief explanation of drawings]

FIG. 1 is a side view of a working vehicle equipped with a fall prevention device for a working vehicle according to the present invention, in which a crane is mounted as a working machine on the vehicle. FIG. 2 is a front view of the same, and FIGS. 3 and 4 are explanatory diagrams of the suction portion in other embodiments. Work vehicle; A, vehicle; 1, work machine (crane);
2. Vacuum suction part; 8. Grounding part; 21.

Claims (1)

[Claims] 1. A fall prevention device for a work vehicle that is equipped with a work machine such as a crane or a lift device for boarding workers, which is provided with a grounding part that protrudes from the side of the vehicle and is capable of touching the ground. An overturning work vehicle characterized in that a vacuum suction part is attached surrounding the work vehicle, and the adhesion force of the vacuum suction part to the ground increases the anti-overturning moment of the work vehicle to prevent the work vehicle from overturning. Prevention device.