JPH08127493A - Fall preventing device for on-truck type crane - Google Patents

Abstract

PURPOSE: To prevent rightward, leftward, and frontward fall of a truck on which a crane is mounted by providing a signal output part to output a stability limit signal in a lateral direction and a signal output part to output a stability limit signal when a distance between an axle for rear wheels mounted through a suspension device and a chassis frame exceeds a given value. CONSTITUTION: A stability limit signal output part to output a signal when the support force of one of jacks is reduced to a value lower than a given value is provided. Further, a frontward stability limit signal output part 12 is mounted on a metallic detecting piece 12a attached to the upper part of an axle A7 and a chassis frame A3 and consists of an approach switch 12b to detect the approach state of the detecting piece 12a. When the axle A7 is spaced away from the chassis frame A3 by a distance exceeding a given value, the frontward stability limit signal output part 12 outputs a stability limit signal. This constitution ensures safety of a crane work for an on-truck type crane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fall prevention device used in a truck-mounted crane.

[0002]

2. Description of the Related Art A truck-mounted crane B is a base 1 having guide tubes 2 and 2 having openings at left and right ends as shown in FIG. Room A
1 mounted on the chassis frame A3 between the carrier 1 and the platform A2 so as to be in a horizontal state, and extendably inserted into the left and right openings of the guide tubes 2 and 2 of the base 1, respectively. A pair of left and right outrigger beams 3, 3 and jacks 4, which are vertically installed at the outer ends of the outrigger beams 3, 3, respectively.
4, a swivel post 5 mounted on the base 1 so as to be swingable, a telescopic boom 6 mounted on the swivel post 5 so as to be hoisted and driven by a boom hoisting cylinder 6a, and the swivel post 5 or the telescopic boom 6 base end And a winch 7 attached to the end of the telescopic boom 6, and a wire rope 8 from the winch 7 that is pulled out via a boom tip pulley 6b arranged at the tip of the telescopic boom 6 is used to suspend the hanger 9. are doing. A4 and A5 are front and rear wheels of the vehicle A, and these front wheels A4 and A5 are respectively attached to the lower side of the chassis frame via elastic suspension devices such as leaf springs, and a front wheel shaft A6 and a rear wheel shaft. It is attached to the left and right outer end positions of A7.

When carrying out a crane operation with this type of truck-mounted crane B, first, the outrigger beams 3 and 3 are appropriately extended and the jacks 4 and 4 are extended to extend the front wheels A4 side of the truck A (driver's cab A1). Side) to stabilize track A. Then, the swivel post 5 is swiveled, the telescopic boom 6 is lifted and retracted, and the hoisting device 9 is hoisted and unwound by the winch 7 to move the suspended load suspended by the hoisting device 9 to an arbitrary position. .

Conventionally, this type of truck-mounted crane B
In order to ensure the safety of the crane work, a safety device as shown in FIG. 4, that is, the stability limit signal a is detected by detecting when the supporting force of one of the jacks 4 and 4 is below a predetermined value. A stability limit signal output unit 10 and an operation stopping unit or an alarm unit 11 that operates by the stability limit signal a from the stability limit signal output unit 10 to stop the operation of the truck-mounted crane B. A safety device is installed.

The stability limit signal output section 10 is, for example, a limit switch 10 arranged at the tip of each guide tube 2, 2.
a and 10a, which are limit switches 10a and 10a for detecting the non-pressed state of the upper surfaces of the outrigger beams 3 and 3 with respect to the inner surfaces of the tip end portions of the guide tubes 2 and 2.
When the upper surfaces of the outrigger beams 3 and 3 are not in pressure contact with the inner surfaces of the tip end portions of the guide tubes 2 and 2, the jacks 4 and 4 are
Since this occurs when the supporting force of the jack is reduced, the stability limit signal output unit 10 composed of the limit switches 10a and 10a has a supporting force of one of the jacks 4 and 4 which is equal to or less than a predetermined value. Then, the stability limit signal a is output.

As another example of the stability limit signal output section 10,
As shown in FIG. 5, the load detecting means 10b, 10b for detecting the loads acting on the jacks 4, 4 respectively, and one of the loads detected by the load detecting means 10b, 10b is equal to or less than a predetermined value. Then, there is a device constituted by the arithmetic means 10c which outputs the stability limit signal a.

When the operation stopping means or the alarm means 11 is the operation stopping means, for example, extension and fall of the telescopic boom 6, hoisting of the winch 7, and turning of the turning post 5 are performed during the operation. The operation signal interruption means is provided in the operation signal transmission path of the vehicle-mounted crane B so as to interrupt the transmission of the operation signal instructing the driving. When the operation stopping means or the alarm means 11 is an alarm means, for example, it is constituted by a buzzer or a warning light.

In the conventional safety device constructed as described above, the stability limit signal output unit is provided for the decrease in the indicating force of the jack 4 on the reverse tilt side, which occurs before the track A falls over to the left and right.
Since the operation is detected by 10 and the operation of the truck-mounted crane B is stopped or an alarm is issued based on the detection result, the truck A can be prevented from tipping over in the left-right direction.

[0009]

However, the risk of the truck A tipping over when the crane is operating exists not only in the left-right direction of the truck A but also in the front direction thereof. A warning must be given in advance of the fall of A to the left and right as well as the fall of A. Therefore, the conventional safety device described above has a problem in that the safety of the crane operation of the truck-mounted crane B cannot be sufficiently ensured.

An object of the present invention is to solve the above-mentioned problems of the conventional safety device, prevent the truck A on which the truck-mounted crane B is mounted from falling to the left and right, and forward the truck A. It is to provide a new safety device capable of preventing a fall.

[0011]

In order to achieve the above-mentioned object, a fall prevention device for a truck-mounted crane according to the present invention is constructed as follows. A base 1 provided with guide cylinders 2 and 2 having openings at the left and right ends, the guide cylinders 2 and 2 being a chassis frame A between a cab A1 of a truck A and a cargo bed A2.
A base 1, which is mounted on top of the base plate 3 in a horizontal state,
A pair of left and right outrigger beams 3, which are telescopically fitted in the left and right openings of the guide tubes 2 and 2 of the base 1, respectively.
3, jacks 4 and 4 vertically provided at the outer ends of the outrigger beams 3 and 3, a swing post 5 mounted on the base 1 so as to be swivel-driving, and a boom hoisting cylinder attached to the swivel post 5 so as to be hoistable. The telescopic boom 6 which is driven up and down by 6a, and the winch 7 attached to the swivel post 5 or the telescopic boom 6 at the base end thereof.
Is a fall prevention device used for a truck-mounted crane B in which a hanger 9 is suspended by a wire rope 8 from the winch 7 pulled out via a boom tip pulley 6b arranged at the tip of Then, the fall prevention device detects that the supporting force of one of the jacks 4 and 4 has become equal to or less than a predetermined value, and outputs a stability limit signal a indicating the stability limit of the track A in the left-right direction. The horizontal stability limit signal output unit 10 detects that the axle A7 of the rear wheel A5 attached to the chassis frame A3 of the truck A via an elastic suspension device is separated from the chassis frame A3 by a predetermined value or more. Then, the forward stability limit signal output section for outputting the stability limit signal b indicating the forward stability limit of the track A, and the stability limit signals from both of these stability limit signal output sections are operated. Rack-mounted crane overturning prevention device of the track-mounted crane, characterized by being configured Te than in the deactivation means or alarm means 11 stops the operation of the B.

[0012]

The fall prevention device for a truck-mounted crane according to the present invention is provided between the conventional fall prevention device and the axle A7 of the rear wheel A5 attached to the chassis frame A3 of the truck A through an elastic suspension device. A front stability limit signal output unit that outputs a stability limit signal b indicating the stability limit of the track A in the forward direction by detecting that the front stability limit signal is output from the front stability limit signal output unit. Since the operation stop means or the alarm means 11 is also activated by the stability limit signal b, it is possible to prevent the truck A, on which the truck-mounted crane B is mounted, from tipping over in the left-right direction. It is possible to prevent the forward fall of the vehicle.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a fall prevention device for a truck-mounted crane according to the present invention will be described below with reference to FIGS.
The fall prevention device of the present invention is configured by adding the forward stability limit signal output unit as described above in addition to the configuration of the conventional fall prevention device for preventing the truck A from falling in the left-right direction. The reference numerals shown in FIGS. 3 and 4 and used in the description of the conventional safety device are used as they have the same meaning in the following description.

In FIG. 1, reference numeral 12 is a forward stability limit signal output section. The front stability limit signal output unit 12 detects that the chassis frame A3 of the track A and the wheel axle A7 of the rear wheel A5 are separated by a predetermined value or more, and indicates the stability limit signal of the front direction of the track A. b is output, and the operation stopping means or alarm means 11 is activated by this signal b.

FIG. 2 shows a specific example of the forward stability limit signal output section 12. In FIG. 2, A3 is a chassis frame of the truck A, A2 is a luggage carrier, A5 is a rear wheel, and A7 is an axle of the rear wheel A5. The wheel axle A7 of the rear wheel A5 is attached to the chassis frame A3 via an elastic suspension device A8 (a leaf spring is used in this example). The front stability limit signal output unit 12 is attached to the upper portion of the wheel axle A7 of the rear wheel A5 (in this example, the upper portion of the leaf spring A8 that constitutes the suspension device) and extends upward to the metallic detection piece 12a and the chassis. The proximity switch 12b is attached to the frame A3 and detects the proximity state of the detection piece 12a. As for the positional relationship between the proximity switch 12b and the detection piece 12a, the detection piece 12a leaves the detection range of the proximity switch 12b when the wheel axle A7 is separated from the chassis frame A3 by a predetermined value or more, and the forward stability limit signal output unit 12 is It is adjusted to output the stability limit signal b. The predetermined value is a value that is slightly smaller than the separation distance when the rear wheel A5 floats above the ground due to the forward falling moment acting on the truck A during crane work.

The forward stability limit signal output unit 12 is not limited to the above-mentioned embodiment, but may be constituted by changing the proximity switch 12b to a limit switch whose actuator is operated by the detection piece 12a. The point is that the stability limit signal b indicating the stability limit in the forward direction of the track A is detected by detecting that the wheel shaft A7 and the chassis frame A3 are separated by a predetermined value or more. .

[0015]

The fall prevention device for a truck-mounted crane of the present invention configured and operated as described above is a conventional safety device for preventing the truck A, on which the truck-mounted crane B is mounted, from falling in the left-right direction. Forward stability limit signal output section
With the addition of 12, the forward stability limit signal output unit 12
Since the truck A is prevented from tipping forward, the safety of the crane operation of the truck-mounted crane B can be reliably ensured with a simple configuration.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a fall prevention device for a truck-mounted crane according to the present invention.

FIG. 2 is an explanatory diagram of a forward stability limit signal output unit.

FIG. 3 is an explanatory diagram of a truck-mounted crane.

FIG. 4 is an explanatory diagram of a conventional fall prevention device for a truck-mounted crane.

FIG. 5 is an explanatory diagram of another example of the stability limit signal output unit in the conventional fall prevention device for a truck-mounted crane.

[Explanation of symbols]

A: truck, A1: driver's cab, A2: cargo bed, A3: chassis frame, A4: front wheel, A5; rear wheel, A6; wheel axle,
A7: Wheel axle, B: Truck-mounted crane, 1; Base,
2, 2; guide tube, 3, 3; outrigger beam, 4, 4;
Jack, 5; Revolving post, 6; Telescopic boom, 6a; Boom hoisting cylinder, 6b; Boom tip pulley, 7; Winch, 8; Wire rope, 9; Lifting tool, 10; Left-right stability limit signal output section, 10a, 10a; limit switch, 11; operation stopping means or alarm means, 12; forward stability limit signal output part, b; stability limit signal, 12a; detection piece, 12b; proximity switch,

Claims (1)

[Claims] 1. Guide cylinders 2, 2 having openings at the left and right ends.
1. A base 1 having guides 2 and 2 mounted on a chassis frame A3 between a cab A1 of a truck A and a cargo bed A2 in a laterally mounted state, and the base 1 described above.
A pair of left and right outrigger beams 3 and 3 which are respectively inserted into the left and right openings of the guide tubes 2 and 2 so as to be extendable and contractible, and jacks 4 and 4, which are vertically installed at the outer ends of the outrigger beams 3 and 3, respectively. A swivel post 5 mounted on the base 1 so as to swivel freely; a telescopic boom 6 hoistably mounted on the swivel post 5 and hoisted and driven by a boom hoisting cylinder 6a;
And a winch 7 attached to the swivel post 5 or the telescopic boom 6 at the base end thereof, and a wire rope 8 from the winch 7 pulled out via a boom tip pulley 6b arranged at the tip of the telescopic boom 6. A fall prevention device for use in a truck-mounted crane B in which the hanging device 9 is suspended, wherein the fall prevention device has a supporting force of one of the jacks 4 and 4 being equal to or less than a predetermined value. The left-right stability limit signal output unit 10 which detects that the stability limit signal a indicating the left-right stability limit of the track A is output, and is attached to the chassis frame A3 of the track A via an elastic suspension device. Rear axle A5 and chassis frame A3
Track A is detected when the distance between
The forward stability limit signal output section 12 that outputs the stability limit signal b indicating the stability limit in the forward direction, and the operation of the truck-mounted crane B by operating the stability limit signals from both of these stability limit signal output sections. A fall prevention device for a truck-mounted crane, comprising an operation stopping means for stopping or an alarm means 11.