JPS6335880Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stability limit warning system suitable for crane equipment, particularly truck-mounted cranes.

As is well known, a truck-mounted crane has a crane device mounted in the space between the driver's cab and the loading platform of the truck.When carrying out cargo handling work, this crane uses a pair of left and right outrigger jacks installed on the crane device and a pair of left and right outrigger jacks at the rear of the truck. It is supported by a pair of rear wheels (usually pneumatic tires supported by leaf springs). When the crane boom is extended to the side of the vehicle body and a load is lifted with four-point support between the outrigger jack and the rear tire, the tipping fulcrum is the contact point of the outrigger jack on the crane boom side and the same rear tire. The outrigger jack on the opposite side of the crane boom to the overturning fulcrum during cargo handling may touch the ground or float due to the torsion of the vehicle body frame even during cargo handling within the stability limit. During cargo handling operations that involve repeated uphill movements and are at the very limit of stability, uplifts of several tens of centimeters are observed. It has a stability characteristic in that it actually falls only when the outrigger jack lifts up more than several tens of centimeters and exceeds the stability limit.

On the other hand, the technology of detecting the backlash that occurs when the outrigger device lifts up and warning of the stability limit of the crane device has existed for a long time.
The structure was as shown in the figure. That is, the inner cylinder 22 is fitted into the outer cylinder 21, and the limit switch 23 is attached to the end of the outer cylinder facing the inner cylinder 22.
The limit switch 23 detects the play that occurs between the inner cylinder 22 and the outer cylinder 21 when the cylinder is tilted together with the vehicle body. Due to this structure,
In this type of conventional example, if the outer cylinder tilts and the inner cylinder lifts up, this is detected and an alarm is issued, so there was a problem in that the crane device frequently issued a limit alarm even though it was within the stability limit. In addition, if the backlash is increased to eliminate this problem, the support during work may become unstable, or the outer cylinder may become unstable.
Even if the backlash varies greatly depending on the amount of insertion of the inner cylinder 22 relative to the inner cylinder 22 and the slope of the vehicle body and the outer cylinder 21 reaches its limit, a warning will be issued depending on the amount of protrusion of the inner cylinder 22. There was a problem that there was no.

The present invention provides a stability limit warning system that overcomes the disadvantages of the prior art and is compatible with the stability characteristics of truck-mounted cranes.

Examples will be described below with reference to FIG. 2 and subsequent figures.

C is equipped with a multi-stage boom 6 that is pivoted by a pin to the upper end of a post 5 that can be rotated by a crane device, and the boom 6 is configured to be able to rise and fall freely by a hoisting cylinder 7 that is interposed between it and the lower part of the post 5. has been done.
A hook 9 is suspended from the tip of the boom 6 with a wire rope 8, and a winch 1 is installed inside the post 5.
The hanging load W is wound and unwound at 0 and is freely transported. A is an outrigger device which is fixed onto the vehicle body frame B with bolts or the like, and the post 5 is mounted on the upper part.

Now, this outrigger device is constructed as follows according to the present invention. The outer cylinder 1 has a linear bottom plate 11
It has a rectangular cross section consisting of two side plates and an upper plate 12, and the vertical inner diameter dimension a of the outer end is approximately the same as the vertical outer diameter dimension b of the inner cylinder 2, and the inner diameter gradually increases as it approaches the center. The vertical dimension is increased and the base is expanded into a tapered shape when viewed in longitudinal section. The angle of inclination is set to a stability limit angle that is designed in relation to the stability limit of the crane device. The inner cylinder 2 is inserted into the outer cylinder 1, and the inner cylinder 2 can be shown in a state in which it is pushed into the outer cylinder 1 (Fig. 3) and in a state in which the inner cylinder 2 is pulled out from the outer cylinder 1 (Fig. 4). It's becoming possible to take it. In either of these two states, the inner cylinder 2 swings up and down within the outer cylinder 1 using the outer end of the outer cylinder bottom plate 11 as a fulcrum. Reference numeral 13 is a jacking device vertically installed at the tip of the inner cylinder 2, and reference numeral 3 is a jacking device that is installed by drilling a hole in a suitable position on the outer cylinder upper plate 12, or a mito switch. A suitable alarm device is connected to this limit switch so that when the limit switch 3 is activated, an alarm is issued or an alarm device for stopping the crane is activated.

Now, the operation in such a configuration is as follows. If the crane boom is turned in the direction opposite to the outrigger jack shown in Figures 3 and 4, and the crane boom is within the stability limit, the inner cylinder 2 will swing within the outer cylinder 1 even if the car body and outer cylinder tilt. Since the tilting movement of the lever is absorbed, the jacking device 13 does not float up, and the inner cylinder 2 does not come into contact with the outer cylinder upper plate 12 and press the limit switch 3. Therefore, the cargo handling operation can be continued without the alarm device being activated. However, when the stability limit is approached, the vehicle body and outer cylinder 1 tilt by the angle θ shown, and as a result, the upper surface of the inner cylinder 2 comes into contact with the outer cylinder upper plate 12, pushing the limit switch 3 and activating the connected alarm device. . Therefore, loading and unloading operations using cranes exceeding safety limits are prevented.

As described above, according to the present invention, the initial tilting of the car body and the outer cylinder 1 that occurs within the stability limit allowed for the crane device is detected, and the tilting of the car body and the outer cylinder 1 reaches the stability limit without issuing an alarm. Only when the jacking device 13 lifts up will it be detected and an alarm will be issued, so that the alarm accuracy will be stabilized. In addition, since the outer cylinder upper plate 12 is configured in a continuously tapered shape, the limit switch 3 is always activated when the vehicle body is tilted at the same angle, regardless of whether the amount of insertion into the outer cylinder 1 is large or small. This has the advantage of maintaining the same alarm accuracy regardless of the amount of output. Furthermore, since the vertical inner diameter of the outer end of the outer cylinder 1 is configured to be approximately the same as the vertical outer diameter of the inner cylinder 2, stable support can be achieved without rattling during cargo handling operations by installing an outrigger device.

Next, another embodiment will be described based on FIG. In this embodiment, the outer tube 1 has the most common structure in which the outer end and the center section have the same diameter cross section, and an appropriate number of stoppers 14, 15, 16 are vertically installed in the upper space of the outer tube 1. There is. And this stopper 14,1
5 and 16 are designed so that the ones toward the center are lower in order than those toward the outer ends, and the insertion distance of the inner cylinder 2 into the outer cylinder 1 is constant regardless of whether it is large, medium, or small. It is designed to be tilted up to a swing angle θ. Reference numeral 17 is a limit switch provided along the stopper 14, and when this is activated, a connected alarm device is activated. Therefore, in this embodiment as well, when the vehicle body approaches the stability limit and leans, a warning is activated as in the previous embodiment, and the stability of the warning accuracy and other advantages are similar to those in the previous embodiment. be.

[Brief explanation of the drawing]

Figure 1 is a structural diagram of a stability limit warning device that detects play in a conventional outrigger device, Figure 2 is a structural diagram of the present invention, and Figure 3 is a stability warning activation when the inner cylinder is reduced and in contact with the ground. FIG. 4 is an explanatory diagram of the stability alarm operation when the inner cylinder is extended and is in contact with the ground, FIG. 5 is a detailed diagram of the main part, and FIG. 6 is a structural diagram of another embodiment.

Claims (1)

[Scope of utility model claims] The outrigger device installed in the crane device consists of an outer cylinder, an inner cylinder slidably inserted into the outer cylinder, and a jacking device fixed to the tip of the inner cylinder, and the outer cylinder has an inner diameter vertical dimension at the outer end. The vertical dimension of the inner diameter of the inner cylinder should be approximately the same as the vertical dimension of the outer diameter of the inner cylinder, and the vertical dimension of the inner diameter of the inner cylinder should be set so that the vertical dimension of the inner diameter of the center part can be set so that the inner cylinder can swing up and down within the outer cylinder using the outer end of the bottom plate of the outer cylinder as a fulcrum. The upper plate of the outer cylinder and the inner cylinder are arranged so that the swing angle of the inner cylinder does not exceed a predetermined angle determined in relation to the stability limit of the crane device. 1. A stability limit warning device for a crane device, characterized in that a restriction device is provided to prevent the inner cylinder from swinging to the predetermined angle, and a detection means is provided to detect that the inner cylinder has swung to the predetermined angle.