JPS6212699Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a device for improving stability and performance of a mobile crane.

A mobile crane has a swivel base mounted on a traveling vehicle body so as to be freely swivelable, and a boom is arranged on the swivel base so as to be adjustable in elevation, and outrigger devices are disposed at the front and rear positions of the traveling vehicle body. There is. This outrigger device has left and right outrigger inner boxes slidably inserted into an outrigger outer box that is horizontally fixed to the vehicle body, and left and right jack cylinders are arranged at the tips of the left and right outrigger inner boxes. This is what happens. During crane work, the left and right jack cylinders are extended outward from the vehicle body, and the vehicle body is supported by the outrigger device.

As a means to improve the lifting performance during crane work, the outrigger device is made into a three-stage telescoping type, increasing the distance between the left and right jack cylinders, and increasing the distance between the center of gravity of the crane and the left and right jacks, which are the fulcrums for tipping during crane work. A known method was to increase the stability moment by increasing the distance from the cylinder.

However, since outrigger devices are generally used as a pair on the left and right, when using a three-stage telescoping type, the overhang width (the distance between the left and right jack cylinders) needs to be wide, and when working in a narrow area, there is a need for a sufficient overhang width. However, the problem was that the stability performance could not be improved.

This invention eliminates the need to increase the spacing between the left and right jack cylinders in the outrigger device, unlike those using conventional three-stage telescoping outrigger devices. It is an object of the present invention to provide a new device for improving the stability performance of a mobile crane, which can increase the stability moment by increasing the distance between the boom and the jack cylinder in the direction in which the boom rotates.

The configuration of the present invention to achieve this purpose is as follows: an outrigger outer box, left and right outrigger inner boxes that are inserted into the outrigger outer box so that they can be freely adjusted and protrude in both left and right outward directions, and hanging from the tips of the left and right outrigger inner boxes. An outrigger device consisting of fixed left and right jack cylinders is slidably supported on guide frames horizontally fixed at the front and rear positions of the traveling vehicle body, and a structure is provided between the outrigger device and the guide frame or between the outrigger device and the guide frame. A moving cylinder device is provided between the traveling vehicle bodies, and the outrigger device can be moved left and right with respect to the traveling vehicle body by the moving cylinder device.

With this configuration, the relative position of the traveling vehicle body and the outrigger device can be freely changed by extending and contracting the moving cylinder, and the left and right outrigger inner boxes are extended outward from the traveling vehicle body. During crane work in which the traveling vehicle body is supported by the left and right jack cylinders, if the traveling vehicle body is moved in the direction away from the jack cylinders in the direction in which the boom for lifting work is rotating, the tipping fulcrum can be prevented. The distance between the jack cylinder and the center of gravity of the crane in the direction in which the barrel lifting boom is rotating can be increased, and the stability of the crane can be improved. In addition, the outrigger device is a two-stage telescopic outrigger device with left and right outrigger inner boxes inside the outrigger outer box, and the spacing between the left and right jack cylinders in the outrigger device is smaller than the conventional 3
It is easier to install in a narrow space compared to the case where a step-extendable outrigger device is used.

Next, one embodiment of the present invention will be described in detail based on FIGS. 1 and 2.

In FIG. 1, 1 is a traveling vehicle body, 2 is a swivel table mounted on the traveling vehicle body 1 so as to be freely swivelable, and 3 is a boom for lifting a load, which is arranged on the swivel table 2 so as to be able to rise and fall freely. Reference numeral A denotes an outrigger device, and the outrigger device A includes an outrigger outer box 5, left and right outrigger inner boxes 6, 6 inserted into the outrigger outer box 5 so as to extend outwardly in both left and right directions, and the left and right outrigger inner boxes. It is composed of left and right jack cylinders 7, 7 which are vertically fixed to the ends of the cylinders 6, 6. Reference numeral 4 denotes a guide frame horizontally fixed to the lower surface of the front and rear positions of the traveling vehicle body 1, and the outrigger outer box 5 of the outrigger device A is slidably supported inside the guide frame 4. Reference numeral 8 denotes a moving cylinder device, in which a cylinder 8' is fixed to a bracket 9 erected on the traveling vehicle body 1, and the tip of a piston rod 8'' is fixed and attached to an outrigger outer box 5, so that the moving cylinder 8 can be expanded and contracted. By moving the vehicle body 1, the vehicle body 1 can be moved relative to the outrigger device A. Reference numeral 10 denotes a slide plate disposed on the inner upper surface of the guide frame 4. The outrigger outer box 5 is made to slide smoothly against the frame 4.

Next, the effect will be explained.

To perform crane work, first move the left and right outrigger inner boxes 6 from the outrigger outer box 5 to the preceding vehicle body 1.
The traveling vehicle body 1 is supported by extending the left and right jack cylinders 7 outward.

When it is necessary to improve the stability performance of the crane, the moving vehicle body 1 is moved in a direction away from the jack cylinder 7 located in the direction in which the boom 3 for lifting work is rotating by operating the moving cylinder device. Just let it happen. (Situation shown in Figure 1). This increases the distance between the center of gravity of the crane and the jack cylinder 7, which is located in the direction in which the boom 3 for hoisting work, which is the tipping point during crane work, is turned, thereby improving the stability performance of the crane.

To store the crane, simply reverse the above steps.

The mobile crane stability performance improving device of the present invention, which is constructed and operates as described above, has the excellent effect of being able to significantly improve the stability performance of the crane while being able to be installed even in narrow spaces. It is something that we have.

[Brief explanation of drawings]

FIG. 1 is a side view of a mobile crane showing one embodiment of the present invention, and FIG. 2 is a view taken along the line H--H in FIG. 1. 1; Traveling vehicle body, 2; Swivel base, 3; Boom, 4;
Guide frame, 7; jack cylinder, 6; outrigger inner box, 5; outrigger outer box, 8; moving cylinder, A; outrigger device.

Claims (1)

[Scope of utility model registration request] An outrigger device consisting of an outrigger outer box, left and right outrigger inner boxes inserted into the outrigger outer box so that they can be freely extended and adjusted in both left and right outward directions, and left and right jack cylinders fixed vertically to the tips of the left and right outrigger inner boxes. are slidably supported by guide frames horizontally fixed at the front and rear positions of the traveling vehicle body, and a cylinder device for movement is provided between the outrigger device and the guide frame or between the outrigger device and the traveling vehicle body, and the movement 1. A stability performance improving device for a mobile crane, characterized in that the outrigger device is configured to be movable left and right with respect to a traveling vehicle body using a cylinder device.