CN201071271Y - Telescoping jib with oval cross-section - Google Patents

Abstract

The utility model discloses a telescopic hoisting arm with elliptical section, which comprises an upper bending plate welded on the upper surface of a lower bending plate, wherein the welding seam between the upper bending plate and the lower bending plate is positioned on both sides of the cylindrical body of the hoisting arm; an elliptical cylindrical section composed of the sections of the upper and the lower bending plates contracts from bottom to top; and the lower bending plate has an elliptical section. For the identical hoisting performance, the weight of the elliptical hoisting arm is reduced by 5-8% in comparison with well-known U-shaped hoisting arm, the length of the long arm is improved greatly, and the hoisting performance during large-amplitude operation is improved. Accordingly, the weight of the hoisting arm is further reduced, the hoisting performance is improved, and the utility model can be used for telescopic box-shaped hoisting arm of engineering crane.

Description

Telescoping jib with oval cross-section

technical field

The utility model relates to a telescopic box-shaped boom used for engineering cranes.

Background technique

The known jib is used as the main load-carrying member of the crane, and its dead weight generally accounts for 13-20% of the weight of the whole vehicle. But on a large crane, the weight of the boom often accounts for more than 23% of the weight of the whole machine. This is also one of the main obstacles to the development of large-scale cranes with telescopic booms. Reducing the weight of the boom and increasing the stiffness of the boom are important ways to improve the lifting performance. Among them, choosing a reasonable boom section shape is an important means to realize this approach.

In order to effectively reduce the weight of the boom and improve the lifting performance, the section form of the boom has been developed from the most primitive quadrilateral section to a polygonal section (above quadrilateral), and then developed to a U-shaped section, and the section form has been continuously optimized.

Although the U-shaped cross-section jib has solved the local stability problem of the lower cover well, the material utilization rate of the upper cover is not high, because the jibs of large cranes are made of ultra-high-strength steel at present, and its resistance The tensile strength is very high, and the two rounded corners of the U-shaped section boom only bear the tensile stress. For the plate-shell structure of the telescopic boom, its tensile performance can be fully exerted. It is known from calculation and actual measurement that The stress of the two rounded corners of this structure is not high.

Contents of the invention

The purpose of the utility model is to provide a telescopic boom with oval cross-section, which can further reduce the weight of the boom itself and improve the lifting performance.

The purpose of this utility model is achieved in this way: the boom includes an upper curved plate and a lower curved plate, the upper curved plate is welded on the lower curved plate, and the weld between the upper curved plate and the lower curved plate is located in the boom tube The low-stress areas on both sides of the body greatly reduce the influence of welding stress on the strength of structural parts. The cross-section of the oval cylinder formed by the sections of the upper curved plate and the lower curved plate shrinks from bottom to top, and the material properties of the upper curved plate are maximized to optimize the weight of the boom. The underbent plate has an elliptical cross-section, which has inherent unique stability and resistance to buckling. The lower curved plate is slightly thicker than the upper curved plate, which effectively improves the stability of the lower part of the lower curved plate under pressure.

The utility model optimizes the known U-shaped cross-section lifting arm to obtain an oval cross-section. In the case of the same lifting performance, the oval jib can reduce the weight by 5 to 8% compared with the simple U-shaped jib, which greatly increases the length of the long jib, greatly improves the lifting performance during work, and further reduces the weight. The jib's own weight can improve the lifting performance, and it can be used as a telescopic box-shaped jib for construction cranes.

Description of drawings

Fig. 1 is a schematic structural view of an embodiment of the utility model. In the figure 1. Upper bent plate, 2. Weld seam, 3. Lower bent plate.

Detailed ways

In Fig. 1, the upper bent plate 1 is welded on the lower bent plate 3, and the weld 2 between the upper bent plate 1 and the lower bent plate 3 is located in the low stress area on both sides of the boom cylinder, the upper bent plate 1 and the lower bent plate 3 The cross-section of the oval cylinder formed by the section of the lower curved plate 3 shrinks from bottom to top, the lower curved plate 3 is an elliptical cross-section, and the lower curved plate 3 is slightly thicker than the upper curved plate 1.

Claims (1)

1. A telescopic boom with an oval cross-section, the boom includes an upper curved plate, which is characterized in that the upper curved plate is welded on the lower curved plate, and the weld between the upper curved plate and the lower curved plate is located at On both sides of the jib cylinder, the cross-section of the oval cylinder formed by the upper curved plate and the lower curved plate shrinks from bottom to top, and the lower curved plate is an elliptical cross-section.

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