JPH1045059A - Track frame structure for crawler crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need of a plate bending process for uprising on a track frame by assembling cross and longitudinal beams into a box-sectional beam structure, flattening the upper and lower frames of the beams and fixing an uprising ring on the upper flanges. SOLUTION: A track frame 8 has front and rear cross beams 8a, 8b in a box sectional structure and vertical beams 8c, 8d in a box sectional structure welded between the cross beams 8a, 8b, which are assembled into a boxed beam structure. The upper flange (c) and the lower flange (d) of the cross beams 8a, 8b and the upper flange (e) and the lower flange (f) of the vertical beams 8c, 8d are flattened. An uprising ring 9 is provided on the upper face of the track frame 8. A swing device arranged thereon is welded or bolted onto the upper flanges (c), (e) of the cross and vertical beams 8a-8d assembled into a boxed beam structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a track frame structure for a crawler crane.

[0002]

FIG. 3 is a front view showing a conventional crawler crane, and FIG. 4 is a plan view of a track frame thereof. As shown in FIGS. 3 and 4, the left and right side frames 2 on which the crawler 1 is mounted are provided with cylindrical guides 3 penetrating left and right, respectively, at two front and rear positions.
Both ends of the horizontal beams 6a and 6b of the track frame 6 on which the upper swing body 5 is mounted are movably fitted via the swing device 4. Reference numeral 7 denotes a link for fixing the side frame 2 to the track frame 6 by using a pin. In transportation, the width of the crawler 2 is reduced to the width of L2.
1 to ensure stability.

In such a crawler crane, as shown in FIG. 3, in order for the upper rotating body 5 to rotate on the upper surface of the crawler 1, a gap h1 is formed between the upper surface of the crawler 1 and the lower surface of the upper rotating body 5. Although necessary, in order to secure this gap h1, the track frame 6 has a structure in which the central portion 6c is raised by h2 from other portions.

Conventionally, the structure of raising the central portion 6c of the track frame 6 is shown in FIG. 5 (B) which is a plan view of FIG. This is realized by bending the vicinity a of the upper plate 6d of each of the lateral beams 6a and 6b on the side joined to the portion 6c on the joining side with the central portion 6c.

As shown in FIG. 5C, which is a cross-sectional view taken along the line GG of FIG.
The beam 6a, 6b of the front and rear box cross-section structure has a cross-girder structure connecting two left and right vertical beams 6e having an I-shaped cross section.

[0006]

However, according to the conventional track frame structure, a plate bending process for bending the upper plate 6d of each of the lateral beams 6a and 6b is required, so that the plate bending process is increased. Due to the presence of such a bent portion a, there is a problem that a complicated structure is difficult to assemble in terms of structure, which requires a lot of assembly man-hours, and that application of a welding robot is difficult.

The front ends of the horizontal beams 6a and 6b before and after the track frame 6 have a straight structure to change the width of the crawler 1. Further, the track frame 6 is simply inserted into the guide 3 of the side frame 2, and the track frame 6 is prevented from slipping out by fixing with the link 7. Therefore, since no bending moment is transmitted between the track frame 6 and the side frame 2,
The unbalanced load (for example, the state of receiving the right front and left rear forces) acting on the left and right side frames 2 must be received by the track frame 6. However, the conventional structure having the I-shaped vertical beam 6e has a problem that it is susceptible to torsion and vulnerable to unbalanced load.

The present invention has been made in view of the above problems, and provides a track frame structure of a crawler crane which has a simple structure, reduces man-hours, facilitates welding robotization, and improves strength against an unbalanced load. With the goal.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a track frame is formed by welding a horizontal beam before and after a box cross-sectional structure and a left and right vertical beam of a box cross-sectional structure into a cross-girder structure, and vertically flanking the vertical and horizontal beams. Is flat, and a swinging device is mounted on the upper flange, and a ring for raising is fixed.

[0010]

In the structure of the present invention described above, the vertical and horizontal beams of the box cross section are assembled in a cross-girder structure, the upper and lower flanges of the beam are flattened, and the ring for raising is fixed on the upper flange. The step of bending the plate for raising is not required. In addition, since the vertical beam has a box sectional structure, it is resistant to torsion due to unbalanced load on the left and right.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A is a plan view of a track frame according to the present invention, FIG.
(C) and (D) are EE and FF in FIG. 1 (A), respectively.
FIG. 2 is a plan view showing a lower structure of the crawler crane to which the track frame of the embodiment is attached.

The track frame 8 of the present embodiment is shown in FIG.
As shown in (A) to (D), the transverse beams 8a and 8b having the front and rear box cross-sectional structures, and the transverse beams 8a and 8b
Vertical beams 8c, 8d of box cross-sectional structure welded between
And upper and lower flanges c and d of the horizontal beams 8a and 8b, upper and lower flanges e of the vertical beams 8c and 8d,
Let f be flat. The upper flanges c and e and the lower flanges d and f may each be a single plate.

Reference numeral 9 denotes a ring on which the above-described swivel device 4 is installed. The swivel device 4 is fixed by welding or bolting on upper flanges c and e of vertical and horizontal beams 8a to 8d assembled in a girder structure. . 10 is an upper and lower flange surrounded by vertical and horizontal beams 8a to 8d for providing a hydraulic source on the upper swing body 5, a hydraulic pipe such as an actuator such as a hydraulic motor for traveling, a center joint for transmitting electric signals, and the like. An opening formed by cutting out a portion.

As shown in FIG. 2, both ends of the horizontal beams 8a and 8b are slidably fitted to guides 3 provided on the left and right side frames 2 as shown in FIG. The link 7 pinned between the frame 2 and the track frame 8 fixes the crawler 1 at the widening and narrowing positions.

With such a structure in which the ring 9 is used for raising, it is not necessary to bend the upper flange for raising, and the plate bending process for that purpose is not required. In addition, even if unbalanced loads on the left and right are applied, the vertical beams 8c, 8c
Since d has a box cross-sectional structure, the torsional strength increases, so that the strength against an unbalanced load increases.

[0016]

According to the present invention, since the ring for raising is provided on the upper surface of the track frame, the bending of the plate for raising is not required. As a result, the structure is simplified and the number of steps of the plate assembly is reduced. Is reduced. Further, the automation rate of welding by the welding robot can be improved. In addition, since the vertical and horizontal beams have a box cross-sectional structure and a structure in which the beams are assembled in a cross-girder, the torsional strength can be improved, and a track frame structure resistant to unbalance load can be realized.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a track frame according to the present invention, FIG. 1 (B) is a view taken in the direction of an arrow H, and FIGS. 1 (C) and 1 (D) are cross-sectional views taken along lines EE and FF of FIG. It is.

FIG. 2 is a plan view showing a lower structure of the crawler crane to which the track frame according to the embodiment of FIG. 1 is attached.

FIG. 3 is a front view showing a conventional crawler crane.

FIG. 4 is a plan view showing a lower structure of a conventional crawler crane.

FIG. 5A is a plan view of a conventional track frame,
(B) is a view on arrow I of (A), and (C) is a cross-sectional view taken along line GG of (A).

[Explanation of symbols]

1: Crawler, 2: Side frame, 3: Guide, 4:
Revolving device, 5: Upper revolving superstructure, 7: Link, 8: Track frame, 8a, 8b: Horizontal beam, 8c, 8d: Vertical beam, 9: Link, 10: Opening, c, e: Upper flange,
d, f: lower flange

Claims (1)

[Claims] 1. A horizontal beam before and after a box cross-section structure and a vertical beam on the left and right sides of a box cross-section structure are welded to a girder structure, the vertical flanges of these vertical and horizontal beams are made flat, and a turning device is installed on an upper flange. A track frame structure for a crawler crane, wherein a ring for raising is fixed.