JPH0213571Y2 - - Google Patents

Description

[Detailed description of the invention] This invention consists of a lower flange with a plurality of swing ring bolt holes provided on the same circumference, a nearly triangular shape, and a boom foot pin hole provided at the top of the lower flange, which is located from the center of rotation. The left and right webs are located at the front and their lower surfaces are fixed on the lower flange, the front plate is fixed integrally with the lower flange at the front lower part between the webs, and the upper surface of the left and right webs is connected from the rear lower part to the front top. The present invention relates to an upper frame of a construction machine, which comprises an upper flange fixed to the upper frame of the construction machine.

First, an example of a construction machine will be explained with reference to FIGS. 1 and 2.

A rotating body 1 is rotatably mounted on the upper part of a traveling body 2 provided with left and right endless tracks 4 and 6 via a turning ring. The endless tracks 4 and 6 are driven by a left travel motor 5 and a right travel motor 7, respectively, and the revolving structure 1 is driven by a swing motor 3. A front attachment A is installed at the front of the revolving structure 1. A boom 8 constituting the front attachment A is supported so as to be movable at the front of the revolving body 1, and an arm 9 is connected to the tip of the boom 8 so as to be swingable. A bucket bag 10 is connected to the tip of the bucket 10 so as to be tiltable. The boom 8 is raised and lowered by a boom cylinder 11 supported at the front of the revolving structure 1, the arm 9 is oscillated by an arm cylinder 12 installed on the boom 8, and the bucket 10 is tilted by a bucket cylinder 12 installed on the arm 9. This is done by cylinder 13.

Next, the upper frame of the conventional rotating body 1 is attached to the third
This will be explained with reference to FIGS.

The main members of the frame 14 include a lower flange 15,
A substantially triangular left and right web 16 fixed on the lower flange 15, a front plate 17 fixed integrally with the lower flange 15 at the front lower part between the left and right webs 16, 16, and a rear lower part of the upper surface of the left and right web 16. Upper flange 1 fixed towards the front top from
It consists of 8. A pin hole 19 is provided in the upper part of the left and right webs 16 to which the base end of the boom 8 is attached, and a pin hole 20 is provided in the lower part of the front edge to which the boom cylinder 11 is attached. Lower flange 15
A plurality of swing ring bolt holes (hereinafter referred to as bolt holes) 21 are provided on the same circumference.

As shown in FIG. 5, an outer ring 23 is fixed to the bottom surface of the lower flange 15 by bolts 22 screwed into bolt holes 21, and an inner ring 23 with internal teeth 24a is attached to the frame of the traveling body 2. is bolt 2
It is fixed by 5. Note that the revolving body 1 includes:
A turning pinion (not shown) meshed with the internal teeth 24a is supported, and the rotating body 1 is configured to turn on the traveling body 2.

The conventional upper frame described above has the following drawbacks.

(a) The distance L between the left and right upper flanges 18, 18 is small, and the upper flange 18 extends to the pin hole 19, so even if you try to weld with an automatic welder, the automatic welder will hit the frame member. Therefore, it is not possible to automate the welding between the web 16 and the lower flange 15, and between the front plate 17 and the lower flange 15.

(b) The digging reaction force applied from the front attachment A is transmitted via the pin hole 19 and the upper flange 18 to the bolt hole 21 on the rear side B, and the inner ring 24 shown in FIG. The signal is transmitted to the traveling body 2 via the vehicle. As a result, the bolts 22 attached to the bolt holes on the rear side B are subjected to a large stress, and may break or fall off due to fatigue fracture, and the rotating body 1 and the traveling body 2 may be separated.

This invention was designed to eliminate the above drawbacks, and included a lower flange with multiple swivel bolt holes on the same circumference, and a boom foot pin hole that was approximately triangular in shape and provided at the top of the flange. The left and right webs are located forward from the center and their lower surfaces are fixed on the lower flange, the front plate is fixed integrally with the lower flange at the front lower part between the webs, and the In an upper frame of a construction machine comprising an upper flange fixed toward the top, the front end of the upper flange on the top side is located at least rearward from the center of rotation, and the width of the end is tapered. It is characterized by the following.

An embodiment of this invention is shown below in Figures 6 to 9.
This will be explained using figures. In FIGS. 6 and 7, the same reference numerals as in FIGS. 3 and 4 represent the same parts.

A low step portion 26a is formed on the upper end surfaces of the left and right webs 26 at least from a position rearward from the center of rotation. An upper flange 27 having a thickness such that 27a is flush with the upper web end surface 26b on the front top side is welded. W in FIG. 9 represents a welded portion at the end of the upper flange 27. By welding the end of the upper flange 27, stress concentration at the welded end can be alleviated. The rest of the structure is similar to the conventional upper frame.

According to this invention explained above, the following effects can be obtained.

(1) By locating the front top end of the upper flange 27 at least rearward from the center of rotation, the length of manual welding between the upper flange 27 and the web 26 can be shortened, and the left and right Since the interval between the upper flanges 27, 27 is widened to the interval between the webs 26, 26, the automatic welding machine does not hit the member, and automatic welding of the part without the upper flange 27 becomes possible. Therefore, it is possible to reduce the cost.

(2) Separate the upper flange 27 from the boom foot pin hole 19 to the rear side, lower the rigidity of the web 26 near the pin hole 19, and transfer the excavation reaction force applied from the front attachment A to the boom foot pin hole 1.
Since the structure is such that the bolts are transmitted downward through the web 26 through the upper flange, which conventionally has high rigidity, the traveling body 2 is concentrated on the bolts 22 on the rear B side.
The structure allows the bolts 22 on the front F side to bear the load transmitted to the bolts 22, reducing the high stress on the bolts 22 on the rear B side, and preventing breakage, falling off, etc.

(3) By forming the end of the upper flange 27 into a stepped tapered shape, stress concentration at the welded portion can be alleviated, and damage to the web 26 can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a side view showing an example of a construction machine, Fig. 2 is a plan view of Fig. 1, Fig. 3 is a plan view showing the upper frame of a revolving body in a conventional construction machine, and Fig. 4 is Fig. 3 5 is an enlarged sectional view of FIG. 3, FIG. 6 is a plan view showing an embodiment of this invention, and FIG. 7 is a view of FIG. 6 as seen from the - line. , FIG. 8 is an enlarged view showing the part shown in FIG. 6, and FIG. 9 is a view of FIG. 8 viewed from the - line. 1... Revolving body, 2... Traveling body, A... Front attachment, 14... Frame, 15... Lower flange, 17... Front plate, 19... Boom foot pin hole, 20... Pin hole , 21...Swivel ring bolt hole, 22...Bolt, 23...Outer ring, 24
...Inner ring, 25...Bolt, 26...Web, 2
6a...low step part, 26b...web upper end surface, 27
...Top flange, 27a...Top end surface.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A lower flange with multiple slewing ring bolt holes provided on the same circumference, and a boom foot pin hole provided at the top of the flange, which is approximately triangular in shape, from the center of rotation. The left and right webs are located at the front and their lower surfaces are fixed on the lower flange, the front plate is fixed integrally with the lower flange at the front lower part between the webs, and the upper surface of the left and right webs is connected from the rear lower part to the front top. In the upper frame of a construction machine, the upper flange is fixed to the upper flange, and the front end of the upper flange is located at least rearward from the center of rotation, and the width of the end is tapered. An upper frame of a construction machine characterized by: (2) The upper frame of the construction machine as set forth in claim 1 of the utility model registration claim, in which the top surface shape of the front top side end of the upper flange and the portion fixed to the web are continuous and the same plane. .