JPH0444681Y2 - - Google Patents

Description

[Detailed Description of the Invention] -Field of Industrial Application- This invention relates to the structure of a bucket arm of a power shovel, and particularly relates to the structure of an extendable bucket arm.

- Prior Art - Power shovels with extendable bucket arms have been provided for the purpose of increasing the excavation depth and transferable area of earth and sand during bucket hoe work and shovel work. Fig. 4 shows a bucket arm of a conventional power shovel equipped with an extendable bucket arm, in which a bucket arm 1 is attached to two arm members 2 and 3 vertically so as to be slidable relative to each other. A bucket 4 is attached to the tip of the upper arm 2. In the figure, 5 is a pin that pivotally connects the bucket arm 1 to the vehicle body side arm 6, 7 is a cylinder that swings the bucket arm 1, and 8 is a pin that allows the upper arm 2 and the lower arm 3 to slide freely. The bracket that is fastened, 9 is the sliding surface between the upper arm 2 and the lower arm 3, 1
0 is a cylinder that moves the upper arm 2 and lower arm 3 forward and backward, and 11 is a cylinder for bucket operation.

The bucket belt 4 is pivotally supported at the tip of the upper arm 2 by a fulcrum pin 12, and the tip of a lever link 13 pivoted to the base end side of the arm from the fulcrum pin and an operation pin provided on the back of the bucket belt 4. 14 are connected by a connecting link 15, and the rod 1 of the cylinder 11
The tip of 6 is pivotally connected to a connecting pin 17 that pivotally connects the lever link 13 and the connecting link 15. The reason why the bucket belt 4 is connected to the cylinder 11 through such a link mechanism is to enable the swing angle of the bucket belt 4 to be increased, and the bucket belt 4 of a power shovel is required to have a swing angle of 180 degrees or more. This is because it has been done.

-Problems to be solved by the invention- However, with the structure shown in Fig. 4, for example, when excavating the trench shown in Fig. 5 with the bucket arm 1 extended, the trench becomes deep. for,
When the bucket 4 is raised from the bottom of the trench, the back surface of the bucket arm 1 collides with or rubs against the excavation end surface 18, causing an accident in which the cylinder 11 and the hydraulic piping to the cylinder are damaged. Furthermore,
Since the upper arm 2 and the lower arm 3 are only partially connected by the bracket 8, there is a problem that the strength is inferior to that of a bucket arm having a single structure.

The above problem can be solved by, for example, as shown in Japanese Utility Model Application Publication No. 60-448, the box structure of the upper arm 2 shown in FIG. By installing it inside the box of the arm 2, this problem can be solved to a certain extent.

However, since the bucket operating arm 11 swings greatly in the vertical direction in FIG. A problem arises in that the width becomes very large.

The above-mentioned Utility Model Application No. 60-448 attempts to solve this problem by guiding the rod of the bucket operation cylinder with a sliding frame that slides within the arm, but compared to the conventional link structure guidance, As the structure becomes more complex, the frictional resistance increases, especially when a large reaction force is applied to the bucket, resulting in a lack of smooth operation and problems with practicality.

This invention aims to solve this problem, and is a technology that can reduce the cross-sectional area of the arm without impairing the smoothness of the bucket operation in a structure in which the bucket operation cylinder is built into the arm. It seeks to provide a means.

-Means for Solving the Problems- The bucket arm 1 of this invention is composed of an outer arm 24 having a box structure and an inner arm 25 having a box structure slidably fitted to the outer arm 24. A bucket belt 31 and a lever link 32 are pivotally connected to the tip of the inner arm 25, and a bucket operating cylinder 28 is provided inside the box of the inner arm 25.

Then, the connecting link 33 connecting the connecting pin 35 provided at the tip of the lever link 32 and the operating pin 34 provided on the back of the bucket bag is connected to the connecting pin 3.
5, and a rod 37 of the bucket operating cylinder 28 is pivotally connected to its extended end 36.

According to a more preferred embodiment of the present invention, a support bracket 29 is provided at the tip of the inner arm 25 and extends downward (towards the vehicle body) of the arm, and a bucket belt 31 and a lever link 3 are attached to the support bracket 29.
2 is pivotally connected.

-Function- The bucket arm 1 according to the present invention includes a bucket 3
The swing width H of the cylinder 28 when swinging the arm 1 can be made smaller than the conventional swing width h, and the cross section of the arm 22 can be made smaller.
That is, as shown in FIG. 3, in the conventional link structure, when the bucket belt 4 is bent toward the arm 1 side, the bucket operating cylinder 11 swings greatly toward the arm 1 side, but as shown in FIG. According to the structure of the embodiment of the present invention, the bucket 31 is connected to the arm 22.
The connecting link 33 connects to the arm 2 when bent to the side.
At this time, the pivot pin 38 that pivotally connects the rod 27 is in a position above the connecting pin 35, and the bucket belt 31 is extended, that is, the connecting link 33 is approximately parallel to the arm 22. Since the pivot pin 38 and the connecting pin 35 are at substantially the same height, the swing width H of the bucket operation cylinder 38 can be reduced.

Furthermore, if a support bracket 29 is provided at the tip of the inner arm 25 that extends toward the vehicle body, and the bucket belt 31 and the lever link 32 are pivotally connected to this bracket, the rod 37 of the bucket operating cylinder 28 and the connecting link 33 are positioned at the center of the inner arm 25. Since the positions are close to each other, the cross-sectional area of the arm 1 can be made smaller.

-Example- Figs. 1 and 2 are sectional views showing the structure of the bucket tort arm of the present invention and explanatory diagrams of the operation of the bucket tot. In the figure, 21 is an arm on the vehicle body side of the power shovel, 22 is a bucket arm pivotally connected to the tip of the arm by a pin 23, and the bucket arm 22 slides on an outer arm 24 having a box structure. It is composed of an inner arm 25 having a box structure that is freely fitted. 26 is a cylinder for swinging the bucket arm 22; 27 is an arm telescopic cylinder whose head side is connected to the outer arm 24; and the rod side is connected to the inner arm 25; 28 is an extension of a connecting link, which will be described later, with the inner arm 25 on the head side and the rod 37 side. A bucket operating cylinder 29 is connected to the end 36, and a support bracket 29 is provided at the tip of the inner arm 25 and extends downward (towards the vehicle body) of the arm.
0 is a fulcrum pin that pivotally supports the bucket 31 at the tip of the bracket, 32 is a lever link that is pivotally supported on the proximal end side of the arm from the fulcrum pin, and 33 is a connecting pin provided at the tip of the lever link. 35 and an operation pin 34 provided on the back surface of the bucket 31.
extends beyond the connecting pin 35, and the rod 3 of the bucket operating cylinder 28 is attached to its extended end 36.
7 are connected by a pivot pin 38. 39 is a hydraulic pipe for the cylinder 27, and 40 is a hydraulic pipe for the cylinder 28. A hydraulic hose 41 having a length corresponding to the longest movement distance of the inner arm 25 is interposed in the pipe 40.

42 is a shoe fixed to the inside of the tip of the outer arm 24 and in sliding contact with the outer surface of the inner arm 25;
is a shoe that is fixed to the outside of the base end of the inner arm 25 and is in sliding contact with the inner surface of the outer arm 24. The inner arm 25 is fitted to the outer arm 24 via these shoes 42 and 43, and by supplying pressure oil to the head side of the arm telescopic cylinder 27,
It is paid out from the outer arm 24. The operation of extending and bending the bucket belt 31 by expanding and contracting the bucket operating cylinder 28 is as explained in the section of the operation above.

-Effects of the invention- As described above, according to the configuration of the present invention, the bucket can be swung without impairing the smoothness during operation in an arm having a box structure in which a bucket operation cylinder is built into the arm. The swing width of the cylinder can be reduced, and the cross section of the arm can be made smaller.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, in which FIG. 1 is a sectional view of a bucket arm, and FIG. 2 is an explanatory diagram of the operation of the bucket. Fig. 3 is an explanatory diagram of the operation of a conventional bucket tote shown in comparison with Fig. 2, Fig. 4 is a side view of a conventional bucket tot arm, and Fig. 5 is a side view schematically showing trench excavation work. . In the figure, 22...bucket arm, 24...outer arm, 25...inner arm, 27...arm telescopic cylinder, 28...bucket operation cylinder, 29...
...Support bracket, 31...Bucket, 32...
Lever link, 33...connection link, 34...operation pin, 35...connection pin, 36...extension end of connection link, 37...rod of bucket operation cylinder.

Claims (1)

[Claims for Utility Model Registration] (1) Box structure outer arm 24 and outer arm 2
4 and an inner arm 25 of a box structure fitted in a slidable manner, and a bucket 31 and a lever link 32 for operating the bucket at the tip of the inner arm 25.
and the bucket operation cylinder 2.
8 is installed in the box of the inner arm 25 in the bucket arm of the power shovel, the end of the lever link 32 and the bucket 31
A connecting link 33 connecting the rear side of the lever link 32 is extended beyond the pivot portion of the lever link 32, and a rod 37 of the bucket operating cylinder 28 is connected to the extended end 36 of the connecting link 33.
The bucket arm of a power shovel is pivoted. (2) A support bracket 29 is provided at the tip of the inner arm 25 and extends toward the vehicle body side of the arm, and a bucket belt 31 and a lever link 32 are pivotally supported on the support bracket 29. Claim 1 of the Utility Model Registration Claim Bucket arm as described.