JPH0715172B2 - Backhoe work equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a backhoe type working apparatus used for construction machines such as hydraulic excavators, and particularly, the shape of a boom or the like can be simplified and weight reduction can be achieved. And a backhoe type working device.

[Conventional technology]

FIG. 5 and FIG. 6 show a hydraulic excavator as an example of a conventional backhoe type working device.

In the figure, 1 is a lower traveling structure, 2 is an upper revolving structure mounted on the lower traveling structure 1 so as to be rotatable, and the upper revolving structure 2 has a cab 2B, a machine room 2C, etc. on a revolving frame 2A. It is provided and constitutes the working machine main body. Reference numeral 3 denotes a backhoe-type working device provided at the front part of the revolving frame 2A of the upper revolving structure 2. The working device 3 is a boom 4 pin-movably connected to the front center of the revolving frame 2A, and the boom. An arm 5 that is pin-coupled to the tip of 4 so that it can be lifted
And a boom cylinder 7, an arm cylinder 8 and a bucket cylinder 9 for operating the backhoe bucket 6 rotatably pin-connected to the tip end of the arm 5 and the like.

Here, as shown in FIG. 6, the boom 4 of the working device 3 is
The left and right webs 4A, 4A, an upper flange (not shown) welded to the upper end surface of each of the webs 4A, and a lower flange 4B welded to the lower end surface of each web 4A are roughly configured to form a box. It is formed as a hollow member having a shape. Further, each web 4A is formed with overhanging portions 4A ₁ , 4A ₁ located on the tip side of the boom 4 and projecting leftward and rightward. The dimension L between the overhanging portions 4A ₁ is determined by bending. Is larger than the dimension 1 between the other parts (1 <L). A rectangular reinforcing partition plate 4C is provided between the webs 4A at the tip end side of each overhanging portion 4A ₁ , and the partition plate 4C is provided for each web 4A.
A, upper flange and lower flange 4B are welded respectively.

Further, the arm 5 is provided with the left and right webs 5 as shown in FIG.
A and 5A, an upper flange (not shown) welded to the upper and lower end surfaces of each web 5A, and a lower flange 5B. The arm 5 also includes each web 5A and upper and lower flanges 5B. And the like are formed as a box-shaped hollow member.

Reference numerals 10 and 10 denote brackets provided at the tip of the boom 4, and each of the brackets 10 is welded to the tip of the overhanging portion 4A ₁ of each web 4A and also fixed to the tips of the upper flange and the lower flange 4B by welding. Further, they are separated from each other by the dimension L in the axial direction of the connecting pin 12 described later. Reference numeral 11 denotes a boss portion provided on the base end side of the arm 5, and both axial ends of the boss portion 11 are fixed to the webs 5A and the lower flange 5B of the arm 5 by means of welding or the like, and Each bracket
It is inserted between 10. 12 is each bracket 10 and boss 11
The connecting pin 12 is inserted into the pin hole 10A of each bracket 10 and the pin hole 11A of the boss portion 11, and the boom 4 and the arm 5 are rotatably pin-coupled. It is supposed to do. Further, 13 is a retaining pin that retains the connecting pin 12.

The hydraulic excavator work device 3 according to the prior art is configured as described above. When excavating earth and sand, the boom cylinder 7 and the arm cylinder 8 raise and lower the boom 4 and the arm 5, respectively, while the bucket cylinder 9 moves the backhoe. The bucket 6 is rotated and the bucket 9 excavates earth and sand. And the earth and sand after excavation is the bucket 9
With the cargo (stored) inside (see FIG. 5), while appropriately rotating the boom 4, the arm 5 and the bucket 9 again,
The upper-part turning body 2 is turned and the earth is discharged to a desired place.

[Problems to be Solved by the Invention]

By the way, in the above-mentioned conventional technique, the brackets 10, 10 are provided on the tip side of the boom 4, and the boss portion 11 is provided on the base end side of the arm 5.
Since the boss portion 11 is inserted between the brackets 10 and these are rotatably connected by the connecting pin 12,
In order to support each bracket 10 on the tip side of each web 4A of the boom 4, it is necessary to form the left and right overhanging portions 4A ₁ and 4A ₁ by bending, which complicates the shape and increases the manufacturing cost. The upper flange and the lower flange 4B are also overhanging
4A ₁ needs to be formed in a wide width, which increases material costs and increases the weight of the boom 4 as a whole.

Further, the distance between the brackets 10 also becomes large in accordance with the dimension L between the overhanging portions 4A ₁ and both ends of one connecting pin 2 are supported by the brackets 10, so that the connecting pin 12 is Since the arm 5 and the bucket 6 are substantially supported by the connecting pin 12, it is necessary to form the connecting pin 12 with a large diameter to increase the strength. The weight of 12 becomes large. Particularly in a large hydraulic excavator, it is necessary to use the connecting pin 12 ranging from several 100 kg to several tons.

For this reason, when exchanging the connecting pin 12 for site work, etc., it is necessary to transport the heavy connecting pin 12 and insert it into each pin hole 10A, 11A using a crane, etc. It has the disadvantage of extremely poor serviceability and serviceability. Further, due to the above reason, the weight of the entire working device 3 becomes large, and the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9 and the like must be upsized, and it is difficult to increase the load of sediment such as sand by the bucket 6, There is a drawback that work performance (front performance) cannot be improved.

The present invention has been made in view of the above-mentioned drawbacks of the prior art. The present invention can simplify the shape of the boom, reduce the overall weight, and improve workability and serviceability when replacing the connecting pin. The backhoe-type working device is provided.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, the present invention operates in a feature that the boom is formed so that the left and right webs extend toward the tip side in parallel to each other, and the left and right web tips and the boom are formed. A pair of left and right bosses are provided at the tips of the upper and lower flanges, and at least a pair of left and right bifurcated brackets are formed by extending at least the left and right webs on the arm in parallel. In addition, each boss portion of the boom is inserted into the bracket, and each boss portion and each bifurcated bracket are connected by the bifurcated bracket so as to be connected to each other via a pair of left and right connecting pins. The purpose is to support both ends of the pin.

In this case, on the tip end side of the boom, the left and right auxiliary webs extending between the left and right webs in parallel with the respective webs and the tips fixed to the respective boss portions, and the auxiliary webs of the respective auxiliary webs. A reinforcing partition plate fixed to the base end and welded to the inner surfaces of the left and right webs and the inner surfaces of the upper and lower flanges, respectively;
The respective auxiliary webs and auxiliary plates welded to the upper and lower flanges are provided on the tip side of the boom with respect to the reinforcing partition plate, and these left and right auxiliary webs and reinforcing partition plates are provided. It is preferable that the auxiliary plate has a frame structure between the left and right webs and the upper and lower flanges.

[Action]

With the above configuration, it is not necessary to bend the left and right webs on the tip side of the boom, the shape can be simplified and the weight of the boom as a whole can be reduced, and a pair of boss portions is provided on the tip side of each web. Since each boss is connected to each bifurcated bracket of the arm with a pair (two) of connecting pins, each connecting pin can be formed to be short and small in diameter, ensuring the strength of the connecting pin. Can be improved. By extending the webs of the arms in parallel to form a pair of bifurcated brackets, it is possible to prevent the arms from becoming complicated in shape, and each bifurcated bracket supports both connecting pins on both sides. You can

Further, by providing the left and right auxiliary webs, the reinforcing partition plates and the reinforcing plates, which are located between the left and right webs and the upper and lower flanges and have a skeleton structure, on the tip end side of the boom, Each boss can be supported with high strength, the strength of the entire boom can be improved, and the plate thickness of each web and the like can be reduced.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. In the embodiment, the same components as those of the prior art shown in FIG. 5 described above are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, reference numeral 21 denotes a backhoe-type working device provided on the revolving frame 2A of the upper revolving structure 2. The working device 21 is similar to the working device 3 described in the related art, and the boom 22 and the arm 2 are substantially the same.
3, a backhoe bucket 24, a boom cylinder 25, an arm cylinder 26, and a bucket cylinder 27. The boom 22 of the working device 21 is formed as a box-shaped hollow member from the left and right webs 22A and 22A and the upper and lower flanges 22B and 22C, as shown in FIGS. 2 to 4. Each web 22A of the boom 22
Are formed so as to extend in parallel to each other from the middle portion in the longitudinal direction of the boom 22 to the tip end side, and the separation dimension l ₁ thereof is substantially equal to the dimension 1 between the webs 4A described in the prior art. .

Further, on the tip side of the boom 22, each web 22A and the upper,
Rectangular reinforcing partition plates 22D respectively welded to the inner surfaces of the lower flanges 22B and 22C, and the partition plates 22D and the upper and lower flanges.
Left and right auxiliary webs 22E and 22E welded to 22B and 22C, respectively, and extending between the webs 22A in parallel with the webs 22A.
And a auxiliary plate which is located closer to the tip of the boom 22 than the partition plate 22D and is welded to the respective auxiliary webs 22E and the upper and lower flanges 22B and 22C, and which is formed in a rectangular shape smaller than the partition plate 22D. 22F are provided, and these form a box shape (frame structure) by defining spaces A, B, and C with each web 22A and upper and lower flanges 22B and 22C as shown in FIGS. 2 and 4. Is formed.

On the other hand, the arm 23, as shown in FIG.
A, 23A, an upper flange (not shown), and a lower flange 23B are formed as a hollow member having a box shape. At the base end side of the arm 23, each web 23A extends from the lower flange 23B so as to extend in parallel with each other. The bracket portion 29A of each bracket 29, which will be described later, is formed.

Reference numerals 28 and 28 denote a pair of left and right boss portions provided at the tip of the boom 22. The boss portions 28 are fixed to the tips of the webs 22A and the auxiliary webs 22E of the boom 22 by welding, and , Also fixed to the tips of the lower flanges 22B and 22C by welding. The bosses 28 are provided on the tip side of the boom 22, and each auxiliary web 22E and reinforcing plate forming a frame structure.
22F and partition plate 22D etc. are designed to increase the strength. Further, each boss portion 28 is provided with a pin hole 28A into which a connecting pin 30 described later is inserted.

Reference numerals 29 and 29 denote a pair of left and right bifurcated brackets provided on the base end side of the arm 23.
The outer bracket portions 29A, 29A formed by extending the respective webs 23A in parallel with each other, and the wall thickness t of each boss portion 28 located between the bracket portions 29A (see FIG. 3).
Is separated from each of the bracket portions 29A by a dimension substantially corresponding to, and the base end side includes inner bracket portions 29B and 29B welded to the lower flange 23B, respectively.
The 9A and 29B are arranged so as to form a bifurcated shape via the lower flange 23B. Further, substantially disc-shaped reinforcing plates 29C, 29C, ... Are fixed to the respective bracket portions 29A, 29B by welding, and pin holes 29D, 2 are formed so as to penetrate the respective reinforcing plates 29C.
9D, ... are drilled.

Reference numerals 30 and 30 denote a pair of left and right connecting pins that connect each boss portion 28 of the boom 22 to each forked bracket 29 of the arm 23, and each connecting pin 30 connects each boss portion 28 to each bracket 29 bracket. Each pin hole 2 when inserted (inserted) between parts 29A and 29B
The boom 22 and the arm 23 are rotatably pin-connected by being inserted into the 8A and 29D. Then, the connecting pins 30 are in a both-supported state between the bracket portions 29A and 29B, and the bosses 28 are rotatably connected to each other, and the load (weight) of the arm 23, the bucket 24, etc. is two. Since it suffices to share and support, it can be formed to have a much shorter length and a smaller diameter than the connecting pin 12 described in the prior art.

The backhoe type working device 21 according to the present embodiment has the above-mentioned configuration, and its basic operation is not particularly different from that according to the prior art.

However, in this embodiment, a pair of boss portions are provided on the tip side of the boom 22.
28, 28 are provided, and a pair of bifurcated brackets 29, 29 into which the bosses 28 are inserted are provided on the base end side of the arm 23, and the bosses 28 and the brackets 29 are paired with a pair of connecting pins 30. , 30 are used to rotatably connect, so that the tip end side of the boom 22 can be formed so that the left and right webs 22A, 22A extend parallel to each other, and bending is performed as in the prior art. There is no need to do so, the shape of the tip end side of the boom 22 can be greatly simplified, and the weight of the entire boom 22 can be reliably reduced.

Further, since the bracket portions 29A, 29B of each bracket 29 and each boss portion 28 are connected by each connecting pin 30, each connecting pin 30 can be formed to be short and small in diameter.
In addition to being able to significantly reduce the weight of, the strength of each connecting pin 30 can also be greatly increased by forming it in a short length,
The arm 23 and the like can be supported with high strength with respect to the boom 22. Further, the total weight of the two connecting pins 30, 30 can be surely made lighter than the one connecting pin 12 described in the prior art, and the weight of the working device 21 as a whole can be reduced.
The load of sediment such as 24 can also be increased, and the work performance (front performance) can be improved.

Further, by reducing the weight of each connecting pin 30, when each connecting pin 30 is replaced in the field work, etc., each connecting pin 30
Can be transported relatively easily, serviceability can be improved, and workability and safety at the time of replacement can be improved.

Further, on the front end side of the boom 22, the partition plate 22 which is located between each web 22A and the upper and lower flanges 22B and 22C and has a frame structure is formed.
Since the D, each auxiliary web 22E and the reinforcing plate 22F are provided, the bosses 28 can be supported with high strength by these, and the strength of the boom 22 can be improved, and the plate thickness of each web 22A and the like can be reduced. it can. Further, the arm 23 is formed by extending the webs 23A in parallel so that the bracket portions of the brackets 29 are formed.
Since the brackets 29A are formed, it is possible to prevent the brackets 29 from protruding leftward and rightward from the webs 23A of the arms 23.
It has various effects such as the simplification of the shape.

〔The invention's effect〕

As described in detail above, according to the present invention, each web of the boom is shaped to extend in parallel, and a pair of left and right boss portions are provided at the left and right web tips and the upper and lower flange tips, and the arm is provided. A pair of left and right forked brackets are formed by extending at least the left and right webs in parallel with each other, and each boss is connected to each of the forked brackets via a pair of connecting pins. Therefore, the shape of the boom can be simplified, the overall weight can be reduced, the workability and serviceability when replacing the connecting pin can be improved, and the load of earth and sand etc. by the backhoe bucket can be increased to improve the work performance. Can be improved. Then, each web of the arm can form a part of each bifurcated bracket, and the shape of the arm can be simplified.

Further, on the tip side of the boom, there are provided left and right auxiliary webs, a reinforcing partition plate and a reinforcing plate which are located between the left and right webs and the upper and lower flanges and form a frame structure. By fixing each boss to the tip of the, it is possible to support each boss with high strength on the tip side of the boom, improve the strength of the entire boom, and reduce the plate thickness of each web, etc. , Various effects are exhibited.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention, FIG. 1 is an overall view of a hydraulic excavator, and FIG. 2 is an arrow II-II in FIG.
Direction enlarged cross-sectional view, FIG. 3 is a plan view of the boom tip side, FIG.
FIG. 5 is an enlarged sectional view in the direction of arrow IV-IV in FIG. 3, FIG. 5 and FIG. 6 show a prior art, FIG. 5 is an overall view of a hydraulic excavator, and FIG. 6 is an arrow VI- in FIG. It is a VI direction enlarged sectional view. 1 ... Lower traveling body, 2 ... Upper revolving body (work machine main body),
21 …… Backhoe work equipment, 22 …… Boom, 22A ……
Web, 22B ... Upper flange, 22C ... Lower flange, 22D
…… Partition plate, 22E …… Auxiliary web, 22F …… Reinforcement plate, 23…
… Arm, 23A… Web, 23B… Lower flange, 24…
Backhoe bucket, 28 …… Boss part, 29 …… Bracket, 29A, 29B …… Bracket part, 30 …… Connecting pin.

Claims (2)

[Claims] 1. A work-machine main body is pin-coupled so that it can be lowered and raised,
A boom formed as a hollow member by the left and right webs and the upper and lower flanges is pin-coupled to the tip end side of the boom so that the boom can be lifted and lowered, and a hollow is formed by the left and right webs and the upper and lower flanges. In a backhoe type working device comprising an arm formed as a member and a backhoe bucket rotatably pin-connected to the tip end side of the arm, the boom has left and right webs extending in parallel to each other toward the tip end side. And a pair of left and right boss portions are provided at the left and right web tips and the upper and lower flange tips of the boom.
A pair of left and right bifurcated brackets are formed by extending at least left and right webs in parallel to the arm, and the boss portions of the boom are inserted into the bifurcated brackets. The boss and each bifurcated bracket are left,
A backhoe-type working device characterized in that both ends of each connecting pin are supported by the respective bifurcated brackets so as to be connected via a pair of right connecting pins. 2. On the tip side of the boom, left and right auxiliary webs extending between the left and right webs in parallel with the respective webs and having their tips fixed to the respective boss portions, and the respective auxiliary webs. Affixed to the base end of the web, the inner and upper surfaces of the left and right webs,
A reinforcing partition plate welded to the inner surface of the lower flange, and auxiliary plates welded to the auxiliary webs located on the tip side of the boom with respect to the reinforcing partition plate and the upper and lower flanges, respectively. The left and right auxiliary webs, the reinforcing partition plate and the auxiliary plate are provided with a frame structure between the left and right webs and the upper and lower flanges. The backhoe type working device described in the item.