JPH02147725A - Hydraulic shovel - Google Patents

Abstract

PURPOSE:To manufacture a hydraulic shovel in an identical manufacturing progress and improve the productivity by inserting a bush with different thickness into a pin hole and using a common arm with the same size for a heavy excavation arm and a short reach arm. CONSTITUTION:When a heavy excavation work device which differs from a short reach work device on only a bucket 44, links 47 ad 48 and a bucket cylinder 49 is used, the same arm 43 of the short reach work device is used, and a bush 53 with small thickness is inserted into the pin hole 43B of the boss section 43A of a pin connection section 51. When the arm 43 is used as the short reach work device, a bush with large thickness is inserted into the pin hole 43. The arm 43 is commonly used by only inserting the different bush 53 according to the usage at the time of assembling, and the same member can be manufactured for the arm 43.

Description

[Detailed Description of the Invention] [Industrial Field of Application J] The present invention relates to a hydraulic excavator that is suitably used, for example, for excavating earth and sand, and in particular, it relates to a hydraulic excavator that can be manufactured in common with a heavy excavation arm and a short reach arm. This article relates to a hydraulic excavator.

[Prior Art] In general, the working device of a hydraulic excavator is roughly composed of a boom, an arm, a bucket, and a boom cylinder, arm cylinder, and bucket cylinder that operate these. Three types are now in use.

Therefore, hydraulic excavators according to the prior art of this type will be explained by dividing them into different types with reference to FIGS. 5 to 9.

In the figure, 1 denotes an undercarriage, and 2 denotes an upper revolving body rotatably mounted on the undercarriage 1. The upper revolving body 2 includes a machine room 2A, a driver's cab 2B, etc., and has a front section thereof. As shown in FIGS. 5 to 7, there are working devices 3, which will be described later.
15 and 27 are respectively provided so as to be movable up and down.

Reference numeral 3 indicates a standard type working device, and the working device 3 has a boom 4 rotatably connected to the front part of the revolving upper body 2 with a pin, and a boom 4 rotatably attached to the tip of the boom 4, as shown in FIG. an arm 5 pin-coupled to the arm 5; a bucket 6 rotatably pin-coupled to the tip of the arm 5; a boom cylinder 7 for rotating the boom 4; an arm cylinder 8 for rotating the arm 5; The bucket 6 is composed of a bucket body 6A and a pair of brackets 6B (only one of which is shown) provided on the bucket body 6A. .

Here, the arm 5 in the standard type working device 3 is formed to have a relatively long length between the pin connecting portion 12 to the boom 4 and the pin connecting portion 13 to each bracket 6B of the bucket 6. , the pin connection part 1
2 and the pin connecting portion 14 to the arm cylinder 8 are formed to have a relatively short length ρ. Then, the arm excavation force F by the arm 5 is calculated as follows, where P is the thrust force of the arm cylinder 8, and the length dimension is long (, since the length dimension β is short, the arm excavation force F is not so large. However, based on the length dimension, the excavation range by bucket 6 can be made thicker (
It is now possible to do so.

In addition, the length of the bucket 6 from the pin joint 13 to the tip of the excavating claw of the bucket body 6A is β, and the width of the bucket body 6A (the dimension perpendicular to the plane of the paper in FIG. 5) is β. (Since there is no thick bucket, the excavation capacity V of earth and sand etc. by the bucket 6 is relatively small.The bucket excavation force F by the bucket 6 is, however, Pg: Thrust force I2 of the bucket cylinder 11 @ Ni bracket 6B, and the bucket excavation force FIl is set to a relatively small predetermined excavation force suitable for ordinary excavation work of earth and sand.

Next, 15 indicates a short reach type working device,
As shown in FIG. 6, the working device 15 has a boom 16. which is different from the standard type working device 3 described above. Arm 17. Bucket 18. A boom cylinder 19 and an arm cylinder 20 are used, and the links 9, 10, bucket cylinder 11, etc. are common to the standard type. The bucket 18 consists of a bucket main body 18A and a pair of brackets 18B, 18B (see Fig. 8), and although its length I2A is the same as the standard type bucket 6, its width is relatively thick ( The excavation capacity V+ is larger than the excavation capacity V of the bucket 6 based on the arm excavation force F1 etc. described later (VI > V
) has become. Incidentally, the bucket digging force FBI is almost the same as that of the standard type.

Here, the arm 17 in the short reach type working device 15 has a pin connection portion 21 to the boom 16 and a pin connection portion 2 to each bracket 18B of the bucket 18.
2 is formed relatively short, and the length dimension β+(
I2+>I! , ) are formed relatively long. Then, the arm excavation force F by the arm 17 is as follows, where the thrust force of the arm cylinder 20 is Pl (P+>P), and the length dimension Ll (
Since L, <L) is short, the excavation range by the bucket 18 is small (although the length dimension I21 (I21>I2) is long (I21>I2), the arm excavation force F is the same as the arm excavation force F of the standard type. It is now possible to definitely make it larger.

Further, the arm 17. Pin joint 2 between buckets 18
2, as shown in FIG. 8, a boss portion 17A provided at the tip of the arm 17 and a pair of pin holes 17B of the boss portion 17A.
A pair of bushes 24, 24 inserted therein, and a pair of pin holes 1 drilled in each bracket 18B of the bucket 18.
8C, 18C and a pin 25 inserted into each bush 24 and rotatably connected between the boss portion 17A and each bracket 18B, and each pin hole 17 of the boss portion 17A.
A pair of oil seals 26, 26 are provided between B and the pin 25 in order to prevent grease, etc. for lubricating each bush 24 from leaking to the outside. The outer diameter of each bushing 24 is dimensioned to correspond to the hole diameter of each pin hole 17B of the boss portion 17A, and the inner diameter is dimensioned to a dimension d corresponding to the outer diameter of the pin 25. .

Next, the working device 27 shown in FIG. 7 is of a heavy excavation type, and the working device 27 has the same boom 16 as the short reach type described above. Although the boom cylinder 19 and the arm cylinder 20 are used, the arm 28. Bucket 2
9. The links 30° 31, bucket cylinder 32, etc. are different. The bucket 29, which consists of a bucket body 29A and a pair of brackets 29B, 29B (see Fig. 9), has the same length ρ, but has a larger width, so its excavation capacity v2 is as described below. It is the maximum (v2>vl>■) based on the arm digging force F2 and the bucket digging force F82.

Here, the arm 28 for heavy excavation has a length dimension between the pin connection part 33 to the boom 16 and the pin connection part 34 to each bracket 29B of the bucket 29, which is equal to that of the short reach type arm 17, and the arm cylinder 20
The length β2 between the pin joint portion 35 and the pin joint portion 33 is longer than the length β1 of the arm 17.Then, the arm excavation force F2 by the arm 28 is as follows. becomes maximum (Fz>F+>F), and bucket 29
The excavation range by the short reach type is almost the same as that of the short reach type.

On the other hand, the bucket excavation force FB□ by the bucket 29 is obtained as follows, similar to the equation (2) above, and compared to the short reach type, the thrust force P of the bucket cylinder 32, □(PB□> p
m ) has become larger, and the pin hole distance Qs2<IIn□≧128) of each bracket 29B has also become equal or larger, so the bucket digging force F, &2 has become the above (
2) Bucket excavation force of the standard type and short reach type is definitely thicker than the standard type and short reach type FB + FBI (it is suitable for excavation work of rocks, etc.).

Also, arm 28. The pin connection portion 34 between the buckets 29 is formed as shown in FIG. 9 (a boss portion 28A provided at the tip of the arm 28, and a pair of bushes 36 inserted into each pin hole 28B of the boss portion 28A). 36, and a pair of pin holes 29C, 2 drilled in each bracket 29B of the bucket 29.
9C and the inside of each bushing 36, and the boss portion 28A
and a pin 37 rotatably connected to each bracket 29B, and between the pin 37 and each pin hole 28B of the boss portion 28A, grease or the like for lubricating each bush 36 is provided externally. A pair of oil seals 38, 38 are provided to prevent leakage. The outer diameter of each bushing 36 is formed to have a dimension D 2 (D 2 > D 1) corresponding to the hole diameter of each pin hole 28B of the boss portion 28A.
The inner diameter corresponds to the outer diameter of the pin 37 and has the dimension ax (ax>a+
) is formed.

A hydraulic excavator according to the prior art has the above-mentioned configuration, and when performing normal excavation work, the hydraulic excavator shown in Fig. 5 equipped with a standard type work device 3 is used, and the excavator is more efficient than the standard type. If it is desired to reduce the range and increase the arm digging force F1 as shown in equation (3) above, a hydraulic excavator shown in FIG. 6 equipped with a short reach type working device 15 is used. Then, as shown in equations (4) and (5) above, even greater arm digging force F2 and bucket digging force F□
If you want to obtain heavy excavation (type) work equipment 27
A hydraulic excavator shown in FIG. 7 is used.

In addition, in the work device 27 for heavy excavation, the bucket excavation force F,
Since the bucket excavation force F1 is made larger than the bucket excavation force F1 for short reach (type), the reaction force that the bucket 29 receives during excavation is larger than the reaction force of the bucket 18. Therefore, arm 28. The pin 37 (see Fig. 9) used for the pin joint 34 etc. between the buckets 29 has an outer diameter d2 of 8.
Larger diameter (d,
> dl) so that it can receive large reaction forces during excavation, etc.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, the standard work device 3 and the short reach work device 15 share the bucket cylinder 11, etc., and the short reach work device 15 and the heavy excavation work device 27 share the same bucket cylinder 11 and the like. The boom 16, arm cylinder 20, etc. are made common to improve productivity.

However, in the prior art, the short reach work device 1
5 and a working device 27 for heavy excavation 17.2
8 is used, these arms 17 and 28 cannot be made common, and the demand for improving productivity cannot necessarily be met.

In particular, arm excavation forces F, , F for the arm 17 for short reach and the arm 28 for heavy excavation.

, bucket excavation force Fall, F1a, etc. are different, and the reaction force received from bucket 18.29 during excavation work is arm 1.
For example, arm 28.7 is larger than arm 28.7. The pin 37 used for the pin joint 34 between the buckets 29 has a diameter larger than that of the pin 25 for short reach (as>
I set it to a+). For this reason, each pin hole 17B of the boss portions 17A and 28A.

28B cannot be made to have the same hole diameter, and the diameter of this pin hole is a major problem when the arms 17 and 18 are made common.

The present invention has been made in view of the problems of the prior art described above, and it is an object of the present invention to provide a hydraulic excavator that uses a heavy excavation arm and a short reach arm in common, thereby improving productivity.

[Means to solve the problem]

The feature of the configuration adopted by the present invention in order to solve the above-mentioned problems is that the arm is formed to have the same dimensions to make the arm for heavy excavation and the arm for short reach common, and at least the bucket The diameter of the pin hole to be connected with the pin is formed to match the diameter of the large pin hole for heavy excavation, and when the arm is used as an arm for short reach, the hole diameter of the pin hole is formed to match the diameter of the large pin hole for heavy excavation. When a bush with a large wall thickness is inserted and the arm is used as an arm for heavy excavation, a bush with a small wall thickness is inserted and fitted to match the large diameter pin.

[Effect]

With the above configuration, it is only necessary to insert bushings with different wall thicknesses into the pin holes when used as an arm for heavy excavation and as an arm for short reach, and the arm can be used in common for both cases. .

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4. In this embodiment, the same components as those of the prior art shown in FIGS. 6 and 7 are given the same reference numerals, and their explanations will be omitted.

In the figure, 41 indicates a working device for heavy excavation, and the working device 4
1 is constructed in the same manner as the heavy excavation work device 27 described in the prior art section, and includes a boom 42. Arm 43, bucket 44. Boom cylinder 45. Arm cylinder 46. Link 47.
48 and a bucket cylinder 49, etc., and the bucket 44 is composed of a bucket body 44A with an excavation capacity of 2 and a pair of brackets 44B, 44B (see FIG. 3). The arm 43 is connected to the boom 42. bucket 4
Pin connection portions 50.51 for each bracket 44B of 4
The length between the pin joints 52 and 50 relative to the arm cylinder 46 is C2, and the arm digging force F is determined by the equation (4) above. The excavation force Fl12 is determined by the above equation (5).

Further, the arm 43. Pin joint 5 between buckets 44
As shown in FIG. 3, 1 is located at a boss portion 43A provided at the tip of the arm 43, and on both left and right sides of the boss portion 43A,
A pair of pin holes 43B drilled with a hole diameter of
, 43B, a pair of small thick bushes 53 and 53 which are inserted into each pin hole 43B and have an outer diameter of dimension D2 and an inner diameter of dimension d2; A pin 54 having an outer diameter of d2 is inserted into the pin hole 44C of the bracket 44B and rotatably connects each bracket 44B and the boss portion 43, and a pair of oil seals 55, 5.
It consists of 5.

Next, reference numeral 56 indicates a short reach working device, and as shown in FIG. 2, this working device 56 includes the aforementioned heavy excavation working device 41 and a bucket 57. Although the links 58, 59, bucket cylinder 60, etc. are different, the boom 42. Arm 43. Boom cylinder 45 and arm cylinder 4
The same one is used for 6th grade. and the bucket 57, the link 58, 59 and the bucket cylinder 6.
0 etc. is the short reach work device 1 mentioned in the prior art.
5 is used, and the bucket 57 has an excavation capacity v
1 bucket body 57A and a pair of brackets 57B, 5
It consists of 7B.

Here, the working device 56 is connected to the arm 43. Since the arm cylinder 46 is the same as the one for heavy excavation, the arm excavation force is equal to the arm excavation force F2 according to equation (4) above, but the bucket 57, bucket cylinder 60, etc. are those for short reach according to the conventional technology. Therefore, the bucket excavation force Fa+ is equal to the bucket excavation force F according to the above equation (2), and the bucket excavation force F
It is smaller than a□.

Also, boom 43. As shown in FIG. 4, the pin joint portion 61 between the buckets 57 is inserted into each pin hole 43B of the boss portion 43A, and has an outer diameter of dimension D2 and an inner diameter of dimension d, (d
,<d,) A pair of thick bushes 62.
62, each bushing 62 and each bracket 57B are inserted into pin holes 57C, and each bracket 57B and boss portion 4
3A, and a pair of oil seals 64, 64.
is the short reach pin 25 (8th pin) described in the prior art.
(see figure) and has the same outer diameter dimension d.

The hydraulic excavator according to this embodiment has the above-mentioned configuration, and its basic operation is not particularly different from that of the prior art.

However, in this embodiment, the same arm 43 is used for the heavy excavation work device 41 and the short reach work device 56, and the arm 43 has the same dimensions as the heavy excavation arm 28 described in the prior art. When used for heavy excavation, each bushing 53 with a small wall thickness is inserted into each pin hole 43B of the boss part 43A, and when used for short reach, a bushing 53 with a small wall thickness is inserted into each pin hole 43B. Since each bushing 62 is inserted, the arm 43 can be used in common for heavy excavation and short reach, and productivity can be improved.

That is, in the prior art, since the arm 17 for short reach and the arm 28 for heavy excavation are different, the cutting, welding, etc. of plate materials are performed in separate manufacturing processes for these. In contrast, in this embodiment, the arm 43 can be used in common for short-reach and heavy-duty excavation, so cutting and welding of plate materials can be performed in the same manufacturing process, increasing the production volume per process. In addition, the production line can be standardized and simplified, and production management and inventory management can be made extremely easy.

In the above embodiment, the arm 4.3 and the bucket 44.
Although the description has been made by taking as an example a case where bushes 53.62 having different wall thicknesses are used at the pin joint portion 51.61 with the arm 43 and the bucket cylinder 49.60, the present invention is not limited to this. Bushes or the like having different wall thicknesses may be used as appropriate for the pin joint portions of the link 47 and the pin joint portions of the links 47 and 58.

[Effects of the Invention] As detailed above, according to the present invention, the arm for heavy excavation and the arm for short reach are formed to have the same dimensions, and the arm has a large diameter hole in accordance with the diameter of the pin hole for heavy excavation. A pin hole is formed, and bushings with different wall thicknesses for heavy excavation and short reach use are inserted into the pin diameter, so when inserting the bushings in the assembly process, it is possible to insert bushings according to the purpose of each use. By simply inserting different bushings into the arm, the heavy excavation arm and the short reach arm can be made common and formed as the same member, which brings about various effects such as improving productivity.

[Brief explanation of the drawing]

Figures 1 to 4 show embodiments of the present invention. Figure 1 is an overall view of a hydraulic excavator for heavy excavation, Figure 2 is an overall view of a short reach hydraulic excavator, and Figure 3 is an overview of the hydraulic excavator for short reach. III
-III enlarged sectional view in the direction of the arrow, Figure 4 is IV in Figure 2
- An enlarged sectional view in the direction of the IV arrow, Figures 5 to 9 show the prior art, Figure 5 is an overall view of a standard hydraulic excavator, Figure 6 is an overall view of a short reach hydraulic excavator, and Figure 7 8 is an enlarged cross-sectional view in the direction indicated by the arrows ■--■ in FIG. 6, and FIG. 9 is an enlarged cross-sectional view in the direction indicated by the arrows IX-IX in FIG. 7. 1... Lower traveling body, 2... Upper rotating body, 41°56
...Working device, 42...Boom, 43...Arm, 43A...Boss part, 43B, 44G, 57C...
Pin hole, 44.57... Bucket, 45... Boom cylinder, 46... Arm cylinder, 47, 48, 5
8゜59... Link, 49.60... Bucket cylinder, 50.51, 52.60... Pin connection part, 53
゜62...butsu, 54.63...pin. Patent applicant Hitachi Construction Machinery Co., Ltd.

Claims (1)

[Claims] an undercarriage body, an upper revolving body rotatably mounted on the undercarriage body, a boom, an arm, and a bucket rotatably provided on the upper revolving body and pin-coupled to each other;
In a hydraulic excavator consisting of a boom cylinder, an arm cylinder, and a bucket cylinder that operate the boom, arm, and bucket, the arm is formed to have the same dimensions to make the heavy excavation arm and the short reach arm common, and the arm is Among the pin holes, at least the hole diameter of the pin hole that is pin-coupled with the bucket is formed to match the diameter of a large pin hole for heavy excavation, and when the arm is used as a short reach arm in the pin hole. In this case, a bush with a large wall thickness is inserted to fit a small diameter pin, and when the arm is used as an arm for heavy excavation, a bush with a small wall thickness is inserted to fit a large diameter pin. A hydraulic excavator featuring: