JP2000248584A - Small swivel type hydraulic excavator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve workability in a small space by setting a turning circle of tip parts of a swivel part in a car width range by tilting an arm backward by pivoting a base part of a boom cylinder via a link mechanism. SOLUTION: A base part of a boom 30 is pivoted on a front side installing part 28 of a swing bracket 27 installed in a front end part of an upper turning body 14, and a base part 38 of a boom cylinder 37 is pivoted via an idler link 36 pivoted on a midway part 35 of a boom 30 and a foot link 33 pivoted on a rear installing part 29. The boom 30 is inclined backward by shortening the cylinder 37, and a turning circle of tip parts P2, P3 of a turning part is set in a car width range, and a falling object from a bucket 22 is protected by the boom 30. When extending the cylinder 37 from this state, a base part interval between the links 33, 36 expands, the boom 30 rotates with the installing part 28 as the center, and can be tilted forward at an optional angle. Thus, workability in a narrow space can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front end of a swing bracket which is connected to the front of an upper revolving structure above a lower traveling structure so as to be able to swing left and right, and a work attachment mainly attached to the swing bracket for excavation work. With the front end,
The present invention relates to a small-swing forward hydraulic excavator that can be set to a minimum turning radius from the turning center of the upper turning body.

[0002]

2. Description of the Related Art FIG. 4 is a side view showing an embodiment of a power shovel described in Japanese Patent Application Laid-Open No. 9-177112. In the embodiment of the power shovel shown in the figure, a part which is bent slightly rearward in the drawing of FIG. 4 on the halfway side of the boom 1 from a position where the boom pin 6 of the boom 1 is attached to the boom foot part 3 of the vehicle body. The first link pin 10 pivotally connects the boom 1 and the first link 8 to each other, and the second link 9 is connected to the boom foot portion 3 of the vehicle body at one end in front of and below the power shovel. The third link pin 12 provided on the side of the first link 8 is rotatably mounted on the shaft, and the other end is rotatably mounted on the other end of the first link 8 by the second link pin 11. The overall height of the boom 1 when the boom cylinder 2 is extended is kept low. In FIG. 4, reference numeral 4 denotes an arm connected to the tip of the boom 1, and reference numeral 5 denotes a bucket for excavation.

Next, FIG. 5 is a side view showing an embodiment of a recently-reduced small turning hydraulic excavator. FIG.
In the hydraulic excavator shown in FIG. 1, a lower traveling body 13, an upper revolving body 14 rotatably mounted on the lower traveling body 13, and a front bracket 15 at the front of the upper revolving body 14 are connected to be swingable in the left-right direction. And a work attachment 17 provided on the swing bracket 16 so as to be able to move up and down. In FIG. 5, 18
Is the swing bracket 16 with respect to the front bracket 15
The vertical axis 19 is connected to a swing cylinder for swingably driving the swing bracket 16 in the left-right direction.
Reference numerals 1 and 22 denote a boom, an arm, and a bucket, which are sequentially connected to the work attachment 17; 23, a boom cylinder for driving the boom 20 up and down; and 24, a boom foot that connects the base end of the boom 20 to the upper part of the swing bracket 16. A pin 25 is a boom cylinder base end pin connecting the boom cylinder 23 base end to a front part of the swing bracket 16, a counterweight 26 is mounted on a rear part of the upper swing body 14, and a center line 0-0. Is the upper revolving superstructure 14
Is the center of rotation.

FIG. 6 is a plan view showing a state in which the hydraulic excavator in FIG. 5 swings the upper swing body 14 in a narrow work site. In the figure, a dimension W is a vehicle width dimension of the lower traveling body 13, a radius Rr is a rear end turning radius of the upper revolving body 14, and a radius Rf is a front end portion P 1 of the work attachment 17 in a plan view.
Is the turning radius of the front end. In the excavator shown in FIG. 6, the swing cylinder 19 is swung by the angle θ by reducing the swing cylinder 19 to a minimum, and the boom cylinder 23 (not visible in FIG. 6) is extended to the maximum. And the boom 20 is standing up.
In addition, the turning circle S1 which is a locus based on the rear end turning radius Rr in FIG. 6 is contained within the range of the vehicle width dimension W.

[0005]

In a power shovel according to one embodiment of the prior art shown in FIG. 4, in order to keep the total height H of the boom 1 in the state where the boom cylinder 2 is extended at the time of standing up low, the boom foot portion 3 is required. The second link 9 is attached to the front side and the lower side, and the first link 8 is provided in the middle of the boom 1.
And attach the tip of each of the links 8 and 9 to the second
The shaft is mounted on the link pin 11. Therefore, since the links 8 and 9 protrude forward from the boom pin 6, a hydraulic excavator that does not have a swing bracket attached to the front portion of the upper revolving unit should be configured as a small forward-rotating hydraulic excavator. It is difficult. When the boom 1 is rotated upward, debris excavated in the bucket 5 often falls on the two links 8 and 9, but since the boom 1 is rotated downward, protection is provided. It is very difficult to attach a cover for the two links 8 and 9.

In the case where the recent small swinging hydraulic excavator shown in FIGS. 5 and 6 swings the upper swing body 14 at a narrow work site, the turning radius Rf at the front end of the tip portion P1 of the work attachment 17 is required. Also need to be reduced. However, for this purpose, the swing bracket 16 must be swing-rotated by a considerably large angle (the angle θ), and there is a problem that workability is poor. Moreover,
Even if the swing rotation and the boom 20 ascent rotation are performed to the maximum, there is a drawback that the tip portion P1 protrudes by a dimension L larger than the range of the vehicle width dimension W as shown in FIG. Was.

According to the present invention, a base end of a boom is pivotally mounted on a front mounting portion of a swing bracket which is swingably connected to a front portion of an upper revolving structure, and the boom is raised and rotated to the rear as much as possible. When the upper revolving unit is swiveled, the turning circles, which are the trajectories drawn by the tip of the work attachment and the tip of the swing bracket, respectively, are approximately within the vehicle width range of the lower traveling unit. An object of the present invention is to provide a swing hydraulic excavator.

[0008]

According to the present invention, a lower traveling structure, an upper revolving structure rotatably mounted on the lower traveling structure, and a bracket device provided at a front portion of the upper revolving structure can be freely raised and lowered. In the construction machine having a work attachment provided in the bracket, the bracket device has a front side mounting portion, and a rear side mounting portion located behind the front side mounting portion, and the work is attached to the front side mounting portion. A base end of the boom of the attachment is pivotally mounted, and a base end of the foot link is rotatably connected to the rear mounting portion, and an idler rotatable in the front-rear direction near the base end of the boom. One end of the link is rotatably connected to the other end of the idler link and the tip of the foot link, and the boom is provided between the connected connection and the bracket of the boom. The rotation drive The boom cylinder is interposed that.

In the hydraulic shovel of the present invention, the base end of the boom is pivotally mounted on the front mounting portion of the swing bracket, and the base end of the foot link is raised and lowered on the rear mounting portion behind the front mounting portion. One end of the idler link is movably connected to the base end of the boom, and the other end of the idler link is freely rotatable in the front-rear direction near the base end of the boom. The other end of the idler link and the tip of the foot link are freely rotatable. Therefore, a lever link mechanism including the foot link and the idler link is configured on the back side of the boom. This allows
When the boom cylinder interposed between the connecting portion in which the tip ends of the foot link and the idler link are rotatably connected to each other and the bracket portion of the boom are reduced, the lever link is actuated. By the action of the mechanism, the boom can be largely rotated rearward. Therefore, the tip of the work attachment in plan view can be moved closer to the center of rotation of the upper revolving unit while the swing bracket is in the neutral position. When the boom is raised and rotated during the operation of the hydraulic excavator of the present invention, even if debris excavated in the bucket may fall, it falls down on the abdominal surface of the boom, so that the components are particularly damaged. It is very advantageous in terms of maintenance.

A boom base end of the boom is pivotally mounted on a front mounting portion on an upper side of the swing bracket, and a base end of a foot link is mounted on a rear mounting portion behind the front mounting portion. Because of the connection, the distance between the front mounting portion and the front end of the swing bracket in plan view can be set to a minimum length. Therefore, the distance between the turning center of the upper swing body and the front end portion of the swing bracket can be minimized, so that the front swing radius of the upper swing body with the swing bracket can be set to the minimum radius.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a side view showing a small-swing forward hydraulic excavator according to one embodiment of the present invention. In the figure, the same reference numerals are given to components using the same components as the recent hydraulic excavator shown in FIG. Reference numeral 27 denotes a swing bracket connected to the front bracket 15 at the front of the upper revolving unit 14 by the vertical axis 18, reference numeral 28 denotes a front side mounting portion provided on the upper side of the swing bracket 27 and forward, and reference numeral 29 denotes a front side. A rear mounting portion P2 provided behind the side mounting portion 28 is a swing bracket 2.
A front end portion 7, 17 ′ is a work attachment provided to be able to move up and down with respect to the swing bracket 27, 30 is a boom of the work attachment 17 ′, 31 is a base end of the boom 30 connected to the front mounting portion 28. The boom foot pin 32 connects the base end of the foot link 33 to the rear mounting portion 2.
9 is a foot link pin, 34 is a boom 30
An idler link pin connecting the base end of the idler link 36 to the middle part 35 of the boom cylinder;
Is a boom cylinder base end pin which rotatably connects the base end of the boom cylinder 37, the front end of the foot link 33, and the front end of the idler link 36, and 39 is a front end of the boom cylinder 37 on the back side of the boom 30. Boom cylinder tip pin connected to bracket 40, P3
Is a front end portion of the work attachment 17 'in a plan view.

FIG. 2 shows the boom cylinder 37 in FIG.
FIG. 3 is a side view of the main part of the present embodiment, showing a state in which the boom 30 is lowered by extending the arm.

FIG. 3 shows the upper revolving unit 14 shown in FIG.
It is a partially cutaway plan view showing a state where the turning operation is performed by 0 °. In the drawing, a radius R2 is a front end turning radius of a front end portion P2 of a swing bracket 27 (when in a neutral position state) attached to a front portion of the upper revolving unit 14, and a radius R3 is a front end turning of a front end portion P3 of the work attachment 17 'in plan view. Radius.

Next, the construction and operation of the small forward turning hydraulic excavator of this embodiment will be described with reference to FIGS. In this embodiment, the front bracket 15 at the front of the upper revolving unit 14 is used.
To the swing cylinder 1
9, the base end of the boom 30 of the work attachment 17 'is axially attached to the front mounting portion 28 on the upper side of the swing bracket 27 which can swing in the left-right direction by driving with the boom foot pin 31, and the front mounting portion 28 The base end of the foot link 33 is connected to the rear mounting portion 29 at the rear of the vehicle by a foot link pin 32 so as to be able to move up and down.
The base end of the idler link 36 is rotatably connected to the middle part 35 near the base end by the idler link pin 34 so that the front end of the idler link 36 and the front end of the foot link 33 are rotated. Freely connected by a boom cylinder base end pin 38, and between the connected connection portion and a bracket portion 40 provided on the back side of the boom 30.
A boom cylinder 37 for rotating the boom 30 is provided.

In the hydraulic shovel of this embodiment, the base end of the boom 30 is pivotally mounted on the front mounting portion 28 of the swing bracket 27, and the foot link 33 is mounted on the rear mounting portion 29 behind the front mounting portion 28. And the base end of the idler link 36 near the base end of the boom 30 so that the front end of the idler link 36 and the front end of the foot link 33 are rotatable. Because of the connection, a lever link mechanism including the foot link 33 and the idler link 36 is configured on the back side of the boom 30. Accordingly, a connecting portion in which the tip ends of the foot link 33 and the idler link 36 are rotatably connected to each other, and the bracket portion 40 of the boom 30
When the boom cylinder 37 interposed therebetween is fully reduced, the boom 30 can be largely rotated rearward by the lever link mechanism as shown in FIG. Therefore, the front end portion P3 of the work attachment 17 ′ in plan view is attached to the swing bracket 2
7, the revolving superstructure 14 can be moved closer to the revolving center 0-0 while maintaining the neutral position. Then, as shown in FIG. 3, a turning circle S3, which is a trajectory drawn by the tip portion P3 when the upper turning body 14 is turned, is substantially contained in the range of the vehicle width dimension W. (In FIG. 3, for ease of explanation, the turning circle S3 is shown so as to protrude slightly outside the vehicle width W.) The boom 30 is raised and rotated during the operation of the hydraulic shovel of the present embodiment. When the excavated debris falls into the bucket 22 when falling, it falls on the abdominal surface of the boom 30,
In particular, the components are not damaged, which is very advantageous for maintenance.

As described above, the swing bracket 2
Since the base end of the boom 30 is pivotally mounted on the front mounting part 28 on the upper side of the front part 7 and connected to the base end of the foot link 33 on the rear mounting part 29 behind the front mounting part 28, The distance between the front mounting portion 28 and the front end portion P2 of the swing bracket 27 in plan view is set to a minimum length L (shown in FIG. 1).
Can be set to Therefore, the upper rotating body 14
Of the upper swing body 14 with the swing bracket 27 since the distance between the swing center 0-0 of the swing bracket 27 and the front end portion P2 of the swing bracket 27 can be minimized.
(Shown in FIG. 3) can be set to the minimum radius. That is, as shown in FIG. 3, a revolving circle S2 which is a trajectory drawn by the front end portion P2 when the upper revolving superstructure 14 is rotated.
Is substantially contained in the range of the vehicle width dimension W.

[0017]

According to the present invention, there is provided a hydraulic excavator having a swing bracket connected to a front portion of an upper revolving structure so as to be swingable in the left-right direction, and a work attachment provided on the swing bracket so as to be able to move up and down. A boom base end of the work attachment is pivotally mounted on a front mounting portion on an upper side of a swing bracket, and a base end portion of a foot link is rotatable up and down on a rear mounting portion behind the front mounting portion. At the same time, a lever link mechanism including the foot link and the idler link is formed on the back side of the boom, and is driven by a boom cylinder. According to this, when the boom cylinder is fully contracted, the boom can be largely rotated rearward by the operation of the lever link mechanism. Therefore, the tip of the work attachment in plan view can be moved closer to the center of rotation of the upper revolving unit while the swing bracket is in the neutral position. Therefore, the turning circle, which is a trajectory drawn by the tip of the work attachment when the upper turning body is turned, is substantially contained in the range of the vehicle width dimension, so that workability in a narrow site can be improved. it can. Also, when the boom is raised and rotated during the operation of the hydraulic excavator, even if the excavated debris falls on the bucket, it may fall on the abdominal surface of the boom, so that particularly the components may be damaged. It is very advantageous for maintenance.

Further, as described above, the boom base end of the boom is pivotally mounted on the front mounting portion on the upper side of the swing bracket, and the foot link is mounted on the rear mounting portion behind the front mounting portion. Since the base ends are connected, the distance between the front mounting portion and the front end of the swing bracket in plan view can be set to a minimum length. Therefore,
Since the distance between the turning center of the upper swing body and the front end of the swing bracket can be minimized, the front swing radius of the upper swing body with the swing bracket can be set to the minimum radius. Thereby, the turning circle, which is a locus drawn by the front end portion of the swing bracket when the upper turning body is turned, is substantially contained in the range of the vehicle width dimension, so that workability and safety in a narrow site are improved. Can be secured.

[Brief description of the drawings]

FIG. 1 is a side view showing a small front swing hydraulic excavator according to an embodiment of the present invention.

FIG. 2 is a side view of a main part of the embodiment, showing a state in which the boom cylinder in FIG. 1 is extended and the boom is lowered.

FIG. 3 is a partially cut-away plan view showing a state where the upper swing body in FIG. 1 is swiveled by 90 °.

FIG. 4 is a side view showing an embodiment of a conventional power shovel.

FIG. 5 is a side view showing one embodiment of a recently-reduced small turning hydraulic excavator.

FIG. 6 is a plan view showing a state in which the hydraulic shovel in FIG. 5 turns the upper turning body in a narrow work site.

[Explanation of symbols]

 1, 20, 30 Boom 2, 23, 37 Boom cylinder 13 Lower traveling body 14 Upper revolving structure 16, 27 Swing bracket 17, 17 'Work attachment 24, 31 Boom foot pin 25, 38 Boom cylinder base end pin 28 Front side Mounting part 29 Rear mounting part 32 Foot link pin 33 Foot link 34 Idler link pin 36 Idler link 39 Boom cylinder tip pin 40 Bracket part

Claims (1)

[Claims] 1. A lower traveling body, an upper revolving body pivotally mounted on the lower traveling body, and a work attachment movably mounted on a bracket device provided at a front portion of the upper revolving body. In the construction machine having the bracket device, the bracket device has a front-side mounting portion, and a rear-side mounting portion located behind the front-side mounting portion, and the front-side mounting portion has a boom base end of the work attachment as an axis. The base end of the foot link is rotatably connected to the rear mounting portion so as to be able to move up and down, and one end of an idler link is rotatably connected to the vicinity of the base end of the boom in the front-rear direction. A boom cylinder that rotatably connects the other end of the idler link and the tip of the foot link, and between the connected portion and the bracket portion of the boom, the boom cylinder that drives the boom to rotate. Interposed A small-swing forward hydraulic excavator, characterized in that: