JP3347053B2 - Offset mechanism of offset boom type construction machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an offset mechanism for an offset boom type construction machine, and more particularly to an offset boom type construction having an offset boom capable of being offset in the left-right direction and suitable for performing work such as digging a gutter. The present invention relates to an offset mechanism of a machine.

[0002]

2. Description of the Related Art An example of a front portion of an offset boom type construction machine according to the prior art is shown in FIGS.
FIG. 6 is a sectional view taken along the line II in FIG. 7, and FIG. 7 is a sectional view.

In these figures, 1 is a lower boom, 2
Is an upper boom, 3 is a cylinder stay, 10 is a stay for a parallel link, 11 is an offset cylinder, 7 is an arm, and 8 is a bucket as an attachment.

A stay 10 is provided with brackets 2 provided on the side of the cylinder stay 3 and the side of the lower boom 1, respectively.
Each end is rotatably fixed to 0 and 21. Also,
The tube-side end of the offset cylinder 11 is rotatably fixed to a bracket 20 provided on the side surface of the lower boom 1, and the rod-side end is rotatably fixed to a bracket 22 provided on the side surface of the upper boom 2. And, lower boom 1, upper boom 2, cylinder stay 10, offset cylinder 1
1 and each bracket 20, 21, 22 form a parallel link mechanism, and an offset boom 30 is configured.

FIG. 8 shows various states when the offset boom shown in FIGS. 6 and 7 is offset in the left-right direction.

A conventional offset boom 30 of this type is:
As shown in the above figures, a stay 10, an offset cylinder 11, and a bracket 2 for supporting them
The reference numerals 0, 21 and 22 are provided on the left side of the upper boom 2, and are provided so as to protrude from the center line C connecting the lower boom 1, the upper boom 2 and the cylinder stay 3 to the left side.

FIG. 9 is a plan view showing an offset device of a hydraulic excavator disclosed in Japanese Utility Model Laid-Open No. 7-8449.

In FIG. 1, reference numeral 12 denotes a first boom, 13 denotes a second boom, 14 denotes an arm stay, 15 denotes a double-acting hydraulic cylinder, and both ends of the second boom 13 are the first boom 12 and the arm stay. 14, and a double-acting hydraulic cylinder 15 is disposed substantially parallel to a side surface thereof. The piston rods 16 at both ends of the double-acting hydraulic cylinder 15 are pivotally mounted on brackets provided on the first boom 12 and the arm stay 14, respectively. Further, the bracket 18 fixed to the side surface of the second boom 13 has an elongated hole 1 perpendicular to the axial direction.
9 is provided, and a pin 17 provided on the double-acting hydraulic cylinder 15 is configured to be swingable in the elongated hole 19. Here, the first boom 12, the second boom 13, the arm stay 14, and the double-acting hydraulic cylinder 15 constitute a parallel four-bar link.

[0009]

The offset boom of the conventional offset boom type construction machine shown in FIGS. 6 to 8 has a stay 10 and an offset cylinder 11 provided on the side of the upper boom 2 so that the offset boom 3
The overall weight becomes very heavy, which degrades the stability of the vehicle body and causes problems in front speed and fuel efficiency.

Further, when excavating a ditch or the like, as shown in FIG. 8, when the offset amount becomes large, the side portion A near the tip of the upper boom 2 and the side portion B near the tip of the stay 10 are likely to come into contact with the ground. , The excavation depth could not be increased. In particular, since the stay 10, the offset cylinder 11, and the brackets 20, 21, and 22 for supporting these protrude greatly on the left side surface of the upper boom 2 with respect to the center line c of the upper boom (d2> d1). When offset to the right, it was easier to contact the ground, and it was not possible to dig deeper than when offset to the left. Further, there is another problem that the stay 10 and the brackets 20, 21, and 22 obstruct the field of view at the time of excavation, resulting in a decrease in work efficiency. Further, since the offset cylinder 11 and the stay 10 are provided on the side surface of the upper boom 2, there is a problem in appearance.

The conventional one shown in FIG. 9 replaces the conventional stay and offset cylinder with one double-acting hydraulic cylinder, and includes a first boom 12 and a second boom 1.
3 and the arm stay 14 constitute a parallel 4-bar link, so that the weight is reduced as compared with the prior art shown in FIGS.

However, in this prior art, the position of the pin 17 fixed to the double-acting hydraulic cylinder 15 with respect to the elongated hole 19 changes in accordance with the operation of the rod 16 of the double-acting hydraulic cylinder 15, whereby the parallelism is increased. A four-bar link is formed. In other words, the positional relationship between the pin 17 and the elongated hole 19, that is, the double-acting hydraulic cylinder 15 and the second boom 13
Is changed in accordance with the operation of the rod 13 to form a parallel four-bar link. For this reason, in order to secure the offset amount, it is necessary to increase the length of the long hole 19 in the longitudinal direction, that is, the length in the direction perpendicular to the operation of the rod 16, and fix it to the second boom 13. The bracket 18 that had been used had to be enlarged. Therefore, in this conventional technique, there is a problem that the double-acting hydraulic cylinder 15 protrudes largely to the side with respect to the second boom 13.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and a first object of the present invention is to reduce the weight of the offset mechanism as compared with the conventional one and to make the left side of the offset mechanism project. An object of the present invention is to provide an offset mechanism of an offset boom type construction machine capable of greatly reducing the amount. A second object is to provide an offset mechanism for an offset boom type construction machine in which the right and left overhangs are made equal and substantially the same excavation depth is obtained for the same offset in the left and right direction.

[0014]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a lower boom connected to an upper revolving body so as to be rotatable in a vertical direction, and a lower boom connected to a lower boom so as to be rotatable in a left and right direction. An upper boom, a cylinder stay connected to the upper boom, and operating substantially horizontally in a horizontal plane with respect to the lower boom with the rotation of the upper boom,
An arm attached to the cylinder stay so that it can rotate up and down, a work attachment attached to the tip of the arm,
In an offset boom type construction machine equipped with a double rod hydraulic cylinder fixed to the upper boom substantially parallel to the upper boom, one end of each link can be rotated at each end of both rods of the double rod hydraulic cylinder , And the other end of each link is rotatably attached to a bracket protruding from a side surface near the tip of the lower boom and the cylinder stay.

Further, in the offset mechanism of the offset boom type construction machine according to claim 1, the rotation shafts at both ends of the upper boom are aligned with a center line of the lower boom and a center line of the cylinder stay. On the side opposite to the side where the hydraulic cylinder is provided, the brackets are mounted eccentrically by a predetermined dimension, and the brackets to which the links are rotatably mounted are mounted close to the center lines. It is characterized by.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An offset mechanism of an offset boom type construction machine according to a first embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a cross-sectional view of the roll of FIG.
Is a side view showing a front portion of the offset boom type construction machine, and FIG. 3 is a side view showing an entire structure of the offset boom type construction machine.

In these figures, reference numeral 9 denotes an upper rotating body.
A lower boom 1 is attached to the lower boom 1 so as to be rotatable in a vertical direction. An upper boom 2 is mounted to a tip of the lower boom 1 so as to be rotatable in a left and right direction. Movable cylinder stay 3
Is installed.

An arm 7 is attached to the tip of the cylinder stay 3 so as to be rotatable in the vertical direction, and a bucket 8 as a work attachment is attached to the tip of the arm 7 so as to be rotatable in the vertical direction.

Further, a two-rod hydraulic cylinder 4 is fixed to the side surface of the upper boom 2 in parallel with the upper boom 2, a first bracket 20 is provided from the side surface of the distal end of the lower boom 1, and the distal end of the cylinder stay 3 is provided. The second brackets 21 are provided to project from the side surfaces, respectively. Then, the first and second brackets 20, 2
1 includes links 5 and 6 that can be rotated in the left and right directions, respectively.
Is axially mounted, and the other ends of the links 5 and 6 are attached to the rods 23a and 23b of the two-rod hydraulic cylinder 4 so as to be rotatable in the left-right direction at the distal ends.

In the offset mechanism of this embodiment configured as described above, for example, when pressure oil is supplied to the oil chamber 22a of the double rod type hydraulic cylinder 4, the rod 23b side extends with respect to the cylinder tube, and conversely, the rod 23a side extends. Shrink. As a result, the link 5 turns around the fulcrum c toward the e-side, and the upper boom 2 turns toward the lower boom 1. On the other hand, the link 6 turns to the side with respect to the fulcrum c ′, and the cylinder stay 3 turns to the side with respect to the upper boom 2.
As a result, it is possible to offset to the left. Conversely, if pressure oil is supplied to the oil chamber 22b, it can be offset to the right.

Therefore, according to the offset mechanism of this embodiment, the offset operation can be performed by one double rod type hydraulic cylinder 4 without providing a stay, and the weight can be reduced. In addition, since the stay is unnecessary, the stay is neat and the appearance of the offset mechanism is improved.

Further, since the double rod type hydraulic cylinder 4 is fixed to the upper boom 2, the stay is extended like the stay 10 with respect to the prior art upper boom 2 shown in FIG. 6 or the second prior art shown in FIG. 9. Large overhang of the double-acting hydraulic cylinder 15 with respect to the boom 13 is eliminated, and when the offset mechanism is offset to the right in trench excavation or the like, when the offset mechanism is offset to the right side, the double rod-type hydraulic cylinder 4 is grounded with other objects such as the ground. Contact can be reduced, and work efficiency can be improved.

Next, an offset mechanism of an offset boom type construction machine according to a second embodiment of the present invention will be described with reference to FIGS.

In this embodiment, a rotation axis B for attaching the upper boom 2 to the distal end of the lower boom 1 so as to be offset in the left-right direction, and a cylinder stay 3 is attached to the distal end of the upper boom 2 so as to be pivotable in the left-right direction. Axis B ′ for the two rod hydraulic cylinders 4 with respect to the center line A of the lower boom 1 and the center line A ′ of the cylinder stay 3.
Is mounted eccentrically by a predetermined dimension on the side opposite to the side where is provided. At the same time, a bracket 20 protruding from the tip of the lower boom 1, a bracket 21 protruding from the cylinder stay 3, both links 5, 6, and both rod-type hydraulic cylinders 4 are attached close to the respective center lines A, A ′. ing. Other configurations are the same as those of the first embodiment.

As a result, as shown in FIG. 5, the left and right overhanging amounts of the double rod hydraulic cylinder 4 and the upper boom 2 are substantially equal (d3 and d4) with respect to the respective center lines A and A '.
Are substantially equal to each other), and the amount of protrusion of the two-rod hydraulic cylinder 4 and the links 5, 6 provided on the left side surface of the upper boom 2 can be reduced. As a result, when excavating a groove, the distance between the groove edge and the overhanging portion with respect to the offset amount in the right direction is longer than that of the prior art shown in FIG. Because of this,
Excavation depth when offset to the right can be increased.

The predetermined size for the eccentricity is determined in consideration of the weight balance of the offset mechanism or the fact that the left and right overhangs of the offset mechanism are substantially equalized.

As described above, according to the present embodiment, similarly to the first embodiment, the weight of the offset mechanism can be reduced and the appearance thereof can be improved. Compared with the embodiment, the trench excavation depth when offset rightward can be increased, and the working efficiency can be improved.

[0029]

As described above, according to the present invention, the stay required in the parallel link type of the conventional offset mechanism is not required, and the offset boom can be reduced in weight and the appearance can be reduced. Also, by mounting the double rod type hydraulic cylinder for offset close to the line connecting the center of the lower boom and the center of the cylinder stay, it is possible to reduce the amount of overhang of each center line of the double rod type hydraulic cylinder. Therefore, during excavation, particularly when the offset mechanism is offset rightward, the offset mechanism is less likely to come into contact with the ground, and work efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of the offset mechanism of an offset boom type construction machine according to a first embodiment of the present invention, taken along a roll line in FIG.

FIG. 2 is a side view showing an offset mechanism of the offset boom type construction machine according to the first embodiment of the present invention.

FIG. 3 is a side view showing the entire structure of the offset boom type construction machine according to the first embodiment of the present invention.

FIG. 4 is a sectional view showing an offset mechanism of an offset boom type construction machine according to a second embodiment of the present invention.

FIG. 5 is a plan view showing a state when an offset mechanism of an offset boom type construction machine according to a second embodiment of the present invention is rotated in the left-right direction.

FIG. 6 is a cross-sectional view of the offset mechanism of the offset boom type construction machine according to the related art, taken along the line II in FIG. 2;

FIG. 7 is a side view showing an offset mechanism of an offset boom type construction machine according to the related art.

FIG. 8 is a plan view showing each state when the offset mechanism of the offset boom type construction machine according to the related art is rotated left and right.

FIG. 9 is a view showing an offset device of a working machine according to another related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower boom 2 Upper boom 3 Cylinder stay 4 Double rod type hydraulic cylinder 5 Link 6 Link 7 Arm 8 Work attachment 9 Upper revolving unit

Claims (2)

(57) [Claims] A lower boom connected to the upper revolving body so as to be rotatable in a vertical direction, an upper boom connected to the lower boom so as to be rotatable in a left and right direction, and a lower boom connected to the upper boom to rotate the upper boom. A cylinder stay that operates substantially horizontally in a horizontal plane with respect to the lower boom, an arm attached to the cylinder stay so as to be vertically rotatable, and a work attachment attached to a tip of the arm,
In an offset mechanism of an offset boom type construction machine comprising: a double rod hydraulic cylinder fixed to the upper boom substantially parallel to the upper boom, and one end of each link is provided at each end of both rods of the double rod hydraulic cylinder. An offset mechanism for an offset boom type construction machine, wherein the other end of each link is rotatably attached to a bracket protruding from a side surface of each of the lower boom and each of the cylinder stays near a tip end of the cylinder stay. 2. The side on which the double rod type hydraulic cylinder is provided, with respect to a center line of the lower boom and a center line of the cylinder stay, with respect to the rotation axes of both ends of the upper boom. An offset boom type construction machine, wherein the brackets are mounted eccentrically by a predetermined dimension on the opposite side, and the brackets to which the links are rotatably mounted are mounted close to the center lines. Offset mechanism.