JPH08209727A - Offset mechanism of construction machinery - Google Patents

Abstract

PURPOSE: To suppress an offset amount on a cap side and to increase an offset amount on an opposite side by slantly moving axial-center combined lines of both mounting pins of an upper boom and an offset bar to the center line of a lower boom. CONSTITUTION: In an offset neutral state, R is the line combined with the axial centers of both upper boom mounting pins 20 and 21 on a lower boom 1 side and an arm 6 side. S is the line combined with the axial centers of both offset bar mounting pins 40 and 41. An upper boom 2 and an offset bar 4 are so arranged that the lines R an S are slantly moved to the center line O in the direction of the width of the lower boom 1 or a parallel line O' therewith. Then, both right and left offset amounts are reduced in inclined sides of the axial center combined lines R and S and are increased in opposite sides of them. Accordingly, an unnecessary offset range is reduced to make it possible to widen an operation range of the good visibility from the cap.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for improving an offset mechanism provided in a construction machine capable of diving.

[0002]

2. Description of the Related Art In the field of construction machines capable of digging trenches, various offset mechanisms have been proposed for performing work such as digging trenches at a position away from the center of the vehicle without changing the direction of the vehicle.

The structure shown in FIG. 8 is a typical example. In this offset mechanism, first, the boom of the front structure is divided into front and rear halves into a lower boom 1 and an upper boom 2, and one end of the upper boom 2 is connected to the lower boom 1. The other end is pivotally attached to the arm 6 or the arm support 3 by pins 20 and 21, respectively.
Next, an offset bar 4 parallel to the upper boom 2 is attached to the lower boom 1 at one end and to the arm 6 or arm support 3 at the other end via the brackets 10 and 30, respectively, and the pins 40,
Pivot at 41. As a result, the upper boom 2 and the offset bar 4 become relative nodes, and their pins 20, 21, 4
A parallel link mechanism in which a parallelogram is formed by the axis connecting lines R, S, T and U is formed. Then, the offset cylinder 5 is arranged and the arm 6 is moved in parallel with the lower boom 1 by the expansion and contraction thereof.

[0004]

As described above, in the conventional offset mechanism, the upper boom 2 and the offset bar 4 are arranged.
The pins 20, 21, 40, 41 pivoting on the shafts will be offset within the parallelogram locus formed by the connecting lines R, S, T, U of the axes. Basically, the offset amount should be as large as possible within the limit of the parallelogram locus, but in the construction machine, since the cab is arranged on one side of the front structure, Depending on the degree of arrangement of the front structure, the bucket edge may be well visible in the gutter work in the offset range on the opposite side of the cab, while the bucket edge may not be visible in the gutter work in the cab side offset range. If the bucket edge is not clearly visible, workability in the offset range deteriorates, and such an offset range is unnecessary. On the other hand, the offset range in which the bucket edge is well visible should be expanded as much as possible. That is, depending on the construction machine, there are cases in which it is preferable from the viewpoint of work that the offset amount on the cab side is larger than the offset amount on the cab side.

In such a case, in order to suppress a meaningless offset amount on the cab side, a system for limiting the expansion and contraction amount of the offset cylinder by using a limiter is adopted, but in this system, a limiter mechanism needs to be additionally provided. In addition, the requirement to increase the offset amount on the opposite side of the cab will not be met. On the other hand, the expansion of the offset range is restricted by the width, length, and arrangement of the offset bar and the offset cylinder forming the parallel link.

The present invention was devised in view of the above problems of the prior art. It is possible to suppress the offset amount on the cab side and, at the same time, increase the offset amount on the opposite side of the cab. It is intended to provide a mechanism.

[0007]

For this reason, the offset mechanism of the construction machine according to the present invention has an offset neutral state,
The line connecting the upper boom mounting pin axes on both the lower boom side and the arm side and the line connecting the offset bar mounting pin axes on both the lower boom side and the arm side are parallel to the width center line of the lower boom. It is characterized in that the upper boom and the offset bar are arranged so as to be oblique to the line.

Here, the offset neutral state means a state in which the offset amount of the boom is zero. In the case of the offset neutral state as shown in FIG. 1, the widthwise centerline O of the lower boom is generally a line that coincides with the widthwise centerlines P and Q of the bucket and the arm.

[0009]

In the offset mechanism of the construction machine, the upper boom and the offset bar form a parallel link relative node, and the pin pivotally connecting them is a link pin. That is, the line connecting the axes of the mounting pins of the upper boom and the offset bar forms a parallelogram, and performs a parallel link motion.

As shown in FIG. 8, in the conventional mechanism, among the lines R, S, T, U forming such a parallelogram, the upper boom mounting pins on both the lower boom 1 side and the arm 6 side are attached. Pins for mounting the offset bar on both the lower boom 1 side and the arm 6 side, and the line R connecting the 20,21 axis
A line S connecting the 40 and 41 axes is aligned with or parallel to the widthwise center line O of the lower boom 1 when the offset boom is in a neutral state.

Therefore, the offset amount of the conventional offset mechanism is uniform left and right as shown in FIG. 12 described later.

On the other hand, in the present invention, among the lines R, S, T, U forming the parallelogram of the parallel link, the line R connecting the upper boom mounting pin shaft centers on both the lower boom side and the arm side is used. Since the line S connecting the offset bar mounting pin shaft centers on both the lower boom side and the arm side is oblique to the widthwise center line O of the lower boom when the offset boom is in the neutral state, the left and right offsets thereof are offset. The amount decreases on the inclined side of the shaft center coupling lines R and S and increases on the opposite side.

For example, FIG. 9 shows an example in which the axis coupling lines R and S are inclined to the left with respect to the center line O or the parallel line in the width direction of the lower boom on the plane (first embodiment described later). Shows the offset amount, but on the inclined side (l on the left side in the figure)
While the operating range decreases, the operating range on the opposite side (right side r toward the drawing) increases correspondingly.

Therefore, if the cab is arranged on the side where the axis connecting lines R and S are inclined, the offset amount on the cab side automatically decreases, while the offset amount on the opposite side to the cab increases. The range of motion from the cab to the side with good visibility is expanded. In other words, in other words, if the shaft center coupling lines R and S are inclined and slanted toward the cab mounting side, the unnecessary offset range is automatically limited, while the cab has a wide operating range with good visibility. , The operability is significantly improved.

[0015]

Embodiments of the present invention will be described with reference to the drawings used in a hydraulic excavator.

In the following embodiments, the basic mechanism for moving the arm 6 in parallel with the lower boom 1 is the same as the conventional one. That is, one end of the upper boom 2 is attached to the lower boom 1 and the other end is attached to the arm support 3 by the pin 2
An offset bar 4 which is pivotally attached to the upper boom 2 at 0, 21 and which is parallel to the upper boom 2 has one end on the bracket 10 of the lower boom 1 and the other end on the bracket 30 of the arm support 3 respectively.
The upper boom 2 and the offset bar 4 are pivoted at 0,41 so that the upper boom 2 and the offset bar 4 become relative nodes, and their pins 20,21,4
0,41 A parallel link mechanism in which a parallelogram is formed by axis connecting lines R, S, T, U, and an arm 6 is moved relative to the lower boom 1 by extending and contracting an offset cylinder 5 arranged between the lower boom 1 and the upper boom 2. And move them in parallel.

1 and 2 show a first embodiment. In this example, as shown in FIGS. 1 (a) and 2 (a), in the offset neutral state, the upper boom mounting pin hole shaft of the lower boom 1 is mounted from the center line O of the lower boom width direction to the offset bar 4 and the offset cylinder 5. On the other side (hereinafter simply referred to as the offset member mounting opposite side, and the opposite side is referred to as the offset member mounting side) while the arm support 3
The pin hole shaft for mounting the upper boom is arranged on the lower boom width direction center line O (also the arm width direction center line Q) as before. Further, the offset bar mounting pin hole axis of the lower boom bracket 10 is opposite to the offset member mounting side with respect to the parallel line O ′ of the lower boom width direction center line O passing through the offset bar mounting pin hole axis of the arm support bracket 30. Place them in a staggered manner.

Therefore, in the first embodiment, the pins 20, 2 for pivotally mounting the upper boom 2 in the offset neutral state.
One axis connecting line R and pin 4 for pivotally mounting offset bar 4
The connecting line S of the 0,41 axes is the center line O of the width direction of the lower boom 1.
Alternatively, the offset member mounting side is inclined with respect to the parallel line, and the upper boom 2 and the offset bar 4 are obliquely arranged in the inclined state.

In the example shown in FIG. 2, a bracket 50 having a height is used, and a shaft hole for mounting an offset cylinder is provided above the bracket 50 so that the offset cylinder 5 is pivoted so as to overlap the offset bar 4 in parallel therewith. The arrangement is different from the example of FIG.

The offset cylinder 5 shown in FIG. 1 is arranged substantially diagonally between the upper boom 2 and the offset bar 4, which has a conventional structure as shown in FIG. . By the way, in the construction machine, a plurality of pipes 9 such as a pressure oil pipe are arranged in the front structure, and also on the side face of the upper boom 2 on which the offset member is attached,
Piping is performed as shown in FIG. However, since the offset cylinders 5 are arranged diagonally, this obstructs the piping space (depending on the front working device, when a pipe having a large diameter is desired to be used or a pipe having a large diameter is used). You may want to increase the number of). The example of the offset cylinder 5 of FIG.
By arranging them so as to be stacked in parallel with each other, the space between the offset cylinder 5 and the upper boom 2 is expanded, the piping space is expanded, and the planar appearance is improved. In addition, it goes without saying that even if the offset cylinder 5 is not strictly parallel to the offset bar 4, if it is substantially parallel, a space for piping can be secured.

4 and 5 show a second embodiment. In this example, as shown in FIGS. 4 (a) and 5 (a), in the offset neutral state, the upper boom mounting pin hole shaft of the lower boom 1 is arranged on the lower boom width direction center line O as before, while the arm is arranged. The upper boom mounting pin hole shaft of the support 3 is arranged so as to be displaced from the lower boom width center line O (also the arm width center line Q) to the offset member mounting opposite side. In addition, with respect to the parallel line O ″ of the lower boom width center line O passing through the offset bar mounting pin hole axis of the lower boom bracket 10, the offset bar mounting pin hole axis of the arm support bracket 30 is arranged on the opposite side of the offset member mounting side. Place them in a staggered manner.

Therefore, in the second embodiment, the pins 20 and 2 for pivotally mounting the upper boom 2 in the offset neutral state.
One axis connecting line R and pin 4 for pivotally mounting offset bar 4
The connecting line S of the 0,41 axes is the center line O of the width direction of the lower boom 1.
Alternatively, it is inclined to the side opposite to the offset member mounting side with respect to the parallel line, and the upper boom 2 and the offset bar 4 are obliquely arranged in the inclined state.

In the example shown in FIG. 5, the offset cylinder 5 is pivotally mounted so as to overlap the offset bar 4 in parallel, and the arrangement is the same as in the example of FIG. It is possible to improve the appearance on the plane.

6 and 7 show a third embodiment. In this example, as shown in FIGS. 6 (a) and 7 (a), in the offset neutral state, the upper boom mounting pin hole axis of the lower boom 1 is displaced from the lower boom width direction center line O to the offset member mounting side, The upper boom mounting pin hole shaft of the arm support 3 is arranged so as to be displaced from the lower boom width direction center line O (also the arm width direction center line Q) to the offset member mounting opposite side. In addition, the arm support bracket is attached to the parallel line O ″ of the lower boom width direction center line O passing on the axis of the pin hole for mounting the offset bar of the lower boom bracket 10.
Offset the pin hole for mounting the offset bar of 30 on the opposite side of the offset member.

Therefore, in the third embodiment, similarly to the second embodiment, in the offset neutral state, the upper boom 2 is
The connecting line R of the axes of the pins 20 and 21 that pivotally attach the pin and the connecting line S of the axes of the pins 40 and 41 that pivotally attach the offset bar 4 to the lower boom 1 center line O in the width direction or its parallel line. The offset member is inclined to the opposite side to the mounting side, and the upper boom 2 and the offset bar 4 are obliquely arranged in the inclined state.

In the example shown in FIG. 7, the offset cylinder 5 is pivotally mounted so as to overlap the offset bar 4 in parallel, and the arrangement is the same as in the examples of FIGS. And the appearance on the plane can be improved.

Next, a test example in which the left and right offset amounts of the above-described first to third embodiments and the conventional structure shown in FIG. 8 are predicted will be described.

FIG. 9 shows the first embodiment, FIG. 10 shows the second embodiment,
FIG. 11 shows a third embodiment, and FIG. 12 shows a conventional structure shown in FIG.
The test results are shown in which the connecting lines R, S, T and U of the 20, 21, 40 and 41 axes are assumed to have the same length. In the figure, O is the center line in the width direction of the lower boom 1, 2 and 4 are the positions of the upper boom and the offset bar in the offset neutral state, 2'and 4'are the left offset limit positions of the upper boom and the offset bar, 2 "and 4". Indicates the right offset limit position of the upper boom and the offset bar. In addition, 1 is a left offset range and r is a right offset range.

As shown in FIG. 12, in the conventional offset mechanism, the left and right offset ranges l and r are uniform.

On the other hand, in the embodiment of the present invention shown in FIGS. 9 to 11, the entire offset range is the same as that of the conventional structure shown in the previous figure, but the left and right offset ranges are
While the offset range on the inclined side of the upper boom and the offset bar (the left side 1 in FIG. 9 and the right side r in FIGS. 10 and 11 in FIG. 9) decreases, the opposite side (in FIG. 9 toward the figure) The right side r, and the left side l) in FIGS. 10 and 11 increases accordingly.

Therefore, in this embodiment, if the cab is arranged on the side where the shaft center coupling lines R and S incline, the offset amount on the cab side is automatically reduced, while the offset amount on the opposite side of the cab is correspondingly reduced. Increases and the operating range on the side with good visibility from the cab expands. In other words, in other words, if the shaft center coupling lines R and S are inclined and slanted to the cab mounting side, the unnecessary offset range is automatically limited,
The range of motion with good visibility is expanded from the cab, and operability is greatly improved.

In the construction machine including the bucket 7 according to the present embodiment, the size of the bucket 7 to be provided is limited due to the balance with the vehicle body and the front structure, but the side of the upper boom 2 is limited. Since the offset bar 4 is attached so as to project from the end, the offset bar 4 may protrude from the end of the bucket 7. In the structure in which the offset bar 4 protrudes from the end of the bucket 7 as described above, during excavation at the time of offset neutrality, the protruding part collides with the soil surface, which not only hinders deep excavation but also may damage the offset bar 4. is there. On the other hand, in the embodiment of FIGS. 4 to 7, the offset bar mounting pin hole on the arm 6 side shifts to the side opposite to the offset member mounting,
The overhang on the tip side of the offset bar 4 will be reduced,
Therefore, depending on the degree of displacement of the pin hole, at least the tip end side of the offset bar 4 can be accommodated within the width of the bucket 7, and not only the above problem can be solved but also a small bucket 7 is positively provided as an attachment. Therefore, it can be used as a construction machine for narrow work.

[0033]

As described above, according to the offset mechanism of the construction machine of the present invention, the offset amount of the upper boom and the offset bar on the inclined side is automatically reduced, while the offset amount on the opposite side of the inclined portion is decreased by the reduced amount. The amount will increase.

Therefore, if the present invention is applied so that the cab is arranged on the inclined side of the upper boom and the offset bar, the unnecessary offset range is automatically limited, while the operation range with a good view from the cab is expanded. The operability is remarkably improved.

Of course, since it is not necessary to provide a limiter mechanism as in the conventional case, the whole apparatus structure is simplified and it is advantageous in cost.

[Brief description of drawings]

FIG. 1 shows a structure of a first embodiment, (a) is a plan view in an offset neutral state, and (b) is a plan view at the time of offset.

2A and 2B show another structure of the first embodiment, wherein FIG. 2A is a plan view in an offset neutral state, and FIG. 2B is a plan view at the time of offset.

FIG. 3 shows the piping position in the offset mechanism, (a)
Is a plan view of the offset neutral state, and (b) is a side view.

FIG. 4 shows a structure of a second embodiment, (a) is a plan view in an offset neutral state, and (b) is a plan view at the time of offset.

5A and 5B show another structure of the second embodiment, wherein FIG. 5A is a plan view in an offset neutral state, and FIG. 5B is a plan view at the time of offset.

6A and 6B show a structure of a third embodiment, wherein FIG. 6A is a plan view in an offset neutral state, and FIG. 6B is a plan view at the time of offset.

FIG. 7 shows another structure of the third embodiment, (a) is a plan view in an offset neutral state, and (b) is a plan view at the time of offset.

FIG. 8 shows a conventional offset mechanism, (a) is a plan view of an offset neutral state, and (b) is a side view thereof.

FIG. 9 is a schematic diagram showing left and right offset amounts, showing a test result of predicting an offset amount in the first embodiment.

FIG. 10 is a schematic diagram showing left and right offset amounts, showing a test result of predicting an offset amount in the second embodiment.

FIG. 11 is a schematic diagram showing the left and right offset amounts, showing the test results of predicting the offset amount in the third embodiment.

FIG. 12 is a schematic diagram showing left and right offset amounts, showing a test result in which the offset amount of the conventional structure shown in FIG. 8 is predicted.

[Explanation of symbols]

 1 Lower boom 2 Upper boom 3 Arm support 4 Offset bar 5 Offset cylinder 6 Arm 7 Bucket 10,30,50 Bracket 20,21 Upper boom pivot pin 40,41 Offset bar pivot pin

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor De Morita 4-10-1 Yoga, Setagaya-ku, Tokyo New Caterpillar Mitsubishi Corporation

Claims (1)

[Claims] 1. A line connecting the upper boom mounting pin shaft centers on both the lower boom side and the arm side in an offset neutral state, and a line connecting the offset bar mounting pin shaft centers on both the lower boom side and the arm side. The offset mechanism of the construction machine, wherein the upper boom and the offset bar are arranged so as to be oblique to the center line in the width direction of the lower boom or its parallel line.