JP3172936B2 - Construction machinery offset mechanism - Google Patents

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 digging a gutter.

[0002]

2. Description of the Related Art In the field of construction machines capable of trenching, various offset mechanisms have been proposed for working on trenches located away from the center of the vehicle without changing the direction of the vehicle.

A typical example is a structure shown in FIG. 8. In this offset mechanism, first, a boom of a front structure is divided into a front and a rear 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 connected to the arm 6 or the arm support 3 with pins 20 and 21, respectively.
Next, the offset bar 4 parallel to the upper boom 2 is connected to the lower boom 1 at one end and to the arm 6 or the arm support 3 at the other end via pins 40 and 30 via brackets 10 and 30, respectively.
At 41 pivot. As a result, the upper boom 2 and the offset bar 4 become relative joints, and their pins 20, 21, 4
A parallel link mechanism in which a parallelogram is formed by the 0,41 axis center connection lines R, S, T, and U is formed. Then, the offset cylinder 5 is arranged, and the arm 6 is moved in parallel to the lower boom 1 by expansion and contraction.

[0004]

As described above, in the conventional offset mechanism, the upper boom 2 and the offset bar 4 are provided.
Will be offset within the parallelogram trajectory formed by the connecting lines R, S, T, U of the axes 20, 21, 40, 41 of the shafts. The offset amount is basically preferably as large as possible within the limit of the trajectory of the parallelogram, but since the cab is arranged on one side of the front structure in the construction machine, the Depending on the degree of arrangement of the front structure, the bucket edge can be clearly seen in the trenching work in the offset range on the opposite side of the cab, but the bucket edge may not be seen in the trenching work in the cab-side offset range. If the bucket edge is not clearly seen, the workability in the offset range is deteriorated, and such an offset range is unnecessary. On the other hand, the offset range in which the bucket edge can be clearly seen should be expanded as much as possible. That is, depending on the construction machine, there may be a case where the mode in which the offset amount on the opposite side of the cab is larger than the offset amount on the cab side is preferable in terms of work.

In such a case, in order to suppress a meaningless offset amount on the cab side, a method is provided in which a limiter is provided to limit the amount of expansion and contraction of the offset cylinder. However, in this method, a limiter mechanism must be provided. In addition, the requirement to increase the offset amount on the opposite side of the cab is not satisfied at all. On the other hand, the expansion of the offset range is restricted by the width, length, arrangement, and the like of offset bars and offset cylinders forming parallel links.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the prior art, and has an offset of a construction machine capable of increasing the offset amount on the opposite side of the cab while suppressing the offset amount on the cab side. It seeks to provide a mechanism.

[0007]

SUMMARY OF THE INVENTION Therefore, an offset mechanism for a construction machine according to the present invention has an offset-neutral state.
The line connecting the lower boom side and the arm side upper boom mounting pin axes and the line connecting both the lower boom side and the arm side offset bar mounting pin axes are parallel to the width center line of the lower boom. The upper boom and the offset bar are arranged so as to be oblique to the line.

Here, the offset neutral state refers to a state in which the offset amount of the boom is zero. In addition, the center line O in the width direction of the lower boom generally coincides with the center lines P and Q in the width direction of the bucket and the arm in the case of the offset neutral state as shown in FIG.

[0009]

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

As shown in FIG. 8, in the conventional mechanism, the upper boom mounting pins on both the lower boom 1 side and the arm 6 side among the lines R, S, T, U forming such a parallelogram. Line R connecting the 20,21 axes and the offset bar mounting pins on both the lower boom 1 side and the arm 6 side
When the offset boom is in the neutral state, the line S connecting the axes 40 and 41 coincides with or is parallel to the center line O in the width direction of the lower boom 1.

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

On the other hand, in the present invention, of the lines R, S, T and U forming the parallelogram of the parallel link, the line R connecting the upper boom mounting pin axes on both the lower boom side and the arm side is connected to the line R. When the offset boom is in the neutral state, the line S connecting the axes of the offset bar mounting pins on both the lower boom side and the arm side is inclined with respect to the center line O in the width direction of the lower boom. The amount will decrease on the sloping side of the axis connection line R, S and increase on the opposite side.

For example, FIG. 9 shows an example in which the axis connecting lines R and S are inclined to the left with respect to the center line O or parallel line in the plane of the lower boom width in the plane (first embodiment described later). Is shown on the inclined side (left side in FIG. 1).
Decreases its operating range, while its opposite side (right side r in the figure) increases its operating range accordingly.

Therefore, if the cab is arranged on the inclined side of the shaft center connecting lines R and S, the offset amount on the cab side automatically decreases, while the offset amount on the opposite side of the cab increases accordingly. Thus, the operating range on the side with good visibility from the cab is expanded. In other words, in other words, if the shaft center connection lines R and S are inclined and inclined toward the cab mounting side, an unnecessary offset range is automatically restricted, while a good operation range of visibility from the cab is expanded. The operability is greatly improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described with reference to the drawings used for 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 mechanism. That is, the upper boom 2 has one end connected to the lower boom 1 and the other end connected to the arm support 3, respectively.
An offset bar 4 pivotally mounted at 0,21 and parallel to the upper boom 2 has a pin 4 at one end thereof and a bracket 30 of the arm support 3 at the other end thereof.
0,41, whereby the upper boom 2 and the offset bar 4 become relative joints and their pins 20,21,4
A parallel link mechanism in which a parallelogram is formed by the 0,41-axis connecting lines R, S, T, and U. The arm 6 is moved relative to the lower boom 1 by expansion and contraction of an offset cylinder 5 disposed between the lower boom 1 and the upper boom 2. In parallel.

1 and 2 show a first embodiment. In this example, as shown in FIG. 1 (a) and FIG. 2 (a), in the offset neutral state, the upper boom mounting pin hole axis of the lower boom 1 is attached to the offset bar 4 and the offset cylinder 5 from the center line O in the lower boom width direction. While the arm support 3 is shifted to the opposite side (hereinafter simply referred to as the offset member mounting side, and the opposite side is referred to as the offset member mounting side).
The upper boom mounting pin hole shaft is disposed on the center line O in the lower boom width direction (the center line Q in the arm width direction) as before. Also, with respect to a parallel line O ′ of the center line O in the width direction of the lower boom passing through the axis of the pin hole for mounting the offset bar of the arm support bracket 30, the pin hole axis for mounting the offset bar of the lower boom bracket 10 is on the opposite side to the mounting of the offset member. To be shifted.

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

In the example shown in FIG. 2, an offset cylinder mounting shaft hole is provided above the bracket 50 having a height, and the offset cylinder 5 is pivoted so as to overlap the offset bar 4 in parallel therewith. This 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 is of a conventional structure as shown in FIG. . By the way, a plurality of pipes 9 such as a pressure oil pipe are arranged on the front structure of the construction machine.
Piping is performed as shown in FIG. However, since the offset cylinder 5 is arranged on a diagonal line, this obstructs the piping space and restricts the piping space. In some cases). The example of the offset cylinder 5 in FIG.
In addition, the space between the offset cylinder 5 and the upper boom 2 is expanded to increase the piping space, and to improve the planar appearance. 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, it will secure a piping space.

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

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

In the example shown in FIG. 5, the arrangement of the offset cylinder 5 is pivotally mounted so as to overlap the offset bar 4 in parallel. The arrangement is the same as that of the example of FIG. The planar appearance can be improved.

FIGS. 6 and 7 show a third embodiment. In this example, as shown in FIGS. 6A and 7A, in the offset neutral state, the upper boom mounting pin hole axis of the lower boom 1 is shifted from the lower boom width direction center line O to the offset member mounting side. The upper boom mounting pin hole axis of the arm support 3 is displaced from the lower boom width center line O (also the arm width direction center line Q) to the opposite side of the offset member mounting. In addition, the arm support bracket is positioned with respect to a parallel line O "of the center line O in the width direction of the lower boom passing on the axis of the pin hole for mounting the offset bar of the lower boom bracket 10.
The 30 offset bar mounting pin hole shafts are shifted to the opposite side of the offset member mounting.

Therefore, in the third embodiment, as in the second embodiment, the upper boom 2
The connecting line R of the pins 20 and 21 for pivoting the shaft and the connecting line S of the pins 40 and 41 for pivoting the offset bar 4 are aligned with the center line O in the width direction of the lower boom 1 or its parallel line. As a result, the upper boom 2 and the offset bar 4 are arranged obliquely in the inclined state.

In the example shown in FIG. 7, the arrangement of the offset cylinder 5 is pivotally mounted so as to overlap the offset bar 4 in parallel. The arrangement is the same as in the examples of FIGS. And the appearance on a 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 a first embodiment, FIG. 10 shows a second embodiment,
FIG. 11 shows the third embodiment, and FIG. 12 shows the conventional structure shown in FIG.
Test results are shown in which each of the connecting lines R, S, T, U of the 20, 21, 40, 41 axes is predicted to have the same length. In the drawing, 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 limit positions of the left offset of the upper boom and the offset bar, 2 ″ and 4 ″ Indicates the limit position of the right offset of the upper boom and the offset bar. Here, 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 1 and r are all uniform.

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

Therefore, in this embodiment, if the cab is arranged on the inclined side of the axis center connection lines R and S, the offset amount on the cab side is automatically reduced, while the offset amount on the opposite side of the cab is correspondingly reduced. And the operating range on the side with good visibility from the cab is expanded. In other words, in other words, if the shaft center connection lines R and S are inclined and inclined toward the cab mounting side, the unnecessary offset range is automatically limited, while
The operating range with good visibility is expanded from the cab, and the operability is significantly improved.

In the construction machine having the bucket 7 as in the present embodiment, the size of the bucket 7 provided is limited due to the balance with the vehicle body and the front structure, etc. In some cases, the offset bar 4 protrudes from the end of the bucket 7 so that the offset bar 4 protrudes 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, the extruded portion collides with the soil surface during excavation at the time of offset neutral, not only obstructing the deep digging but also damaging the offset bar 4. is there. On the other hand, in the embodiment of FIGS. 4 to 7, the pin holes for attaching the offset bar on the side of the arm 6 are shifted to the side opposite to the attachment of the offset member.
The overhang of the tip of the offset bar 4 will decrease,
Therefore, depending on the degree of the shift 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, not only can the above-mentioned problem be solved, but also the small bucket 7 can be actively 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 according to the present invention, while the offset amount of the upper boom and the offset bar on the inclined side is automatically reduced, the offset amount on the opposite side of the inclined side 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 restricted, and the operation range with a good view from the cab is expanded. Operability is greatly improved.

Needless to say, since it is not necessary to provide a limiter mechanism as in the prior art, the overall apparatus configuration is simplified and the cost is advantageous.

[Brief description of the drawings]

FIGS. 1A and 1B show a structure of a first embodiment, wherein FIG. 1A is a plan view of an offset neutral state, and FIG. 1B is a plan view of an offset state.

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

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

FIGS. 4A and 4B show a structure of a second embodiment, in which FIG. 4A is a plan view in an offset neutral state, and FIG.

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

FIGS. 6A and 6B show a structure of a third embodiment, in which FIG. 6A is a plan view of an offset neutral state, and FIG. 6B is a plan view of an offset state.

FIGS. 7A and 7B show another structure of the third embodiment, wherein FIG. 7A is a plan view in a neutral state of offset, and FIG.

8A and 8B show a conventional offset mechanism, wherein FIG. 8A is a plan view of an offset neutral state, and FIG. 8B is a side view thereof.

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

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

FIG. 11 is a schematic diagram showing a test result of predicting an offset amount according to the third embodiment and showing left and right offset amounts.

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

[Explanation of symbols]

 DESCRIPTION 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 pivoting pin 40,41 Offset bar pivoting pin

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Izumi Morita 4-10-1, Yoga, Setagaya-ku, Tokyo New Caterpillar Mitsubishi Co., Ltd. (56) References JP-U 5-38045 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) E02F 3/32 E02F 9/00

Claims (1)

(57) [Claims] 1. A line connecting the lower boom side and arm side upper boom mounting pin axes in an offset neutral state, and a line connecting both the lower boom side and arm side offset bar mounting pin axes. Wherein the upper boom and the offset bar are arranged so as to be inclined with respect to the center line in the width direction of the lower boom or a parallel line thereof.