JPH0213693B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a telescopic telescoping arm that is attached to the boom of a hydraulic excavator, and more specifically, to a hydraulic cylinder using two wire ropes attached between the inner and outer arm members of the telescoping arm. The present invention relates to a telescoping arm that is capable of applying driving force by a rope in both compression and expansion directions by engaging two moving pulleys.

Hydraulic excavators are known in which a clam shell bucket or the like is attached to the tip of a telescoping arm in which an outer arm, an intermediate arm, and an inner arm are connected in a telescopic manner, thereby making it possible to excavate to deep depths.

Conventional rope-type telescoping arms used in this type of excavator generally extend the entire length of the arm by simply winding or unwinding the wire rope attached to the lowermost arm onto a drum installed at the upper end of the uppermost arm. Since the structure is extendable, the extension operation of the arm depends on the unwinding of the wire by the weight of the bucket and the movable arm. Therefore, there is a drawback that effective digging cannot be performed because downward pressure from the outside does not work on the bucket attachment.Furthermore, as the arm approaches the horizontal position, it becomes impossible to extend and retract, reducing the scope of work. The reality is that its uses are severely limited.

Incidentally, there is a known device in which a telescoping telescopic arm has a telescopic cylinder extending in the internal axis direction, and a lowermost arm is connected to the tip of the telescopic arm, thereby applying a forward pressing force to the bucket. However, since the cylinder is built into the cylindrical body of the telescoping arm, maintenance is difficult, and since the cylinder is long and directly connected to the bucket support arm, it is easily twisted and damaged during work. The drawback was that it also increased costs.

The present invention was made to solve these problems, and its purpose is to improve the functionality of a hydraulic shovel by providing a telescoping arm that can apply driving force from a rope in both compression and extension directions. The aim is to improve the quality of the technology and further expand the scope of its use.

Embodiments of the present invention will be described below based on the drawings. In the figure, reference numeral 1 denotes a telescoping arm whose upper part is pivoted to the boom 3 of a hydraulic shovel 2, and whose tip is connected to a digging attachment such as a clam shell bucket 4 to enable deep excavation.
As shown in Fig. 2, the inner arm 1 of the lowermost stage
A is slidably connected to the intermediate arm 1b, and the intermediate arm 1b is further slidably fitted into the uppermost outer arm 1c as shown in FIGS. 1a and 3, thereby making the entire telescope. It is configured to be able to expand and contract like a scope. Each arm 1a, 1b, 1c
are reinforcing plates 1a' and 1 extending in the axial direction on the opposing wall surfaces, respectively.
b' and 1c' are fixed, and are adapted to slide in a telescopic manner using their opposing surfaces as sliding surfaces.

On the outer arm 1c, an upper fixed pulley 5 is pivotally attached to an upper bracket 5' extending outward, a lower fixed pulley 6 is pivoted to a lower bracket 6', and a hydraulic cylinder 7 is fixed between the fixed pulleys 5 and 6. It has been set up. Further, two systems of movable pulleys 9a and 9b are pivotally supported on the rod 8 of the cylinder 7, and the structure is such that these movable pulleys 9a and 9b simultaneously reciprocate between the fixed pulleys 5 and 6 by the piston movement of the cylinder 7. has been done.

In the embodiment shown in FIG. 1a, a single-rod type cylinder 7 with a piston rod 8 protruding only in one direction is used. In this case, the proximal end of the cylinder 7 is fixed to the upper bracket 5' and
As shown in Figure 4, two systems of movable pulleys 9 are installed at the tip
a and 9b are preferably coaxially mounted. The movable pulleys 9a and 9b are preferably provided facing either the upper fixed pulley 5 or the lower fixed pulley 6, and are formed to have approximately the same diameter as the opposing movable pulley.

Next, inside the intermediate arm 1b, as shown in FIG. 1a, pulleys 10 and 11 are provided via brackets at the lower and upper parts of the intermediate arm 1b that project inwardly.
The lower pulley 10 is connected to the intermediate arm 1 as shown in FIG.
Bracket 1 integrally protruding inside the lower end of b
2 via a pin 12', and the entire pulley 10 is located within the intermediate arm 1b, and the upper end of the inner arm 1a is located within the lower pulley 10 even when the telescopic arm is at its maximum extension. It is assembled so that it is located at the top. On the other hand, intermediate arm 1b
Similarly, the upper pulley 11 of the arm 1b is attached to a bracket 13 that integrally projects inside the upper end of the arm 1b.
3', the groove of the upper pulley 11 protrudes outside the intermediate arm 1b, and the outer arm 1
It is arranged so as to face the lower fixed pulley 6 of c.

One end of two wire ropes 14a and 14b is fixed to the upper part of the lowermost inner arm 1a, and one wire 14a passes from the inner arm 1a to the upper fixed pulley 5 of the outer arm 1c to one side of the cylinder 7. It is wound around a movable pulley 9a, and its tip is fixed to the upper bracket 5' of the outer arm 1c. Incidentally, a pulley 15 provided at the upper end of the outer pulley 1c serves as a guide for the wire 14a. On the other hand, one wire rope 14b goes downward from the upper end of the inner arm 1a, passes through the lower pulley 10 of the intermediate arm 1b, winds back around the upper pulley 11, and then passes through the lower fixed pulley 6 of the outer arm 1c to the other end of the cylinder 7. The movable pulley 9b is rolled back and its tip is fixed to the lower bracket 6' of the outer arm 1c.
Each of these wires 14a and 14b has one fixed portion fixed by a bolter 16 and the other fixed portion fixed via an adjustment screw 17, so that the tension of the wire can be adjusted.

FIG. 5 shows another embodiment of the present invention, in which a double-rod type hydraulic cylinder 7 with a pair of rods 8, 8 protruding from both sides of a common piston is connected to the upper and lower fixed pulleys 5 of the outer arm 1c. , 6, and one movable pulley 9a, 9b is pivotally supported at the tip of each rod 8, 8, so that the movable pulleys 9a, 9b can reciprocate in the same direction at the same time. , otherwise has substantially the same structure as the embodiment of FIG. 1a.

In the figure, 18 is a locking plate fixed to the end of the inner arm 1a and engaged with the intermediate arm 1b, and 19 is a drum for winding up a hydraulic hose for opening and closing the bucket.

Next, the operation of the telescoping arm according to the present invention will be explained. FIG. 1a is a longitudinal cross-sectional view of the telescopic arm 1 when it is fully extended. When shortening the arm from this state and raising the bucket 4 upwards, the rod 8 of the cylinder 7 is extended and the tip of the rod is extended. When the movable pulleys 9a and 9b are lowered simultaneously, the wire 14a
is pulled up in the direction of the arrow in FIG.
As shown in the figure, the telescopic arm 1 is shortened to a minimum. At this time, since the wire 14b is fed out in the direction of the arrow in FIG. 1a, it does not interfere with the shortening operation of the telescoping arm.

Furthermore, when lowering the bucket 4 from the state shown in FIG. 1b to the digging position again and applying digging pressure, the cylinder 7 is compressed as shown in FIG. 1c, and the movable pulley 9
When the movable pulley 9b is raised, the wire 14b is pulled in the direction of the arrow in FIG. The combined intermediate arm 1b is forcibly pushed forward together. Then, when the intermediate arm 1b is pushed out to the maximum extension position, the inner arm 1a is further pushed out independently, and is pushed out to the state shown in FIG. 1a. In this case, the wire 1 is moved upward by the movable pulleys 9a and 9b.
Since arm 4a is extended in the direction of the arrow, arm 1a,
The lowering of 1b is not interfered with in any way.

The operation of the embodiment of FIG. 5 is also similar to that described above.

In the illustrated embodiment, for ease of explanation, the fixed pulleys 5 and 6 of the outer arm 1a and the cylinder movable pulleys 9a and 9b are each arranged in one row, but the arrangement is not limited to this and can be arranged in multiple rows. By winding the wire around each pulley, the extension and contraction stroke of the arm can be increased even if the movement stroke of the movable pulley is small.

As described above, in the present invention, when the cylinder movable pulley is lowered, the wire 14a is pulled and the arm is contracted.
When the movable pulley is raised, the wire 14b is pulled and a force is exerted to push the arm forward. Therefore, in addition to the lifting action of the bucket, the bucket can be forcibly pushed downward during excavation, which significantly improves work efficiency.The arm can also be extended horizontally or upward, dramatically increasing the work range. to expand.

Furthermore, since there is no winding part for the wire in the present invention, not only is the wire less likely to be crushed or cut, but since the two wire systems work independently, there is no risk of the bucket falling if one of the wires breaks. It is extremely safe.

[Brief explanation of drawings]

Fig. 1a is a longitudinal cross-sectional view of a telescoping arm according to an embodiment of the present invention at its maximum extension, Figs. 1b and 1c are explanatory views of the action of the telescoping arm of the present invention, and Fig. 2 is a line taken along the - line in Fig. 1a. 3 is an enlarged sectional view taken along the - enlarged line in Fig. 1a, and Fig. 4 is a - enlarged sectional view taken in Fig. 1a.
The enlarged line sectional view and FIG. 5 are longitudinal sectional views of main parts according to another embodiment of the present invention. 1... Telescopic arm, 1a... Inner arm, 1b... Intermediate arm, 1c... Outer arm, 5... Upper fixed pulley, 6... Lower fixed pulley, 7... Cylinder, 9a, 9
b...Moving pulley, 10...Lower pulley, 11...Upper pulley,
14a, 14b...wire rope, 17...adjustment screw, 18...locking plate, 19...hydraulic hose winding drum.

Claims (1)

[Claims] 1. In a rope-type telescopic arm of a hydraulic excavator in which an outer arm, an intermediate arm, and an inner arm are connected in a telescopic manner, an upper fixed pulley 5 and a lower fixed pulley 6 are pivotally attached to the outside of the outer arm 1c. At the same time, two systems of movable pulleys 9 are installed at the tip of the piston rod 8.
A hydraulic cylinder 7 with shafts a and 9b mounted thereon is fixed so that these movable pulleys 9a and 9b reciprocate between the upper and lower fixed pulleys 5 and 6 at a predetermined stroke, and upper pulleys are mounted on the upper and lower parts of the intermediate arm 1b. 11. Two wire ropes 14 each having a lower pulley 10 pivoted thereon and one end fixed to the inner arm 1a.
One of wire ropes 14a and 14b is wound back from the upper fixed pulley 5 of the outer arm 1c to one of the movable pulleys 9a and 9b of the cylinder 7, and its end is fixed to the upper part of the outer arm 1c, and the other wire rope 14
b is wound back from the lower pulley 10 of the intermediate arm 1b to the upper pulley 11, and further wound back from the lower fixed pulley 6 of the outer arm 1c to the other movable pulley 9b of the cylinder 7, and its end is fixed to the lower part of the outer arm 1c. A rope-type telescoping arm for a hydraulic excavator featuring: 2. Claim 1, characterized in that one end of the single-rod type hydraulic cylinder 7 is fixed to the upper part of the outer arm 1c, and two systems of movable pulleys 9a and 9b are coaxially provided at the other end. telescopic arm. 3 Connect the double rod type hydraulic cylinder 7 to the outer arm 1.
Claim 1, characterized in that two systems of movable pulleys 9a and 9b are pivotally attached to the tips of a pair of rods 8 and 8 that are fixedly installed outside of the piston and project on both sides of a common piston. telescopic arm.