JP3142051B2 - Multi-stage telescopic arm of construction machine for deep foundation excavation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multistage telescopic arm of a construction machine, and more particularly to a multistage telescopic arm of a construction machine for excavating a deep foundation.

[0002]

2. Description of the Related Art Conventionally, many construction machines for excavating a deep foundation have a multistage telescopic arm as shown in FIG. 33, for example. The structure of such a construction machine will be described with reference to FIG. 33. The construction machine 1 is provided with an upper swing body 9 that can swing freely on a lower traveling body 8 and can swing vertically on the upper swing body 9. And a multi-stage telescopic arm which is also swingable in the vertical direction at the tip thereof. For example, 3
The multi-stage telescopic arm in the case of a multi-stage telescopic arm includes a base arm 3, a second-stage arm 4, and a third-stage arm 5. An excavating bucket such as a hydraulic clam bucket 7 is provided at the end of the third-stage arm 5, for example. The clam bucket 7 is driven to open and close by a hydraulic cylinder (not shown).

[0003] During excavation work, the construction machine 1 moves the ground surface G. L
The boom 2 and the multi-stage telescopic arm are set on the top, and are swung to the excavation posture. When the base arm 3, the second arm 4, and the third arm 5 extend to reach the depth at which the hydraulic clam bucket 7 is excavating, the clam bucket 7 is operated and soil and the like are removed. 7. Thereafter, each arm is reduced, and the clam bucket 7 is moved to the ground surface G. Lifted to near L, and boom 2
Is swung to the position of the boom 2a and the base arm 3
Is pulled up to the position of the base arm 3a. Next, the upper swing body 9 of the construction machine 1 is swiveled to a predetermined position, and the base arm 3 is swung to the position of the base arm 3b. Is loaded. Until the trench is at the desired drilling depth
The above operation is repeated.

[0004] In order to extend and retract such a multi-stage telescopic arm, for example, a driving device as shown in FIG. 34 is generally used. Hereinafter, the configuration and operation of the conventional driving device will be described with reference to FIG. FIG. 34 shows an example in which the hydraulic cylinder 10 is used as a drive device, and the hydraulic cylinder 10 is provided with the base arm 3, the second-stage arms 4 and 3.
It is provided inside the step arm 5. The rod-side end 10 a of the hydraulic cylinder 10 is fixed to the upper end of the base arm 3,
On the other hand, the rod side end portion 10b of the tube of the hydraulic cylinder 10
Is fixed to the upper end of the second-stage arm 4 and is of a so-called trunnion type. The sheave 11 is provided at the upper end of the second stage arm 4 so as to be built in the base arm 3, and the sheave 12 is provided at the lower end of the second stage arm 4. Then, one end is connected to the inner lower end 1 of the base arm 3.
The wire rope 13 fixed at 3 a is guided to the third arm 5 via the fixed sheave 11, and the other end of the wire rope 13 is fixed at the upper end 13 b of the third arm 5. In addition, one end is connected to the outer lower end 14a of the base arm 3.
The wire rope 14 fixed by the
The wire rope 14 is guided to the third arm 5 through the second arm 2, and the other end of the wire rope 14 is fixed to the upper end 14 b of the third arm 5.

When the hydraulic cylinder 10 is extended, the second stage arm 4 is lowered by the driving force, and the fixed sheave 12 is moved downward accordingly. By this movement, one end 14b of the wire rope 14 is pushed down, and the third arm 5 is driven downward. The hydraulic cylinder 10
Is reduced, the second-stage arm 4 is pulled upward,
The fixed sheave 11 moves upward. By this movement, one end 13b of the wire rope 13 is pulled upward, and 3
The step arm 5 is driven upward. At this time, the driving force to be lifted upward is transmitted to the hydraulic cylinder 10, the second-stage arm 4, the fixed sheave 11, the wire rope 13, the third-stage arm 5, and the clam bucket 7 in this order.

[0006]

In the conventional multi-stage telescopic arm driving device as described above, since the driving force for pulling up the multi-stage telescopic arm acts on the wire rope 13, the wire rope 13 is gradually used during use. Tired,
It may be broken at the end of its life. If the wire rope 13 is broken, the third stage arm 5 and the clam bucket 7 may fall, which is extremely dangerous. In addition, since the wire rope 13 is inside the base arm 3 and the second arm 4, it takes a very long time to replace the broken wire rope 13, and the workability at the time of replacement is not very good. Therefore, it is required to prolong the life of the wire rope 13, which has conventionally been dealt with by increasing the diameter of the wire rope.

On the other hand, the diameter of the wire rope is limited by the diameter of the fixed sheave 11. That is, the radius of curvature is restricted according to the size of the wire rope diameter, and the diameter of the fixed sheave 11 needs to be larger than the minimum radius of curvature. Therefore, the diameter of the fixed sheave 11 must be increased as the diameter of the wire rope is increased. However, in the conventional multi-stage telescopic arm driving device as described above, the fixed sheave 1
1 is built in the base arm 3, and there is a restriction on the function of the fixed sheave 11 that leads the wire rope 13 to the upper end 13 b of the third arm 5. As a result, there arises a problem that the diameter of the fixed sheave 11 cannot be made larger than the length L1 shown in FIG.

[0008] Prediction of the life of the wire rope is also strongly demanded, as is the improvement of the life. As a method for performing this prediction, conventionally, fixed sheaves 11 and 12 are used.
There is a method of counting the number of rotations and determining that the life is reached when the number of rotations reaches a predetermined number of rotations.
Some units output an alarm or instruction to replace the 3. However, according to this method, it is not possible to take into account factors such as the magnitude of the load and the trauma that greatly affect the life of the wire rope 13. Therefore, since the life is predicted in vain for safety, the frequency of replacement of the wire rope 13 is increased, or an unexpected disconnection is often caused. As described above, the hydraulic cylinder 10, the fixed sheaves 11, 12
And wire ropes 13 and 14 are incorporated in each arm. For this reason, the workability at the time of replacing the wire ropes when the wire ropes 13 and 14 reach the end of their life, the lubrication to the hydraulic cylinder 10 and the fixed sheaves 11 and 12, the pressure to the hydraulic cylinder 10 and the clam bucket 7 Maintainability such as inspection of oil supply hose is impaired. Therefore, a drive device for a multi-stage telescopic arm that can improve maintainability and maintainability in the above-described structure is desired.

[0009] Further, in order to increase the work efficiency and improve the productivity, it is also required to improve the workability during excavation and the amount of soil carried. That is, during the excavation work, the operator extends the base arm 3, the second-stage arm 4, and the third-stage arm 5 until the hydraulic clam bucket 7 reaches the excavation depth. At this time, the operator checks the descent position of the hydraulic clam bucket 7 while looking into the bottom of the excavation groove from the driver's seat. To land. Further, the hydraulic clam bucket 7 is mounted on the ground surface G. When the operator lifts the arm up to L, the operator confirms the position of the clam bucket while looking into the bottom of the excavation groove from the driver's seat, and contracts each arm at a high speed. Then, the ground surface G. When approaching L, reduce the ascending speed of each arm,
When the arm is in the contracted state, the boom 2 and the upper swing body 9 are operated. Such an operation is a very troublesome operation for the operator, and often impairs the efficiency of the excavation operation. Furthermore, in order to increase the amount of soil carried during one excavation, it is desired to increase the bucket capacity. However, if the bucket capacity is increased excessively, the weight of the entire work equipment becomes heavy, and the balance is lost. Therefore, there is a limit to increase the bucket capacity because the danger of falling of the construction machine is increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances, and an object of the present invention is to extend the life of a wire rope supporting a load such as a clam bucket or an arm, and to extend the life of the wire rope. Foreseeably improving the maintainability of the wire rope, and further improving the maintainability and maintainability of the wire rope and drive device built in the arm,
An object of the present invention is to provide a multi-stage telescopic arm for a construction machine for excavation of a deep foundation, in which a large-capacity bucket can be mounted to improve work performance and improve operability of an operator's arm during excavation work to improve workability. .

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a multi-stage telescopic arm of a construction machine for excavating a deep foundation, by driving a telescopic drive between a last stage arm and an arm immediately before the last stage arm. And a driving device 60 built in these arms, and pulling sheaves 21, 22 provided at least below the arm immediately before the final stage and having a diameter equal to or greater than the inner width of the arm immediately before the final stage. And a configuration including:

Further, in a multistage telescopic arm of a construction machine for deep foundation excavation having a base arm 3 mounted via a boom mounting portion 3g at a tip end of a boom 2 which can swing up and down, the second and subsequent stages Telescopic drive between adjacent arms of
A driving device 60 built in these arms, lifting sheaves 21 and 22 provided at least below the arms in which the driving devices 60 are built, and having a diameter equal to or greater than the inner width of these arms; And a base arm 3 from which the arm body 3c above the mounting portion 3g is deleted.

In the multistage telescopic arm of the construction machine for excavating a deep corner, at least two pulling sheaves 21, 21, 22, 22 and one end are fixed to the arm, and the other end is connected to the two sheaves. Pulling sheaves 21, 21, 2
Two wire ropes 25,2 led by 2,22
5, 26, 26, and the other ends of the two wire ropes 25, 25, 26, 26 are fixed to both ends which are attached to the arms 3, 4 and are divided by the center of rotation. Book wire rope 25,25,26,26
It is preferable to include an equalizer bar 40 for equalizing the load applied to the first and second stoppers, and a stopper 42 for stopping the rotation of the equalizer bar 40 when the equalizer bar 40 rotates by a predetermined angle.

Further, in the multi-stage telescopic arm of the construction machine for excavating a deep foundation described above, when the arm is contracted, the upper part of the arm 3
base arm 3 from which the upper part of second stage arm 4 protrudes
And a mark, a letter, or a number on the side of the arm, which indicates the digging depth, or is displayed.
It is better to have the step arm 4.

In the above-described multi-stage telescopic arm of the construction machine for excavating a deep foundation, the driving device 60 includes the tube mounting end 10.
b is the hydraulic cylinder 1 mounted inside the third stage arm 5
0, the multi-stage telescopic arm has an outer peripheral groove that can simultaneously guide a plurality of pressure oil supply hoses and wire ropes on a circumference provided in parallel and separated from each other in the direction of the rotation center axis, and at least The hydraulic oil supply hoses 50b and 50c to the hydraulic cylinder 10 and at least one of the wire rope 28 for pushing down the arm and the hydraulic oil supply hose 50a to the clam bucket 7 are connected to the third stage from the base arm 3. Sheaves 24A, 24a to 24d leading to the inside of the arm 3 may be provided.

In the above-described multi-stage telescopic arm of the construction machine for excavating a deep foundation, it is preferable that the multi-stage telescopic arm is a three-stage telescopic arm, and the driving device 60 is a trunnion-type hydraulic cylinder 10.

In the above-described multi-stage telescopic arm of the construction machine for excavating a deep corner, a step is provided on one surface of the base arm 3, and a wire rope 28 and / or a pressure oil supply hose 50a are provided on an outer surface 3d inside the arm. It is desirable to provide connection ends of 50b and 50c.

Further, in the multi-stage telescopic arm of the construction machine for excavating a deep foundation according to the preceding claim, the base stage arm 3 has an upper end portion of the second stage arm 4 which extends into a lower portion when the arm is extended, and On the inner surface of the step arm 3, the second step arm 4
A pad 78 continuously provided from a position below the upper end of the second stage arm 4 when the arm is fully extended to an upper end of the base arm 3 so as to contact the outer surface of the base arm 3; It is desirable to have the pad 77 provided.

Further, in the multi-stage telescopic arm of the above-mentioned construction machine for excavating a deep corner, the multi-stage telescopic arm is a telescopic arm of four or more stages, and includes a hose reel 52 provided on the base arm 3 and a hose reel 52. And a hose sheave provided in the second-stage arm 4 for receiving the hose and guiding the same to the fourth and subsequent arms.

[0020]

A telescopic drive between the last stage arm and the arm immediately before the arm is driven by a driving device built in these arms, and a pulling sheave is provided at least below the arm immediately before the last stage. Therefore, the diameter of the pulling sheave, which affects the life of the pulling wire rope, is not restricted by the inner width of the arm. Thus, the diameter of the pulling sheave can be made arbitrarily large, so that the cross-sectional diameter and the radius of curvature of the pulling wire rope can be increased. Therefore, the service life of the pulling wire rope is significantly improved as compared with the related art.

Further, a drive device 60 built in these arms for extending and contracting between adjacent arms of the second and subsequent stages is provided, and a pulling device is provided below these arms in which the drive devices 60 are built. Provide a sheave. Then, the diameter of these pulling sheaves is made larger than the inner width of the arm. Thereby, the arm main body part above the boom mounting part in the base arm can be deleted, and the life of the wire rope on the pulling sheave can be remarkably improved as compared with the related art. As a result, since the weight of the multi-stage telescopic arm can be reduced, the bucket capacity can be increased by the reduced weight of the arm while keeping the total weight of the telescopic arm and the bucket constant.

When two pulling sheaves are provided below each of the predetermined arms, two pulling wire ropes are used accordingly. At this time, when one end of the pair of pulling wire ropes is fixed to the arm via the equalizer bar, the load is evenly applied to the pair of pulling wire ropes. And
Assuming that one pulling wire rope is weaker than the other (the rope is more easily stretched with respect to the tensile load), the weaker wire rope gradually grows, and accordingly, the inclination angle of the equalizer bar gradually increases. Become. Further, the service life of the weaker wire rope is unilaterally shorter than that of the other wire ropes, so that the weaker one is more likely to break.
Then, as the life approaches, the inclination angle of the equalizer bar approaches a predetermined angle, so that the life can be predicted visually and the like, and the wire rope can be replaced before breaking. Also, if it breaks, the equalizer bar hits the stopper and the remaining strong wire rope supports it, eliminating the danger of falling of the bucket.

When the telescopic arm is in the contracted state, the upper part of the second stage arm projects from the upper part of the base arm. At this time, if at least one of a mark, a letter, and a number is provided on the side surface of the second-stage arm as a guide of the excavation depth, or if the mark is displayed, the mark or the like is visually observed and the approximate bucket is formed. Position can be determined. This allows the operator to estimate the bucket position when lowering or raising the bucket without looking into the excavation groove during the excavation work. As a result, operator fatigue is reduced and workability is improved.

A hydraulic cylinder is used as the driving device, and the mounting end of the hydraulic cylinder on the tube side is 3
Attach inside the step arm. By doing so, the number of pressure oil supply hoses and wire ropes that are guided from the base arm to the third arm is increased and increased. Therefore, it becomes necessary to treat these hoses and wire ropes in a space-saving manner. At this time, since a single sheave 24A or a sheave assembly 24a to 24d capable of simultaneously guiding a plurality of hoses and wire ropes on a coaxial sheave is used, the processing space for these can be made compact.
Further, when the multistage telescopic arm is a three-stage telescopic arm, if a trunnion type hydraulic cylinder is used as the driving device, the mounting position of the hydraulic cylinder, the fixed end position of the wire rope, and the like are concentrated near the upper part of the arm. Therefore, it is possible to perform maintenance, maintenance, and the like at one place in the state where the arm is in the most contracted state, and workability is greatly improved.

A step is provided on one surface of the base arm to make the outer surface 2
A step structure is provided, and a connection end for attaching or connecting a wire rope or a pressure oil supply hose is provided on the outer surface closer to the inner side of the arm among the two outer surfaces. In this way, inspection points can be collected, and inspection and maintenance can be easily performed from the outside of the arm, thereby improving maintainability.

When the arm is extended, the upper end of the second-stage arm is inserted into the lower part of the base arm.
At this time, pads are continuously provided on the inner surface of the base arm from a position below the upper end of the second stage arm in the most extended state to a position on the upper end of the base arm. Pads are also provided at the lower end. Thus, when the arm is reduced, the second stage arm can be prevented from swinging in the base arm, so that the expansion and contraction operation of the arm is stabilized.

When the multistage telescopic arm has four or more stages, a hose reel is provided on the base stage arm, a hose sheave is provided on the second stage arm, and a pressure oil supply hose is connected from the hose reel to the fourth stage via the hose sheave. Lead to the subsequent arm. As a result, the length of the hose leading to the hydraulic device such as the hydraulic cylinder for opening and closing the clam bucket 7 mounted on the fourth and subsequent arms is set to be the same as the conventional case, and only the hose reel is provided on the second arm. Can be very short compared to the case. As a result, it is possible to reduce the size of the hose reel and the weight of the arm.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment will be described with reference to FIGS.
This will be described in detail with reference to FIG. 1 and 2 show a side view and an X view of an example of a four-stage telescopic arm, respectively, and will be described first with reference to the figure. The lower part of the base arm 3 of the four-stage telescopic arm is swingably attached to the tip end of a boom 2 that can swing vertically in a construction machine or the like via a boom attachment part 3g. Here, the hydraulic cylinder 10 is used as an example of the arm expansion / contraction drive device 60, and the hydraulic cylinder 10 is built in the fourth arm 6 at the final stage and the third arm 5 before this. The rod mounting end 10a of the hydraulic cylinder 10 is mounted on the upper end of the third stage arm 5, while the tube mounting end 10b of the hydraulic cylinder 10
Is attached to the upper end of the fourth arm 6. Further, fixed sheaves 21 and 22 for lifting are provided at the lower end of the third-stage arm 5 and the lower end of the second-stage arm 4, respectively. In this embodiment, as can be seen in FIG.
1 and 22 each having two fixed sheaves 2
Reference numerals 1 and 21 are provided on both left and right sides so as to sandwich the fourth arm 6 as viewed from the boom 2, and fixed sheaves 22 and 22 are provided on the boom 2
The left and right sides are arranged so as to sandwich the third-stage arm 5 as viewed from above.

A wire rope 25 for pulling up the third-stage arm 5, one end of which is connected at a connection end 25 a at the outer lower end of the second-stage arm 4, is connected to the inside of the third-stage arm 5 via the fixed sheave 21. Then, the other end of the wire rope 25 is connected to a connection end 25b at the outer upper end of the fourth arm 6. A wire rope 26 for pulling up the second-stage arm 4, one end of which is connected at a connection end 26 a at the lower end of the outside of the base-stage arm 3, passes through the inside of the second-stage arm 4 via the fixed sheave 22. And the other end of the wire rope 26 is connected to the third arm 5.
Are connected at the connection end 26b at the upper end of the outside.

The fixed sheaves 23 and 24 for pressing are provided at the upper end of the third arm 5 and the upper end of the second arm 4, respectively. In the present embodiment, the fixed sheaves 23, 24
Are shown in the figure. This 2
Fixed sheaves 23, 23 and fixed sheaves 24, 2 each
Reference numeral 4 denotes a left and right side when viewed from the boom 2, and is disposed at a position where the third arm 5 and the second arm 4 are lifted and the whole arm is in the most contracted state and does not interfere with each other.

The wire rope 27 for pushing down the third arm 5, one end of which is connected at the connection end 27 a at the lower end inside the second arm 4, is connected to the third arm 5 via the fixed sheave 23. The wire rope 27 is guided to the fourth-stage arm 6 through the inside, and the other end of the wire rope 27 is connected to a connection end 27 b at the upper end of the outside of the fourth-stage arm 6. A wire rope 28 for pushing down the second-stage arm 4, one end of which is connected at the connection end 28 a at the lower end of the inside of the base arm 3, passes through the inside of the second-stage arm 4 via the fixed sheave 24. Then, the other end of the wire rope 28 is connected to a connection end 28b at the outer upper end of the third stage arm 5.

The operation of the above configuration will now be described.
First, when the hydraulic cylinder 10 is extended, the fourth stage arm 6 is pushed down by the driving force so as to protrude from the lower part of the third stage arm 5. Accordingly, the wire rope 27 connected to the connection end 27b at the upper end of the fourth arm 6 is pulled downward. At this time, fixed sheave 2
Since 3 is pushed down, the third arm 5 is pushed down so as to protrude from the lower part of the second arm 4. Further with this, the wire rope 28 connected to the connection end 28b at the upper end of the third-stage arm 5 is pulled downward. Then, since the fixed sheave 24 is pushed down, the second-stage arm 4 is pushed down so as to protrude from the lower portion of the base arm 3.

When the hydraulic cylinder 10 contracts, the fourth-stage arm 6 is pulled up and drawn into the third-stage arm 5. Accordingly, the wire rope 25 connected to the upper end connection end 25b of the fourth arm 6 is pulled upward. At this time, since the fixed sheave 21 is pulled up, the lower end of the third-stage arm 5 comes closer to the lower end of the second-stage arm 4. Drawn into. Further with this, the wire rope 26 connected to the connection end 26b at the upper end of the third-stage arm 5 is pulled upward. At this time, since the fixed sheave 22 is pulled up, the lower end of the second-stage arm 4 approaches the lower end of the base arm 3, and as a result, the second-stage arm 4 is drawn into the base arm 3. It is.

According to the above configuration, the driving force for pulling up and the load of the second and subsequent arms and the clam bucket 7 act on the wire ropes 25 and 26. Therefore, in order to improve the life of the wire rope 25 and the wire rope 26, it is necessary to increase the diameter of the fixed sheaves 21 and 22 as the diameter of the wire rope increases. Fixed sheaves 21, 22 as described above
Is provided outside the third-stage arm 5 and the second-stage arm, the diameter thereof can be arbitrarily set without being restricted by the inner width of the arm. As a result, the diameter of the wire rope can be increased and the radius of curvature of the wire rope can be increased as compared with the related art, so that the life of the wire rope can be greatly improved. Further, as a result, the number of times of replacing the wire rope is reduced, so that maintainability is also improved.

In this embodiment, the fixed sheaves 21, 22,
Although an example is shown in which two of the fixed sheaves 23 and 24 are arranged on the left and right, respectively, the present invention is not limited to this. The effect is the same. The hydraulic cylinder 10 has a trunnion type mounting structure, but may have another mounting structure.

Next, an example of another sheave position in this embodiment will be described. FIGS. 3 and 4 show a side view and a U view of a four-stage telescopic arm of another example, respectively, which will be described below with reference to FIG. Here, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof is omitted. The fixed sheave 22 for raising the second stage arm 4 is
It is rotatably mounted below the second stage arm 4. A wire rope 26 for pulling up the second-stage arm 4, one end of which is connected at a connection end 26 a at the outer lower end of the base arm 3.
Is guided to the third arm 5 through the inside of the second arm 4 via the fixed sheave 22, and the other end of the wire rope 26 is connected to a connection end 26 b at the outer upper end of the third arm 5. Have been. The fixed sheave 21 for lifting the third-stage arm 5 is rotatably mounted below the third-stage arm 5. A wire rope 25 for pulling up the third-stage arm 5, one end of which is connected to a connection end 25 a at the outer lower end of the second-stage arm 4, passes through the inside of the third-stage arm 5 via the fixed sheave 21. The wire rope 25 is guided to the fourth-stage arm 6, and the other end of the wire rope 25 is connected to a connection end 25 b at the outer upper end of the fourth-stage arm 6. In this example, as in the previous example, two fixed sheaves 22 are provided on the left and right of the second arm 4 as viewed from the boom 2, and two fixed sheaves 21 on the left and right of the third arm 5. Holes 4a, 4a and holes 5a, 5a are provided at positions where the fixed sheaves 22, 22 and the fixed sheaves 21, 21 respectively come out of the second-stage arm 4 and the third-stage arm 5, respectively. I have.
Then, each fixed sheave 22, 22 and fixed sheave 21,
The lower part of 21 is protected from interference with the outside by guards 72, 72 and guards 71, 71 provided outside the lower part of the second-stage arm 4 and the third-stage arm 5, respectively.

A pad 75 is attached to the lower end of the inner surface of the second stage arm 4. FIG. 5 is a cross-sectional view taken along the line CC of FIG. A pad 75 is provided at the lower end of the inner surface of the second-stage arm 4. The pad 75 is provided on the third-stage arm so that there is no play between the lower end of the second-stage arm 4 and the third-stage arm 5. 5 is uniformly in contact with the outer surface. Further, similarly, a pad 76 is mounted on the upper end of the outer surface of the third arm 5, and this pad 76 has no backlash between the upper end of the third arm 5 and the second arm 4. As described above, the second stage arm 4 is provided in uniform contact with the inner surface. These pads 75 and 76 are attached with screws or the like, so that they can be easily attached and detached during maintenance when the pads are worn. Similarly, a pad 73 is provided at the lower end of the inner surface of the third-stage arm 5, and the pad 75 uniformly contacts the outer surface of the fourth-stage arm 6. A pad 74 is attached to the upper end of the outer surface of the fourth arm 6.
The pad 74 is provided in uniform contact with the inner surface of the third-stage arm 5.

In the multi-stage telescopic arm having such a configuration, the operation at the time of expansion and contraction is the same as that described above. That is, when the hydraulic cylinder 10 as the driving device 60 is reduced, the third-stage arm 5 moves up via the wire rope 25 and the fixed sheave 21, and accordingly, the second stage arm 5 moves through the wire rope 26 and the fixed sheave 22. The arm 4 moves up.
When the hydraulic cylinder 10 extends, the third-stage arm 5 descends via the wire rope 27 and the fixed sheave 23, and accordingly, the second-stage arm 4 descends via the wire rope 28 and the fixed sheave 24.

Also in this case, the driving force for pulling up and the loads on the second and subsequent arms and the clam bucket 7 act on the wire ropes 25 and 26 as in the previous example. Since the diameter of the fixed sheaves 21 and 22 can be arbitrarily large without being restricted by the inner width of the arm and the like, the diameter of the fixed sheaves 21 and 22 can also be increased. As a result, the wire diameter of the wire rope 25 and the wire rope 26 can be increased and the radius of curvature of the wire rope can be increased as compared with the related art, so that the life of the wire rope can be greatly improved. Further, as a result, the number of times of replacing the wire rope is reduced, so that maintainability is also improved. In addition, as shown in FIG. 3, the wire ropes 25 and 26 do not necessarily need to be parallel to the longitudinal axis of each arm. The fixed sheaves 21 and 21 and the fixed sheaves 22 and 22 are connected to the third arm 5 and the second arm 4 respectively.
The pad 73 and the pad 7 are provided above the lower end of the pad.
5 can be easily replaced and maintenance workability is good. Further, since the guards 72, 72 and the guards 71, 71 are also provided, the fixed sheaves 21, 21 and the fixed sheave 22,
The contact between the arm 22 and an external obstacle from below each arm can be eliminated.

Next, a case of a three-stage telescopic arm as another example of a multi-stage telescopic arm will be described with reference to FIGS.
6 and 7 show a side view and a Y view of FIG. 6, respectively. Here, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted. The hydraulic cylinder 10 is used as an example of the arm expansion / contraction drive device 60 as in the previous example, but this hydraulic cylinder 10 is incorporated in the third-stage arm 5 at the final stage and the second-stage arm 4 just before the third stage. The rod mounting end 10a of the hydraulic cylinder 10 is mounted on the upper end of the second stage arm 4, while the tube mounting end 10b of the hydraulic cylinder 10 is mounted on the upper end of the third stage arm 5.

The pulling-up fixed sheave 22 is provided at the lower end of the second arm 4. Note that the fixed sheave 22 may be provided below the second stage arm 4 as shown in FIG. Also in this example, the fixed sheave 2
The fixed sheaves 22, 22 are disposed on both left and right sides so as to sandwich the third arm 5 as viewed from the boom 2. One end is a connection end 26 at the lower end of the outside of the base arm 3
The wire rope 26 for pulling up the second-stage arm 4 connected at a is guided to the third-stage arm 5 through the inside of the second-stage arm 4 via the fixed sheave 22, and the other ends of the wire rope 26 The end is a connection end 26b at the outer upper end of the third stage arm 5.
Connected.

The fixed sheave 24 for pushing down is provided at the upper end of the second stage arm 4. Fixed sheave 2 as before
4 and two fixed sheaves 24 are provided on the left and right as viewed from the boom 2. The wire rope 28 for pushing down the second-stage arm 4, one end of which is connected to the connection end 28 a at the lower end inside the base-stage arm 3, passes through the interior of the second-stage arm 4 via the fixed sheave 24 and becomes three-stage. The wire rope 28 is guided to the eye arm 5, and the other end of the wire rope 28 is connected to a connection end 28 b at the outer upper end of the third arm 5.

The operation of this embodiment is almost the same as that of the embodiment shown in FIG. 1, but will be briefly described below. When the hydraulic cylinder 10 is extended, the third-stage arm 5 is lowered by the driving force so as to protrude from the lower portion of the second-stage arm 4. Accordingly, the wire rope 28 connected to the connection end 28b at the upper end of the third arm 5 is pulled downward, and the fixed sheave 2
4 is pushed down, the second arm 4 descends so as to protrude from the lower part of the base arm 3. When the hydraulic cylinder 10 contracts, the third-stage arm 5 rises and is drawn into the second-stage arm 4, and accordingly, the wire rope 26 connected to the connection end 26 b at the upper end of the third-stage arm 5. Is pulled upward. At this time, the fixed sheave 22 is lifted upward, so that the second stage arm 4
Comes closer to the lower end of the base arm 3, and as a result, the second arm 4 is drawn into the base arm 3 and rises.

With such a configuration, the diameter of the fixed sheave 22, which is related to the improvement of the life of the wire rope 26, can be arbitrarily set without being limited by the inner width of the arm, as in the previous example. Therefore, the life of the wire rope can be greatly improved as compared with the related art, and as a result, the maintainability of the wire rope is also improved. In addition, even if the fixed sheaves 22 and 24 are provided one by one at predetermined positions, and the hydraulic cylinder 10 has another mounting structure different from the trunnion type, the operation and the effect are the same. It is.

Next, another embodiment using a device other than the hydraulic cylinder as the arm driving device 60 will be described. First, FIGS. 8 and 9 show an example in which a rack and a pinion are provided and the pinion is rotated by a drive motor.
FIG. 8 is a schematic side view of the arm, and FIG. 9 is an AA sectional view of FIG. 8 showing details of a rack and a pinion portion. In these figures, the same components as those in FIG. 1 are denoted by the same reference numerals, and are the same as those described above.
0 will be explained. The drive motor 32 is mounted on the upper end of the fourth stage arm 6 at the last stage, and the pinion 31 is mounted on the rotation shaft of the drive motor 32. The direction of the rotation axis of the drive motor 32 is orthogonal to the direction of movement of the fourth arm 6, and the outer dimensions of the drive motor 32 and the pinion 31 are smaller than the inner width of the cross section of the third arm 5. is there. A rack 30 is provided on the inner surface of the third-stage arm 5 just before the last stage in parallel with the moving direction of the fourth-stage arm 6, and the rack 30 is mounted so as to mesh with the pinion 31. still,
As the drive motor 32, for example, a hydraulic motor or an electric motor can be used. Further, the positions of the fixed sheave for driving the arm and the connection position of the wire rope and the like are the same as those in the above-described embodiments, and are omitted in the drawings, and description thereof is omitted.

The operation in the above configuration is as follows. When the drive motor 32 rotates and the fourth stage arm 6 moves so as to protrude downward by the rack 30 and the pinion 31, the operation is the same as when the hydraulic cylinder is extended in the case of the hydraulic cylinder described above. When the drive motor 32 rotates, the fourth-stage arm 6 becomes the third-stage arm 5.
When the hydraulic cylinder rises so as to be drawn inside, the operation is the same as when the hydraulic cylinder is contracted.

FIGS. 10 and 11 show an example in which a chain and a sprocket are provided and the sprocket is rotated by a drive motor. FIG. 10 is a schematic side view of the arm, and FIG. 11 is a sectional view taken along the line BB of FIG. 10 showing details of the chain and the sprocket. In the figure,
The same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. Hereinafter, the driving device 60 will be described. The drive motor 35 is mounted on the upper end of the fourth stage arm 6 in the final stage, and the sprocket 34 is mounted on the rotation shaft of the drive motor 35. The direction of the rotation axis of the drive motor 35 is orthogonal to the direction of movement of the fourth arm 6, and the outer dimensions of the drive motor 35 and the sprocket 34 are smaller than the inner width of the cross section of the third arm 5. is there. On the inner surface of the third stage arm 5 just before the last stage, the chain 3 is set in parallel with the movement direction of the fourth stage arm 6.
3 is provided, and the chain 33 is attached so as to mesh with the sprocket 34. The arrangement position of the fixed sheave for driving the arm, the connection position of the wire rope, and the like are the same as those in the above-described embodiments, so that illustration and description are omitted.

The operation in the above configuration is the same as described above. When the drive motor 32 rotates, the sprocket 34 moves downward or upward along the chain 33, whereby the multi-stage telescopic arm extends or contracts.

FIGS. 12 and 13 show an example in which a wire rope and a winch are provided, and the winch is rotated by a driving motor. FIG. 12 is a schematic side view of the arm, and FIG. 13 is a Z view of FIG. 12 showing details of a wire rope and a winch portion. In the figure, the same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted. The drive device 60 will be described below. A winch 38 having a built-in drive motor 39 is mounted on the upper end of the fourth arm 6 at the last stage. The direction of the rotation axis of the drive motor 39 and the winch 38 is orthogonal to the moving direction of the fourth arm 6, and the size of the winch 38 is
Is smaller than the inner width of the section. Wire rope 36
Is connected to the winch 38 at one end, wound around the winch 38 a predetermined number of times, and the other end is connected to the inner upper end of the third arm 5. The wire rope 37 has one end connected to the winch 38, wound around the winch 38 a predetermined number of times in the direction opposite to the wire rope 36, and the other end connected to the lower end inside the third arm 5. The arrangement position of the fixed sheave for driving the arm, the connection position of the wire rope, and the like are the same as those in the above-described examples, and thus illustration and description are omitted.

The operation in the above configuration is the same as that described above. When the winch 38 is rotated by the drive motor 39, one of the wire ropes 36 and 37 is wound around the winch 38, and the other rope is unreeled from the winch 38. The winch 38 moves downward or upward along the wire rope and drives the fourth arm 6. Thereby, the multi-stage telescopic arm extends or contracts.

As described above, the other three examples of the driving device 60 operate in the same manner as the example using the hydraulic cylinder. Therefore, similarly to the embodiment described with reference to FIG. 1 described above, the diameter of the fixed sheaves 21 and 22 relating to the life of the pulling wire ropes 25 and 26 can be set to an arbitrary size. As a result, the wire ropes 25 and 26 can be obtained. Can be extended.

Next, a second embodiment will be described with reference to FIGS. The present embodiment uses the wire ropes 25, 26 in a case where the pulling fixed sheaves 21, 22 and the corresponding pulling wire ropes 25, 26 as shown in the first embodiment are used in pairs.
The structure is such that it is easy to determine that the life of the 26 is near. The case of a three-stage telescopic arm will be described below. However, the present invention is not limited to this, and the operation and effect are the same in the case of another multi-stage telescopic arm such as a four-stage telescopic arm.

FIG. 14 is a schematic side view of the arm. In the figure, the same components as those in the previous embodiment are denoted by the same reference numerals, and description thereof will be omitted.Also, the positions of the fixed sheaves for driving the arm and the connection position of the wire rope are the same as those in the previous embodiment. It is not shown in the figure. As in the previous embodiment, the fixed sheave 22 is attached to the lower end of the second arm 4 by two.
The third arm 5 is disposed on the left and right sides of the boom 2 so as to sandwich the third-stage arm 5. One end of each of the two pulling wire ropes 26, 26 is connected to a connection end 26b outside the upper end of the third-stage arm 5, and the other end passes through the inside of the second-stage arm 4, and includes two fixed sheaves 22, It is guided to the outer lower end of the base arm 3 via 22. An equalizer bar 40 is provided at an outer lower end of the base arm 3, and the other ends of the wire ropes 26, 26 are connected to connection ends 26 a, 26 a at both left and right ends of the equalizer bar 40.

FIG. 15 is a W view of the equalizer bar 40, and based on FIG.
The parts will be described in detail. A support shaft 43 that is substantially perpendicular to the moving direction of each arm is provided at the outer lower end of the base arm 3, and the equalizer bar 40 is rotatably provided around the support shaft 43 as a fulcrum. The other ends of the wire ropes 26 are connected to the left and right connection ends 26 of the equalizer bar 40 when viewed from the boom 2.
a, 26a. Stoppers 41, 41 are provided on the left and right sides below the equalizer bar 40 so that the rotation of the equalizer bar 40 stops when the equalizer bar 40 rotates by a predetermined angle. Further, in this embodiment, detectors 42 and 42 are attached to the side surfaces of the stoppers 41 on the left and right sides, respectively. The detector 42 detects that the equalizer bar 40 has rotated by a predetermined angle, and includes, for example, a limit switch and a proximity switch. Note that the detector 42 may detect that the equalizer bar 40 has rotated and hit the stopper 41.

Next, the operation in such a configuration will be described. First, when a predetermined load is applied to the two wire ropes 26, 26, the connection ends 26 of the wire ropes 26 are set so that the equalizer bar 40 is in a substantially horizontal state.
a, 26a to adjust. Since the load is evenly applied to the two wire ropes 26 while working with the multi-stage telescopic arm, the equalizer bar 40 keeps a substantially horizontal state at the beginning of use. As the frequency of use increases, the one of the two wire ropes 26, 26, which has a shorter life, gradually weakens against the tensile load and thus gradually expands, and its cross section becomes thinner. When one of the wire ropes 26 is slightly stretched, the equalizer bar 40 is slightly tilted so that the load is evenly applied to the two wire ropes 26, 26, and the equalizer bar 40 is balanced at that angle. However, since the cross section becomes thinner, the stretched wire rope 26 becomes weaker against the tensile load than before, and thus the wire rope 26 becomes easier to stretch. In this way, one wire rope 26 is
As compared with, the cross section becomes thinner and the deterioration proceeds.
Accordingly, the inclination angle of the equalizer bar 40 gradually increases.

Therefore, by visually observing the inclination angle of the equalizer bar 40, it can be easily determined that the life of the wire rope 26 is approaching. Therefore, when the service life is approaching, the wire rope 26 can be replaced before the wire breaks. Then, the old wire rope 26 before the replacement and the new wire rope 26 are connected, and the old wire rope 2 is connected.
Since it is possible to take a working method such as pulling the wire rope 6, the replacement work of passing a new wire rope 26 through the arm can be easily performed. Therefore, maintainability and maintainability of the wire rope 26 are improved.

When one of the wire ropes 26 breaks due to its end of life, the equalizer bar 40 rotates and stops until it hits the stopper 41. At this time, the other wire rope 26 supports the entire load, but since the wire rope 26 retains almost the original strength, it does not break even if supported by this one rope. Therefore, there is no danger of falling of the clam bucket 7, etc., and it is very safe.

Further, when the stoppers 41, 41 are set at their positions so that the equalizer bar 40 hits the stopper 41 on either side before the wire rope 26 breaks at the end of its life, the left and right detectors 42, 42 It is possible to detect that the life of the wire rope 26 is approaching.
Using such detectors 42, 42, for example, a lamp, a buzzer, or the like is operated, or a message or the like is displayed or transmitted by inputting to a controller (not shown) using, for example, a microcomputer. This makes it possible to automatically notify the operator or another external control device of the replacement timing of the wire rope. The detectors 42, 42
When a limit switch, a proximity switch, or the like is used for the switch, a circuit that can operate the lamp, the buzzer, and the like by the output contact signal can be easily configured. For example, although not shown in the circuit diagram, when the a contacts of the left and right limit switches are connected in parallel and this parallel circuit is connected in series with a power supply and a lamp (or a buzzer or the like), the left or right limit switch operates. By doing so, the lamp (or buzzer or the like) operates.

Next, a third embodiment will be described with reference to FIGS. The present embodiment shows an example in which the upper portion of the base arm 3 is eliminated and the upper portion of the second arm 4 projects from the upper portion. With this structure, the weight of the entire arm portion can be reduced, and the workability can be improved by marking the outer side surface of the second-stage arm 4 with a mark or the like as a measure of the depth of the excavation groove. Here, the case of a three-stage telescopic arm will be described, but the following operation and effect will not be changed in the case of a four-stage telescopic arm. FIG. 16 is a side view of a three-stage telescopic arm according to the present embodiment, and the same components as those in the previous examples are denoted by the same reference numerals and description thereof will be omitted. In this embodiment, the basic configuration is the same as that of the three-stage telescopic arm described in FIG. 6 of the first embodiment, but the upper part 3 above the boom mounting part 3g of the base arm 3 as described so far.
The structure eliminates c. Lower part 3h of base arm 3
The boom mounting portion 3g is swingably attached to the tip of the boom 2. Further, as an example of the driving device 60, an example is shown in which the hydraulic cylinder 10 is attached between the third-stage arm 5 at the final stage and the second-stage arm 4 before the third stage arm.

FIG. 17 shows a state in which the telescopic arm according to this embodiment is close to the most contracted state. As described above, since the upper part 3c of the base arm 3 is eliminated, the upper part of the second-stage arm 4 can be protruded from the upper part of the base arm 3.
A mark or the like is provided on the outer side surface of the second stage arm 4 as a guide for the depth of the excavation groove. FIG. 18 shows an example of a reference mark or the like. For example, in FIG. 18A, parallel lines perpendicular to the longitudinal direction of the arm are drawn at predetermined intervals M. At this time, FIG. 19 shows a state immediately before the start of excavation in the retracted state of the telescopic arm, and FIG. 20 shows a state of excavating work in an extended state of the telescopic arm. At the start of excavation, the operator previously counts and stores the number (referred to as N1) of marks 45 attached to the side surface of the second arm 4 projecting from the upper part of the base arm 3 as shown in FIG. . Next, as shown in FIG. 20, when the clam bucket 7 reaches the depth of the excavation groove, the number of marks 45 on the side surface of the second-stage arm 4 protruding from the lower portion of the base arm 3 when the clam bucket 7 reaches the excavation groove depth as shown in FIG. N2).

Then, the excavated earth and sand are transferred to the ground surface G. When retracting the telescopic arm to lift to L, the operator counts the markings 45 on the side of the second arm 4 that protrude from the top of the base arm 3. When the number approaches the stored number N1, the clam bucket 7 is moved to the ground surface G.
Assuming that it is close to L, the reduction speed of the telescopic arm is reduced.
When the counted number reaches N1, the boom 2 is swung upward and the upper swing body 9 is swung to discharge the soil and the like in the clam bucket 7 to a predetermined position or a loading truck or the like. When lowering the clam bucket 7 to the depth of the excavation groove, the operator counts the mark 45 on the side surface of the second-stage arm 4 projecting from the lower portion 3h of the base arm 3. When the number approaches the stored number N2, the extension speed of the telescopic arm is reduced on the assumption that the clam bucket 7 will soon reach the depth of the excavation groove. When the counted number reaches N2, the excavation work is started.

As described above, the upper part 3c of the base arm 3 is eliminated, and the upper part of the second arm 4 projects from this upper part. Since markings are provided as a guide, workability during excavation can be improved. In addition, the weight of the base arm 4 can be reduced by eliminating the upper portion 3c, so that the entire multi-stage telescopic arm can be reduced in weight. Since the bucket capacity of the clam bucket 7 can be increased by the reduced weight, the efficiency of excavation work can be improved accordingly.

In the above description, the driving device 60
May be changed to a member having an equivalent function other than the hydraulic cylinder 10 as in the previous embodiment, or the pulling fixed sheave 22 may be used.
The above-described operation and effect of the present embodiment are the same even when a pair of wire ropes 26 are provided on the left and right sides and the wire ropes 26, 26 are connected to the equalizer bar 40 similar to the previous embodiment. Further, if other examples such as a mark serving as a guide of the depth of the excavation groove are raised, as shown in FIG.
Alternatively, it may be constituted by a figure, a pattern, or a combination thereof. The color or figure of each mark may be changed at predetermined intervals as shown in FIG. 18C, or the color of the band may be changed at predetermined intervals as shown in FIG. 18D.

Next, another example of the driving position of the driving device 60 in this embodiment will be described with reference to FIG. FIG. 21 is a side view of a four-stage telescopic arm in which the hydraulic cylinder 10 as the driving device 60 is driven to expand and contract between the second-stage arm 4 and the third-stage arm 5, and is the same as FIG. The same reference numerals are given to the components, and the description thereof will be omitted. Also in this example, the upper part 3c of the base arm 3 is deleted. The hydraulic cylinder 10 is built in the second-stage arm 4 and the third-stage arm 5. The rod attachment end 10a of the hydraulic cylinder 10 is attached to the upper end of the second-stage arm 4, while the tube attachment end 10b of the hydraulic cylinder 10 is attached to the third-stage arm 5.
It is attached to the upper end. Although the hydraulic cylinder 10 has a trunnion-type mounting structure, the hydraulic cylinder 10 is not limited to this as described above. The positions of the fixed sheaves 21 and 22 are respectively set to the third-stage arms 5 and 2 as shown in FIG.
Although it is provided outside the lower end of the stage arm 4, it is not limited to this position. For example, as shown in FIG.
And may be provided below the second-stage arm 4.

The operation in such a configuration is as follows. First, when the hydraulic cylinder 10 is extended, the third-stage arm 5 is pushed down by the driving force so as to protrude from the lower portion of the second-stage arm 4. Accordingly, the wire rope 28 connected to the connection end 28b at the upper end of the third-stage arm 5 is pulled downward. Then, since the fixed sheave 24 is pushed down, the second-stage arm 4 is pushed down so as to protrude from the lower portion of the base arm 3. Further, as the third arm 5 descends, the fixed sheave 21 below the third arm 5 descends, and the connection end 25b of the wire rope 25 is pulled down via the fixed sheave 21, whereby: The fourth arm 6 descends. When the hydraulic cylinder 10 contracts, the third-stage arm 5 is drawn into the second-stage arm 4 and rises. Thereby, the fourth arm 6 supported by the wire rope 27 via the fixed sheave 23 above the third arm 5 is raised. At this time, the wire rope 26 connected to the connection end 26b at the upper end of the third-stage arm 5 is pulled upward, and accordingly, the fixed sheave 2
Since 2 is pulled upward, the lower part of the second-stage arm 4 approaches the lower end of the base arm 3, and as a result, the second-stage arm 4 is drawn into the base arm 3 and rises.

As described above, in the example of this configuration, the wire rope 26 and the fixed sheave 22 are used for lifting the second-stage arm 4. In this case, the life of the wire rope 26 can be improved. further,
As in the previous example, the weight of the entire telescopic arm can be reduced, so that the bucket capacity of the clam bucket 7 can be increased. Therefore, the efficiency of excavation work can be improved.

Next, another example of this embodiment will be described with reference to FIGS.
5 will be described. This means that when the arm is fully extended,
This is an example in which the upper end of the second stage arm 4 and the fixed sheave 24 completely enter the inside of the lower portion 3h of the base stage arm 3. With this configuration, the total arm length when the arm is reduced can be shortened. FIG. 22 shows a third example of this configuration.
FIG. 17 is a side view of the most extendable state of the step extendable arm, and the same components as those in FIG. 16 are denoted by the same reference numerals and description thereof is omitted. 16, the upper part 3c of the base arm 3 is omitted as in FIG. 16, and the upper end of the second arm 4 and the fixed sheave 24 are completely connected to the lower part 3h of the base arm 3 in the most extended state of the arm.
It is configured to enter inside.

FIG. 23 is a view as viewed from T (top view) of FIG. 22, and FIG. 24 is a sectional view taken along line DD of FIG.
In the figure, pads 77 and 78 are provided on the inner surface of the lower part 3 h of the base arm 3 and are in contact with the outer surface of the second-stage arm 4. These pads 77 and 78 correspond to FIG.
As in the case of the pads 73, 74, 75, 76, etc., there is no gap between the outer surface of the second-stage arm 4 and the inner surface of the base arm 3, so that the vibration of the second-stage arm 4, play, etc. Has been prevented. The pad 77 is provided at the lower end of the inner surface of the lower portion 3h, and the pad 78 is continuous from the position below the upper end of the second stage arm 4 when the arm is fully extended to the upper end of the lower portion 3h. Is provided. Thus, even if the second-stage arm 4 enters the lower portion 3h of the base arm at the time of the maximum extension of the arm, the two upper and lower pads of the pad 77 at the lower end portion of the base arm 3 and the pad 78 above the lower end are removed. It can be pressed against the second stage arm 4 from all sides. Therefore, the second stage arm 4 does not vibrate or rattle in the base stage arm 3 during expansion and contraction.

FIG. 25 is a schematic side view showing how the total arm length is reduced when the arm of this embodiment is contracted. In FIG. 25A, the most extended state in this example is indicated by a solid line and a broken line, and the most reduced state is indicated by a two-dot chain line. Similarly, in FIG. 25B, the most extended state in the case where the upper end of the second-stage arm 4 protrudes above the lower part 3h of the base arm 3 in the most extended state is shown by a solid line and a broken line. The reduced state is indicated by a two-dot chain line.
As is apparent from FIG. 3, if the difference between the lengths of the second-stage arms 4 between them is L, the total arm length in the minimum contraction state is shorter by L in this example. Therefore, this allows the arm to be horizontal in the minimum contracted state (equivalent to the base arm position 3b in FIG. 33) for loading on a dump truck or the like after the excavation is completed.
Thus, the turning radius when turning the arm can be reduced. As a result, the operator can operate without worrying about the interference of the arm at the time of turning, and the operability can be improved. Further, the weight of the entire arm can be reduced, so that the bucket capacity can be increased, thereby improving the working efficiency.

Next, as a fourth embodiment, an example of a multi-stage telescopic arm for improving maintainability of a wire rope and a pressure oil supply hose will be described with reference to FIGS. First, an example of a three-stage telescopic arm will be described. FIG. 26 shows a side view of the state near the most contracted state. Here, the same reference numerals are given to the same components as those in the above-described examples, and description thereof will be omitted.

The hydraulic cylinder 10 is built in the third stage arm 5 at the last stage and the second stage arm 4 just before the third stage arm 5.
The rod mounting end 10a of the hydraulic cylinder 10 is mounted on the upper end of the second stage arm 4, while the tube mounting end 10b of the hydraulic cylinder 10 is mounted on the upper end of the third stage arm 5, a so-called trunnion type. Mounting structure. The mounting structure of the hydraulic cylinder 10 is not limited to the above. For example, the rod mounting end 10a may be connected to the second stage arm 4
At the upper end of the tube, and attach the end of the tube
It may be attached to the lower end of the step arm 5. In either case, the tube side of the hydraulic cylinder 10 is fixed to the inside of the third-stage arm 5, so the pressure oil supply hose 50b
It is necessary to guide 50 c from the base arm 3 to the third arm 5.

Since the hydraulic clam bucket 7 is provided at the end of the third arm 5 at the final stage, the hydraulic oil supply hose 50a for the hydraulic clam bucket is also connected to the base arm 3 in the same manner as described above. Must be guided to the third-stage arm 5.

Therefore, in this embodiment, the hydraulic oil supply hoses 50a, 50b, 50c for the hydraulic clam bucket and the hydraulic cylinder 10 are connected via the fixed sheave 24A provided at the upper end of the second stage arm 4. To the third arm 5. FIG. 27 shows the fixed sheave 24A in FIG.
FIG. 2 is an explanatory diagram of a portion where the hydraulic cylinders 10 are disposed, as viewed from the front of the construction machine (from the side opposite to the boom 2). Hereinafter, a method for connecting the fixed sheave 24A and the pressure oil supply hose will be described with reference to FIG. The fixed sheave 24A is a single sheave that can simultaneously guide a plurality of wire ropes and a pressure oil supply hose, and has a plurality of guide grooves that are spaced apart in the axial direction of the rotating shaft. is there. The fixed sheave 24A of this embodiment has two wires for the wire rope 28.
One for the pressure oil supply hose 50a of the clam bucket 7
One, the hydraulic oil supply hoses 50b, 50c of the hydraulic cylinder 10
Three guide grooves. These guide grooves have the same radius of rotation, and the fixed sheave 24A
Is designed to rotate as an integral sheave. Thereby, the wire rope 28 and the pressure oil supply hose 50a,
The fixed sheave 24A is moved from the base arm 3 to the fixed sheave 24A.
Can be led to the third stage arm 5 in a compact manner.

In the above configuration, when the hydraulic cylinder 10 has a trunnion type structure, when the arm is in the most contracted state, the mounting portion (for example, 10
b) The connection ends (for example, 26b and 28b) of the wire rope at the upper end of the third arm and the fixed sheave 24A at the upper end of the second arm gather at the upper part of the arm. As a result, the maintenance and inspection work range is concentrated at one place, so that maintainability and maintainability are greatly improved.

The base arm 3 has the upper part 3 as described above.
The structure may be such that c is eliminated, or may not be the structure. Wire rope 28 and pressure oil supply hose 5
In order to facilitate the maintenance of the connecting portions of 0a, 50b and 50c at the lower part of the base arm 3, a step is provided near the lower part of the boom mounting part 3g of the base arm 3 to form a two-stage structure. That is, the outer surface on the boom 2 side near the lower portion of the base arm 3 is composed of 3d and 3f.

FIGS. 28A and 28B are views for explaining the two-stage structure in detail. FIG. 28A is a view of the two-stage structure as viewed from V in FIG. 26, and FIG. 28B is a side view thereof. The outer surface 3f of the base arm 3 on the boom 2 side and closer to the boom 2
Is provided with a boom mounting portion 3g. A wire rope 28 is provided on the other outer surface 3d of the base arm 3 on the boom 2 side.
Connection end 28a for connecting one end of the cylinder and the pressure oil supply hose 5
Each connection end 51 of 0a, 50b, and 50c is provided. These wire rope 28 and pressure oil supply hose 50
a, 50b, and 50c pass through the inside of the base arm 3 through the fixed sheave 24, and from the inside of the base arm 3 to the outside surface 3d at the opening 3g located at the boundary between the outer surface 3d and the outer surface 3f.
Led to.

As described above, since a single fixed sheave 24A capable of simultaneously guiding a plurality of wire ropes and pressure oil supply hoses is used, the wire rope 28 and the pressure oil supply hoses 50a, 50b, 50c are connected to three. Step arm 5
Can be led compactly. Also, the base arm 3
Is formed in a two-stage structure, and the connection end 28a of the wire rope 28 and the connection end 51 of the pressurized oil supply hoses 50a, 50b, 50c can be collectively provided on the outer surface 3d of the base arm 3. Work is very easy during maintenance such as replacement of ropes and pressure oil supply hoses.

Next, another embodiment of a fixed sheave capable of simultaneously guiding a plurality of wire ropes and a pressure oil supply hose as described above will be described. FIG. 29 shows a telescopic arm using a fixed sheave of another embodiment, which will be described below with reference to FIG. First, the sheave 24a for the pressure oil supply hose 50a of the clam bucket, the sheave 24b for the pressure oil supply hose 50b, 50c of the hydraulic cylinder 10, and the sheave 24c
And a predetermined number of sheaves 24d for the wire ropes 28 are provided, and the individual sheaves 24a, 24b, 24c, 24
d are arranged adjacently on the same rotation axis. At this time, the sheave 24a and the sheaves 24b and 24c and the sheave 24d are each independently rotatable, and the radius of rotation may be the same or different. With this configuration, each pressure oil supply hose and wire rope are
6 and FIG. 27, the guide can be compactly guided from the base arm 3 to the third arm 5 via the fixed sheaves 24a, 24b, 24c, 24d.

Next, an example of improving the maintainability of a wire rope and a pressure oil supply hose in the case of a four-stage telescopic arm will be described with reference to FIG. Here, the arrangement configuration of the fixed sheave 24A and the hydraulic cylinder 10 related to the maintainability of the wire rope and the pressure oil supply hose, which is the purpose of the description of the present example, will be described, and illustration and description of other configurations will be omitted. Fixed sheave 24A
Is the same as the single fixed sheave 24A shown in FIGS. 26 and 27 of the fourth embodiment, which can simultaneously guide a plurality of wire ropes and a pressure oil supply hose. The hydraulic cylinder 10 includes the fourth stage arm 6 at the final stage and the third arm
It is built into the step arm 5. The rod attachment end 10a of the hydraulic cylinder 10 is attached to the lower part of the fourth stage arm 6,
On the other hand, the tube mounting end 10 b of the hydraulic cylinder 10 on the side opposite to the rod is mounted on the upper end of the third-stage arm 5.

The operation of this embodiment is as follows. Since the tube of the hydraulic cylinder 10 is attached inside the third-stage arm 5, the hose 5 for supplying the hydraulic oil to the hydraulic cylinder 10
The processing of 0b and 50c is the same as the case of the three-stage telescopic arm. Further, the processing of the pressure oil supply hose 50a to the clam bucket 7 can be similarly performed. Therefore, even in the case of the four-stage telescopic arm, the wire rope 28 and the pressure oil supply hose 50a,
50b, 50c, and 50d can be compactly guided from the base arm 3 to the third arm 5 by the fixed sheave 24A. In this embodiment, the operation and the effect are not changed even if a trunnion type mounting structure is used as in the previous embodiment.

In the case of a multistage telescopic arm having four or more stages, a hose (for example, a hose for supplying pressure oil to hydraulic equipment (eg, a clam bucket 7 or a hydraulic cylinder for telescopic drive) disposed in the fourth and subsequent stages). For example, the pressurized oil supply hoses 50b and 50c and the pressurized oil supply hose 50a) need to expand and contract in accordance with the expansion and contraction of the arm. Therefore, it is necessary to provide a hose reel in order to make the hose that supplies the pressure oil to the fourth and subsequent stages extend and contract. FIG. 31 shows another embodiment.
A schematic side view of an example in which a hose reel 52 for this purpose is provided on the outer surface 3d at the lower portion of the base arm 3 is shown. conventionally,
As shown in FIG. 32, since the hose reel 52 is provided at the upper end of the second-stage arm 4, the total arm length at the time of the maximum extension and the minimum contraction of the hose in accordance with the extension of the second and subsequent arms. Will be extended by a length corresponding to the difference between. Therefore, conventionally, a hose reel large enough to wind up a hose corresponding to this length has been used. On the other hand, when the hose reel 52 is provided on the base arm 3 as in this example, it is only necessary to wind up the hose corresponding to the stroke length when the fourth and subsequent arms are extended. Therefore, the hose reel can be downsized, and as a result, the hose processing apparatus can be made compact and the arm can be reduced in weight.

[0082]

According to the present invention, the last stage arm and the arm immediately before it are driven to expand and contract by a drive device built in these arms, and the diameter of at least the lower part of the immediately preceding arm is raised to a diameter larger than the inner width of the arm. Since the wire sheave is mounted, the diameter of the wire rope and the radius of curvature of the wire rope can be increased as compared with the related art. As a result, the life of the wire rope is dramatically increased, so that the replacement interval of the wire rope due to breakage is extended, and the maintainability is improved.

Since the upper portion of the base arm is removed from the boom mounting portion, the weight of the multi-stage telescopic arm can be reduced, and the bucket capacity can be increased. As a result, work efficiency is improved, and productivity can be increased.

Since the two pulling wire ropes are connected to the equalizer bar via the two pulling sheaves, when the life of one of the wire ropes becomes short, the inclination angle of the equalizer bar increases, and this tilting angle increases. The angle can be visually observed or detected by a detector. Thus, it is possible to determine that the life of the wire rope is near, and to replace the wire rope before breaking. Therefore, it is safe to prevent the bucket or the like from dropping, and it is possible to improve the workability when replacing the wire rope by using the wire rope that is not broken.

Further, since the upper portion of the base arm is removed and the second arm is projected from the upper portion, a mark or the like is provided on the outer side surface of the second arm so as to indicate the depth of the excavation groove. The workability during excavation can be improved, and the degree of operator fatigue can be reduced. Therefore, productivity can be improved. Further, since the upper portion of the base arm is eliminated, the weight of the multi-stage telescopic arm can be reduced, thereby increasing the bucket capacity. As a result, work efficiency is improved, and productivity can be increased.

In the above-described three-stage telescopic arm or four-stage telescopic arm, when a hydraulic cylinder is used as a driving device, a tube of the hydraulic cylinder is attached to the third-stage arm, and a plurality of wire ropes and pressure oil supply are provided. Since the fixed sheave capable of simultaneously guiding the hose is provided at the upper end of the second arm, the wire rope and the pressure oil supply hose can be compactly guided from the base arm to the third arm. Thereby, the sheave installation space is reduced, and the maintainability and maintainability of the wire rope and the pressure oil supply hose are improved.

In the above-mentioned three-stage telescopic arm, when a trunnion type hydraulic cylinder is used as the driving device, when the arm is in the most contracted state, the hydraulic cylinder mounting portion, the wire rope connecting portion at the upper end of the third stage arm, and Fixed sheaves at the upper end of the second stage arm gather at the upper part of the arm. As a result, the maintenance and inspection work range is concentrated at one place, so that maintainability and maintainability are greatly improved.

Further, the outer surface of the base arm has a two-stage structure, a portion where the outer surfaces of the two stages do not overlap is provided, and a connection end of a wire rope or a pressure oil supply hose is provided on the outer surface of the base arm in this portion. Therefore, the maintainability and maintainability of the wire rope and the pressure oil supply hose can be improved.

When the arm is extended, the upper end of the second arm extends into the lower part of the base arm, so that the minimum length of the multistage telescopic arm can be shortened. Therefore, when loading excavated soil on a dump truck or the like, the turning radius of the arm is reduced, and turning operability is improved. At this time, pads are provided on the upper and lower ends of the inner surface of the base arm to prevent the second arm from swinging even when the upper end of the second arm enters the lower part of the base arm. Thereby, the arm expansion and contraction operation can be stably performed, the work efficiency can be improved, and the productivity can be improved.

In a multi-stage telescopic arm having four or more stages, a hose reel is provided on the base arm and a hose sheave is provided on the second stage arm, so that the hose length can be shortened, the hose reel can be downsized, and the arm can be lightened. Can be As a result, the bucket capacity can be increased, and the productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a side view of a four-stage telescopic arm representing a first embodiment according to the present invention.

FIG. 2 is a view as viewed in the direction X in FIG. 1 of the first embodiment according to the present invention.

FIG. 3 is a side view of a four-stage telescopic arm showing another example of a sheave position of the first embodiment.

FIG. 4 is a U view of FIG. 3 of the first embodiment.

FIG. 5 is a cross-sectional view taken along line CC of FIG. 3 of the first embodiment.

FIG. 6 is a side view of a three-stage telescopic arm representing another multistage example of the first embodiment.

FIG. 7 is a Y view of FIG. 6 of the first embodiment.

FIG. 8 is a side view of another example of the driving device of the first embodiment.

FIG. 9 is a sectional view taken along line AA of FIG. 8 of the first embodiment.

FIG. 10 is a side view of another example of the driving device of the first embodiment.

FIG. 11 is a sectional view taken along line BB of FIG. 10 of the first embodiment.

FIG. 12 is a side view of another example of the driving device of the first embodiment.

FIG. 13 shows a Z view of FIG. 12 of the first embodiment.

FIG. 14 is a schematic side view of a multi-stage telescopic arm according to a second embodiment of the present invention.

FIG. 15 shows a W view of FIG. 14 of the second embodiment according to the present invention.

FIG. 16 is a side view of a multi-stage telescopic arm according to a third embodiment of the present invention.

FIG. 17 is a side view of the multistage telescopic arm representing the third embodiment (a state close to the most contracted state).

FIG. 18 is an example of a mark, a character, a numeral, and the like of a guide of the excavation depth in the third embodiment.

FIG. 19 shows a state before the start of excavation work in the third embodiment.

FIG. 20 shows a state where the excavation depth has been reached in the third embodiment.

FIG. 21 is a side view of a four-stage telescopic arm showing another example of a driving position of the first embodiment.

FIG. 22 is a side view of a three-stage telescopic arm showing another example of the third embodiment.

FIG. 23 is a view as viewed from T in FIG. 22 of the third embodiment.

FIG. 24 is a sectional view taken along line DD of FIG. 23 of the third embodiment.

FIG. 25 is a comparative diagram showing the operation of the example of FIG. 22 of the third embodiment with the related art.

FIG. 26 is a side view (close to the most contracted state) of a multi-stage telescopic arm according to a fourth embodiment of the present invention.

FIG. 27 is a diagram illustrating a sheave of a multi-stage telescopic arm according to a fourth embodiment.

FIG. 28 shows a V view of FIG. 26 and a side view of the fourth embodiment.

FIG. 29 is a diagram illustrating another sheave example of the fourth embodiment.

FIG. 30 is a diagram illustrating a hydraulic cylinder of a four-stage telescopic arm according to a fourth embodiment.

FIG. 31 is an explanatory diagram of an example of a mounting position of a hose sheave according to a fourth embodiment.

FIG. 32 is an explanatory view of a conventional example for comparing hose hose mounting positions of the fourth embodiment.

FIG. 33 is a diagram for explaining a state of excavation work using a multi-stage telescopic arm according to the related art.

FIG. 34 is a side view of a multi-stage telescopic arm according to the related art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Construction machine, 2 ... Boom, 3 ... Base arm, 3c ... Upper part, 3d ... Base arm two-stage structure outer surface (inside), 3f ... Base arm two-stage structure outer surface (outside), 3g ... Boom mounting part ,
3h: Lower part, 4: Second stage arm, 4a, 5a: Hole, 5 ...
3rd stage arm, 6 ... 4th stage arm, 7 ... bucket, 8 ...
Lower traveling body, 9: upper revolving superstructure, 10: hydraulic cylinder, 1
0a: rod attachment end, 10b: tube attachment end, 11,
12, 21, 22, 23, 24 ... fixed sheave, 13, 1
4, 25, 26, 27, 28, 36, 37 ... wire rope, 24a, 24b, 24c, 24d ... sheave, 25
a, 25b, 26a, 26b, 27a, 27b, 28
a, 28b, 51 connection end, 30 rack, 31 pinion, 32, 35, 39 drive motor, 33 chain, 34 sprocket, 38 winch, 40 equalizer bar, 41 stopper, 42 detection 43, support shaft, 45, mark, 50a, 50b, 50c, pressure oil supply hose, 52, hose reel, 60, drive device, 71, 72
... guard, 73, 74, 75, 76 ... pad, G. L ...
Ground surface.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E02F 3/39 E02F 3/413 E02F 5/02

Claims (9)

(57) [Claims] 1. A multi-stage telescopic arm of a construction machine for excavation of a deep foundation, comprising: a driving device (60) which telescopically drives between a last stage arm and an arm immediately before the last stage arm; At least at the bottom of the arm just before the last stage,
A multi-stage telescopic arm for a construction machine for deep foundation excavation, comprising: pulling sheaves (21) and (22) having a diameter equal to or greater than the inner width of the arm immediately before the last stage. 2. A base arm mounted via a boom mounting portion (3g) to a distal end portion of a boom (2) that can swing vertically.
(3) A multi-stage telescopic arm of a construction machine for deep foundation excavation having a driving device (60) which telescopically drives between adjacent arms after the second stage and which is built in these arms; Raising sheaves (21), (22) which are provided at least below the above-mentioned arms in which (60) is built-in, and have a diameter equal to or greater than the inner width of these arms, and an arm above the boom mounting part (3g) A multistage telescopic arm for a construction machine for excavating a deep foundation, comprising: a base stage arm (3) from which a main body (3c) is deleted. 3. At least two lifting sheaves (2)
One end is fixed to the arm and the other end is two wire ropes (21, 21) and (22, 22) guided by the two pulling sheaves (21, 21) and (22, 22). 25, 25), (26, 26), and the two wire ropes (25, 2) attached to the arms (3), (4),
5) and (26,26) are fixed at the other end, and equalize a bar (40) for equalizing the load applied to the two wire ropes (25,25) and (26,26). 3. The construction machine according to claim 1, further comprising a stopper (42) for stopping rotation of the equalizer bar (40) when the (40) rotates by a predetermined angle. Multi-stage telescopic arm. 4. The multi-stage telescopic arm of a construction machine for excavating a deep corner according to claim 1, 2 or 3, wherein the second stage arm from an upper portion of the arm (3c) when the arm is reduced.
A base arm (3) protruding from the upper part of (4), and a second-stage arm (4) with at least one of markings, letters, and / or numbers indicating or indicating the excavation depth on the side of the arm. A multistage telescopic arm for a construction machine for deep foundation excavation, comprising: 5. The multistage telescopic arm of a construction machine for excavating a deep foundation according to claim 1, 2, 3 or 4, wherein the drive unit (60) has a tube mounting end (10b) having a third stage arm (5). ), Wherein the multi-stage telescopic arm is provided with a plurality of pressure oil supply hoses and wire ropes on a circumference provided in parallel and separated from each other in the direction of the rotation center axis. And at least a pressure oil supply hose (50b) (50c) to the hydraulic cylinder (10), and a wire rope (28) for pushing down the arm and the clam bucket (7). Connect at least one of the pressure oil supply hoses (50a) to the base arm
A sheave (24A) leading from (3) to the inside of the third arm (5),
A multi-stage telescopic arm for a construction machine for deep foundation excavation, comprising (24a to 24d). 6. The multi-stage telescopic arm according to claim 5, wherein the multi-stage telescopic arm is a three-stage telescopic arm, and the driving device (60) is a trunnion-type hydraulic cylinder (10). A multi-stage telescopic arm for a construction machine for deep foundation excavation, characterized in that: 7. A multi-stage telescopic arm for a construction machine for deep foundation excavation according to claim 1, wherein a step is provided on one surface of the base arm (3), and an outer surface (3d) inside the arm. A multistage telescopic arm for a construction machine for excavating a deep foundation, wherein a connection end of a wire rope (28) and / or a pressure oil supply hose (50a) (50b) (50c) is provided thereon. 8. The multi-stage telescopic arm according to claim 7, further comprising a base arm (3) into which the upper end of the second-stage arm (4) enters into the lower part when the arm is extended. And base arm
The upper surface of the base arm (3) from the position below the upper end of the second stage arm (4) when the arm is fully extended so that the inner surface of (3) is in contact with the outer surface of the second stage arm (4). A multi-stage telescopic arm for a construction machine for excavating a deep foundation, comprising: a pad (78) provided continuously up to and a pad (77) provided at an upper end of a base arm (3). 9. The multi-stage telescopic arm according to claim 1, wherein the multi-stage telescopic arm is a telescopic arm having four or more stages, and is provided on the base stage arm (3). And a hose sheave provided in a second arm (4) for receiving the hose from the hose reel (52) and guiding the hose to the fourth and subsequent arms. Multi-stage telescopic arm for construction equipment for deep foundation excavation.