TW201433676A - Multi-stage telescopic arm device and deep-digging excavator comprising multi-stage telescopic arm device - Google Patents

Abstract

A telescopic arm (12), comprising an outer cylinder (13) and multiple stages of inner cylinder (21, 23), is provided on the distal end of a boom (4). The outer cylinder (13) has a telescopic cylinder (25) disposed thereon and telescopic stationary sheaves (31, 31') fixed thereon. The telescopic cylinder (25) is mounted on the outer cylinder (13) with a rod (25B) facing upward, and moves along the outer cylinder (13) with a tube (25A) as a free end. The tube (25A) of the telescopic cylinder (25) is provided with a sheave mounting fixture (30), and the sheave mounting fixture (30) is provided with telescopic movable sheaves (33, 33'). An expansion and contraction rope (34, 34') is wound on the telescopic stationary sheaves (31, 31') and the telescopic movable sheaves (33, 33').

Description

Multi-stage telescopic arm device and deep excavator with multi-stage telescopic arm device

The present invention relates to, for example, a multi-stage telescopic arm device suitable for ground deep excavation work in civil engineering and a deep excavation type excavator having a multi-stage telescopic arm device.

In general, in the case of deep excavation of the ground to form a vertical pit in civil engineering, a deep excavation type excavator is applied. The deep excavation type excavator includes a self-propelled vehicle body, a crane boom provided for the pitching motion of the vehicle body, and a plurality of telescopic arm devices provided on the front end side of the crane boom. The multi-stage telescopic boom device includes a telescopic arm having an outer cylinder extending in the vertical direction and a plurality of inner cylinders, a telescopic fixing sheave fixedly disposed on the outer cylinder, and a telescopic cylinder disposed along the longitudinal direction of the outer cylinder. A sheave attachment that is attached to the telescopic cylinder and that is movable in the longitudinal direction, and a movable sheave that is provided in the reel for the sheave attachment, one end side of which is locked to the outer cylinder and the other end of which is locked to the inner cylinder and is halfway The part is wound around the telescopic fixing sheave and the telescopic cable for the telescopic movable sheave. In addition, a clamshell grab for earth and sand excavation is installed at the front end of the inner cylinder.

The deep excavation type excavator of the prior art is that the telescopic arm provided on the front end side of the crane boom is kept perpendicular to the ground, and the telescopic cylinder is reduced, whereby the inside of the telescopic arm can be made The barrel is extended downward from the outer tube. Therefore, the excavator can perform the excavation work of the soil sand using the clamshell type grab which is attached to the front end portion (lower end portion) of the inner cylinder.

After holding the earth sand excavated by the clamshell grab, the telescopic cylinder is extended, whereby the inner cylinder and the clamshell grab are pulled up into the outer cylinder by the telescopic cable. In this state, the excavator's upper revolving body is rotated toward a predetermined earthing position, and the clamshell type grapple is opened to perform the earthing operation of the excavated earth sand (refer to Patent Document 1).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Laid-Open Patent Publication No. 62-82131

However, in the above-described deep excavation type excavator, the pipe of the telescopic cylinder is an outer cylinder mounted on the telescopic arm, and the rod of the telescopic cylinder protrudes downward from the pipe. Therefore, the sheave attachment (slinger) for supporting the movable sheave for telescopic movement is attached to the lower end of the rod.

Therefore, in the conventional excavation type excavator, when the clamshell type grab is pulled up, the rod of the telescopic cylinder is extended downward to move the sheave mounting device downward. In this way, the telescopic cable will be wound up. The movable sheave for supporting the expansion and contraction of the sheave attachment and the telescopic fixed sheave fixed to the outer cylinder can pull the inner cylinder into the outer cylinder.

However, the structure of the deep excavation type excavator of the prior art, the pipe of the telescopic cylinder is mounted on the outer cylinder. Therefore, by extending the rod from the pipe of the telescopic cylinder downward, the sheave attachment can be moved downward, and the telescopic cable can be wound between the telescopic movable sheave and the telescopic fixed sheave. The clamshell grab can be pulled up. Therefore, according to this prior art, when the clamshell grab is pulled up, although the weight of the sheave attachment is applied to the telescopic cable, the weight of the telescopic cylinder does not act on the telescopic cable. . Therefore, the deep excavation type excavator of the prior art cannot utilize the weight of the tube of the telescopic cylinder as the pulling force when the soil sand excavated by the clamshell grab is pulled up into the outer cylinder together with the inner cylinder. Therefore, there is a problem in that the operation of pulling up the inner cylinder by the telescopic cylinder cannot be performed efficiently.

The present invention has been developed in view of the above problems of the prior art, and an object of the present invention is to provide a multi-stage telescopic arm device and a deep excavation type excavator having a multi-stage telescopic arm device which are manufactured by elongating a telescopic cylinder When the inner cylinder is pulled up, the pull-up force of the inner cylinder can be increased by utilizing the weight of the pipe of the telescopic cylinder.

(1) The present invention is applicable to a multi-stage telescopic boom device, comprising: a crane boom having an object to be mounted; an outer cylinder extending in a vertical direction of a front end side of the crane boom; a telescopic arm of a plurality of inner cylinders that can expand and contract in the longitudinal direction on the inner side of the outer cylinder; and an expansion and contraction along the longitudinal direction of the outer cylinder constituting the telescopic arm a cylinder fixed; a telescopic fixing sheave fixedly disposed on the outer cylinder; and a sheave mounting device mounted on the telescopic cylinder to move in a longitudinal direction of the outer cylinder so as to be close to or away from the telescopic fixing sheave a movable sheave for telescopic movement of the sheave attachment; one end side of the inner cylinder is locked to the outer cylinder and the other end side is an inner cylinder that is locked in the innermost side of the inner cylinder, and the middle portion is It is configured by winding the telescopic cable for the telescopic fixed sheave and the movable sheave for expansion and contraction.

The structure adopted in the present invention is characterized in that the telescopic cylinder has: a pipe; one side of the pipe is fixed to the piston in the pipe, and the other side is a hydraulic pressure of the rod protruding from the pipe to the outside. In the state in which the rod of the telescopic cylinder is facing upward, the front end portion of the rod is attached to the outer tube of the telescopic arm, and the tube of the telescopic cylinder is a free end, and the groove is mounted. The tool is a pipe that is mounted on the telescopic cylinder.

According to this configuration, when the inner cylinder to which the excavating tool is attached is pulled down, the rod is pulled into the tube of the telescopic cylinder to narrow the telescopic cylinder. In this state, the telescopic movable sheave that is supported by the sheave attachment moves upward, and approaches the telescopic fixing sheave that is fixed to the outer cylinder. Therefore, the cable for stretching and contracting which is originally wound around the fixed sheave for expansion and contraction and the movable sheave for expansion and contraction is released, and the inner cylinder which is locked at the other end side of the telescopic cable can be extended toward the outside of the outer cylinder. On the other hand, in the case where the inner cylinder to which the excavating tool is mounted is pulled up, the rod is protruded from the pipe to elongate the telescopic cylinder. In this state, the movable sheave of the telescopic support supported by the sheave attachment is facing downward. Move away from the telescopic fixed sheave that is fixed to the outer cylinder. Therefore, the telescopic cable is wound between the telescopic fixed sheave and the movable sheave for stretching, and the inner cylinder that is locked at the other end side of the telescopic cable is pulled toward the inside of the outer cylinder, so that The telescopic arm can be made smaller.

In this case, the rod of the telescopic cylinder is in an upward state, and the front end portion of the rod is attached to the outer cylinder. Therefore, when the telescopic cylinder is extended, the pipe material which is itself a weight is moved downward together with the sheave attachment, and is wound by the telescopic cable for the telescopic movable sheave and the telescopic fixed sheave. The inner cylinder is pulled up toward the inside of the outer cylinder. In this case, the downwardly loaded load generated by the weight of the pipe and the sheave mounting device acts on the pipe body. Therefore, the weight of the pipe and the sheave mounting device can be utilized to increase the pulling force of the inner cylinder, so that the action of pulling the inner cylinder upward by the telescopic cylinder can be performed efficiently.

(2) According to the structural feature of the present invention, the front end portion of the rod member of the telescopic cylinder is attached to the upper side of the outer cylinder.

In this way, the pipe of the telescopic cylinder to which the sheave attachment is attached can be moved in the vertical direction in the vicinity of the upper half of the outer cylinder extending in the vertical direction. Therefore, for example, when the vertical pit is dug, even if the lower half of the outer cylinder is submerged, the operator on the side of the vehicle body provided with the crane boom can visually confirm the expansion and contraction movement of the telescopic cylinder, etc. It can improve the workability and safety of excavation work.

(3) According to the structural feature of the present invention, the outer side of the outer cylinder is provided to be parallel to the outer cylinder The sheave attachment rail that is attached to the outer cylinder is extended, and the sheave attachment moves along the sheave attachment rail in accordance with expansion and contraction of the telescopic cylinder.

According to this configuration, when the telescopic cylinder is used to move the sheave attachment, the sheave attachment is guided by the sheave attachment rail and can always be moved on a certain track. As a result, the telescopic cable that is wound around the fixed telescopic retaining sheave and the retractable movable sheave can smoothly follow the movement of the telescopic movable sheave supported by the sheave attachment, and can lift the inner cylinder to the outer cylinder. The stability of the telescopic action. Moreover, the strength of the outer cylinder can be increased by the sheave mounting rail provided on the outer cylinder, so that the overall reliability of the telescopic arm can be improved.

On the other hand, the pipe to which the sheave mounting device is mounted can also be moved along a sheave mounting rail on a certain track. As a result, the frustration strength of the telescopic cylinder and the strength against the lateral load can be increased, thereby improving the reliability of the telescopic cylinder.

(4) According to a structural feature of the present invention, a pair of crane boom brackets are provided on a lower side of the outer cylinder than the aforementioned sheave mounting device, and the pair of crane boom brackets are The front and rear sides of the crane boom are oscillated in the left-right direction at intervals, and the pipe of the telescopic cylinder is disposed in a gap formed between the pair of crane boom brackets.

According to this configuration, the telescopic cylinder is disposed in a gap formed between one of the outer sides of the outer cylinder and the crane boom bracket, so that the telescopic cylinder can be visually viewed from the side of the vehicle body provided with the crane boom A sheave attachment for a pipe of a telescopic cylinder, a movable sheave for telescopic support supported by a sheave attachment, and a telescopic cable for winding the telescopic fixed sheave and the movable sheave for expansion and contraction. In this way, the operator on the vehicle body side can surely perform the operation of expanding and contracting the inner cylinder to the outer cylinder while directly viewing the telescopic cylinder or the like.

On the other hand, among the side faces of the outer cylinder, on the side opposite to the side on which the crane boom bracket is provided, that is, on the side on the side opposite to the vehicle body, it is not necessary to provide a telescopic cylinder. , fixed sheave for telescopic movement, sheave attachment, and movable sheave for telescopic movement. Therefore, when excavating the vertical pit or the like, the damage of the member such as the telescopic cylinder and the obstacle does not occur, and the workability of the excavation work can be improved.

Moreover, in order to hold the multi-stage telescopic arm device in the transport position and place the outer cylinder on the ground, the other side of the outer cylinder opposite to the side on which the crane boom is mounted may be placed on the ground. . In this way, when the outer cylinder is placed on the ground, the telescopic cylinder, the sheave attachment, the telescopic fixed sheave, and the movable sheave for telescopic movement can be held without using a separate storage table or the like. Let the weight of the telescopic arm act on the upward facing position of these members.

Therefore, in a state in which the multi-stage telescopic boom device is held in the transport posture, the telescopic cylinder attached to the outer cylinder, the telescopic fixed sheave, the sheave mounting device, and the movable sheave for telescopic movement can be executed at a position closer to the ground. Maintenance work such as this can improve the workability of such maintenance work.

(5) According to the structural feature of the present invention, a pipe guide member is provided on the outer side of the outer cylinder, and the pipe guide member accommodates the pipe in a manner that allows the pipe of the telescopic cylinder to move. And guiding the tube in the longitudinal direction of the outer cylinder.

According to this configuration, the free end side of the pipe material of the telescopic cylinder is guided by the pipe guide in the longitudinal direction of the outer cylinder, so that the pipe to which the sheave mounting device is attached can be smoothly and smoothly moved. Therefore, the tubing of the telescopic cylinder can be moved along a certain direction of the rail guide to increase the strength of the telescopic cylinder and the strength against the lateral load. Further, by accommodating the tube in the tube guide, it is possible to protect the tube from being damaged by falling stones or the like when excavated.

(6) According to the structural feature of the present invention, the outer cylinder is formed in a rectangular tubular shape having a polygonal cross-sectional shape, and has at least a side surface which is attached to the front end side of the crane boom, and is in the front-rear direction. a left side surface and a right side surface facing the left side in the left-right direction, and a left side surface which is inclined obliquely between the rear side surface and the left side surface, which are opposed to the rear side surface, and the rear side surface and the front side surface a right inclined surface that is obliquely disposed obliquely between the rear side surface and the right side surface, and the movable sheave for stretching and contracting is disposed on the outer side in the left-right direction as compared with the left side surface and the right side surface constituting the outer tube At the office.

According to this configuration, the outer cylinder is formed into a cylindrical shape having a polygonal cross-sectional shape, and the left and right inclinations are provided between the rear side surface and the left and right side surfaces which are attached to the front end side of the crane boom. Therefore, it is possible to increase the frustration strength against the load acting on the outer cylinder. As a result, It can extend the life of the outer cylinder and improve the reliability of the telescopic arm.

Further, the movable sheave for expansion and contraction supported by the sheave attachment is disposed at the outer side in the left and right directions of the left side surface and the right side surface of the outer cylinder, thereby suppressing the movable movement for expansion and contraction. The sheave presents a large protrusion on the side of the rear side of the outer cylinder. As a result, even when a movable sheave for expansion and contraction of a large-diameter sheave is used, the circumference of the movable sheave for expansion and contraction can be reduced in size. Therefore, it is possible to use a large-diameter sheave for expansion and contraction. The movable sheave can be used to extend the life of the telescopic cable.

Since the structure for extending the life of the telescopic cable can be used, the load acting on the telescopic cable can be set to be large. As a result, the capacity of the clamshell type grab can be mounted on the inner cylinder connected to the telescopic cable can be made large, and a large amount of soil sand can be excavated.

(7) According to the structural feature of the present invention, the outer cylinder is formed in a rectangular tubular shape having a hexagonal cross-sectional shape, and the hexagonal cross-sectional shape is mounted on the front end side of the crane boom a side surface, a front side surface that faces the rear side surface in the front-rear direction, a left side surface and a right side surface that face each other in the left-right direction with the rear side surface and the front side surface interposed therebetween, and an oblique direction between the rear side surface and the left side surface The left inclined surface that is disposed obliquely is formed by a right inclined surface that is obliquely disposed obliquely between the rear side surface and the right side surface. In this way, the frustration strength against the load acting on the outer cylinder can be increased, and the life of the outer cylinder can be prolonged.

(8) According to the structural feature of the present invention, the first outer section of the outer cylinder and the inner cylinder of the plurality of sections is located at the outermost side Between the cylinders, an ejection mechanism is provided. When the first inner cylinder is extended from the outer cylinder by using the telescopic cylinder, the first inner cylinder is pushed out in an extending direction; the ejection mechanism is: a lower side of the outer cylinder, the push-out fixing sheave provided in the outer cylinder, and a lower movable side of the telescopic movable sheave, and a movable sheave for pushing out the sheave attachment, One end side is locked to the outer tube, and the other end side is locked to the first inner tube by the inner side of the outer tube, and the intermediate portion is wound around the push-out fixing groove wheel and the aforementioned push-out A wire for pushing out the movable sheave is provided at a position where the push-out fixing sheave is provided on a lower side of the outer cylinder, and a groove mounting opening is provided, and a part of the push-fixing sheave is passed through The groove mounting opening is disposed inside the outer cylinder.

According to this configuration, even if the diameter of the push-out fixing sheave is set to be large, the push-out fixing sheave can be tightly attached to the outer cylinder. As a result, a large-diameter fixed sheave for pushing out can be used, and the life of the push-out cable can be extended.

Further, in comparison with a conventional structure in which the fixing groove is disposed at the lower end portion of the outer cylinder, when the first inner cylinder is housed in the outer cylinder, the first protruding from the lower end portion of the outer cylinder can be reduced. The amount of protrusion of the lower end of a section of the inner cylinder. As a result, the total length when the telescopic arm is minimized can be shortened, and for example, when the deep excavator is conveyed, it can be held in a compact conveying posture.

(9) The present invention is applicable to: a deep excavation type excavator, which is provided with: a self-propelled vehicle body, which can be placed on the vehicle body a crane boom that is moved up, and a multi-stage telescopic arm device that is provided on a front end side of the crane boom; the multi-stage telescopic arm device includes a cylinder that extends in the vertical direction and is housed inside the outer cylinder a telescopic arm of a plurality of inner cylinders that can expand and contract in the longitudinal direction; a telescopic cylinder disposed along a longitudinal direction of the outer cylinder constituting the telescopic arm; and a telescopic fixing sheave fixedly disposed on the outer cylinder; a sheave attachment for moving the telescopic cylinder in a longitudinal direction of the outer cylinder so as to be close to or away from the telescopic fixed sheave; and a movable sheave for extending and contracting the sheave attachment; The outer cylinder is locked to the inner cylinder, and the other end side is an inner cylinder that is locked in the innermost portion of the inner cylinder, and the middle portion is a telescopic cable that is wound around the telescopic fixed sheave and the movable telescopic retractable sheave. And constituted.

Further, the present invention is characterized in that the telescopic cylinder is composed of a hydraulic cylinder having a pipe and a rod on one side of which is fixed to the piston, and the other side of which is a rod protruding outward from the pipe. In the state in which the rod of the telescopic cylinder is facing upward, the front end portion of the rod is attached to the outer tube of the telescopic arm, and the tube of the telescopic cylinder is regarded as a free end. It is a pipe installed in the above-mentioned telescopic cylinder.

According to this configuration, the rod constituting the telescopic cylinder is directed upward, and the front end portion of the rod is attached to the outer cylinder. Therefore, when the telescopic cylinder is extended, the pipe and the sheave mounting device, which are themselves heavy objects, will move downward together, and the telescopic cable is wound around the movable sheave for telescopic expansion and the fixed sheave for telescopic expansion. The inner cylinder is pulled up toward the inside of the outer cylinder. This situation Next, the downward load generated by the weight of the pipe and the sheave mounting device acts on the body of the pipe moving downward. Therefore, the weight of the pipe and the sheave attachment can be utilized to increase the pull-up force of the inner cylinder, and the pull-up operation of the inner cylinder by the telescopic cylinder can be performed efficiently.

2‧‧‧Lower driving body (body)

3‧‧‧Upper revolving body (body)

4‧‧‧ crane boom

12‧‧‧ Telescopic arm

13‧‧‧Outer tube

13A‧‧‧ rear side

13B‧‧‧ front side

13C‧‧‧Left side

13D‧‧‧ right side

13E‧‧‧Left inclined surface

13F‧‧‧Right slope

13G‧‧‧Upper

13H‧‧‧Bottom

16‧‧‧ Openings for sheave installation

17‧‧‧ Crane boom bracket

21‧‧‧The first inner tube

23‧‧‧The second inner cylinder

25‧‧‧ Telescopic cylinder

25A‧‧‧Tubing

25B‧‧‧ rods

26‧‧‧Tube guides

28‧‧‧Slotted wheel mounting rails

30‧‧‧Slot wheel mounting tools

31, 31'‧‧‧Fixed fixed sheave

33, 33'‧‧‧ movable trough for telescopic

34, 34'‧‧‧ Telescopic cable

35, 35'‧‧‧Support fixed sheave

38, 38'‧‧‧ Launching agencies

39, 39'‧‧‧ Launched with fixed sheave

41, 41'‧‧‧ Launched with movable sheave

42, 42'‧‧‧ Launched steel cable

Fig. 1 is a side view showing a state in which a deep excavation type excavator according to an embodiment of the present invention has its telescopic arm in a most reduced state.

Fig. 2 is a side view showing the state in which the excavator of the deep excavator has its telescopic arm in the most extended state.

Fig. 3 is a side view showing the multi-stage telescopic arm device of Fig. 1 in a single unit.

Fig. 4 is a front elevational view showing the multi-stage telescopic boom device viewed from the direction of arrows IV-IV in Fig. 3.

Fig. 5 is a perspective view showing a multi-stage telescopic arm device displayed in a single body.

Fig. 6 is an enlarged perspective view showing important parts such as the outer cylinder, the telescopic cylinder, the telescopic fixed sheave, the sheave attachment, the movable sheave for telescopic movement, and the sheave attachment rail in Fig. 5.

Fig. 7 is an enlarged perspective view showing important parts such as a sheave attachment, a movable sheave for telescopic movement, a movable sheave for push-out, and a guide rail for sheave.

Fig. 8 is an enlarged front elevational view showing an important part of the expansion/contraction fixed sheave or the like in Fig. 4 enlarged.

Figure 9 shows the telescopic mechanism of the telescopic arm being reduced by the telescopic arm. Schematic diagram shown.

Fig. 10 is a schematic view showing the telescopic mechanism of the telescopic arm in an extended state of the telescopic arm.

Fig. 11 is a cross-sectional view showing the telescopic boom, the crane boom bracket, and the like in the direction of the arrow XI-XI in Fig. 3.

Fig. 12 is a cross-sectional view showing the telescopic boom, the telescopic cylinder, the sheave attachment, the movable sheave for expansion and contraction, and the like from the direction of the arrow XII-XII in Fig. 3.

Fig. 13 is a cross-sectional view of the telescopic boom, the telescopic cylinder, the sheave attachment, the push-out movable sheave, and the like when viewed from the direction of the arrow XIII-XIII in Fig. 3.

Fig. 14 is a cross-sectional view showing the telescopic boom, the sheave mounting opening, the push-out fixing sheave, and the like when viewed from the direction of the arrow XIV-XIV in Fig. 3 .

Fig. 15 is a side view showing a state in which the excavator is held in the conveying posture and the telescopic arm is placed on the ground.

Fig. 16 is a front elevational view showing a modification in which a telescopic cylinder, a telescopic fixing sheave, a sheave attachment, a telescopic movable sheave, a sheave attachment rail, and the like are disposed on the front side surface side of the outer cylinder.

Hereinafter, an embodiment of the deep excavation type excavator of the present invention will be described in detail with reference to the drawings.

In Fig. 1, reference numeral 1 denotes a deep excavation type excavation of the present embodiment. The excavation type excavator 1 is a vehicle body including a crawler-type lower traveling body 2 that can be self-propelled, and a swingable upper revolving body 3 that is mounted on the lower traveling body 2. This vehicle body is an object to be attached to the multi-stage telescopic boom device 11 to be described later.

The upper revolving structure 3 is substantially composed of a swing frame 3A as a base, a cover 3B disposed on the left side of the front portion of the swing frame 3A, and a balance weight provided on the rear end side of the swing frame 3A. 3C, which is housed inside a casing cover 3D that is equipped with an engine, a hydraulic pump, etc. (all of which are not shown in the figure).

4 is a crane boom that can be used as a pitching motion provided on the front side of the upper revolving body 3. The base end side of the crane boom 4 is attached to the front side of the swing frame 3A, and a multi-stage telescopic boom device 11 to be described later is attached to the front end side of the crane boom 4. Between the crane boom 4 and the swing frame 3A, a crane boom cylinder 4A is provided, and by moving the crane boom cylinder 4A, the crane boom 4 performs a pitching operation with respect to the upper swing body 3. On the upper side of the crane boom 4, the bottom side of the excavating device swing cylinder 4B is attached, and the rod side of the excavating device swing cylinder 4B is attached to the multi-stage telescopic arm device 11.

Next, a multi-stage telescopic boom device 11 that is mounted on the front end side of the crane boom 4 for performing the excavation of the vertical pit in depth will be described.

11 is a multi-stage telescopic arm device that is attached to the front end side of the crane boom 4, and includes a telescopic arm 12, a telescopic cylinder 25, a sheave attachment 30, and a telescopic fixing sheave 31 which will be described later. The telescopic movable sheave 33 and the telescopic cable 34 are formed.

Reference numeral 12 denotes a telescopic telescopic telescopic boom that is attached to the front end side of the crane boom 4 and that can extend in the vertical direction. As shown in FIG. 9 and the like, the telescopic arm 12 is configured such that the outer cylinder 13 positioned at the outermost side and the inner circumferential side of the outer cylinder 13 can be expanded and contracted in the longitudinal direction (moving) The one-stage inner cylinder 21 is housed in the inner peripheral side of the first-stage inner cylinder 21 and is configured to extend and contract in the longitudinal direction to the second inner cylinder 23 which will be described later.

Here, as shown in FIGS. 11 to 14, the outer cylinder 13 is provided with a rear side surface 13A attached to the front end side of the crane boom 4 and a rear side surface 13A spaced apart from each other in the front-rear direction. The front side surface 13B facing the front side, the left side surface 13C and the right side surface 13D facing each other in the left-right direction with the rear side surface 13A and the front side surface 13B interposed therebetween, and the left side surface inclined obliquely between the rear side surface 13A and the left side surface 13C The inclined surface 13E is formed between the rear side surface 13A and the right side surface 13D so as to be obliquely inclined to the right inclined surface 13F. Therefore, the outer cylinder 13 as a whole is formed into a corner cylinder having a hexagonal cross-sectional shape.

Therefore, the outer cylinder 13 is provided between the rear side surface 13A and the left side surface 13C which are attached to the front end side of the crane boom 4, and is provided with a left inclined surface 13E, and is provided between the rear side surface 13A and the right side surface 13D. Right inclined surface 13F. As a result, the outer cylinder 13 constitutes a structure which can increase the frustration strength against the load acting on the outer cylinder 13. On the other hand, the upper end portion 13G and the lower end portion 13H of the outer cylinder 13 respectively form open ends.

The upper flange plate 14 is located at an intermediate portion in the longitudinal direction of the outer cylinder 13 and is integrally provided on the outer peripheral side of the outer cylinder 13. The following introduction One end 42A of the cable 42 is locked to this upper flange plate 14. On the other hand, the lower flange plate 15 is integrally provided at the lower end portion of the outer cylinder 13. One end 37A of the support cable 37 to be described later is locked to this lower flange plate 15.

On the lower side of the outer cylinder 13, left and right sheave mounting openings 16, 16' are provided. As shown in Fig. 14, the left-hand groove mounting opening 16 is formed at a portion where the left side surface 13C constituting the outer tube 13 and the left inclined surface 13E meet, and the right-hand groove mounting opening 16' is formed. A portion where the right side surface 13D of the outer cylinder 13 and the right inclined surface 13F meet. The sheave mounting openings 16, 16' are open to the inside of the outer cylinder 13, and the sheave mounting openings 16, 16' are inserted into a part of the push-out securing sheaves 39, 39' which will be described later.

Reference numeral 17 denotes a left and right pair of crane boom brackets provided on the outer side of the outer cylinder 13 at a lower portion of the sheave attachment 30 to be described later, and the pair of crane boom brackets 17 are mounted. On the front end side of the crane boom 4. Here, as shown in Fig. 5 and Fig. 11, a pair of crane boom brackets 17 are constituted by a plate body that faces each other with a space in the left-right direction, and a cylindrical crane crane Both sides of the arm connecting portion 17A in the left-right direction are fixed to the respective brackets 17. The pair of crane boom brackets 17 are integrally fixed to the rear side surface 13A of the outer cylinder 13 by means of fixing means such as welding, and the crane boom connecting portion 17A of the crane boom bracket 17 uses the bolt 18 (please refer to Fig. 1) is coupled to the front end side of the crane boom 4. Further, a gap 17B is formed between the pair of crane boom brackets 17, and the gap 17B is disposed in the gap 17B. Telescopic cylinder 25.

19 is a pair of left and right cylinder cylinders provided on the outer side of the outer cylinder 13 at a higher side than the crane boom bracket 17, and the pair of cylinder brackets 19 are mounted on the excavating device. The rod side of the cylinder 4B is swung. Here, the pair of cylinder brackets 19 are formed of a plate body that faces at intervals in the left-right direction, and includes a cylinder connecting portion for connecting the rod end portion of the excavating device swing cylinder 4B. . The pair of cylinder brackets 19 are integrally fixed to the rear side surface 13A of the outer cylinder 13 by means of fixing means such as welding, and are located beside the upper side of the crane boom bracket 17, and the excavating device swings the rod of the cylinder barrel 4B. The front end portion is a cylinder connection portion rotatably coupled to the pair of cylinder brackets 19 by using a bolt 20 (refer to FIG. 1).

Therefore, when the excavating device swing cylinder 4B is expanded and contracted, the outer cylinder 13 of the telescopic boom 12 swings in the front-rear direction or the vertical direction around the plug 18 on the front end side of the crane boom 4. Further, the cylinder bracket 19 will sometimes be disposed at a lower position than the crane boom bracket 17 due to the difference in the mounting position of the excavating device swing cylinder 4B.

Reference numeral 21 denotes a first-stage inner cylinder which is movably accommodated at the outermost position while maintaining a proper gap with the inner side of the outer cylinder 13. As shown in FIGS. 11 to 14, the first stage inner cylinder 21 has a quadrangular cross-sectional shape surrounded by the rear side surface 21A, the front side surface 21B, the left side surface 21C, and the right side surface 21D. The inner cylinder 21 is formed into a corner cylinder as a whole, and both ends in the up and down direction form an open end. In addition, inside The cylinder 21 is housed inside the outer cylinder 13 from the lower end portion 13H of the outer cylinder 13, and is movable in the longitudinal direction (vertical direction) with respect to the outer cylinder 13.

Here, between the inner side surface of the outer cylinder 13 and the outer side surface of the first inner cylinder 21, a sliding plate (not shown) is provided for making the inner cylinder 21 smoothly and smoothly along the outer cylinder 13. slide. On the other hand, a lower flange plate 22 is provided at a lower end portion of the inner cylinder 21, and a support fixing sheave 35 to be described later is attached to the lower flange plate 22.

Reference numeral 23 denotes a second-stage inner cylinder that is movably accommodated at the innermost position with an appropriate gap therebetween with the inner side of the first inner cylinder 21. This inner cylinder 23 is formed by a rear side surface 23A, a front side surface 23B, a left side surface 23C, and a right side surface 23D. The second stage inner cylinder 23 is formed into a rectangular cylinder having a quadrangular sectional shape smaller than the first inner cylinder 21. The second inner cylinder 23 is housed inside the inner cylinder 21 from the lower end side of the first inner cylinder 21, and is movable in the longitudinal direction (vertical direction) of the inner cylinder 21.

Here, between the inner side surface of the first inner cylinder 21 and the outer side surface of the second inner cylinder 23, a sliding plate (not shown) is provided for allowing the inner cylinder 23 to be along the inner cylinder 21 Smooth and smooth sliding. On the other hand, a mounting eye ring 24 is provided at the lower end portion of the inner tube 23, and a clamshell type grab 43 to be described later is attached to the mounting eye ring 24.

Next, the telescopic cylinder 25 of the present embodiment, the pipe guide 26 attached to the telescopic cylinder 25, the sheave attachment rail 28, the sheave attachment 30, and the like will be described.

Reference numeral 25 denotes a telescopic cylinder disposed along the longitudinal direction of the outer cylinder 13 constituting the telescopic arm 12. The telescopic cylinder 25 is a hydraulic cylinder that can be expanded and contracted by supplying or discharging hydraulic oil. The telescopic cylinder 25 is composed of a pipe 25A and a piston (not shown) slidably provided in the pipe 25A, one side of which is fixed to the piston in the pipe 25A, and the other side is the pipe 25A. It is formed by the rod 25B that protrudes to the outside.

Here, the telescopic cylinder 25 is on the side of the rear side 13A of the outer cylinder 13 on which the crane boom bracket 17 is provided, and is located at the center position of the outer cylinder 13 in the left-right direction, and is arranged such that the rod 25B faces The state on the top. As shown in Fig. 8, the distal end portion 25C of the rod 25B of the telescopic cylinder 25 is coupled to the bracket 13J provided at the side of the upper end portion 13G of the outer cylinder 13 by the plug 25D.

On the other hand, the pipe 25A of the telescopic cylinder 25 extends downward as a free end, and is disposed in a gap 17B formed between the crane boom brackets 17 that form a pair in the left-right direction. Further, on the upper side of the pipe member 25A, a sheave attachment 30 to be described later is attached. Therefore, by expanding and contracting the telescopic cylinder 25 between the most extended state shown in FIG. 1 and the most reduced state shown in FIG. 2, the pipe 25A can be along the outer cylinder 13 along with the sheave attachment 30. Move up and down.

Here, when the telescopic cylinder 25 is reduced to the most reduced state as shown in FIG. 2, the length dimension from the bottom portion 25A1 of the pipe 25A to the front end portion 25C of the rod member 25B (the position of the plug 25D) is minimized. The length dimension of the telescopic cylinder 25 in the state is L1, and it is assumed that the upper end portion 13G1 is attached from the upper end of the outer cylinder 13 (the rod 25B is coupled to the outer cylinder 13) When the length of the pin 25D (the length of the outer cylinder 13) is L2, the length L1 of the telescopic cylinder 25 in the most reduced state is set to the length of the outer cylinder 13 Nearly 1/2 of the length of L2.

In other words, the length dimension L1 of the telescopic cylinder 25 and the length dimension L2 of the outer cylinder 13 in the most reduced state are set in the relationship shown by the following formula (1).

More preferably, the length dimension L1 of the telescopic cylinder 25 and the length dimension L2 of the outer cylinder 13 in the most reduced state are set in the relationship shown by the following formula (2).

By setting the length L1 of the telescopic cylinder 25 in the most reduced state to the length dimension of the longitudinal dimension L2 of the outer cylinder 13 in this manner, the stroke of the telescopic cylinder 25 can be largely ensured. In this manner, the telescopic cable 34 is wound between the two fixed sheaves 31A and 31B of the telescopic fixed sheave 31 and the two movable sheaves 33A and 33B of the telescopic movable sheave 33, which will be described later. Four times, you can push out The contraction arm 12 expands and contracts between the most reduced state shown in Fig. 1 and the most extended state shown in Fig. 2 .

Reference numeral 26 denotes a pipe guide provided outside the rear side surface 13A of the outer cylinder 13, and the pipe guide 26 is a pipe 25A that movably houses the telescopic cylinder 25. As shown in Fig. 12 and Fig. 13, the pipe guide member 26 is formed by a corner cylinder having a substantially square sectional shape. The pipe guide 26 is disposed in the gap 17B formed between the pair of crane boom brackets 17, and is fixed to the rear side surface 13A along the longitudinal direction of the outer cylinder 13. Therefore, the pipe 25A which is the free end of the telescopic cylinder 25 can be moved toward the longitudinal direction of the outer cylinder 13 while being guided by the pipe guide 26.

A slide plate 27 is provided on the outer side surface of the bottom side of the pipe 25A of the telescopic cylinder 25. The pipe 25A of the telescopic cylinder 25 is fitted to the inner peripheral side of the pipe guide 26, and the slide plate 27 is moved along the inner side of the pipe guide 26. In this way, the pipe 25A can smoothly and smoothly move along the pipe guide 26 in the longitudinal direction of the outer cylinder 13.

Reference numeral 28 denotes two sheave attachment rails provided on the outer side of the outer cylinder 13, and the sheave attachment rail 28 is for guiding a sheave attachment 30 to be described later. The two sheave attachment rails 28 are disposed on the rear side surface 13A of the outer cylinder 13 with a telescopic cylinder 25 interposed therebetween and one on each of the right and left sides.

Here, the sheave attachment rail 28 is formed by a rectangular cylinder having a rectangular cross-sectional shape. The upper end portion of the sheave attachment rail 28 is fixed to the upper end portion 13G of the outer cylinder 13 by the bracket 28A, and the lower end portion of the sheave attachment rail 28 is by the bracket 28B. It is fixed to the vicinity of the upper flange plate 14 of the outer cylinder 13. As a result, the sheave attachment rail 28 is kept at a constant interval from the rear side surface 13A of the outer cylinder 13, and extends in the longitudinal direction in parallel with the rear side surface 13A. In this case, the two sheave attachment rails 28 composed of the corner cylinders are fixed to the outer cylinder 13, so that the strength of the outer cylinder 13 can be increased.

29 is a sheave mounting board that is fixed to the upper end portion 13G of the outer tube 13, and the sheave mounting board 29 is attached to the substrate by a telescopic fixing sheave 31, 31' or the like which will be described later. Here, the sheave mounting board 29 is provided with a sheave attachment portion 29A that projects from the rear side surface 13A of the outer cylinder 13 toward the rear side (the crane boom 4 side), and is located on the front side of the sheave mounting portion 29A. The cable lock portion 29B. The sheave attachment portion 29A of the sheave mounting plate 29 rotatably supports the telescopic fixing sheaves 31, 31', and the cable locking portion 29B is a telescopic cable 34, 34' which will be described later. One of the ends 34A, 34A' is locked there.

Reference numeral 30 denotes a sheave attachment to be attached to the tubing 25A of the telescopic cylinder 25 for attaching the telescopic movable sheaves 33 and 33' and the push-out movable sheaves 41, 41' to be described later. . Here, as shown in FIGS. 7 , 12 , and 13 , the sheave attachment 30 is provided by the main body portion 30A fixed to the upper side of the pipe 25A of the telescopic cylinder 25, and located at the main body portion 30A. The upper side of the upper movable sheave 33, 33' is rotatably supported, and is located on the lower side of the main body 30A, and rotatably supports the lower movable movable sheaves 41, 41' to be described later. The side sheave support portion 30C is formed. The groove wheel mounting tool 30 The body 30A is bent into a mountain shape to avoid the tube guide 26.

On the other hand, as shown in Fig. 12, the main body portion 30A of the sheave attachment 30 is provided with a left-right and right guide insertion portion 30D for the left and right sheaves. The guide rail 28 is slidably inserted into the left and right guide insertion portions 30D, and the sheave attachment 30 can receive the guide of the left and right sheave attachment rails 28 while being in the longitudinal direction of the outer cylinder 13. Move in the up and down direction.

Next, a description will be given of a structure for telescopically coupling the outer cylinder 13 constituting the telescopic arm 12 with the first inner cylinder 21 and the second inner cylinder 23, that is, the fixed sheave for telescopic expansion. 31, 31', movable sheaves 33, 33' for expansion and contraction, steel cables 34, 34' for expansion and contraction, fixed sheaves 35, 35' for support, and support cables 37, 37'.

Here, the telescopic fixing sheaves 31, 31', the telescopic movable sheaves 33, 33', the telescopic cables 34, 34', the supporting fixed sheaves 35, 35', and the supporting cables 37, 37' are The outer cylinder 13 is disposed so as to be bilaterally symmetrical with respect to the telescopic cylinder 25, and has the same configuration. Therefore, in the following description, only the telescopic fixing sheave 31, the telescopic movable sheave 33, the telescopic cable 34, the supporting fixed sheave 35, and the supporting cable 37 which are disposed on the left side of the outer cylinder 13 will be described. For the same member disposed on the right side, a single suffix "'" is added to the component symbol of the corresponding member, and the description thereof is omitted.

31 is a telescopic fixing sheave that is fixed to the upper end side of the outer cylinder 13 by the sheave mounting board 29, and the telescopic fixing sheave 31 is composed of two fixed sheaves 31A and 31B having the same diameter. of. As shown in Fig. 8, one of the fixed sheaves 31A is rotatably supported by a bracket 32A provided on one of the brackets 32 of the sheave mounting portion 29A of the sheave mounting board 29, and the other One of the fixed sheaves 31B is rotatably supported by the other bracket 32B. In this case, the support shafts (not shown) of the respective fixed sheaves 31A and 31B are arranged such that the rear side faces 13A of the outer cylinder 13 are not kept parallel.

Reference numeral 33 denotes a movable sheave for expansion and contraction that is rotatably supported by the sheave attachment 30. The movable sheave 33 for stretching and contracting is constituted by two movable sheaves 33A and 33B having the same diameter. Here, as shown in Fig. 12, one of the movable sheaves 33A and the other movable sheave 33B are adjacent to each other and rotatably supported by the upper sheave mounted on the sheave attachment 30. One of the support portions 30B is supported on the shaft 33C. In this case, the support shaft 33C of each of the movable sheaves 33A and 33B is disposed in a state in which the rear side surface 13A of the outer cylinder 13 is kept parallel. Since the telescopic movable sheave 33 is engaged with the expansion and contraction of the telescopic cylinder 25 and the shifting attachment 30 is moved in the vertical direction, the telescopic movable sheave 33 approaches or moves away from the telescopic fixing sheave 31.

The expansion/contraction movable sheave 33 supported by the sheave attachment 30 is disposed on the outer side of the left side surface 13C of the outer cylinder 13, and is spaced apart from the left side surface 13C by a slight interval, and is mutually spaced in the left-right direction. Opposite. In this way, the phenomenon that the movable sheave 33 for expansion and contraction largely protrudes toward the side of the rear side surface 13A of the outer tube 13 can be suppressed, and the periphery of the movable sheave 33 for expansion and contraction can be reduced in size.

Reference numeral 34 denotes a telescopic cable for connecting the outer cylinder 13 and the inner cylinder 23 located at the innermost side, and the telescopic cable 34 is composed of a steel wire rope. Here, as shown in FIG. 9 and FIG. 10, one end 34A of the telescopic cable 34 is a cable locking portion 29B that is locked to the sheave mounting substrate 29 provided on the upper end portion 13G of the outer cylinder 13 The other end 34B of the telescopic cable 34 is locked to the upper side of the second inner cylinder 23. Further, the intermediate portion of the telescopic cable 34 is wound between the two fixed sheaves 31A and 31B constituting the telescopic fixing sheave 31 and the two movable sheaves 33A and 33B constituting the movable sheave 33 for expansion and contraction. Hang four times.

In other words, the one end 34A of the telescopic cable 34 is locked to the sheave mounting board 29, and the intermediate portion of the telescopic cable 34 is sequentially wound around one of the movable sheaves 33A of the telescopic movable sheave 33, One of the fixed sheave 31A of the telescopic fixed sheave 31, the other movable sheave 33B of the telescopic movable sheave 33, and the other fixed sheave 31B of the telescopic fixed sheave 31. Further, the telescopic cable 34 is inserted into the outer cylinder 13 and the inner side of the first inner cylinder 21 from the other fixed sheave 31B of the telescopic fixed sheave 31, and the other end 34B of the telescopic cable 34 is locked. On the upper side of the inner cylinder 23 of the second stage.

In this manner, the telescopic fixed sheave 31 is configured by the two fixed sheaves 31A and 31B, and the telescopic movable sheave 33 is configured by the two movable sheaves 33A and 33B. Further, the telescopic cable 34 is wound four times in total on the two fixed sheaves 31A, 31B and the two movable sheaves 33A, 33B. In this way, if, for example, the party of the prior art In the case where the telescopic cable is compared between the four sheaves of the telescopic fixed sheave and the four sheaves of the telescopic movable sheave, and the structure is wound eight times in total, the structure of this type can be The number of times the telescopic cable 34 contacts the sheave is halved.

35 is a support fixing sheave which is provided in the lower flange plate 22 of the first stage inner cylinder 21. This support fixing sheave 35 is rotatably supported by a bracket 36 that is fixed to the lower flange plate 22 of the inner cylinder 21.

Reference numeral 37 denotes a support wire for supporting the inner tube 21 between the outer tube 13 and the inner tube 23, and the support cable 37 is composed of a steel wire cable. Here, as shown in Fig. 9 and Fig. 10, one end 37A of the support cable 37 is locked to the lower flange plate 15 of the outer cylinder 13, and the middle portion of the support cable 37 is wound around the support. The sheave 35 is fixed. Further, the support cable 37 is inserted into the inner side of the first inner cylinder 21 from the support fixed sheave 35, and the other end 37B of the support cable 37 is locked to the upper side of the second inner cylinder 23.

Next, an ejecting mechanism 38, 38' that pushes the first inner cylinder 21 in the extending direction when the inner cylinder 21 is extended from the outer cylinder 13 by the telescopic cylinder 25 will be described.

That is, between the outer cylinder 13 and the first inner cylinder 21, left and right ejection mechanisms 38, 38' are provided. Each of the push-out mechanisms 38, 38' is for holding the inner cylinder 21 in an extended state when the inner cylinder 21 is extended from the outer cylinder 13 by the telescopic cylinder 25.

Here, as shown in FIG. 13 and FIG. 14, The push-out mechanisms 38, 38' are composed of the push-out fixed sheaves 39, 39', the push-out movable sheaves 41, 41', and the push-out steel cables 42, 42'. Each of the ejecting mechanisms 38 and 38' is a telescopic cylinder 25 interposed therebetween, and is provided in the outer cylinder 13 in a bilaterally symmetric manner, and has the same structure. Therefore, in the following, only the push-out mechanism 38 disposed on the left side of the outer cylinder 13 will be described. For the member disposed on the right side, a single suffix "'" is added to the component symbol of the corresponding member, and the description is omitted. Its description.

39 is a push-out fixing sheave that is provided on the lower side of the outer cylinder 13. As shown in Fig. 14, the push-out fixing sheave 39 is rotatably supported by the bracket 40 by the support shaft 39A, and the bracket 40 is mounted across the sheave formed on the outer cylinder 13. The opening 16 is fixed to the outer cylinder 13. In this case, the support shaft 39A of the push-out fixing sheave 39 is disposed so as to have an inclination angle of an angle θ smaller than 90 degrees with respect to the left side surface 13C of the outer cylinder 13. In other words, the support shaft 39A for the push-out fixing sheave 39 is disposed so as not to be parallel to the rear side surface 13A of the outer cylinder 13, and a part of the push-out fixing sheave 39 supported by the support shaft 39A is housed. On the inner side of the outer cylinder 13.

41 is a push-out movable sheave that is provided on the sheave attachment 30 at a position lower than the telescopic movable sheave 33. As shown in Fig. 13, the push-out movable sheave 41 is rotatably supported by the lower sheave support portion 30C of the sheave attachment 30 by the support shaft 41A. In this case, the support shaft 41A of the push-out movable sheave 41 is disposed in a state of being kept parallel to the rear side surface 13A of the outer cylinder 13. The movable movable sheave 41 is adapted to the expansion and contraction of the telescopic cylinder 25 so that the sheave mounting device Since the movement 30 moves in the up and down direction, the push-out movable sheave 41 approaches or moves away from the push-out fixed sheave 39.

Reference numeral 42 denotes a push-out cable for connecting the outer cylinder 13 and the first-stage inner cylinder 21, and the push-out cable 42 is composed of a steel wire rope. Here, as shown in FIG. 9 and FIG. 10, the one end 42A of the push-out cable 42 is locked to the upper flange plate 14 of the outer cylinder 13, and the intermediate portion of the push-out cable 42 is wound around the push-out. The movable sheave 41 and the push-out fixed sheave 39 are provided. Further, the other end 42B of the push-out cable 42 is inserted into the inner side of the outer cylinder 13 from the push-out fixing sheave 39, and the inner side of the outer cylinder 13 is locked to the upper side of the inner cylinder 21.

Therefore, when the telescopic cylinder 25 is to be reduced from the most extended state shown in FIGS. 1 and 9 to the state shown in FIG. 10, the pipe 25A of the telescopic cylinder 25 will be moved together with the sheave attachment 30. Moving upward, the movable sheave 33 for telescopic movement will approach the fixed sheave 31 for expansion and contraction. As a result, the telescopic cable 34 originally wound around the telescopic movable sheave 33 and the telescopic fixed sheave 31 is released, and the second inner cylinder 23 is biased downward from the outer cylinder 13 by its own weight. elongation. At this time, the other end 37B of the support cable 37 that is locked to the upper side of the inner cylinder 23 moves downward together with the second inner cylinder 23, so that the first section supported by the support cable 37 is inside. The cartridge 21 is also elongated downward from the outer cylinder 13 by its own weight. As a result, as shown in Fig. 2 and Fig. 10, the pipe 25A will move to the upper limit position, and the telescopic cylinder 25 will reach the most contracted state, so that the telescopic arm 12 will be in the most extended state.

Here, when the sheave attachment 30 is close to the telescopic fixing sheave 31, the push-out cable 42 is wound between the push-out movable sheave 41 and the push-out fixed sheave 39, and the push-out cable 42 is The other end 42B will move downward together with the first segment inner cylinder 21. As a result, the cable 42 is pushed to maintain a certain tension. Further, since the inner cylinder 21 is extended in a state of being supported by the support cable 37, the support cable 37 also maintains a constant tension.

Therefore, in the state in which the inner cylinders 21 and 23 are extended from the outer cylinder 13, the excavation work is performed using the clamshell type grab 43 which will be described later, whereby even the upward excavating reaction force acts on the inner cylinders 21, 23 At the same time, it is possible to suppress the movement of the inner cylinders 21 and 23 toward the reduction side by the tension of the push-up wire 42 and the support wire 37.

Next, when the telescopic cylinder 25 is to be extended from the most reduced state shown in FIGS. 2 and 10, the pipe 25A of the telescopic cylinder 25 moves downward together with the sheave attachment 30, and is movable for expansion and contraction. The sheave 33 will be moved away from the telescopic fixing sheave 31. As a result, the telescopic cable 34 is wound between the telescopic movable sheave 33 and the telescopic fixed sheave 31, and the second inner cylinder 23 is moved upward to be accommodated in the first inner cylinder 21 Inside. At this time, the other end 37B of the supporting wire 37 that is locked to the upper side of the inner tube 23 moves upward together with the inner tube 23, so that the first inner tube 21 supported by the supporting wire 37 is also It moves upward and is housed in the outer cylinder 13. As a result, as shown in Figs. 1 and 9, the pipe 25A will move to the lower limit position, and the telescopic cylinder 25 will become the most extended state, whereby the telescopic arm 12 becomes The most reduced state.

On the other hand, when the telescopic arm 12 is expanded and contracted between the most reduced state and the most extended state, the telescopic fixed fixing sheave 31', the telescopic movable sheave 33', and the telescopic expansion are disposed on the right side with the telescopic cylinder 25 interposed therebetween. The wire rope 34', the supporting fixed sheave 35', the supporting wire 37', and the push-out fixing sheave 39' constituting the push-out mechanism 38', the push-out movable sheave 41', and the push-out wire 42' are also The same action as above.

Here, as shown in FIG. 13 and FIG. 14, the outer cylinder 13 is surrounded by the rear side surface 13A, the front side surface 13B, the left side surface 13C, the right side surface 13D, the left inclined surface 13E, and the right inclined surface 13F. The hexagonal cross-sectional shape, the push-out movable sheave 41 is disposed at a position facing the left inclined surface 13E in the left-right direction. Therefore, as shown by the arrow X in Fig. 13, the push-out movable sheave 41 can be disposed so as to be close to the left inclined surface 13E. More preferably, the movable sheave 41 for pushing out is provided at a position equivalent to the left side surface 13C or a position further inside. When the movable sheave 41 is approached to the left inclined surface 13E of the outer cylinder 13 in this manner, the amount of the push-out movable sheave 41 that protrudes in the left-right direction with respect to the left side surface 13C of the outer cylinder 13 can be suppressed. Further, the amount by which the movable sheave 41 for pushing out protrudes in the front-rear direction with respect to the rear side surface 13A of the outer cylinder 13 can be suppressed.

On the other hand, if the push-out movable sheave 41 is disposed in this manner, the support shaft 39A of the push-out fixing sheave 39 of the push-out cable 42 is wound between the push-out movable sheave 41 and the push-out movable sheave 41. The angle θ formed by the left side surface 13C of the outer cylinder 13 can be increased. As a result, As shown by the arrow Y in Fig. 14, a part of the push-out fixing sheave 39 accommodated in the outer cylinder 13 can be sufficiently separated from the inner cylinder 21. Further, it is possible to reduce the amount of protrusion of the push-out fixing sheave 39 from the left side surface 13C. As a result, it is not necessary to increase the size between the left and right side faces 13C, 13D of the outer cylinder 13, so that a sufficient interval between the push-out fixing sheave 39 and the first-stage inner cylinder 21 can be ensured without By letting the two interfere with each other, the entire telescopic arm 12 can be made very compact. This configuration is also the same for the push-out movable sheave 41' and the push-out cable 42' which are disposed on the right side with the telescopic cylinder 25 interposed therebetween.

43 is a clamshell type grab that is attached to the attachment eye ring 24 provided on the distal end side (lower end side) of the inner tube 23 in a swingable manner. By expanding and contracting the grab cylinder 44, the clamshell grab 43 can be caused to open and close to perform the excavation work of the soil sand.

The deep excavation type excavator 1 of the present embodiment has the above-described configuration, and an operation of excavating the vertical pit 101 for the floor 100 intended to be deep-excavated using the excavation type excavator 1 will be described below.

First, as shown in Fig. 1, the deep excavation type excavator 1 urges the telescopic cylinder 25 to be the most elongated to bring the telescopic arm 12 into the most reduced state, and the telescopic arm 12 is moved with respect to the ground 100 intended to excavate the vertical pit 101. Keep it in a vertical position.

Next, as shown in Fig. 2, the telescopic cylinder 25 is caused to be contracted so that the telescopic arm 12 is in an extended state. In other words, the pipe 25A of the telescopic cylinder 25 is caused to move upward together with the sheave attachment 30 to urge the expansion/contraction movable sheave 33 to approach the expansion/contraction sheave 31. Such a The two expansion sheaves 33A and 33B that are originally wound around the movable sheave 33 for expansion and contraction and the linear cable 34 of the two fixed sheaves 31A and 31B of the expansion/contraction sheave 31 are released. As a result, the second-stage inner cylinder 23 is extended downward from the outer cylinder 13 by its own weight, and the first-stage inner cylinder 21 supported by the support cable 37 is also used from the outer cylinder 13 by its own weight. Elongate downwards.

At this time, the push-out cable 42 is taken up between the push-out movable sheave 41 supported by the sheave attachment 30 and the push-out fixed sheave 39, so that the push-out cable 42 can be kept at all times. For a certain tension. Further, the support cable 37 for supporting the first inner cylinder 21 between the outer cylinder 13 and the second inner cylinder 23 also maintains a constant tension.

As a result, the inner cylinders 21 and 23 can be held in the state of being extended from the outer cylinder 13 by the tension of the pushing cable 42 and the supporting cable 37, and the clamshell grab 43 can be pressed toward the bottom surface 102 of the vertical pit 101. Go in. In this state, the grabbing cylinder 44 is used to cause the clamshell grab 43 to open and close, and the clamshell grab 43 can be used to excavate the vertical pit 101, which can be grasped by the clamshell type. Bucket 43 digs a lot of soil sand.

After the soil sand is excavated by the clamshell grab 43, the telescopic cylinder 25 is caused to extend, so that the pipe 25A of the telescopic cylinder 25 moves downward together with the sheave attachment 30, so that the movable sheave 33 for telescopic movement can be fixed from the telescopic The sheave 31 leaves.

In this way, the telescopic cable 34 will be wound for expansion and contraction. Between each of the movable sheaves 33A and 33B of the movable sheave 33 and each of the fixed sheaves 31A and 31B of the expansion/contraction fixed sheave 31, the inner cylinder 23 moves upward and is housed in the inner cylinder 21. At this time, the other end 37B of the support cable 37 for connecting the outer cylinder 13 and the inner cylinder 23 is moved upward together with the inner cylinder 23, so that the inner cylinder 21 supported by the support cable 37 is also It moves upward and is housed in the outer cylinder 13. As a result, the telescopic arm 12 again becomes the most reduced state as shown in FIG.

Next, as shown in Fig. 1, the telescopic cylinder 25 reaches the most extended state, and after the telescopic arm 12 is in the most reduced state, the front end side of the crane boom 4 is lifted upward, and the clamshell grab 43 is removed. The vertical pit 101 is pulled out. Then, the lower traveling body 2 is maintained in a stopped state, and the upper revolving body 3 is caused to swing toward a predetermined earthing position, and then the earth sand held by the clamshell grab 43 is discharged to the earthing position.

Here, according to the excavation type excavator 1 of the present embodiment, the distal end portion 25C of the rod 25B of the telescopic cylinder 25 is coupled to the bracket 13J provided in the outer tube 13 of the telescopic arm 12 by the plug 25D. On the other hand, the sheave attachment 30 for supporting the movable sheave 33 and the push-out movable sheave 41 is a pipe 25A attached to the telescopic cylinder 25 as a free end. Therefore, if the earthen sand excavated by the clamshell grab 43 is lifted upward to urge the telescopic cylinder 25 to elongate, the pipe 25A, which is itself a weight, moves downward together with the sheave attachment 30.

In this way, it is wound around the movable sheave 33 for stretching and stretching. When the telescopic cable 34 of the fixed sheave 31 is contracted, the downward load due to the weight of the pipe 25A and the sheave attachment 30 is received. As a result, the telescopic arm 12 can increase the pull-up force of the inner cylinders 21, 23 by the weight of the pipe 25A and the sheave attachment 30, so that the inner cylinder 21 can be more efficiently executed by the telescopic cylinder 25, 23 pull up action.

According to the deep excavation type excavator 1 of the present embodiment, the telescopic fixing sheave 31 is composed of two fixed sheaves 31A and 31B, and the telescopic movable sheave 33 is composed of two movable sheaves 33A and 33B. of. Further, the telescopic cable 34 is wound four times in total on the two fixed sheaves 31A and 31B and the two movable sheaves 33A and 33B. As a result, for example, in the conventional technique, the telescopic cable is connected between the four sheaves of the telescopic fixing sheave and the four sheaves of the telescopic movable sheave, and the structure is wound eight times in total. In comparison, the structure of this method can extend the life of the telescopic cable.

Further, the telescopic cable 34 is wound four times between the two fixed sheaves 31A and 31B constituting the expansion/contraction fixed sheave 31 and the two movable sheaves 33A and 33B that constitute the movable sheave 33 for expansion and contraction. As a result, the pull-up amount of the inner cylinders 21 and 23 using the telescopic cable 34 can be made four times as large as the stroke of the telescopic cylinder 25, and the inner cylinders 21 and 23 can be efficiently pulled up.

According to the present embodiment, the rod member 25B of the telescopic cylinder 25 is fixed to the upper side of the outer cylinder 13 at a position lower than the telescopic fixing sheave 31. In this way, the telescopic cylinder 25 to which the sheave mounting device 30 is mounted is provided. The pipe 25A is movable in the vertical direction within a range of the upper half of the outer cylinder 13 that extends in the vertical direction. Therefore, for example, as shown in Fig. 1, when the excavation of the vertical pit 101 is performed, even if the lower half of the outer cylinder 13 has been submerged, the operator located in the cover 3B of the upper revolving body 3 remains The expansion and contraction operation of the telescopic cylinder 25 and the like can be confirmed visually. As a result, the workability and safety of excavating work using the excavation type excavator 1 can be improved.

According to the present embodiment, the two sheave attachment rails 28 are fixed to the outer side of the outer cylinder 13 in a state of extending in the longitudinal direction in parallel with the outer cylinder 13. On the other hand, the sheave attachment 30 moves in the longitudinal direction of the outer cylinder 13 along the sheave attachment rail 28 in response to the expansion and contraction of the telescopic cylinder 25.

Therefore, the sheave attachment 30 is guided by the sheave attachment rail 28 and can always move on a certain track. As a result, the telescopic cable 34 that is wound around the telescopic fixed sheave 31 and the telescopic movable sheave 33 can smoothly and smoothly follow the movement of the telescopic movable sheave 33, so that the inner cylinders 21 and 23 can be lifted. The stability of the expansion and contraction operation of the outer cylinder 13 is achieved. Moreover, since the two sheave attachment rails 28 are fixed to the outer cylinder 13, the sheave attachment rails 28 can be used to raise the strength of the outer cylinders 13, thereby improving the overall reliability of the telescopic arms 12.

On the other hand, the pipe 25A to which the telescopic cylinder 25 of the sheave attachment 30 is attached can be moved along a sheave attachment rail 28 on a certain track. As a result, the anti-frustration strength and the strength against the lateral load of the telescopic cylinder 25 can be improved, and the reliability of the telescopic cylinder 25 can be improved. degree.

According to the present embodiment, the pair of crane boom brackets 17 are provided on the rear side surface 13A of the outer cylinder 13 on the side of the lid body 3B of the upper revolving body 3, and the pair of crane boom brackets 17 are mounted on the crane boom The front end side of 4. Further, the telescopic cylinder 25 is disposed between the pair of crane boom brackets 17.

In this way, the sheave attachment 30 attached to the pipe 25A of the telescopic cylinder 25, the telescopic movable sheave 33 supported by the sheave attachment 30, and the telescopic fixed sheave 31 can be wound and stretched. The steel cable 34 for expansion and contraction of the movable sheave 33 is disposed at a position facing the lid body 3B of the upper revolving body 3. As a result, the operator in the lid body 3B can control the inner cylinders 21 and 23 to expand and contract the outer cylinder 13 while visually recognizing the telescopic cylinder 25 or the like, and can reliably perform the manipulation of the expansion and contraction operation.

Since the crane boom bracket 17 is provided on the rear side surface 13A of the outer cylinder 13, it is not necessary to provide the telescopic cylinder 25, the telescopic fixing sheave 31, the sheave attachment 30, the expansion/contraction movable sheave 33, and the like in the outer cylinder 13 Front side 13B. Therefore, when the excavation of the vertical pit 101 is performed, members such as the telescopic cylinders 25 do not collide with the obstacle and are damaged, and the workability of the excavation work can be improved.

On the other hand, as shown in Fig. 15, the crane boom bracket 17 is provided on the rear side surface 13A of the outer cylinder 13, so that the front of the outer cylinder 13 can be changed in order to change the deep excavator 1 into a conveying posture. The side 13B is placed on the ground. In this way, it is no longer necessary to use a separate mounting table, etc. The telescopic cylinder 25, the sheave attachment 30, the telescopic fixed sheave 31, the telescopic movable sheave 33, and the like can be held in an upward posture, and the weight of the telescopic arm 12 does not act on the body.

Therefore, in the state in which the excavation type excavator 1 is changed to the conveyance posture, the telescopic cylinder 25 attached to the outer cylinder 13, the expansion/contraction sheave 31 for the expansion and contraction, the sheave attachment 30, and the movable sheave 33 for expansion and contraction are provided. If maintenance work is performed, it can be carried out at a position close to the ground, so that the workability of such maintenance work can be improved.

According to the present embodiment, the cylindrical tubular guide 26 is provided on the rear side surface 13A of the outer cylinder 13, and the tubing of the telescopic cylinder 25 can be accommodated in the tubular guide 26 in a movable (sliding) manner. 25A. In this way, the pipe 25A of the telescopic cylinder 25 as the free end can be guided by the pipe guide 26 in the longitudinal direction of the outer cylinder 13. Therefore, even if the sheave attachment 30 is mounted on the pipe 25A, this pipe 25A can be smoothly and smoothly moved along the pipe guide 26.

Moreover, the tube 25A of the telescopic cylinder 25 can be moved along a certain direction of the rail along the pipe guide 26, so that the anti-frustration strength and the strength against the lateral load of the telescopic cylinder 25 can be improved. Further, by accommodating the pipe member 25A in the pipe guide 26, the pipe member 25A can be protected from the falling rock or the like at the time of excavation work of the vertical pit 101.

According to the present embodiment, the outer cylinder 13 is formed in a tubular shape having a hexagonal cross-sectional shape, and the outer cylinder 13 is disposed between the rear side surface 13A and the left and right side surfaces 13C and 13D, and is provided with left and right sides. Slant Faces 13E, 13F. As a result, the frustration strength against the load acting on the outer cylinder 13 can be increased, and the life of the outer cylinder 13 can be prolonged, so that the overall reliability of the telescopic arm 12 can be improved.

Further, since the movable sheave 33 for the expansion and contraction is disposed outside the left side surface 13C of the outer cylinder 13, the left and right surfaces 13C of the expansion and contraction pulley 33 and the left side surface 13C of the outer cylinder 13 are spaced apart from each other in the left-right direction. On the opposite side. In this manner, the movable sheave 33 for expansion and contraction can be prevented from protruding largely toward the side of the rear side surface 13A of the outer cylinder 13, and even when the movable sheave 33 for expansion and contraction having the movable sheaves 33A and 33B having a large diameter is used, The circumference of the movable sheave 33 for expansion and contraction can be miniaturized. As a result, the life of the telescopic cable 34 can be extended by using the movable sheave 33 for expansion and contraction of the movable sheaves 33A and 33B having a large diameter. Further, the movable sheave 33' for stretching and contracting is disposed further outward than the right side surface 13D of the outer cylinder 13, so that the same effects as described above can be obtained.

In the deep excavation type excavator 1 of the present embodiment, the structure for extending the life of the telescopic cable 34 can be extended. Therefore, the load acting on the telescopic cable 34 can be set to be larger. As a result, the second inner cylinder 23 connected to the telescopic cable 34 can be used to pull up a larger load, and the capacity of the clamshell type grab 43 attached to the front end side of the inner cylinder 23 can be increased. Improve the efficiency of excavation by digging a large amount of earth and sand.

Further, according to the excavation type excavator 1 of the present embodiment, the sheave mounting openings 16 and 16' are provided on the lower side of the outer cylinder 13, and a part of the push-out fixing sheaves 39 and 39' is mounted by the sheave. Opening 16, 16' is disposed inside the outer cylinder 13. In this way, even when the diameters of the push-out fixing sheaves 39, 39' are made large, the push-out fixing sheaves 39, 39' can be attached to the outer cylinder 13 very tightly. As a result, the life of the push-out wires 42, 42' can be extended by using the push-out fixing sheaves 39, 39' having a larger diameter.

Further, since the push-out fixing sheaves 39, 39' are disposed at the positions of the sheave mounting openings 16, 16' provided on the lower side of the outer cylinder 13, it is not necessary to use the fixing sheaves in the same manner as in the prior art. It is placed at the lower end of the outer cylinder. In this manner, even when the first inner cylinder 21 is housed in the outer cylinder 13, the lower flange plate 22 provided at the lower end portion of the inner cylinder 21 does not occur with the push-out fixing sheaves 39, 39'. collision. Therefore, the lower flange plate 22 of the inner cylinder 21 can be brought close to the lower end portion 13H of the outer cylinder 13 (that is, beside the lower flange plate 15). As a result, the total length when the telescopic boom 12 is in the most reduced state can be further shortened. For example, when the deep excavation type excavator 1 is transported, it can be held in a compact transport posture.

Further, the configuration of the example described in the above embodiment is a telescopic cylinder 25, a sheave attachment rail 28, a sheave attachment 30, a telescopic fixing sheave 31, a telescopic movable sheave 33, and the like. It is disposed on the side of the rear side surface 13A on which the crane boom bracket 17 is attached, among the outer cylinders 13 constituting the telescopic arm 12. However, the present invention is not limited thereto, and such a configuration as that of the modification shown in Fig. 16 can be produced. In other words, the telescopic cylinder 25, the sheave attachment rail 28, the sheave attachment 30, the telescopic fixed sheave 31, the telescopic movable sheave 33, and the like may be disposed on the front side 13B of the outer cylinder 13. Side structure. So, right In the case of an operator who has become accustomed to the conventional telescopic boom, it is not uncomfortable to operate the deep excavator, and the operability can be improved.

In the above-described embodiment, the telescopic fixing sheaves 31, 31', the telescopic movable sheaves 33, 33', the telescopic cables 34, 34', the supporting fixed sheaves 35, 35', and the supporting wire 37, 37', the push-out fixed sheaves 39, 39', the push-out movable sheaves 41, 41', the push-out steel cables 42, 42', and the like are exemplified by the left and right telescopic cylinders 25 being bilaterally symmetrical. The case where two methods are provided on the outer cylinder 13 will be described as an example. However, the configuration of the present invention is not limited thereto, and the expansion/contraction sheave 31 for expansion and contraction, the movable sheave 33 for expansion and contraction, the cable for expansion and contraction 34, the fixed sheave 35 for support, the support cable 37, and the push-out may be used. Each member of the fixed sheave 39, the push-out movable sheave 41, the push-out wire 42 and the like is provided with only one configuration in the center portion of the outer cylinder 13 in the left-right direction.

Further, in the example given in the above embodiment, the sheave attachment rail 28 for guiding the sheave attachment 30 is formed by a rectangular cylinder having a rectangular cross-sectional shape. However, the structure of the present invention is not limited thereto, and for example, a sheave attachment rail may be formed of a steel material having an L-shaped cross-sectional shape.

11‧‧‧Multi-section telescopic arm device

12‧‧‧ Telescopic arm

13‧‧‧Outer tube

13C‧‧‧Left side

13J‧‧‧ bracket

14‧‧‧Upper flange plate

15‧‧‧ Lower flange plate

16‧‧‧ Openings for sheave installation

17‧‧‧ Crane boom bracket

17A‧‧‧ Crane boom joint

19‧‧‧Cylinder bracket

21‧‧‧The first inner tube

22‧‧‧ Lower flange plate

23‧‧‧The second inner cylinder

25‧‧‧ Telescopic cylinder

25A‧‧‧Tubing

25B‧‧‧ rods

25C‧‧‧ front end of the rod

26‧‧‧Tube guides

28‧‧‧Slotted wheel mounting rails

28A‧‧‧ bracket

29‧‧‧Slot wheel mounting substrate

29A‧‧‧Slot wheel installation

29B‧‧‧Steel cable lock

30‧‧‧Slot wheel mounting tools

30A‧‧‧ Body Department

30B‧‧‧Upper sheave support

30C‧‧‧Bottom sheave support

31, 31'‧‧‧Fixed fixed sheave

31A, 31A'‧‧‧ fixed sheave

31B, 31B'‧‧‧ fixed sheave

32A‧‧‧ bracket

32B'‧‧‧ bracket

33, 33'‧‧‧ movable trough for telescopic

33A, 33A'‧‧‧ movable trough

33B, 33B'‧‧‧ movable trough

34, 34'‧‧‧ Telescopic cable

35, 35'‧‧‧Support fixed sheave

34A, 34A'‧‧‧ One end of the telescopic cable

36, 36'‧‧‧ bracket

37, 37'‧‧‧Support cable

38‧‧‧ Launching agency

37A, 37A'‧‧‧ one end of the support cable 37

40‧‧‧ bracket

39‧‧‧ Launched with fixed sheave

41, 41'‧‧‧ Launched with movable sheave

42, 42'‧‧‧ Launched steel cable

42A, 42A'‧‧‧ One end of the steel cable

Claims (9)

A multi-stage telescopic arm device is provided. An outer cylinder (13) extending in the vertical direction of the front end side of the crane boom (4) provided with the object to be mounted, and a plurality of sections that are accommodated inside the outer cylinder (13) and extendable in the longitudinal direction The telescopic arm (12) of the cylinder (21, 23) and the telescopic cylinder (25) disposed along the longitudinal direction of the outer cylinder (13) constituting the telescopic arm (12) are fixedly disposed on the outer cylinder ( 13) The telescopic fixed sheave (31, 31') is attached to the telescopic cylinder (25) and is in proximity to or away from the telescopic fixed sheave (31, 31') in the outer cylinder ( 13) a sheave attachment (30) that moves in the longitudinal direction, and a movable sheave (33, 33') for telescopic movement provided in the sheave attachment (30), one end side of which is locked to the outside The cylinder (13) and the other end side thereof are locked in the innermost inner cylinder (23) among the inner cylinders (21, 23), and the intermediate portion is wound around the telescopic fixing sheave (31, 31) a multi-stage telescopic boom device comprising a telescopic cable (34, 34') for a telescopic movable sheave (33, 33'), characterized in that the telescopic cylinder (25) is provided with: a pipe (25A) One side is in the tube The material (25A) is fixed to the piston, and the other side is composed of a hydraulic cylinder of a rod (25B) protruding outward from the pipe (25A); and a rod (25B) of the above-mentioned telescopic cylinder (25) The upwardly facing state, the front end portion of the rod member (25B) is attached to the outer cylinder (13) of the telescopic arm (12) and the tube (25A) of the telescopic cylinder (25) is regarded as a free end; The sheave mounting device (30) is mounted on the aforementioned telescopic cylinder (25) Pipe (25A). The multi-stage telescopic boom device according to claim 1, wherein a front end portion of the rod member (25B) of the telescopic cylinder (25) is attached to an upper side of the outer cylinder (13). The multi-stage telescopic boom device according to the first aspect of the invention, wherein the outer cylinder (13) is provided with an outer cylinder extending in a longitudinal direction parallel to the outer cylinder (13). The sheave mounting rail (28) of (13); the sheave attachment (30) is moved along the sheave attachment rail (28) in accordance with expansion and contraction of the telescopic cylinder (25). The multi-stage telescopic boom device according to claim 1, wherein the outer side of the outer cylinder (13) is located at a lower side of the sheave mounting device (30), and is spaced apart in the left-right direction. a pair of oppositely facing crane boom brackets (17) that are swingable toward a front end side of the crane boom (4); the tubing (25A) of the telescopic cylinder (25) is disposed in the pair of crane cranes A gap (17B) formed between the arm brackets (17). The multi-stage telescopic arm device according to claim 1, wherein a pipe guiding member (26) is provided on the outer side of the outer cylinder (13), which is capable of allowing the telescopic cylinder (25) The pipe (25A) accommodates the pipe (25A) while moving, and guides the pipe (25A) in the longitudinal direction of the outer cylinder (13). The multi-stage telescopic arm device according to claim 1, wherein the outer cylinder (13) is a corner cylinder having a polygonal cross-sectional shape. The cross-sectional shape of the polygon has at least a rear side surface (13A) attached to the front end side of the crane boom (4) and a front side surface (13B) facing the front side surface (13A) in the front-rear direction. a left side surface (13C) and a right side surface (13D) that face each other in the left-right direction with the rear side surface (13A) and the front side surface (13B) interposed therebetween, and the rear side surface (13A) and the left side surface (13C) a left inclined surface (13E) obliquely disposed obliquely between the right side, and a right inclined surface (13F) obliquely inclined between the rear side surface (13A) and the right side surface (13D); and the movable sheave (33) for telescopic stretching 33') is disposed on the outer side in the left-right direction as compared with the left side surface and the right side surface (13C, 13D) constituting the outer cylinder (13). The multi-stage telescopic arm device according to claim 1, wherein the outer cylinder (13) is formed in a rectangular tubular shape having a hexagonal cross-sectional shape, and the hexagonal cross-sectional shape is: a rear side surface (13A) on the front end side of the crane boom (4), a front side surface (13B) facing the front side surface (13A) in the front-rear direction, a rear side surface (13A) and a front side surface ( 13B) a left inclined surface (13C) and a right side surface (13D) facing each other in the left-right direction, and a left inclined surface (13E) obliquely inclined between the rear side surface (13A) and the left side surface (13C), The right inclined surface (13F) is disposed obliquely obliquely between the rear side surface (13A) and the right side surface (13D). The multi-stage telescopic arm device according to claim 1, wherein the first inner cylinder (21) located at the outermost side among the outer cylinder (13) and the inner cylinders (21, 23) of the plurality of sections Between, there is a launching mechanism (38, 38'), when the first telescopic cylinder (25) extends the first inner cylinder (21) outward from the outer cylinder (13), the first inner cylinder (21) is elongated The push-out mechanism (38, 38') is provided with a fixing groove (39, 39') for being pushed out of the outer cylinder (13) on the lower side of the outer cylinder (13). The movable sheave (33, 33') for expansion and contraction is further positioned at the lower side, and is provided on the push-out movable sheave (41, 41') of the sheave attachment (30), and one end side thereof is locked The outer cylinder (13) and the other end side thereof are locked to the first inner cylinder (21) through the inner side of the outer cylinder (13), and the intermediate portion is wound around the push-out fixing pulley (39, 39). ') and the push-out cable (42, 42') for the push-out movable sheave (41, 41'); and the push-out fixing sheave (39) provided on the lower side of the outer cylinder (13) The position of 39') is provided with a slot mounting opening (16, 16'); a part of the push-out fixing sheave (39, 39') is through the aforementioned slot mounting opening (16, 16') It is disposed on the inner side of the outer cylinder (13). A deep excavation type excavator is provided with: a self-propellable vehicle body (2, 3), and a crane boom (4) provided for the pitching motion of the vehicle body (2, 3), which is disposed at the a deep excavator formed by a multi-stage telescopic arm device (11) on the front end side of the crane boom (4); The multi-stage telescopic arm device (11) includes an outer cylinder (13) extending in the vertical direction and an inner cylinder (21, 23) that is accommodated inside the outer cylinder (13) and that can expand and contract in the longitudinal direction. a telescopic arm (12), a telescopic cylinder (25) disposed along a longitudinal direction of the outer cylinder (13) constituting the telescopic arm (12), and a telescopic cylinder (13) fixedly disposed in the outer cylinder (13) The fixed sheave (31, 31') is attached to the telescopic cylinder (25) so as to be close to or away from the telescopic fixed sheave (31, 31'), in the longitudinal direction of the outer cylinder (13) a moving sheave attachment (30), a telescopic movable sheave (33, 33') provided on the sheave attachment (30), and one end side thereof is locked to the outer cylinder (13) and The other end side is locked to the inner tube (23) located at the innermost side among the inner cylinders (21, 23), and the intermediate portion is wound around the telescopic fixing sheave (31, 31') and the movable groove for expansion and contraction. The telescopic cable (34, 34') of the wheel (33, 33') is characterized in that the telescopic cylinder (25) is composed of: a pipe (25A), and one side of the pipe (25A) ) is fixed inside the piston, and the other One side is a hydraulic cylinder of a rod (25B) protruding outward from the pipe (25A); the rod (25B) is in a state in which the rod (25B) of the telescopic cylinder (25) faces upward The front end portion is attached to the outer cylinder (13) of the telescopic arm (12) and the pipe (25A) of the telescopic cylinder (25) is regarded as a free end; the aforementioned sheave mounting device (30) is mounted on the aforementioned telescopic tube On the tubing (25A) of the cylinder (25).