KR101650676B1 - Multi-stage telescopic arm device and deep-digging excavator comprising multi-stage telescopic arm device - Google Patents

Abstract

On the tip end side of the boom (4), a telescopic arm (12) composed of an outer tube (13) and a plurality of inner tubes (21, 23) The extensible cylinder 25 and the fixed sheave unit 31, 31 'for extension and contraction are provided on the outer cylinder 13. A sheave mount 30 is mounted on the extensible cylinder 25 and movable sheave units 33 and 33 'are provided on the sheave mount 30. The stretch rope 34 is wound four times between the sheaves 31A and 31B of the fixed sheave unit 31 for stretch and shrinkage and the sheaves 33A and 33B of the movable sheave unit 33 for stretch and shrink. A stretch rope 34 'is provided between the sheaves 31A' and 31B 'of the fixed sheave unit 31' for extension and contraction and the sheaves 33A 'and 33B' of the movable sheave unit 33 ' Is wound four times.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a multi-stage telescopic arm device and a multi-stage telescopic arm device,

The present invention relates to a deep drawing excavator equipped with a multi-stage stretching arm device and a multi-stage stretching arm device, which are suitably used, for example, in a work for deeply digging the ground in civil engineering work.

Generally, a digging excavator is suitably used when excavating a ground depth trellis for civil engineering work. This deep excavator is provided with a vehicle body capable of self-running, a boom provided so as to be able to move on the vehicle body, and a multi-stage stretching arm device provided on a front end side of the boom. The multi-stage stretching arm device comprises: a stretching arm having an outer cylinder extending in an upward and downward direction and an inner cylinder at a plurality of stages; a fixed sheave unit for retracting and extending fixed to the outer cylinder; a stretching cylinder arranged along the longitudinal direction of the outer cylinder; A movable sheave unit which is mounted on the extensible cylinder and moves in the longitudinal direction of the outer cylinder; and a movable sheave unit for extension and retraction provided on the sheave mount; And a retractable rope wound around the fixed sheave unit and the retractable movable sheave unit. Further, a clam shell bucket for excavation is attached to the tip of the inner tube.

In this deep excavator according to the related art, the expansion / contraction cylinder is contracted while the expansion / contraction arm provided at the front end side of the boom is kept perpendicular to the ground, thereby extending the inner cylinder of the expansion / contraction arm downward from the outer cylinder. Therefore, the excavator can excavate the gravel by using the clam shell bucket attached to the front end (lower end) of the inner cylinder.

After gripping the soil excavated by the clam shell bucket, the stretching cylinder is stretched to raise the inner tube together with the clam shell bucket by the stretching rope into the outer cylinder. In this state, the upper swing body of the excavator is turned with the swing body facing a predetermined clay position, and the clam shell bucket is opened, so that the excavated soil can be clogged (see Patent Document 1).

Japanese Patent Application Laid-Open No. 62-82131

In the deep-drawn excavator according to the prior art described above, four sheaves constituting a fixed sheave unit for expansion and contraction are mounted on the outer cylinder of the expansion and contraction arm, and four sheaves constituting a movable sheave unit for expansion and contraction Respectively. On the other hand, the stretchable rope has one end side engaged with the outer tube and the other end side engaged with the inner tube. The intermediate portion of the stretchable rope is divided into four pieces of a sheave of a retractable fixed sieve unit and four pieces of movable sheave units In total eight times in total.

As a result, the stretchable rope passes through four sheaves of the four sheaves of the fixed sheave unit for retracting and the four sheaves of the movable sheave unit for stretching and shrinking, and is thereby fatigued in the early stage due to repeated bending. As a result, there is a problem that the frequency of replacing the rope for stretching increases with the conventional deep excavator. In addition, since the number of sheaves constituting the sheave constituting the fixed sheave unit for the expansion and contraction and the sheaves constituting the movable sheave unit for the expansion and contraction are large, the diameter of each sheave is increased The mass of each sheave is increased. As a result, there arises a problem that the mass of the whole stretchable arm increases and the stability of the deep excavator is impaired.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a deep drawing excavator having a multi-stage stretching arm device and a multi-stage stretching arm device which can extend the life of the stretching rope.

(One). The present invention relates to a telescopic arm comprising a telescopic arm which is provided so as to extend upward and downward on a boom tip side of an object to be mounted and has a plurality of inner cylinders accommodated in an outer cylinder and an outer cylinder in a longitudinally stretchable manner, A pair of left and right fixed sheave units fixed to the outer cylinder and arranged to extend or retract in the longitudinal direction of the outer cylinder; A movable sheave unit for left and right extending and retracting movable sheave units provided in the sheave mounting opening and a movable sheave unit having one end side engaged with the outer cylinder and the other end side being the innermost one of the inner cylinders, And the left and right stretching ropes wound around the respective movable sheave units for extension and contraction It is applied on a multi-stage telescopic arms composed of devices.

A feature of the present invention resides in that each of the fixed sheave units for expansion and contraction is constituted by two sheaves each, and each of the movable sheave units for expansion and contraction is constituted by two sheaves each, And four turns are taken between the movable sheave unit for each extension and contraction and each of the movable sheave units for extension and contraction.

According to this configuration, when the stretching and shrinking cylinder is contracted, the telescopic movable sheave unit supported by the sheave mount moves upward and approaches the telescopic fixed sheave unit fixed to the outer barrel. As a result, the sheave of the fixed sheave unit for retractable shrinkage and the stretchable rope wound on the sheave of the movable sheave unit for retractable shrinkage are drawn out, and the inner tube is pulled out from the outer tube to extend the stretching arm. On the other hand, when the extensible cylinder is extended, the extendable movable sheave unit supported by the sheave mount moves downward and is separated from the fixed sheave unit fixed to the outer cylinder. As a result, the stretchable rope is wound between the sheave of the fixed sheave unit for retracting and the sheave of the movable sheave unit for retracting, and the inner tube enters the inside of the outer tube, so that the stretching arm can be contracted.

In this case, the rope for extension and contraction is configured to be wound four times in total between two sheaves constituting the fixed sheave unit for the expansion and contraction and two sheaves constituting the movable sheave unit for expansion and contraction. Thus, for example, as in the prior art, there is a configuration in which four ropes for stretching and shrinking are wound eight times in total between four sheaves constituting a fixed sheave unit for stretching and a four sheaves constituting a movable sheave unit for stretching The number of times the rope for bending and stretching is bent by the sheave can be reduced by half, and the life of the rope for extending and retracting can be prolonged. Further, by reducing the number of sheaves of the sheave of the fixed sheave unit for retractable shrinkage and the movable sheave unit for retractable shrinkage, even if the diameter of each sheave is increased to prolong the life of the stretchable rope, And the stability of the multi-stage stretching arm device can be secured.

(2). According to the present invention, the outer tube is provided with a boom bracket having a connecting portion connected to the boom, and a connecting portion connected to the boom bracket at a space above or below the swing cylinder for pivotally moving the telescopic arm against the boom Wherein the expansion cylinder has a tube and a rod whose one side is fixed to the piston in the tube and the other side is protruded outward from the tube, and the sipe fitting hole Wherein one end of the tube and the rod is located above the connecting portion of the bracket located above the boom bracket and the cylinder bracket when the expansion cylinder is in its minimized state, The one end of the tube and the other end of the rod are connected to the boom bracket and the cylinder bracket Than the connecting portion of the bracket, which is located in a room that has a configuration in which a place positioned on the lower side.

According to this configuration, when the extensible cylinder is expanded and contracted between the minimized state and the latest state, one end of the tube and the rod of the extensible cylinder equipped with the sheave mount is moved upward and downward with respect to the boom bracket and the cylinder bracket Move. As described above, the expansion and contraction cylinder moves upward and downward with respect to the boom bracket and the cylinder bracket, thereby making it possible to take a large stroke of the expansion and contraction cylinder. Therefore, a larger excavation depth can be secured.

(3). According to the present invention, the extensible cylinder is constituted by a tube, a hydraulic cylinder having one side fixed to the piston in the tube and the other side projecting outwardly from the tube, and in the minimized state of the extensible cylinder And the length from the bottom of the tube to the distal end of the rod is set to a length that is approximately 1/2 of the length of the outer tube.

According to this configuration, since the extensible cylinder can be extended most within the length dimension of the outer cylinder, the stroke of the extensible cylinder can be set large, and the amount of movement of the sheave mount can be secured to a large extent. Therefore, the stretching and contracting arm can be stretched and contracted only by winding the stretchable rope four times between two sheaves of the two sheaves of the fixed sheave unit for retracting and the movable sheave unit for retracting.

(4). According to the present invention, the distal end portion of the rod of the extensible cylinder is mounted on the upper side of the outer cylinder in an upward state, and the sheave mount is mounted on the tube of the extensible cylinder.

According to this configuration, the distal end portion of the rod of the extensible cylinder is mounted on the outer cylinder in an upward state. As a result, when the stretchable cylinder is stretched, the heavy tube and the sheave mount move together downward, and the sheave of the movable sheave unit for retracting and the sheave of the fixed sheave unit for retracting, The inside of the outer tube is raised. In this case, a downward load acts on the tube moving downward by the weight of the tube and the sheave mount. Therefore, the pulling force of the inner tube can be increased by using the weight of the tube and the sheave mount, and the lifting operation of the inner cylinder by the stretching cylinder can be efficiently performed.

(5). According to the present invention, each of the fixed sheave units for expansion and contraction is provided symmetrically with respect to the outer cylinder, with the extensible cylinder being interposed therebetween, and each of the movable sheave units for expansion and contraction has, Wherein the ropes are provided with a sheave of the movable sheave unit for extension and retraction and a sheave of the movable sheave unit for extension and retraction which are disposed on the left side with the extensible cylinder therebetween, And between the sheave of the movable sheave unit for expanding and contracting and the sheave of the movable sheave unit for expansion and contraction arranged on the right side with the extensible cylinder interposed therebetween.

According to this construction, since one set of the fixed sheave unit for expansion and contraction, the movable sheave unit for expansion and contraction, and the expansion and contraction rope are disposed symmetrically in the left and right direction with the extensible cylinder interposed therebetween, Can be reduced. As a result, the life of the stretchable rope can be prolonged, and the stretching arm can be stretched and contracted stably for a long period of time. Further, even if one of the stretch ropes is cut off, the inner barrel can be supported by the other stretchable rope, so that the safety of the excavation work can be secured.

(6). According to the present invention, a sheave mounting guide rail is provided on the outer side of the outer cylinder so as to extend in the longitudinal direction in parallel with the outer cylinder and mounted on the outer cylinder, and the sheave mounting opening includes a sieve mounting portion And moves along the rectangular guide rails.

According to this configuration, when the sheave mount is moved by the stretching and shrinking cylinder, the sheave mount can always move on a constant orbit by being guided by the sheave mount guide rail. As a result, the sheave of the retractable fixed sheave unit and the retractable rope wound on the sheave of the retractable movable sheave unit can smoothly follow the movement of the retractable movable sheave unit supported by the sheave mounting opening, It is possible to enhance the stability of the stretching operation of the inner tube. Further, since the sheave mounting guide rail provided on the outer cylinder can increase the strength of the outer cylinder, the reliability of the entire stretchable arm can be enhanced.

On the other hand, the tube equipped with the sheave mount can also move on a constant orbit along the sheave mount guide rail. As a result, it is possible to increase the strength against buckling and lateral load of the stretchable cylinder, thereby enhancing the reliability of the stretchable cylinder.

(7). According to the present invention, a pair of boom brackets are provided on the outer side of the outer cylinder and below the sheave mount so as to be pivotally mounted on the front end side of the boom, And the tube of the extensible cylinder is arranged in a gap formed between the pair of boom brackets.

According to this configuration, since the extensible cylinder is disposed in the gap formed between the pair of boom brackets provided on the outer side of the outer cylinder, it is possible to use the extensible cylinder, the sheave mounting hole mounted on the tube of the extensible cylinder, The movable sheave unit, the fixed sheave unit for the expansion and contraction, and the extension and contraction rope wound around the movable sheave unit for expansion and contraction can be seen visually from the vehicle side provided with the boom. As a result, the operator on the vehicle body side equipped with the boom can accurately perform the operation of stretching and contracting the inner cylinder relative to the outer cylinder while visually observing the extensible cylinder or the like directly with the naked eye.

A retractable cylinder, a fixed sheave unit for retracting, a sheave attaching member, a movable sheave unit for retracting and the like are provided on the side face opposite to the face on which the boom bracket is mounted during the outer cylinder, There is no need to install. This prevents the extensible cylinder or the like from being damaged by contact with the obstacle during the excavation of the boats and the like, thereby enhancing the workability of excavation work.

Further, in order to set the multi-stage stretchable arm device in the transportation posture, when the outer cylinder is placed on the ground, the face opposite to the face mounted on the boom can be placed on the ground. Thereby, it is possible to prevent the expansion / contraction cylinder, the sheave mounting section, the fixed sheave unit for expansion and contraction, the movable sheave unit for expansion and contraction, and the like due to the weight of the expansion and contraction arm It is possible to maintain the upward posture without any.

Therefore, in a state in which the multi-stage stretchable arm device is in the transporting posture, the maintenance work for the stretchable cylinder, the retractable fixed sheave unit, the sheave mount, and the retractable movable sheave unit mounted on the outer cylinder can be performed at a position close to the ground , The workability of this maintenance work can be enhanced.

(8). According to the present invention, on the outside of the outer cylinder, a tube guide for accommodating a tube of the extensible cylinder movably and guiding the tube in the longitudinal direction of the outer cylinder is provided.

According to this configuration, the tube fitted with the sheave mount can be smoothly moved by guiding the free end side of the tube of the stretching / shrinking cylinder in the longitudinal direction of the outer cylinder by the tube guide. As a result, the tube of the extensible cylinder can move along a predetermined orbit along the tube guide, thereby increasing the strength against buckling and lateral load of the extensible cylinder. Further, by accommodating the tube in the tube guide, the tube can be protected from falling stones or the like during excavation.

(9). According to the present invention, the outer tube has at least a rear surface mounted on at least the front end side of the boom, a front surface facing the rear surface in the forward and backward directions, and a front surface facing the rear surface in the left and right And a left side inclined surface disposed obliquely between the rear surface and the left side surface and a right side inclined surface disposed obliquely between the rear surface and the right side surface, And the movable sheave unit for expansion and contraction is disposed outside the left and right sides of the left and right sides constituting the outer cylinder.

According to this configuration, since the outer cylinder is formed in a cylindrical shape having a polygonal cross-sectional shape and left and right slopes are formed between the rear face and the left and right side faces mounted on the front end side of the boom, The buckling strength can be increased. Thereby, the life of the outer tube can be prolonged, and the reliability of the stretching arm can be enhanced.

Further, by disposing the movable sheave unit, which is supported by the sheave mount, in the left and right outer sides of the left and right side faces constituting the outer cylinder, the expansion and contraction movable sheave unit is prevented from projecting greatly toward the rear face side of the outer cylinder can do. As a result, even in the case of using the movable sheave unit for expansion and contraction made of a sheave having a large diameter, it is possible to downsize the periphery of the movable sheave unit for expansion and contraction. Therefore, by using the movable sheave unit having a large- The life of the rope can be prolonged.

In this way, since the lifetime of the rope for extension and contraction can be extended, the load acting on the rope for extension and contraction can be set to a large value. As a result, the capacity of the clamshell bucket mounted on the inner cylinder to which the rope for extension and contraction is connected can be increased, and a large amount of gravel can be excavated.

(10). According to the present invention, the outer tube has a rear surface mounted on the front end side of the boom, a front surface facing the rear surface in the forward and backward directions, and a front surface facing the rear surface in the left and right directions And a left side inclined surface disposed obliquely between the rear surface and the left side surface and a right side inclined surface disposed obliquely between the rear surface and the right side surface, It is on. Thereby, the buckling strength can be increased with respect to the load acting on the outer tube, and the life of the outer tube can be prolonged.

(11). According to the present invention, when the first-stage inner cylinder is extended from the outer cylinder by the stretching cylinder between the outer cylinder and the first-stage inner cylinder located at the outermost of the plurality of inner cylinders, Wherein the press fitting mechanism includes a left and right press-fitting fixed sheave positioned on the lower side of the outer cylinder and provided in the outer cylinder, and a sheave mounting portion on the lower side of the movable sheave unit for extension and retraction, And the other end side of the movable sheave is engaged with the inner cylinder of the first stage through the inner side of the outer cylinder and the middle portion of the movable sheave is engaged with the left and right press- And left and right press-fitting ropes respectively wound on the left and right press-fitting movable sheaves, and the left and right press- And a portion of the left and right press-fitting fixed sheaves is disposed inside the outer cylinder through the sheave mounting opening.

With this configuration, even when the diameter of the press-fitting fixed sheave is set large, the press-fitting fixed sheave can be mounted compactly on the outer cylinder. As a result, it is possible to use a fixed sheave for press-fitting having a large diameter, and the life of the press-in rope can be prolonged.

As compared with the configuration in which the press-fitting fixing sheave is disposed at the lower end portion of the outer cylinder as in the prior art, when the inner cylinder of the first stage is accommodated in the outer cylinder, the projecting amount of the lower end portion of the inner cylinder at the first stage protruding from the lower end portion of the outer cylinder is reduced . As a result, the entire length of the telescopic arm can be shortened when the telescopic arm is minimized. For example, a compact telescopic attitude can be achieved when the telescopic arm device is transported.

(12). The present invention is characterized in that it comprises a body which can be frequently freed, a boom installed to be able to move in the body, and a multi-stage stretching arm device provided on a front end side of the boom, A telescopic cylinder having a plurality of inner cylinders retractably received in the longitudinal direction in the outer cylinder, an extensible cylinder arranged along the longitudinal direction of the outer cylinder constituting the telescopic arm, A sieve mounting portion which is mounted on the extensible cylinder and moves in the longitudinal direction of the outer cylinder so as to be approachable or spaced apart from each of the extensible sheave units for extension and retraction; The sheave unit and the sheave unit are engaged with an inner cylinder whose one end side is engaged with the outer cylinder and the other end side is the innermost side of the inner cylinder, And the left and right stretching ropes wound around the respective movable sheave units for extension and contraction are applied to the deep-drawing excavator.

Each of the movable sheave units for extension and contraction is constituted by two sheaves each, and each of the expansion and contraction ropes is fixed to each of the elastic shafts And the take-up unit is wound four times between the sheave unit and each of the movable sheave units for extension and contraction.

According to this configuration, the stretchable rope is wound four times in total between the two sheaves of the fixed sheave unit for retracting and the two sheaves of the movable sheave unit for stretching and shrinking. Thus, for example, as in the prior art, there is a configuration in which four ropes for stretching and shrinking are wound eight times in total between four sheaves constituting a fixed sheave unit for stretching and a four sheaves constituting a movable sheave unit for stretching It is possible to prolong the service life of the rope for stretching. Further, by reducing the number of seats of the retractable fixed sheave unit and the retractable movable sheave unit, it is possible to suppress the increase of the mass of the retractable arm even when the diameter of each sheave is increased to prolong the life of the retractable rope Thus, the stability of the digging excavator can be secured.

1 is a side view showing a deep-drawn excavator according to an embodiment of the present invention in a state in which the expansion and contraction arm is minimized.
2 is a side view showing the deep drawing excavator in a state in which the stretching arm is extended most.
3 is a side view showing the multi-stage stretching arm device shown in Fig. 1 as a single unit.
Fig. 4 is a front view of the multi-stage stretchable arm device seen from the direction of arrows IV-IV in Fig. 3;
5 is a perspective view showing a multi-stage stretching arm device as a single unit.
Fig. 6 is an enlarged perspective view of a main portion showing an outer cylinder, a stretching cylinder, a retractable fixed sheave unit, a sheave mount, a retractable movable sheave unit, a sheave mounting guide rail, and the like in Fig.
7 is an enlarged perspective view of a main part showing a sheave mounting portion, a movable sheave unit for expansion and contraction, a movable sheave for press-fitting, a sheave mounting guide rail, and the like.
Fig. 8 is an enlarged front view of a main part showing an enlarged view of the retractable fixed sheave unit or the like in Fig. 4;
9 is a schematic diagram showing a telescopic arm extending and contracting mechanism in a state in which the telescopic arm is contracted.
Fig. 10 is a schematic diagram showing the elongating and contracting mechanism of the elongating and contracting arm in a state in which the elongating and contracting arm is elongated.
Fig. 11 is a sectional view of the telescopic arm, the boom bracket, and the like as viewed in the direction of arrows XI-XI in Fig. 3;
Fig. 12 is a sectional view of the telescopic arm, the telescopic cylinder, the sheave mount, the telescopic movable sheave unit, and the like as viewed from the direction of arrows XII-XII in Fig. 3;
Fig. 13 is a sectional view of the telescopic arm, the telescopic cylinder, the sheave mount, the press-fitting movable sheave, and the like as viewed from the direction of arrows XIII-XIII in Fig.
14 is a sectional view of the telescopic arm, sheave mounting opening, press fitting sheave, and the like as viewed in the direction of arrows XIV-XIV in Fig. 3;
15 is a side view showing a state in which the expandable arm is placed on the ground with the deep-drawn excavator as a transport posture.
16 is a front view showing a modified example in which a stretching cylinder, a fixed sheave unit for stretching and shaving, a sheave attaching member, a movable sheave unit for stretching and shrinking guide rails, and the like are disposed on the front side of the outer cylinder.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a deep drawing excavator according to the present invention will be described in detail with reference to the accompanying drawings.

1, reference numeral 1 denotes a deep trench excavator according to the present embodiment, wherein the deep trench excavator 1 has a crawler type lower traveling body 2 which can be freely freely pivoted on the lower traveling body 2, And a vehicle body composed of an upper swing body 3 mounted thereon. This body is an object to be mounted of the multi-stage stretch arm device 11 to be described later.

The upper revolving structure 3 includes a revolving frame 3A as a base, a cap 3B disposed on the left side of the front portion of the revolving frame 3A, a counterweight 3B provided on the rear end side of the revolving frame 3A, (Not shown) such as an engine, a hydraulic pump, and the like.

And reference numeral 4 denotes a boom provided so as to be able to move in a forward direction of the upper revolving structure 3. [ The proximal end side of the boom 4 is mounted on the front side of the revolving frame 3A and the distal end side of the boom 4 is equipped with a multi-stage stretch arm device 11 described later. A boom cylinder 4A is provided between the boom 4 and the revolving frame 3A and the boom 4 moves toward the upper revolving body 3 by expanding and contracting the boom cylinder 4A. The bottom side of the excavator rocking cylinder 4B is mounted on the upper face side of the boom 4 and the rod side of the excavator rocking cylinder 4B is mounted on the multi-stage stretch arm device 11.

Next, the multi-stage stretching arm device 11 mounted on the front end side of the boom 4 for excavating the bottom depth deck will be described.

Reference numeral 11 denotes a multi-stage stretch arm device mounted on the front end side of the boom 4. The multi-stage stretch arm device 11 includes a stretchable arm 12, a stretchable cylinder 25, 30, a fixed sheave unit 31 for expansion and contraction, a movable sheave unit 33 for expansion and contraction, and a stretchable rope 34.

Reference numeral 12 denotes a telescopic type stretching arm mounted so as to extend in the upward and downward directions on the distal end side of the boom 4. As shown in Fig. 9 and the like, the telescopic arm 12 includes an outer tube 13 located at the outermost position, a first-stage (later-described) And an inner cylinder 23 of a second stage which is accommodated so as to be able to expand and contract in the longitudinal direction on the inner circumference side of the first stage inner cylinder 21. [

Here, as shown in Figs. 11 to 14, the outer cylinder 13 is spaced apart from the rear face 13A mounted on the front end side of the boom 4 and the rear face 13A in the forward and backward directions A left side face 13C and a right side face 13D which face each other in the left and right directions with the rear face 13A and the front face 13B interposed therebetween and the rear face 13A and the left side face 13B, A left inclined face 13E arranged obliquely between the face 13C and a right inclined face 13F arranged obliquely between the rear face 13A and the right face 13D. Therefore, the outer cylinder 13 is formed as a cylinder having a hexagonal cross-sectional shape as a whole.

As described above, the outer cylinder 13 is provided with the left inclined face 13E between the rear face 13A and the left face 13C mounted on the front end side of the boom 4, and the rear face 13A and the right side face 13D are provided on the right side slope 13F. Thus, the outer tube 13 is structured to increase the buckling strength with respect to the load acting on the outer tube 13. [0054] On the other hand, the upper end portion 13G and the lower end portion 13H of the outer cylinder 13 each have an opening end.

The upper flange plate 14 is integrally provided on the outer circumferential side of the outer cylinder 13 at the middle portion in the longitudinal direction of the outer cylinder 13. The upper flange plate 14 is engaged with one end 42A of the press-in rope 42 to be described later. On the other hand, the lower flange plate 15 is integrally provided at the lower end of the outer cylinder 13. [ The lower flange plate 15 is engaged with one end 37A of a support rope 37 described later.

On the lower side of the outer cylinder 13, left and right sheave mounting openings 16 and 16 'are provided. 14, the left sheave attachment opening 16 is formed at a portion where the left side face 13C and the left side slope face 13E constituting the outer cylinder 13 intersect, and the right sheave attachment opening 16 'Is formed at a portion where the right side face 13D and the right side slope face 13F of the outer cylinder 13 intersect. The sheave attaching openings 16 and 16 'are opened in the outer cylinder 13 and a part of a press-fitting securing sheave 39 and 39' described later is inserted into the sheave attaching openings 16 and 16 '.

Reference numeral 17 denotes a pair of left and right boom brackets provided on the outer side of the outer cylinder 13 and below the sheave mounting mouth 30 to be described later. The pair of boom brackets 17 are connected to the boom 4 And is mounted on the tip side. As shown in Figs. 5 and 11, the pair of boom brackets 17 is formed of a plate facing each other in the left and right direction. Each of the brackets 17 is provided with a cylindrical boom- Both sides in the left and right direction are fixed to each other. The pair of boom brackets 17 are integrally fixed to the rear face 13A of the outer cylinder 13 by means of welding or the like and the boom connecting portion 17A of the boom bracket 17 is fixed to the pin 18 (See Fig. 1) to the front end side of the boom 4, as shown in Fig. A gap 17B is formed between the pair of boom brackets 17 and the expansion and contraction cylinder 25 described later is disposed in the gap 17B.

Reference numeral 19 denotes a pair of left and right cylinder brackets disposed on the outer side of the outer cylinder 13 and positioned above the boom bracket 17. The pair of cylinder brackets 19 are connected to the excavator rocking cylinder 4B, As shown in Fig. Here, the pair of the cylinder brackets 19 is formed of a plate facing each other at left and right directions, and has a cylinder connecting portion to which the rod end portion of the excavator rocking cylinder 4B is connected. The pair of the cylinder brackets 19 are integrally fixed to each other at a position near the upper side of the boom bracket 17 by means of welding or the like on the rear face 13A of the outer cylinder 13, The rod end portion of the excavator rocking cylinder 4B is rotatably and pin-coupled to the cylinder connecting portion of the rocking cylinder 19 using a pin 20 (see Fig. 1).

Therefore, by expanding and contracting the excavator rocking cylinder 4B, the outer cylinder 13 of the expansion and contraction arm 12 is moved forward, backward, or upward and downward about the pin 18 at the tip end side of the boom 4 And is configured to oscillate. The cylinder bracket 19 may be disposed below the boom bracket 17 depending on the mounting position of the excavator rocking cylinder 4B.

Reference numeral 21 denotes an inner cylinder located at the outermost position of the outer cylinder 13 movably accommodated with a suitable gap therebetween. 11 to 14, the first-stage inner tube 21 has a rectangular sectional shape surrounded by a rear surface 21A, a front surface 21B, a left surface 21C and a right surface 21D have. The inner cylinder 21 is formed as a whole as an entire cylinder, and both end portions in the upper and lower directions are open end portions. The inner cylinder 21 is received in the inner side of the outer cylinder 13 from the lower end portion 13H of the outer cylinder 13 and is movable in the longitudinal direction (up and down direction) with respect to the outer cylinder 13. [

A slide plate (not shown) is provided between the inner surface of the outer tube 13 and the outer surface of the first-stage inner tube 21 to smoothly slide the inner tube 21 along the outer tube 13 have. On the other hand, a lower flange plate 22 is provided at the lower end portion of the inner cylinder 21, and a fixing sheave 35 for support, which will be described later, is mounted on the lower flange plate 22.

Reference numeral 23 denotes an inner cylinder located at the innermost position of the inner cylinder 21 which is movably housed in the first inner cylinder 21 with a proper gap therebetween. The inner cylinder 23 is surrounded by a rear surface 23A, a front surface 23B, a left surface 23C and a right surface 23D. The inner cylinder 23 of the second stage is formed as a cylinder having a rectangular cross-sectional shape smaller than the inner cylinder 21 of the first stage. The second stage inner cylinder 23 is accommodated in the inner side of the inner cylinder 21 from the lower end side of the first stage inner cylinder 21 and is movable in the longitudinal direction (up and down direction) with respect to the inner cylinder 21 .

A slide plate (not shown) for smoothly sliding the inner tube 23 along the inner tube 21 is disposed between the inner surface of the first-stage inner tube 21 and the outer surface of the second- Respectively. On the other hand, a mounting eye 24 is provided on the lower end portion of the inner cylinder 23, and a clam shell bucket 43 described later is mounted on the mounting eye 24.

Next, the extensible cylinder 25 according to the present embodiment, the tube guide 26 attached to the extensible cylinder 25, the sheave mount guide rail 28, the sheave mount 30, and the like will be described.

Reference numeral 25 denotes a stretching cylinder arranged along the longitudinal direction of the outer cylinder 13 constituting the stretching arm 12, and a hydraulic cylinder which is stretched or contracted by the pressure difference of the pressure stroke is used as the stretching cylinder 25. The extensible cylinder 25 includes a tube 25A and a piston (not shown) slidably movable in the tube 25A. The piston 25A has one side fixed to the piston in the tube 25A and the other side fixed to the piston 25A And a rod 25B protruding outward from the rod 25B.

The extensible cylinder 25 is provided on the rear face 13A side of the outer cylinder 13 provided with the boom bracket 17 and at the center position in the left and right direction of the outer cylinder 13 by moving the rod 25B upward As shown in FIG. The distal end portion 25C of the rod 25B of the extensible cylinder 25 is provided with a pin 25D on the bracket 13J provided in the vicinity of the upper end portion 13G of the outer cylinder 13 Lt; / RTI >

On the other hand, the tube 25A of the extensible cylinder 25 extends downward as a free end and is disposed in a gap 17B formed between the pair of boom brackets 17 in the left and right directions. Further, on the upper side of the tube 25A, a sheave mounting hole 30 to be described later is mounted. The tube 25A is elastically deformed in the outer tube 13 together with the sheave fitting 30 by expanding and contracting the extensible cylinder 25 between the latest state shown in Fig. 1 and the state shown in Fig. 2, As shown in Fig.

The length from the bottom 25A1 of the tube 25A to the distal end 25C of the rod 25B (the position of the pin 25D) (The length of the extensible cylinder 25 in the minimized state) is L1 and the position of the pin 25D in the vicinity of the upper end portion 13G1 (the rod 25B of the outer cylinder 13 is connected to the outer cylinder 13) The length L1 of the extensible cylinder 25 in the minimized state is set to be substantially equal to the length L2 of the length L2 of the outer cylinder 13 when the length dimension from the lower end 13H to the lower end 13H / 2. ≪ / RTI >

That is, the length L1 of the extensible cylinder 25 in the minimized state and the length L2 of the outer cylinder 13 are set in the following relationship.

More preferably, the length L1 of the extensible cylinder 25 in the minimized state and the length L2 of the outer cylinder 13 are set in the following relationship.

In this way, by setting the length L1 of the extensible cylinder 25 in the minimized state to a length of about 1/2 of the length L2 of the outer cylinder 13, , The extensible cylinder 25 can be extended most and the stroke of the extensible cylinder 25 can be secured to a large extent. Thus, only by winding the stretch rope 34 four times between a later-described fixed sheave unit for expansion and contraction 31 and a movable sheave unit 33 for extension and contraction, It can be expanded or contracted between the reduced state and the latest field state shown in Fig.

2, the bottom portion 25A1 of the tube 25A is connected to the pin 20 (the connecting portion of the cylinder bracket 19 and the excavator rocking cylinder 4B), which is the connecting portion of the cylinder bracket 19 and the excavator rocking cylinder 4B, As shown in Fig. On the other hand, when the extensible cylinder 25 is in the latest state shown in Fig. 1, the bottom portion 25A1 of the tube 25A is moved downward from the pin 18, which is the connecting portion of the boom bracket 17 and the boom 4, .

The bottom portion 25A1 of the tube 25A of the stretching and shrinking cylinder 25 is elastically deformed by the extension of the boom bracket 17 provided on the outer tube 13, And the cylinder bracket 19, the operation of the extensible cylinder 25 can be stabilized.

Reference numeral 26 denotes a tube guide provided outside the rear face 13A of the outer cylinder 13 and the tube guide 26 movably accommodates the tube 25A of the extensible cylinder 25. [ As shown in Figs. 12 and 13, the tube guides 26 are formed by respective cylinders having a substantially square cross-sectional shape. The tube guide 26 is disposed in the gap 17B formed between the pair of boom brackets 17 and fixed to the rear face 13A of the outer cylinder 13 along the longitudinal direction thereof. The tube 25A of the extensible cylinder 25 at the free end can be moved in the longitudinal direction of the outer cylinder 13 while being guided by the tube guide 26. [

A slide plate (27) is provided on the outer surface of the bottom side of the tube (25A) of the stretching and shrinking cylinder (25). The tube 25A of the extensible cylinder 25 is inserted into the inner circumferential side of the tube guide 26 and the slide plate 27 moves along the inner surface of the tube guide 26. [ Thereby, the tube 25A can smoothly move along the tube guide 26 in the longitudinal direction of the outer tube 13. [

Reference numeral 28 denotes two sheave mounting hole guide rails provided outside the outer cylinder 13. Each sheave mounting hole guide rail 28 guides a sheave mounting hole 30 to be described later. These two sheave mounting guide rails 28 are arranged on the left and right sides of the rear face 13A of the outer cylinder 13 with the extensible cylinder 25 interposed therebetween.

Here, the sheave mounting port guide rails 28 are formed by respective cylinders having a rectangular cross-sectional shape. The upper end portion of the sheave mounting port guide rail 28 is fixed to the vicinity of the upper end portion 13G of the outer cylinder 13 through the bracket 28A and the lower end portion of the sheave mounting port guide rail 28 is fixed to the outer cylinder 13 And is fixed in the vicinity of the upper flange plate 14 via a bracket 28B. The sheave mounting guide rail 28 extends in the longitudinal direction in parallel with the rear surface 13A in a state in which the sheave mounting guide rail 28 is spaced apart from the rear surface 13A of the outer cylinder 13 by a predetermined distance. In this case, by securing the two sheave mounting port guide rails 28 constituted by square cylinders to the outer cylinder 13, the strength of the outer cylinder 13 can be increased.

Reference numeral 29 denotes a sheave mounting substrate fixed to the upper end portion 13G of the outer cylinder 13. The sheave mounting substrate 29 is to be mounted with the later-described fixed sheave units 31 and 31 'for expansion and contraction. The sheave mounting board 29 has a sheave mounting portion 29A projecting from the rear face 13A of the outer cylinder 13 to the rear side (on the side of the boom 4), and a sheave mounting portion 29A on the front side of the sheave mounting portion 29A And a rope fastening portion 29B positioned thereon. The fixed sheave units 31 and 31 'are rotatably supported on the sheave mounting portion 29A of the sheave mounting board 29. The rope holding portion 29B is provided with a plurality of ropes 34 and 34' (34A, 34A ') of the upper surface

Reference numeral 30 denotes a sheave mount fitted to the tube 25A of the extensible cylinder 25. The sheave mount 30 includes a movable sheave unit 33, 33 'for expansion and contraction and a movable sheave 41, 41 'are mounted. 7, 12, and 13, the sheave fitting 30 includes a main body portion 30A fixed to the upper side of the tube 25A of the extensible cylinder 25, and a main body portion 30A An upper side sheave support portion 30B located on the upper side of the main body portion 30A and rotatably supporting the movable sheave units 33 and 33 ' And a lower sheave support portion 30C for rotatably supporting the lower sheave support portions 41, 41 '. The main body portion 30A of the sheave mount 30 is curved in a mountain shape so as to avoid the tube guide 26. [

On the other hand, as shown in Fig. 12, on the main body portion 30A of the sheave mounting opening 30, there are provided left and right sipe-like guide rails 28, which are slidably inserted through the left and right sheave mounting opening guide rails 28, And the sheave mounting hole 30 is movable in the longitudinal direction (up and down direction) of the outer cylinder 13 while being guided by the left and right sheave mounting hole guide rails 28 have.

Next, the structure for connecting the outer tube 13 constituting the stretching arm 12 with the inner tube 21 of the first stage and the inner tube 23 of the second stage in a stretchable manner, that is, , The movable sheave units 33 and 33 'for stretching and shrinking, the stretching ropes 34 and 34', the fixing sheaves 35 and 35 'for supporting and the supporting ropes 37 and 37' will be described.

The movable sheave units 31 and 31 'for expansion and contraction, the movable sheave units 33 and 33' for expansion and contraction, the expansion and contraction ropes 34 and 34 ', the fixing sheaves 35 and 35' (37, 37 ') are arranged symmetrically with respect to the outer cylinder (13) with the extensible cylinder (25) interposed therebetween, and have the same structure. The movable sheave unit 33 for stretching and shrinking, the stretching rope 34, the fixing sheave 35 for supporting, the support rope 34, and the support rope 34, which are disposed on the left side of the outer cylinder 13, Quot; is given to the code of the corresponding constituent element, and the description thereof is omitted.

Reference numeral 31 denotes a fixed sheave unit for extension and retraction which is fixed to the upper end side of the outer cylinder 13 through a sheave mounting board 29. The fixed sheave unit 31 for expansion and contraction includes two fixed sheaves 31A , And 31B. 8, one of the fixed sheaves 31A is rotatably supported by one of the brackets 32A provided on the sheave mounting portion 29A of the sheave mounting board 29, The fixed sheave 31B on the other side is rotatably supported on the other bracket 32B. In this case, the support shafts (not shown) of the respective fixed sheaves 31A and 31B are arranged so as to be non-parallel to the rear surface 13A of the outer cylinder 13, respectively.

And reference numeral 33 denotes an expandable movable sheave unit rotatably supported on the sheave mounting hole 30. [ The movable sheave unit 33 for expansion and contraction is constituted by two movable sheaves 33A and 33B having the same diameter. 12, the one movable sheave 33A and the other movable sheave 33B are connected to one support shaft 33C mounted on the upper sheave support portion 30B of the sheave mount 30, And is rotatably supported adjacent thereto. In this case, the support shafts 33C of the movable sheaves 33A and 33B are arranged in parallel to the rear surface 13A of the outer tube 13. [ The movable sheave unit 33 for expanding and shrinking is moved toward or away from the fixed sheave unit 31 for extension and retraction by moving the sheave mounting hole 30 upward and downward as the expanding cylinder 25 expands and shrinks.

The movable sheave unit 33 for extension and retraction supported by the sheave mounting opening 30 is disposed on the outer side of the left side face 13C of the outer cylinder 13 and extends in the left and right direction . This makes it possible to prevent the movable sheave unit 33 for extensible shafts from projecting greatly toward the rear surface 13A side of the outer casing 13 and to downsize the periphery of the movable sheave unit 33 for expansion and contraction.

Reference numeral 34 denotes an extension rope connecting the outer cylinder 13 and the innermost second inner cylinder 23, and the extension rope 34 is constituted by a wire rope. 9 and 10, the one end portion 34A of the stretchable rope 34 is connected to the rope latching portion 29B of the sheave mounting board 29 provided on the upper end portion 13G of the outer tube 13 And the other end 34B of the stretchable rope 34 is hooked on the upper side of the inner tube 23 of the second stage. The intermediate portion of the rope 34 for extension and contraction is composed of two fixed sheaves 31A and 31B constituting the fixed sheave unit 31 for expansion and contraction and two fixed sheaves 31A and 31B constituting the expandable movable sheave unit 33 And is wound four times between the movable sheaves 33A and 33B.

That is, the one end portion 34A of the stretchable rope 34 is caught by the sheave mounting substrate 29 and the middle portion of the stretchable rope 34 is positioned on one of the movable sheaves One of the fixed sheaves 31A of the movable sheave unit 33A and the movable sheave 33B of the movable sheave unit 33 for expansion and contraction and the other fixed sheave 31B of the fixed sheave unit 31 for expansion and contraction, (31B). The stretchable rope 34 is inserted into the outer tube 13 and the inner tube 21 of the first stage from the other fixed sheave 31B of the retractable fixed sheave unit 31, And the other end 34B of the inner tube 34 is hooked on the upper side of the inner tube 23 of the second stage.

As described above, the two movable sheave units 33A and 33B are constituted by the two fixed sheaves 31A and 31B, and the movable sheave unit 33 for expansion and contraction is constituted by the two movable sheaves 33A and 33B Respectively. The stretchable rope 34 is wound on the two fixed sheaves 31A and 31B and the two movable sheaves 33A and 33B four times in total. As compared with the construction in which, for example, as in the prior art, the rope for expansion and contraction is wound eight times in total between the four sheaves of the four sheaves of the fixed sheave for retracting and the movable sheave for retracting, 34 can contact with the sheave in half.

And reference numeral 35 denotes a single fixed sheave for support provided on the lower flange plate 22 of the first stage inner cylinder 21. [ The support securing sheave 35 is rotatably supported by a bracket 36 fixed to the lower flange plate 22 of the inner tube 21. [

Reference numeral 37 denotes a support rope for supporting the inner cylinder 21 between the outer cylinder 13 and the inner cylinder 23 and the support rope 37 is constituted by a wire rope. 9 and 10, the one end 37A of the support rope 37 is caught by the lower flange plate 15 of the outer tube 13 and the middle portion of the support rope 37 Is wound around a support securing sheave 35. [ The support rope 37 is inserted into the inner tube 21 of the first stage from the support securing sheave 35 and the other end 37B of the support rope 37 is inserted into the inner tube 23 As shown in Fig.

Next, the press-fitting mechanisms 38 and 38 'for press-fitting the first inner cylinder 21 in the extension direction when the inner cylinder 21 is extended from the outer cylinder 13 by the stretching and shrinking cylinder 25 will be described.

That is, left and right press-fitting mechanisms 38 and 38 'are provided between the outer cylinder 13 and the first-stage inner cylinder 21. Each of the press fitting mechanisms 38 and 38 'holds the inner cylinder 21 in a stretched state when the inner cylinder 21 is extended from the outer cylinder 13 by the stretching and shrinking cylinder 25.

Here, as shown in Figs. 13 and 14, the press-fitting mechanisms 38 and 38 'are provided with press-fitting securing sheaves 39 and 39', press-fitting movable sheaves 41 and 41 ' (42, 42 '). Each press-fitting mechanism 38, 38 'is provided so as to be symmetrical to the left and right with respect to the outer cylinder 13 with the extensible cylinder 25 therebetween, and has the same structure. Hereinafter, the press-fitting mechanism 38 disposed on the left side of the outer cylinder 13 will be described, and the prime "'" is assigned to the component elements arranged on the right side, do.

And reference numeral 39 denotes a press-fitting fixed sheave provided on the lower side of the outer cylinder 13. As shown in Fig. 14, the press-fitting securing sheave 39 is provided with a bracket 40 fixed to the outer cylinder 13 by passing a sheave mounting opening 16 formed in the outer cylinder 13, and a support shaft 39A As shown in Fig. In this case, the support shaft 39A of the press-fitting securing sheave 39 is disposed at an inclination angle of less than 90 degrees with respect to the left side face 13C of the outer cylinder 13 at an angle? That is, the support shaft 39A of the press-fitting securing sheave 39 is disposed in a non-parallel manner with respect to the rear surface 13A of the outer cylinder 13 and is supported by the press-fitting securing sheave 39 Is partly housed inside the outer cylinder 13. [0050]

Reference numeral 41 denotes a press-fitting movable sheave provided in the sheave mounting hole 30 at a position lower than the movable sheave unit 33 for expansion and contraction. As shown in Fig. 13, the press-fitting movable sheave 41 is rotatably supported on the lower sheave support portion 30C of the sheave mount 30 through a support shaft 41A. In this case, the support shaft 41A of the press-fitting movable sheave 41 is disposed parallel to the rear surface 13A of the outer cylinder 13. [ The press-fitting movable sheave 41 is moved toward or away from the press-fitting fixed sheave 39 by moving the sheave fittings 30 upward and downward as the expanding and contracting cylinder 25 expands and shrinks.

Reference numeral 42 denotes a press-in rope connecting the outer cylinder 13 and the first-stage inner cylinder 21, and the press-in rope 42 is constituted by a wire rope. 9 and 10, the one end portion 42A of the press-in rope 42 is caught by the upper flange plate 14 of the outer cylinder 13 and the middle portion of the press-in rope 42 Is wound around the press-fitting movable sheave (41) and the press-fitting fixed sheave (39). The other end 42B of the press-in rope 42 is inserted into the outer cylinder 13 from the press-fitting securing sheave 39 and is inserted from the inner side of the outer cylinder 13 to the upper side of the inner cylinder 21 It is hanging.

1 and Fig. 10, the tube 25A of the extensible cylinder 25 is inserted into the sheave mounting hole 30, The movable sheave unit 33 for expansion and contraction approaches the fixed sheave unit 31 for expansion and contraction. Thus, the stretch rope 34 wound around the stretchable movable sheave unit 33 and the stretchable sheave unit 31 for stretch and shrink is led out and the second inner barrel 23 is pulled downward from the outer barrel 13 by its own weight . At this time, since the other end 37B of the support rope 37 hooked on the upper side of the inner barrel 23 moves downward together with the inner barrel 23 of the second row, The inner tube 21 of the outer tube 13 extends downward from the outer tube 13 by its own weight. Thus, as shown in Figs. 2 and 10, the tube 25A moves to the upper limit position and the extensible cylinder 25 reaches the minimized state, so that the extensible arm 12 is in the latest state.

When the sheave mount 30 approaches the retracting fixed sheave unit 31, the press-in rope 42 is wound between the press-fitting movable sheave 41 and the press-fitting securing sheave 39, And the other end 42B of the rope 42 moves downward along the inner bottom 21 of the first row. Thereby, the press-in rope 42 always maintains a constant tension. Further, since the inner tube 21 is stretched while being supported by the support rope 37, the support rope 37 always maintains a constant tension.

Therefore, in the state where the inner tubes 21 and 23 are extended from the outer cylinder 13, an excavating operation is performed using the clam shell bucket 43 to be described later, whereby an upward excavating reaction force acts on the inner cylinders 21 and 23 The inner tubes 21 and 23 can be prevented from moving to the reduced side due to the tension of the press-in rope 42 and the support rope 37. [

2 and 10, the tube 25A of the extensible cylinder 25 moves downward together with the sheave mounting hole 30 (see FIG. 2) , The movable sheave unit 33 for expansion and contraction is separated from the fixed sheave unit 31 for expansion and contraction. Thus, the stretching rope 34 is wound between the retractable movable sheave unit 33 and the retractable fixed sheave unit 31, the second inner cylinder 23 moves upward, and the first inner cylinder 21 ). At this time, the other end 37B of the support rope 37 hanging on the upper side of the inner barrel 23 moves upward together with the inner barrel 23, so that the first-stage inner barrel 21 also move upward and are accommodated in the outer cylinder 13. [ Thus, as shown in Figs. 1 and 9, the tube 25A moves to the lower limit position and the extensible cylinder 25 reaches the latest length state, so that the extensible arm 12 is brought into the minimized state.

On the other hand, when the expansion and contraction arm 12 is expanded or contracted between the minimized state and the latest state, the fixed sheave unit 31 'for expansion and contraction and the movable sheave unit for expansion and contraction The fixing roots 34 'for the press-fitting, the fixing sheave 35' for supporting, the support rope 37 'and the press-fitting fixing sheave 39' constituting the press-fitting mechanism 38 ' The movable sheave 41 'and the press-in rope 42' also operate as described above.

13 and 14, the outer cylinder 13 has a rear surface 13A, a front surface 13B, a left surface 13C, a right surface 13D, a left inclined surface 13E, 13F, and the press-fitting movable sheave 41 is arranged at a position facing the left slope 13E in left and right directions. Thus, as shown by the arrow X in FIG. 13, the press-fitting movable sheave 41 can be arranged close to the left slope 13E. Preferably, the press-fitting movable sheave 41 is positioned at the same position as the left side surface 13C, or at a more inward position. As described above, by moving the press-fitting movable sheave 41 toward the left inclined face 13E of the outer cylinder 13, the press-fitting movable sheave 41 with respect to the left face 13C of the outer cylinder 13 can be moved in the left- It is possible to suppress the protrusion of the movable sheave 41 against the rear face 13A of the outer cylinder 13 and also to suppress the protrusion in the forward and backward directions.

On the other hand, when the press-fitting movable sheave 41 is arranged in this manner, the support shaft 39A of the press-fitting securing sheave 39, in which the press-in rope 42 is wound with the press-fitting movable sheave 41, , And the angle? Formed by the left side face 13C of the outer cylinder 13 can be increased. Thus, as shown by the arrow Y in FIG. 14, a part of the press-fitting fixing sheave 39 accommodated in the outer cylinder 13 can be sufficiently separated from the inner cylinder 21. [ Further, the projecting amount of the press-fitting fixed sheave 39 from the left side surface 13C can be reduced. As a result, the gap between the press-fitting fixed sheave 39 and the first-stage inner cylinder 21 is maintained at a sufficient interval (distance) between the press-fitting fixed sheave 39 and the first-stage inner cylinder 21 without increasing the dimension between the left and right side surfaces 13C, And the entire stretchable arm 12 can be made compact. This also applies to the press-fitting movable sheave 41 'and press-fitting rope 42' disposed on the right side with the extensible cylinder 25 therebetween.

Reference numeral 43 denotes a clam shell bucket mounted to be able to swing on a mounting eye 24 provided on the front end side (lower end side) of the inner cylinder 23. [ The clam shell bucket 43 is opened and closed by expanding and contracting the bucket cylinder 44 to excavate the gravel.

The deep drawing excavator 1 according to the present embodiment has the structure as described above and is hereinafter referred to as an operation for excavating the stock 101 by using the deep drawing excavator 1 with respect to the ground surface 100 to be deep excavated .

First, as shown in Fig. 1, the deep drawing excavator 1 causes the extensible cylinder 25 to be extended most, thereby causing the expansion and contraction arm 12 to be in a minimized state, The arm 12 is held in a vertical posture.

Next, as shown in Fig. 2, the telescopic cylinder 25 is contracted to bring the telescopic arm 12 into a stretched state. That is, the tube 25A of the extensible cylinder 25 is moved upward together with the sheave mounting opening 30 to bring the movable sheave unit 33 for extension and retraction to approach the fixed sheave unit 31 for expansion and contraction. The two movable sheaves 33A and 33B of the movable sheave unit 33 for extension and contraction and the two sheaves 31A and 31B of the fixed sheave unit 31 for expansion and contraction 34). As a result, the second-stage inner cylinder 23 is extended downwardly from the outer cylinder 13 by its own weight, and the first-stage inner cylinder 21 supported by the support rope 37 is also self- Lt; / RTI >

At this time, the press-in rope 42 is wound between the press-fitting movable sheave 41 supported by the sheave mount 30 and the press-fitting securing sheave 39 so that the press-in rope 42 always maintains a constant tension do. Further, the support rope 37 that supports the first inner cylinder 21 between the outer cylinder 13 and the second-stage inner cylinder 23 always maintains a constant tension.

As a result, the inner cylinders 21 and 23 can be maintained in a stretched state from the outer cylinder 13 by the tension of the press-in rope 42 and the support rope 37, 101 to the bottom surface 102 of the housing. In this state, by opening and closing the clam shell bucket 43 by the bucket cylinder 44, the clam shell bucket 43 can be used to deeply excavate the stock 101, A large amount of soil can be plowed by.

The tube 25A of the stretching and shrinking cylinder 25 is moved downward together with the sheave fitting 30 by stretching the stretching cylinder 25 after the clay shell bucket 43 has spread the gravel, The sheave unit 33 is separated from the fixed sheave unit 31 for expansion and contraction.

Thereby, the stretch ropes 34 are wound between the movable sheaves 33A and 33B of the movable sheave unit 33 for extension and contraction and the fixed sheaves 31A and 31B of the fixed sheave unit for expansion and contraction 31 , The inner cylinder 23 moves upward and is accommodated in the inner cylinder 21. [ At this time, the other end 37B of the support rope 37 connecting between the outer cylinder 13 and the inner cylinder 23 is moved upward together with the inner cylinder 23 to be supported by the support rope 37 The inner cylinder 21 also moves upward and is accommodated in the outer cylinder 13. [ As a result, the telescopic arm 12 is again in the minimized state shown in Fig.

Next, as shown in Fig. 1, after the extensible cylinder 25 reaches the latest length state and the extensible arm 12 is brought into the minimized state, the tip end side of the boom 4 is lifted, The bucket 43 is pulled out of the stock 101. Then, with the lower cruising body 2 stopped, the upper cruising body 3 is pivoted toward the predetermined clay position, and the clay held by the clamshell bucket 43 is discharged to the clay position .

According to the deep drawing excavator 1 of the present embodiment, the fixed sheave unit 31 for expansion and contraction is constituted by two fixed sheaves 31A and 31B, and the movable sheave unit 33 for expansion and contraction is composed of two pieces And the movable sheaves 33A and 33B of the movable sheave 33B. The stretchable rope 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, as compared with the configuration in which, for example, the stretchable rope is wound eight times in total between four sheaves of the fixed sheave unit for retracting and four sheaves of the movable sheave unit for stretching and shrinking, The number of times the rope 34 contacts the fixed sheaves 31A and 31B and the movable sheaves 33A and 33B can be reduced by half and thus the service life of the stretch rope 34 can be extended.

In this case, the stretch rope 34 disposed on the left side with the extensible cylinder 25 interposed therebetween is wound four times on the two fixed sheaves 31A and 31B and the two movable sheaves 33A and 33B And the extension rope 34 'disposed on the right side with the extensible cylinder 25 interposed therebetween is provided with two fixed sheaves 31A' and 31B 'and two movable sheaves 33A' and 33B ' . As compared with the large-scale construction in which, for example, the conventional stretch rope is wound eight times between the four fixed sheaves and the four movable sheaves, on both the left and right sides of the outer cylinder 13, The ropes 34 and 34 'and the like can be arranged compactly.

Further, even if one of the stretch ropes 34, 34 'disposed on the left and right sides with the stretching cylinder 25 interposed therebetween is cut off, the inner tube 23 can be supported by the other stretching rope , It is possible to secure the safety of excavation work.

The stretchable rope 34 is composed of two fixed sheaves 31A and 31B constituting the fixed sheave unit 31 for expansion and contraction and two movable sheaves 31A and 31B constituting the expandable movable sheave unit 33 33A, and 33B. As a result, the lifting amount of the inner tubes 21, 23 using the stretchable rope 34 can be made four times as large as the stroke of the stretching and contracting cylinder 25, and the inner tubes 21, 23 can be efficiently lifted.

On the other hand, in the deep drawing excavator 1 according to the present embodiment, the length dimension L1 when the extensible cylinder 25 is in the minimized state is set to a length dimension which is approximately 1/2 of the length dimension L2 of the outer cylinder 13 . Therefore, the extensible cylinder 25 can be stretched to the greatest extent within the range of the length L2 of the outer cylinder 13, and a large stroke of the extensible cylinder 25 can be ensured. As a result, two pieces of fixed sheaves 31A and 31B of the fixed sheave unit 31 for expansion and contraction and two movable sheaves 33A and 33B of the movable sheave unit 33 for expansion and contraction It is possible to stretch and contract the expansion and contraction arm 12 between the minimized state shown in Fig. 1 and the latest state shown in Fig.

The distal end portion 25C of the rod 25B of the elongating and contracting cylinder 25 is connected to the bracket 13J provided on the outer cylinder 13 of the telescopic arm 12 by the pin 25D ). ≪ / RTI > On the other hand, the sheave mounting opening 30 for supporting the expandable movable sheave unit 33 and the press-fitting movable sheave 41 is mounted on the tube 25A of the extensible cylinder 25 which is a free end. Therefore, when the stretchable cylinder 25 is stretched to lift up the soil excavated by the clam shell bucket 43, the heavy tube 25A moves downward together with the sheave mount 30.

The expansion and contraction rope 34 wound around the expansion and contraction movable sheave unit 33 and the expansion and sheave unit 31 for extension and contraction can reduce the downward load caused by the weight of the tube 25A and the sheave installation hole 30 Receive. As a result, the stretching arm 12 can increase the pulling force of the inner tubes 21 and 23 by using the weight of the tube 25A and the sheave fittings 30, , 23) can be efficiently performed.

According to this embodiment, the rod 25B of the extensible cylinder 25 is fixed to the upper side of the outer cylinder 13 and below the fixed sheave unit 31 for expansion and contraction. The tube 25A of the extensible cylinder 25 on which the sheave mount 30 is mounted can move upward and downward in the range of substantially the upper half of the outer cylinder 13 extending in the upward and downward directions. 1, for example, even when the lower half of the outer cylinder 13 is dropped into the underground during the excavation of the stock 101, the operator in the cap 3B of the upper revolving structure 3, The expansion and contraction of the stretching and shrinking cylinder 25 can be visually confirmed. As a result, workability and safety of the digging operation using the deep drawing excavator 1 can be enhanced.

According to the present embodiment, the two sheave mounting port guide rails 28 are fixed to the outside 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 mounting hole 30 is configured to move in the longitudinal direction of the outer cylinder 13 along the sheave mounting port guide rail 28 in accordance with the expansion and contraction of the expansion and contraction cylinder 25.

Therefore, the sheave mount 30 is guided by the sheave mount guide rail 28 and can always move on a constant orbit. As a result, the stretch rope 34 wound around the retractable fixed sheave unit 31 and the retractable movable sheave unit 33 can smoothly follow the movement of the retractable movable sheave unit 33, It is possible to enhance the stability of the expansion and contraction of the inner tubes 21 and 23 with respect to the inner tube 13. Since the two sheave mounting port guide rails 28 are fixed to the outer cylinder 13, the strength of the outer cylinder 13 can be increased by the sheave mounting port guide rails 28, It is possible to increase the reliability.

On the other hand, the tube 25A of the extensible cylinder 25 on which the sheave mount 30 is mounted can move on a constant orbit along the sheave mount guide rail 28. As a result, it is possible to increase the strength against the buckling and the lateral load of the stretching and shrinking cylinder 25, thereby enhancing the reliability of the stretching and contracting cylinder 25.

According to the present embodiment, the pair of boom brackets 17 are provided on the rear face 13A of the outer cylinder 13 positioned on the cap 3B side of the upper revolving structure 3, The bracket 17 is attached to the front end side of the boom 4. In addition, the extensible cylinder 25 is disposed between the pair of boom brackets 17.

Thereby, the sheave mounting hole 30 mounted on the tube 25A of the extensible cylinder 25, the movable sheave unit 33 for expansion and contraction supported on the sheave mounting hole 30, the fixed sheave unit 31 for expansion and contraction, The rope 34 and the like wound around the movable sheave unit 33 for extension and contraction can be disposed at a position facing the cap 3B of the upper revolving structure 3. [ As a result, the operator in the cap 3B can expand and contract the inner cylinders 21 and 23 with respect to the outer cylinder 13 while visually observing the extensible cylinder 25 or the like, and can accurately perform this expansion and contraction.

Since the boom bracket 17 is provided on the rear face 13A of the outer cylinder 13, the expansion cylinder 25, the fixed sheave unit 31 for expansion and contraction, the sheave mounting hole 30, the movable sheave unit 33 And the like need not be provided on the front face 13B of the outer cylinder 13. [ As a result, during the excavation of the stock 101, the extensible cylinders 25 and the like are prevented from being brought into contact with the obstacle and damaged, and workability of excavation work can be enhanced.

15, since the boom bracket 17 is provided on the rear face 13A of the outer cylinder 13, the front face of the outer cylinder 13 (13B) can be placed on the ground. Thereby, the extensible cylinder 25, the sheave mount 30, the fixed sheave unit 31 for expansion and contraction, the movable sheave unit 33 for expansion and contraction, and the like are mounted on the extensible arm 12 Can be maintained in an upward posture in which the weight of the backrest can not act.

Therefore, in the state in which the deep drawing excavator 1 is in the transporting posture, the extensible cylinder 25 mounted on the outer cylinder 13, the fixed sheave unit 31 for expansion and contraction, the sheave mounting hole 30 and the movable sheave unit 33 and the like can be performed at a position close to the ground, so that the workability of this maintenance work can be enhanced.

According to the present embodiment, the square tubular guide 26 is provided on the rear face 13A of the outer cylinder 13 and the tube 25A of the extensible cylinder 25 is moved Movement). The tube 25A of the extensible cylinder 25 as the free end can be guided in the longitudinal direction of the outer tube 13 by the tube guide 26. [ Therefore, even if the sheave mount 30 is mounted on the tube 25A, the tube 25A can be smoothly moved along the tube guide 26. [

The tube 25A of the stretching and shrinking cylinder 25 can move along a predetermined orbit along the tube guide 26 so that the strength of the stretching and shrinking cylinder 25 against buckling and lateral load can be increased. In addition, the tube 25A can be protected from falling stone or the like due to excavation of the stock 101 by accommodating the tube 25A in the tube guide 26. [

According to the present embodiment, the outer cylinder 13 is formed in a cylindrical shape having a hexagonal cross-sectional shape, and the outer cylinder 13 is provided between the rear face 13A and the left and right side faces 13C and 13D. (13E, 13F). As a result, the buckling strength can be increased with respect to the load acting on the outer cylinder 13, and the life of the outer cylinder 13 can be prolonged, so that the reliability of the entire stretchable arm 12 can be enhanced.

The movable sheave unit 33 for expansion and contraction is arranged on the outer side with respect to the left side face 13C of the outer cylinder 13 so that the movable sheave unit 33 for expansion and contraction is slightly smaller than the left side face 13C of the outer cylinder 13. [ They face each other in left and right directions at intervals. This makes it possible to prevent the movable sheave unit 33 from being greatly projected toward the rear face 13A side of the outer cylinder 13. Even when the movable sheaves 33A and 33B having a large diameter are used, The periphery of the sheave unit 33 can be downsized. As a result, by using the movable sheaves 33A and 33B having a large diameter, the life of the stretch rope 34 can be extended. Further, the movable sheave unit 33 'for expansion and contraction is disposed outside the right side face 13D of the outer cylinder 13, so that the same effect as described above can be obtained.

Thus, the deep excavator 1 according to the present embodiment has a structure that can extend the service life of the stretch rope 34, so that the load acting on the stretch rope 34 can be set to be large. As a result, a large load can be hung up by the second-stage inner tube 23 to which the expansion and contraction rope 34 is connected, and the capacity of the clam shell bucket 43 mounted on the tip end side of the inner cylinder 23 can be increased So that the excavation efficiency can be increased by digging a large amount of soil.

According to the deep drawing 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 part of the press-fitting fixed sheaves 39 and 39' And is disposed inside the outer cylinder 13 through the sheave mounting openings 16 and 16 '. Thus, even when the diameters of the press-fitting fixed sheaves 39 and 39 'are set to be large, the press-fitting fixed sheaves 39 and 39' can be compactly mounted on the outer cylinder 13. [ As a result, the life of the press-in ropes 42, 42 'can be prolonged by using the press-fitting fixed sheaves 39, 39' having a large diameter.

Since the press-fitting fixing sheaves 39 and 39 'are disposed at the positions of the sheave mounting openings 16 and 16' provided on the lower side of the outer cylinder 13, There is no need to deploy a sheave. The lower flange plate 22 provided at the lower end of the inner cylinder 21 is prevented from interfering with the press-fitting fixed sheaves 39, 39 'even when the first-stage inner cylinder 21 is accommodated in the outer cylinder 13. [ There is no. The lower flange plate 22 of the inner tube 21 can be brought close to the vicinity of the lower end portion 13H of the outer cylinder 13, that is, the lower flange plate 15. [ As a result, the entire length of the telescopic arm 12 when the telescopic arm 12 is minimized can be shortened. For example, a compact telescopic attitude can be achieved when the deep-drawn excavator 1 is transported.

In the above-described embodiment, the outer cylinder 13 constituting the stretchable arm 12 is provided with the extensible cylinder 25 and the sheave mounting guide rail 28, a sheave mount 30, a fixed sheave unit 31 for expansion and contraction, and a movable sheave unit 33 for expansion and contraction are arranged. However, the present invention is not limited to this, and may be configured as a modified example shown in Fig. 16, for example. That is, on the front face 13B side of the outer cylinder 13, the extensible cylinder 25, the sheave mounting hole guide rail 28, the sheave mounting hole 30, the fixed sheave unit 31 for expansion and contraction, Unit 33 or the like may be disposed. Thereby, the operator who is familiar with the existing stretching arm can avoid the discomfort when operating the deep drawing excavator, and the operability thereof can be improved.

In the above-described embodiment, the sheave mounting guide rails 28 for guiding the sheave mounting holes 30 are formed by respective cylinders having a rectangular cross-sectional shape. However, the present invention is not limited to this. For example, a sheave mounting guide rail may be formed by using a steel material having an L-shaped cross-sectional shape.

2: Lower traveling body (body)
3: Upper revolving body (body)
4: Boom
12: stretching arm
13: outer tube
13A: rear face
13B: front side
13C: Left side
13D: Right side
13E: Left slope
13F: right side slope
13G:
13H: Lower end
16: Sheave mounting opening
17: Boom bracket
21: First inner cylinder
23: The second inner cylinder
25: Extension cylinder
25A: tube
25A1:
25B: Load
25C:
26: Tube guide
28: Sheave mounting guide rail
30: Sheave mounting hole
31, 31 ': Fixed sheave unit for extension and contraction
33, 33 ': a movable sheave unit for stretching and shrinking
34, 34 ': stretch rope
35, 35 ': a fixed sheave for supporting
38, 38 ': press-fitting mechanism
39, 39 ': Fixed sheave for press fitting
41, 41 ': press-fitting movable sheave
42, 42 ': press-in rope

Claims (12)

A telescopic arm provided on the distal end side of the boom of the object to be mounted, the telescopic arm having a plurality of inner cylinders extending in the up and down direction and accommodated in the outer cylinder and the outer cylinder in such a manner as to extend and retract in the longitudinal direction; A fixed sheave unit for left and right extending and retracting fixed to the outer cylinder; and a fixed sheave unit mounted on the extending and retracting cylinder so as to approach or separate from the respective fixed sheave units for extension and retraction, And a movable sheave unit for left and right extension and retraction of the movable sheave unit which is provided in the sheave mount and which is engaged with the inner cylinder whose one end side is engaged with the outer cylinder and the other end side is the innermost side of the inner cylinder, The left and right stretching ropes wound around the respective movable sheave units for stretching and shrinking are provided with the above- In the multi-stage stretching arm device,
Wherein each of the fixed and sheathing units for extension and contraction is constituted by two sheaves,
Each of the movable sheave units for expansion and contraction is constituted by two sheaves,
Each of the above-mentioned ropes for extension and contraction is constituted to be wound four times between the above-mentioned movable sheave unit for expansion and contraction and each of the movable sheave units for extension and contraction,
A pair of boom brackets are provided on the outer side of the outer cylinder and below the sheave mount so as to be pivotally mounted on the front end side of the boom,
The expansion cylinder is constituted by a tube and a hydraulic cylinder having a rod whose one side is fixed to the piston in the tube and the other side is a rod protruding outward from the tube,
The distal end portion of the rod of the stretchable cylinder is mounted on the upper side of the outer cylinder in an upward state,
Wherein the tube of the extensible cylinder is arranged in a gap formed between the pair of boom brackets. The method according to claim 1,
Wherein the outer cylinder is provided with a cylinder bracket having the boom bracket and a connecting portion connected to a swing cylinder provided above or below the boom bracket so as to be spaced apart from the boom bracket and pivotally moving the telescopic arm against the boom,
And the sheave mount is mounted on one of the tube and the rod of the stretching and shrinking cylinder,
Wherein one end of the tube and the rod is located above a connecting portion of a bracket positioned above one of the boom bracket and the cylinder bracket when the expansion cylinder is in a minimized state, Is disposed below the connecting portion of the bracket located below the boom bracket and the cylinder bracket. The method according to claim 1,
And a length from the bottom of the tube to the distal end of the rod in a minimized state of the stretching and shrinking cylinder is set to a half of the length of the outer tube. The method according to claim 1,
And the sheave mount is mounted on a tube of the extensible cylinder. The method according to claim 1,
Wherein each of the fixed sheave units for the expansion and contraction is provided symmetrically with respect to the outer cylinder through the extensible cylinder,
Wherein each of the movable sheave units for expansion and contraction is provided symmetrically with respect to the sheave mounting opening through the extensible cylinder,
Wherein each of the ropes for extension and contraction is provided between a sheave of the movable sheave unit for extension and retraction and a sheave of the movable sheave unit for expansion and contraction arranged on the left side with the extensible cylinder therebetween, And a sheave of the fixed sheave unit for retracting and a sheave of the movable sheave unit for retracting, respectively. The method according to claim 1,
And a sheave mounting guide rail extending in the longitudinal direction parallel to the outer cylinder and mounted on the outer cylinder is provided on the outer side of the outer cylinder,
And the sheave mounting portion is configured to move along the sheave mounting port guide rail in accordance with the expansion and contraction of the expansion and contraction cylinder. The method according to claim 1,
And a tube guide for accommodating the tube of the extensible cylinder movably and guiding the tube in the longitudinal direction of the outer cylinder is provided outside the outer tube. The method according to claim 1,
Wherein the outer cylinder has at least a rear face mounted on a front end side of the boom, a front face facing in the front and rear directions with respect to the rear face, and a left front face facing the left and right sides with the rear face and the front face in- And a polygonal cross-sectional shape having a right sloped surface inclined at an angle between the rear surface and the right surface,
Wherein the movable sheave unit for extension and contraction is arranged outside the left and right sides of the left and right sides of the outer cylinder. The method according to claim 1,
Wherein the outer tube has a rear surface mounted on a front end side of the boom, a front surface facing the rear surface in front and rear directions, and a left side surface facing the left and right sides with the rear surface and the front surface in- And a left side inclined surface arranged obliquely between the rear surface and the left side surface and a right side inclined surface disposed obliquely between the rear surface and the right side surface. Arm device. The method according to claim 1,
Wherein when the inner cylinder of the first stage is extended from the outer cylinder by the extensible cylinder, the inner cylinder is press-fitted into the inner cylinder of the first-stage inner cylinder at the outermost one of the inner cylinders of the plurality of stages, The instrument is installed,
Wherein the press fitting mechanism includes a left and right press-fitting fixed sheave positioned on the lower side of the outer cylinder and provided in the outer cylinder,
A left and right press-fitting movable sheave provided in the sheave mounting opening at a lower position than the movable sheave unit for expansion and contraction,
The one end side is caught by the outer cylinder and the other end side is caught by the inner cylinder of the first stage through the inside of the outer cylinder and the midway portion is wound around the left and right press fitting fixed sheave and the left and right press- Left and right indentation ropes,
And a sheave mounting opening is provided at a position where the left and right press-fitting fixing sheaves are provided on the lower side of the outer cylinder,
And a part of the left and right press-fitting fixed sheaves is disposed inside the outer cylinder through the sheave mounting opening. A boom provided so as to be capable of elevating and lowering in the vehicle body, and a multi-stage stretching arm device provided at a front end side of the boom,
The multi-stage stretch arm device includes: an extensible arm having an outer cylinder extending in an upward and downward direction and a plurality of inner cylinders retractably received in the longitudinal direction in an inner side of the outer cylinder; A fixed sheave unit for left and right extending and retracting fixed to the outer cylinder, and a fixed sheave unit mounted on the extensible cylinder and moved in the longitudinal direction of the outer cylinder so as to approach or separate from the fixed sheave unit for extension and retraction A movable sheave unit for left and right expanding and contracting movable sheave units provided in the sheave mounting opening and an inner cylinder in which one end side is engaged with the outer cylinder and the other end side is the innermost side of the inner cylinder, And a left and right stretching rope wound around the movable sheave unit for stretching and shrinking In the deep excavator,
Wherein each of the fixed and sheathing units for extension and contraction is constituted by two sheaves,
Each of the movable sheave units for expansion and contraction is constituted by two sheaves,
Each of the above-mentioned ropes for extension and contraction is constituted to be wound four times between the above-mentioned movable sheave unit for expansion and contraction and each of the movable sheave units for extension and contraction,
A pair of boom brackets are provided on the outer side of the outer cylinder and below the sheave mount so as to be pivotally mounted on the front end side of the boom,
The expansion cylinder is constituted by a tube and a hydraulic cylinder having a rod whose one side is fixed to the piston in the tube and the other side is a rod protruding outward from the tube,
The distal end portion of the rod of the stretchable cylinder is mounted on the upper side of the outer cylinder in an upward state,
The tube of the stretching cylinder is arranged in a gap formed between the pair of boom brackets
Wherein the excavator comprises: delete

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