JPH11336112A - Construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly drill by preventing damage to a supply/discharge hose for an arm cylinder and a supply/discharge hose for working tool cylinder. SOLUTION: A supply/discharge hose 32 for an arm cylinder is provided on the left side surface 14C of an upper boom 14 so that a bent portion 32A bent from the end of the upper boom 14 to an arm cylinder 25 is gently curved at a small curvature to reduce bending stress on the bent portion 32A. The supply/discharge hose 37 for a bucket cylinder connected to a bucket cylinder 28 is provided on the upper face 9A of a lower boom 9 and the upper face 14A of the upper boom 14 so that the loose portion of the supply/discharge hose 37 is minimized when the upper boom 14 is oscillated to the right and left to prevent damage to the loose portion due to interference with an obstacle and ensure smooth drilling work.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction machine such as a hydraulic shovel suitably used for excavating earth and sand.

[0002]

2. Description of the Related Art In general, among construction machines such as hydraulic excavators, a hydraulic excavator of a gutter digging type suitably used for excavating a gutter is composed of a construction machine main body and a working device provided on the construction machine main body. The working device includes a lower boom whose base end is provided on the construction machine main body so as to be capable of elevating and driven by a boom cylinder, and a lower end provided on the distal end of the lower boom so as to be swingable in the left-right direction and is driven by an offset cylinder. An upper boom, an arm connecting member provided on the distal end side of the upper boom so as to be swingable in the left-right direction, an arm provided on the arm connecting member so as to be able to move up and down, and driven by an arm cylinder; And a work implement driven by a work implement cylinder.

[0003] In the above-mentioned hydraulic excavator of the side groove excavation specification, a supply / discharge hose for the arm cylinder for supplying / discharging the pressure oil to / from the arm cylinder usually extends to the arm side along the upper surface of the lower boom and the upper boom. The upper boom is connected to the arm cylinder in a state of being bent from the distal end side to the arm cylinder side.

[0004] A supply / discharge hose for the supply / discharge cylinder for supplying / discharging the pressurized oil to / from the supply tool cylinder is normally connected to the supply tool while extending along the side surfaces of the lower boom and the upper boom. .

[0005]

However, when the supply / discharge hose for the arm cylinder is provided on the upper surface of the lower boom and the upper boom, the supply / discharge hose for the arm cylinder is folded from the distal end of the upper boom to the arm cylinder. The curvature of the bent portion formed when bending is increased.
For this reason, there is a problem that a large bending stress acts on the bent portion when the working device is operated, and the supply / discharge hose for the arm cylinder is easily damaged.

Further, when the supply / discharge hose for the working tool cylinder is provided along the side surface of the lower boom and the upper boom, when the arm and the working tool are moved in the lateral direction with respect to the lower boom in the digging work. In order to prevent the upper boom from swinging in the left-right direction on the distal end side of the lower boom, it is necessary to provide an appropriate slack in the supply / discharge hose for the working tool cylinder in advance.

For this reason, when the upper boom swings in the left-right direction with respect to the lower boom, the slack portion of the supply / discharge hose for the working tool cylinder projects laterally from, for example, a connecting portion between the lower boom and the upper boom. Interferes with obstacles such as road signs and trees, thereby causing damage to the supply / discharge hose for the working tool cylinder.

As another conventional technique, for example, Japanese Utility Model Laid-Open Publication No. 5-38045 discloses a supply / discharge hose for an arm cylinder, a supply / discharge hose for a working tool cylinder, and the like, which are inserted into the lower boom and the upper boom. There is disclosed a hydraulic excavator with a gutter digging configuration.

However, in the above-described hydraulic excavator according to the related art, since each supply / discharge hose is provided inside the lower boom and the upper boom, workability at the time of maintenance and inspection work is very poor. is there.

The present invention has been made in view of the above-described problems of the prior art, and prevents damage to the supply / discharge hose for the arm cylinder, the supply / discharge hose for the working tool cylinder, and the like, and enables a smooth excavation operation. The purpose is to provide a construction machine that can be used.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention comprises a construction machine body and a working device provided on the construction machine body, the working device having a base end on the construction machine body side. A lower boom that is provided to be capable of raising and lowering and is driven by a boom cylinder; an upper boom that is provided at the distal end of the lower boom so as to be swingable in the left-right direction; and an upper boom that is driven by an offset cylinder. An arm connector movably provided, an arm movably provided on the arm connector and driven by an arm cylinder, and an arm rotatably provided at the distal end side of the arm and driven by a work implement cylinder The present invention is applied to a construction machine including a work tool.

A feature of the structure adopted by the first aspect of the present invention is that an arm cylinder supply / discharge hose for supplying / discharging the pressure oil to / from the arm cylinder is provided on a side surface of the lower boom and the upper boom, The supply / discharge hose for the working tool cylinder for supplying / discharging the pressure oil is provided on the upper surface of the lower boom and the upper boom.

With this configuration, the supply / discharge hose for the arm cylinder can be gently bent from the tip end of the upper boom to the arm cylinder, and the life of the supply / discharge hose for the arm cylinder can be extended. In addition, by providing the supply / discharge hose for the work implement cylinder on the upper surface of the lower boom and the upper boom, the size of the slack portion to allow the upper boom to swing left and right with respect to the lower boom can be minimized. it can.

According to a second aspect of the present invention, the supply / discharge hose for the arm cylinder is provided along the length direction on the side surface of the upper boom, and is gradually gently moved from the tip end side of the upper boom to the arm cylinder side with a small curvature. In that it is bent to

[0015] With this configuration, the bent portion when the arm cylinder supply / discharge hose is bent from the distal end side of the upper boom toward the arm cylinder can be formed into a gentle curved shape.

Further, the invention of claim 3 is characterized in that the supply / discharge hose for the working tool cylinder is provided on the upper surface of each of the booms at a position substantially at the center of the width direction of the lower boom and the upper boom.

With this configuration, when the upper boom swings in the left-right direction at the distal end side of the lower boom, the supply / discharge hose for the working tool cylinder does not hinder the swinging of the upper boom, and the swinging of the upper boom can be performed. Follow.
Therefore, the supply / discharge hose for the working tool cylinder can minimize the extra slack.

According to a fourth aspect of the present invention, the lower boom is formed in a U-shape with a bent portion near the distal end, and the lower boom has a supply / discharge pipe for a working tool cylinder disposed on the upper surface and a base end on the upper surface. And a supply / discharge pipe for the arm cylinder disposed on the side part with the tip side detouring around the bent part, and the base end side of the supply / discharge hose for the work tool cylinder is the distal end side of the supply / discharge pipe for the work tool cylinder. And a base end side of the arm cylinder supply / discharge hose is connected to a distal end side of the arm cylinder supply / discharge pipe.

With this configuration, the supply / discharge hose for the arm cylinder has its base end connected to the supply / discharge pipe for the arm cylinder disposed on the side surface of the lower boom.
The upper boom is connected to the arm cylinder in a state where the upper boom is bent to the arm cylinder. The supply / discharge hose for the working tool cylinder has its base end connected to a supply / discharge pipe for the working tool cylinder disposed on the upper surface of the lower boom, and has extended to the working tool cylinder along the upper surface of the lower boom and the upper boom. In this state, it is connected to the work implement cylinder.

Further, the invention of claim 5 is characterized in that the offset cylinder supply / discharge hose for supplying / discharging the pressure oil to / from the offset cylinder is provided on the side surface of the lower boom so as to overlap the arm cylinder supply / discharge hose. is there.

With this configuration, the supply / discharge hose for the offset cylinder and the supply / discharge hose for the arm cylinder can be disposed on the side surface of the lower boom.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a construction machine according to the present invention will be described below with reference to FIGS.

In the drawing, reference numeral 1 denotes crawler tracks 1A, 1 on both left and right sides.
A shows a tracked lower traveling body provided with A
A discharge plate 2 is provided at the front side of the pallet so as to be able to move up and down.

Reference numeral 3 denotes an upper revolving structure provided on the lower traveling structure 1 so as to be pivotable. The upper revolving structure 3 has a substantially circular thickness provided on the lower traveling structure 1 via a revolving device. A turning frame 4 made of a plate, a cab 5 provided on the left side of the left and right sides of the turning frame 4, a right side of the turning frame 4 and a rear side of the cab 5, and a motor, a hydraulic power source ( (Neither is shown), etc., and an arc-shaped counterweight 7 disposed at the rear of the turning frame 4 and disposed between the turning frame 4 and the building cover 6. ing. And the turning frame 4
A center beam 4A for mounting a lower boom 9 described later is provided at a central portion in the left-right direction and extends upward in the front-rear direction.

Here, in the upper revolving unit 3, the cab 5, the building cover 6, and the counterweight 7 are set within a turning radius R from the turning center OO to the rear surface of the counterweight 7, and the lower traveling unit 1 In the vehicle width W determined by the interval between the crawler belts 1A provided in the vehicle.

Reference numeral 8 denotes a working device which is located on the right side of the cab 5 and is provided at the front of the upper revolving unit 3 so as to be able to move up and down. The working device 8 includes a lower boom 9 and an upper boom 1 which will be described later.
4, the arm 23, the bucket 26 and the like. When the small turning posture shown in FIG. 1 is taken, the working device 8 is configured to fit within the above-described turning radius R together with the cab 5, the building cover 6, and the counterweight 7 of the upper turning body 3.

Reference numeral 9 denotes a lower boom which is provided on the upper swing body 3 so as to be able to move upward and downward, and forms a boom bent in a U-shape together with the upper boom 14.
A, a bottom surface 9B, a left side surface 9C, and a right side surface 9D.
As a result, it is rotatably pin-connected to the center beam 4A of the revolving frame 4. The lower boom 9 is raised and lowered by a boom cylinder 11 provided between the lower boom 9 and the turning frame 4.

Here, the lower boom 9 is a bent portion 12 in which an upper portion near the distal end side is bent in a U-shape, and the bent portion 12 is formed in a U-shape so that the working device 8 can be small. Turning radius R when taking a turning posture
It is the part that comes closest to. Further, a plurality of brackets 13, 13,... For mounting an offset cylinder 17, which will be described later, and a link 22 are protruded from a left side surface portion 9C of the lower boom 9 located near the bent portion 12.

An upper boom 14 is provided at the tip end of the lower boom 9 so as to be swingable in the left-right direction. The upper boom 14 includes an upper surface portion 14A, a lower surface portion 14B, and a left side surface portion 14C.
And a rectangular tube having a right side surface portion 14D,
As shown in FIG. 3, the base end of the lower boom 9 is rotatably connected to the distal end of the lower boom 9 by a pin 15. Also,
A bracket 16 protrudes from the left side surface portion 14C of the upper boom 14 at an intermediate portion in the longitudinal direction, and an offset cylinder 17 is disposed between the bracket 16 and the bracket 13 on the lower boom 9 side. Then, the upper boom 14 swings in the left-right direction with respect to the lower boom 9 by the offset cylinder 17.

Reference numeral 18 denotes an arm connecting member provided at the distal end of the upper boom 14 so as to be swingable in the left-right direction. The arm connecting member 18 has a base end on the distal end side of the upper boom 14 as shown in FIG. Are rotatably connected to each other by a pin 19. In addition, the link 2 is
2 and a pair of right and left stays 21 for swingably supporting an arm cylinder 25 described later are integrally provided.

Reference numeral 22 denotes a link connecting between the lower boom 9 and the arm connecting member 18. The link 22 has a pin rotatably connected at both ends to the bracket 13 on the lower boom 9 side and the bracket 20 on the arm connecting member 18 side. The brackets 13 and 20 and the upper boom 14 form a parallel link mechanism. Then, when the upper boom 14 is swung in the left-right direction with respect to the lower boom 9 by the offset cylinder 17, the link 22 swings the arm connecting body 18 in the opposite direction to the tip side of the upper boom 14. , Arm 23 is always kept parallel to the lower boom 9.

Reference numeral 23 denotes an arm whose base end is pin-connected to the distal end of the arm connector 18 so as to be able to move up and down.
A pair of left and right stays 24 are provided integrally on the base end side of
An arm cylinder 25 is provided between the stay 24 and the stay 21 of the arm connector 18. Here, the arm cylinder 25 is disposed on the upper side of the upper boom 14 by being pin-coupled to the stay 21 of the arm connecting body 18, and swings in the left-right direction on the distal end side of the upper boom 14 together with the arm connecting body 18 and the arm 23. Is what you do. The arm 23 is configured to move up and down with respect to the arm connector 18 by the arm cylinder 25.

Reference numeral 26 denotes a bucket as a working tool rotatably pin-connected to the distal end side of the arm 23.
A bucket link 27 is provided between the arm 6 and the arm 23, and a bucket cylinder 28 is provided between the bucket link 27 and the stay 24 of the arm 23. The bucket 26 is vertically rotated on the distal end side of the arm 23 by a bucket cylinder 28 via a bucket link 27, and performs excavation work such as earth and sand.

Numerals 29, 29 designate two arm cylinder supply / discharge pipes provided on the upper surface 9A and the left side 9C of the lower boom 9 for supplying / discharging the pressure oil to / from the arm cylinder 25. The proximal end of the pipe 29 is connected to a hydraulic pressure source housed in the building cover 6 of the upper swing body 3 via a flexible hose (not shown).
Here, as shown in FIG. 4, the supply / discharge pipe 29 for the arm cylinder extends from the upper part of the lower boom 9 to the middle part in the length direction closer to the base end side than the bent part 12 of the lower boom 9 by the fixture 30. 9A, the distal end from the middle part in the length direction is bent toward the cab 5 bypassing the bent portion 12 of the lower boom 9, and is fixed to the left side surface portion 9C of the lower boom 9 by the fixture 31.

Reference numerals 32, 32 denote flexible arm cylinder supply / discharge hoses each having a base end connected to the distal end of each arm cylinder supply / discharge pipe 29 and a distal end connected to the arm cylinder 25. Supply / discharge hose 32 for cylinder
As shown in FIGS. 3 and 5, the lower boom 9 is provided on the left side surface 9C and the left side surface 14C of the upper boom 14 by a fixing member 33 or the like provided near the distal end side of the upper boom 14 and provided on the left side portion 14C. And extend toward the arm cylinder 25.

The arm cylinder supply / discharge hose 32
Is connected to the arm cylinder 25 in a state where the distal end side from the fixing tool 33 is bent in the opposite direction in the arm connecting body 18, and the bent portion becomes a bent portion 32 </ b> A that curves gently with a small curvature. I have.

Numerals 34, 34 are two bucket cylinder supply / discharge pipes provided on the upper surface 9A of the lower boom 9 for supplying / discharging pressure oil to / from the bucket cylinder 28. The end side is connected to a hydraulic pressure source housed in the building cover 6 of the upper swing body 3 via a flexible hose (not shown). Here, as shown in FIG. 4, the supply / discharge pipe 34 for the bucket cylinder has a base end side of the bent portion 12 of the lower boom 9 which is biased to the right side of the middle MM in the width direction of the lower boom 9 by the fixture 35. The lower end is bent leftward from the bent portion 12, and is fixed by the fixing tool 36 in a state of being located on the middle MM in the width direction of the lower boom 9.

Reference numerals 37, 37 denote flexible bucket cylinder supply / discharge hoses each having a proximal end connected to the distal end of each bucket cylinder supply / discharge pipe 34 and a distal end connected to the bucket cylinder 28. As shown in FIGS. 5 to 7, the cylinder supply / discharge hose 37 has an upper surface 9A of the lower boom 9 and an upper surface 14A of the upper boom 14.
And extends toward the bucket cylinder 28. Here, the supply / discharge hose 37 for the bucket cylinder is connected to the fixture 3 provided on the upper surface 14A of the upper boom 14.
8, a fixing member 39 provided on the upper end surface of the pin 15 connecting the lower boom 9 and the upper boom, and the upper boom 1
4 is fixed to the upper end surface of the pin 19 connecting the arm connecting member 18 to the bucket cylinder 28 by being positioned on the middle MM of the lower boom 9 and the upper boom 14 in the width direction. It is configured to extend.

Therefore, as shown in FIGS. 6 and 7, when the upper boom 14 swings in the left-right direction with respect to the lower boom 9 by the offset cylinder 17, the supply / discharge hose 37 for the bucket cylinder swings the upper boom 14. And follow the swing of the upper boom 14 without hindering the movement. Therefore, the slack portion for allowing the upper boom 14 to swing can be minimized, and the length of the bucket cylinder supply / discharge hose 37 can be minimized.

Reference numerals 41, 41 denote two offset cylinder supply / discharge pipes provided on the upper surface 9A and the left side 9C of the lower boom 9 for supplying / discharging the pressure oil to / from the offset cylinder 17. The base end side of the pipe 41 is connected to a hydraulic pressure source housed in the building cover 6 of the upper swing body 3 via a flexible hose (not shown). Here, as shown in FIG. 4, the supply / discharge pipe 41 for the offset cylinder is provided with a fixture 42 at a position in the length direction on the base end side with respect to the bent portion 12 of the lower boom 9.
The lower end of the lower boom 9 is fixed to the upper surface 9 </ b> A of the lower boom 9.
And is bent to the cab 5 side, and the lower boom 9 is fixed by the fixture 31 together with the supply / discharge pipe 29 for the arm cylinder.
Is fixed to the left side surface portion 9C.

Then, the supply / discharge pipe 4 for the offset cylinder
A flexible supply / discharge hose 43 for the offset cylinder is connected to the distal end of the lower cylinder 1. The lower end of the offset cylinder supply / discharge hose 43 overlaps the supply / discharge hose 32 for the arm cylinder. 9 left side 9C
And is connected to the offset cylinder 17.

Note that in FIGS. 1, 3 and 5,
A state in which the two bucket cylinder supply / discharge pipes 34 and the bucket cylinder supply / discharge hose 37 overlap, and the offset cylinder supply / discharge pipe 41 overlaps the arm cylinder supply / discharge pipe 29 (for the arm cylinder). Supply / discharge piping 29
Is hidden). FIG. 2 illustrates a state in which the two supply / discharge pipes 29 for the arm cylinder and the supply / discharge pipe 41 for the offset cylinder overlap each other.

The hydraulic excavator according to the present embodiment has the above-described configuration. When the excavator is used for digging a ditch, for example, the upper cylinder 14 is moved right and left by the offset cylinder 17 on the distal end side of the lower boom 9. To the arm 23 with respect to the lower boom 9.
And the bucket 26 are translated in the left-right direction. Then, the arm 23 is moved up and down on the distal end side of the upper boom 14 by the arm cylinder 25, and the bucket 26 is rotated by the bucket cylinder 28 on the distal end side of the arm 23 to excavate earth and sand.

Here, when the arm 23 is moved up and down by the arm cylinder 25 at the tip end side of the upper boom 14, the arm cylinder 25 swings up and down around the joint portion of the arm connector 18 with the stay 21. The bending stress acts on the bent portion 32A of the arm cylinder supply / discharge hose 32 connected to the arm cylinder 25.

In this case, in this embodiment, the supply / discharge hose 32 for the arm cylinder is connected to the left side surface 1 of the upper boom 14.
4C, the bent portion 32A of the arm cylinder supply / discharge hose 32, which is bent from the tip end side of the upper boom 14 to the arm cylinder 25, can be gently bent with a small curvature. The acting bending stress can be reduced.

Here, as a comparative example with the present embodiment,
8, a case where an arm cylinder supply / discharge hose 51 is provided on the upper surface portion 14A of the upper boom 14 will be described. In the arm cylinder supply / discharge hose 51, as shown in FIG. The bent portion 51A bent back to the arm cylinder 25 is suddenly bent with a large curvature. For this reason, a large bending stress acts on the bent portion 51A when the arm cylinder 25 is operated, and the supply / discharge hose 51 for the arm cylinder may be damaged at an early stage.

On the other hand, in the present embodiment, the bent portion 32A of the supply / discharge hose 32 for the arm cylinder, which is folded back from the distal end side of the upper boom 14 to the arm cylinder 25,
Since it can be gently curved with a small curvature, the bending stress acting on the bent portion 32A when the arm cylinder 25 is operated can be reduced, and the supply / discharge hose 32 for the arm cylinder can be prevented from being damaged early. Prevent,
Its life can be extended.

Next, when the offset cylinder 17 is operated, the upper boom 14 swings with respect to the lower boom 9 and the arm 23 swings with respect to the upper boom 14, as shown in FIGS. become.

In this case, in this embodiment, the supply / discharge hose 37 for the bucket cylinder connected to the bucket cylinder 28 is located substantially at the middle of the width direction of the lower boom 9 and the upper boom 14 and the upper surface 9A of the lower boom 9 and Since the upper boom 14 is provided on the upper surface 14A of the upper boom 14, when the upper boom 14 swings in the left-right direction with respect to the lower boom 9, the bucket cylinder supply / discharge hose 37 is provided.
Follows the swing of the upper boom 14 without hindering the swing of the upper boom 14. Therefore, it is possible to minimize the slack or the like for allowing the upper boom 14 to swing.

Here, as a comparative example with the present embodiment,
6 and 7, the right side 9D of the lower boom 9 and the right side 1 of the upper boom 14 are provided.
The case where the supply / discharge hose 52 for the bucket cylinder is provided in the 4D will be described. In the supply / discharge hose 52 for the bucket cylinder, when the upper boom 14 swings in the left-right direction with respect to the lower boom 9, the lower boom 9 and the upper boom 14 (Pin 15) and upper boom 1
A large slack portion 52A is formed at a portion corresponding to a coupling portion (pin 19) between the armature 4 and the arm connector 18. Therefore, the slack portion 5 of the bucket cylinder supply / discharge hose 52
There is a possibility that the 2A may be damaged by interference with an obstacle such as a road sign or a tree during excavation work.

On the other hand, in the present embodiment, when the upper boom 14 swings in the left-right direction with respect to the lower boom 9, the bucket cylinder supply / discharge hose 37 is displaced following the upper boom 14. The slack can be minimized. Therefore, it is possible to reliably prevent the bucket cylinder supply / discharge hose 37 from interfering with an obstacle and being damaged, and to perform a smooth excavation operation.

Further, since the excess slack portion can be minimized, the bucket cylinder supply / discharge hose 37 can be shortened, which can contribute to cost reduction.

In the above-described embodiment, the tracked hydraulic excavator in which the crawler belt 1A is provided on the lower traveling body 1 has been described as an example. However, the present invention is not limited to this. Can also be applied.

[0054]

As described above in detail, according to the first aspect of the present invention, the supply / discharge hose for the arm cylinder for supplying / discharging the pressure oil to / from the arm cylinder is provided on the side of the lower boom and the upper boom. Workpiece cylinder supply / discharge hoses for supplying / discharging pressurized oil are provided on the upper surface of the lower boom and upper boom, so the arm cylinder supply / discharge hose is gently bent from the top end of the upper boom to the arm cylinder. A large bending stress can be prevented from acting on the cylinder supply / discharge hose, and the life of the arm cylinder supply / discharge hose can be extended.

On the other hand, by providing the supply / discharge hose for the working tool cylinder on the upper surface of the lower boom and the upper boom, a slack portion for allowing the upper boom to swing right and left with respect to the lower boom can be minimized. Therefore, it is possible to prevent the loosened portion from interfering with an obstacle or the like to damage the supply / discharge hose for the working tool cylinder, and to perform a smooth excavation operation.

According to the second aspect of the present invention, the supply / discharge hose for the arm cylinder is disposed along the length direction on the side surface of the upper boom, and is provided with a small curvature from the tip side of the upper boom toward the arm cylinder. Since the arm cylinder supply / discharge hose is bent toward the arm cylinder from the distal end side of the upper boom, the bent portion can be formed into a gentle curved shape. Therefore, a large bending stress can be prevented from acting on the supply / discharge hose for the arm cylinder, and the life of the supply / discharge hose for the arm cylinder can be extended.

Further, according to the third aspect of the present invention, the supply / discharge hose for the working tool cylinder is provided on the upper surface of each of the lower and upper booms at substantially the center in the width direction of the lower and upper booms. When the rocker swings in the left-right direction on the distal end side of the lower boom, the supply / discharge hose for the working tool cylinder can follow the swing of the upper boom without hindering the swing of the upper boom. For this reason, the slack portion of the work tool cylinder supply / discharge hose can be minimized, and the work tool cylinder supply / discharge hose can be prevented from being damaged due to the interference of the slack portion with an obstacle. Excavation work can be performed.

According to the fourth aspect of the present invention, the supply / discharge hose for the arm cylinder is connected to the supply / discharge pipe for the arm cylinder disposed on the side surface of the lower boom, with its base end connected to the distal end of the upper boom. Since the arm cylinder is bent from the side, the bent portion can have a gentle curved shape. On the other hand, the supply / discharge hose for the work tool cylinder is
The base end is connected to the work implement cylinder supply / discharge pipe arranged on the upper surface of the lower boom, and connected to the work implement cylinder while extending along the upper faces of the lower boom and the upper boom. Excessive slack in the discharge hose can be minimized.

Further, according to the fifth aspect of the present invention, the supply / discharge hose for the offset cylinder for supplying / discharging the pressure oil to / from the offset cylinder is provided on the side surface of the lower boom so as to overlap the supply / discharge hose for the arm cylinder. Therefore, the supply / discharge hose for the offset cylinder and the supply / discharge hose for the arm cylinder can be disposed on the side surface of the lower boom.

[Brief description of the drawings]

FIG. 1 is a front view showing a small turning hydraulic excavator according to an embodiment of the present invention.

FIG. 2 is a plan view of FIG. 1 showing the small turning hydraulic excavator.

FIG. 3 is an enlarged front view of a main part of the working device, each supply / discharge hose, and the like in FIG. 1;

FIG. 4 shows the working device, each supply / discharge pipe and the like in FIG. 3 by arrows IV-IV.
It is the right view seen from the direction.

FIG. 5 is a front view showing the working device in FIG. 1 in an extended state.

FIG. 6 is an enlarged plan view showing a state in which the upper boom swings leftward with respect to the lower boom.

FIG. 7 is an enlarged plan view showing a state where the upper boom swings rightward with respect to the lower boom.

FIG. 8 is an enlarged front view showing a main part of an arm cylinder, an arm cylinder supply / discharge hose, and the like in FIG. 3;

[Explanation of symbols]

 Reference Signs List 3 upper revolving superstructure (construction machine main body) 8 working device 9 lower boom 9A upper surface portion 9C left side surface portion 14 upper boom 14A upper surface portion 14C left side surface portion 17 offset cylinder 18 arm connected body 23 arm 25 arm cylinder 26 bucket (work implement) 28 bucket cylinder ( (Work tool cylinder) 29 Supply / discharge pipe for arm cylinder 32 Supply / discharge hose for arm cylinder 34 Supply / discharge pipe for bucket cylinder 37 Supply / discharge hose for bucket cylinder 43 Supply / discharge hose for offset cylinder

Claims (5)

[Claims] 1. A construction machine comprising: a construction machine main body; and a working device provided on the construction machine main body, wherein the working device includes a lower boom provided at a base end side of the construction machine main body so as to be able to move up and down and driven by a boom cylinder. An upper boom provided on the distal end of the lower boom so as to be swingable in the left-right direction and driven by an offset cylinder; an arm connector provided on the distal end of the upper boom so as to be swingable in the left-right direction; A construction machine comprising: an arm provided so as to be able to move up and down and driven by an arm cylinder; and a work tool rotatably provided at the distal end side of the arm and driven by a work tool cylinder. Arm cylinder supply / discharge hoses for supplying / discharging pressure oil to the working tool cylinder are provided on the side surfaces of the lower boom and upper boom. Supply and discharge hoses for the implement cylinder to the construction machine, characterized in that the configuration of providing the upper surface of the lower boom and the upper boom. 2. The supply / discharge hose for an arm cylinder is disposed along a length direction on a side surface of the upper boom, and
2. The construction machine according to claim 1, wherein the construction machine is configured to gently bend toward the arm cylinder side with a small curvature from a tip end side of the upper boom. 3. 3. The construction machine according to claim 1, wherein the supply / discharge hose for the working tool cylinder is provided substantially on the middle of the width direction of the lower boom and the upper boom on the upper surface of each of the booms. 4. The lower boom is formed in a rectangular shape with a bent portion near the distal end, and the lower boom has a supply / discharge pipe for a working tool cylinder disposed on an upper surface and a proximal end disposed on the upper surface. And a supply / discharge pipe for an arm cylinder disposed on a side face side of the bent part, and a base end of the supply / discharge hose for the work tool cylinder is connected to a distal end of the supply / discharge pipe for the work tool cylinder. 4. The construction machine according to claim 1, wherein a base end of the arm cylinder supply / discharge hose is connected to a distal end of the arm cylinder supply / discharge pipe. 5. 5. The offset cylinder supply / discharge hose for supplying / discharging pressure oil to / from the offset cylinder is provided on a side surface of the lower boom so as to overlap with the arm cylinder supply / discharge hose. The construction machine according to 3 or 4.