JP5160401B2 - Swivel work machine - Google Patents

Description

  The present invention relates to a turning work machine such as a backhoe.

2. Description of the Related Art Conventionally, as a turning work machine, a turning frame supported on a traveling body so as to be turnable around a vertical axis is provided, and an excavation work device provided with an offset type boom is provided on a support portion provided at a front portion of the turning frame. There is an ultra-small swivel backhoe attached.
The support portion of the backhoe includes a pair of vertical plates opposed to each other in the left-right direction, a bottom plate provided between the vertical plates, and a pair of left and right cylinder brackets fixed to a front portion on the bottom plate. Yes.
Each of the left and right vertical plates is provided with a boom pivot supporting portion that supports the boom on the rear side of the cylinder bracket, and a cylinder pivot supporting portion is provided at an upper portion of the cylinder bracket, the cylinder pivot supporting portion being the boom pivot supporting portion. It is located on the front side and the lower side.

Further, the excavation work device includes an offset boom, an arm, and a bucket.
The boom includes a main boom whose base side is pivotally supported on the boom pivoting portion about the left and right axis and is swingable up and down, and a base side pivotally connected to the distal end side of the main boom. An offset boom that is swingable, an arm bracket that is pivotally connected to the tip side of the offset boom and that is swingable to the left and right, a front end side that is pivotally connected to the arm bracket, and a rear end side that is the tip of the main boom And an offset link pivotally connected to the side.

The main boom is swung up and down by an expansion and contraction operation of a main boom cylinder having one end pivotally supported by the cylinder pivot and the other end pivoted by the main boom tip.
The offset boom and the offset link are swung to the left and right by the expansion and contraction operation of the offset cylinder provided between the main boom tip side and the offset boom tip side, and both the offset link and the offset boom swing to the left and right to arm bracket Can be translated (offset) from side to side.
The arm has a base side pivotally connected to the arm bracket so as to be rotatable about a left-right axis, and is swung back and forth by an expansion / contraction operation of an arm cylinder provided between the arm bracket and the base side of the arm.

The bucket is pivotally connected to the distal end side of the arm so as to be rotatable around the left and right axis, and is extended and retracted by a bucket cylinder provided between the arm distal end side and the link mechanism pivotally connected to the bucket and the base side of the arm. Squee dump operation is enabled.
The main boom cylinder, the offset cylinder, the arm cylinder, and the bucket cylinder are constituted by hydraulic cylinders.
A tank room is provided on the right side of the support portion on the swivel frame, and in this tank room, a hydraulic oil tank for storing hydraulic oil for hydraulic equipment, the main boom cylinder, the offset cylinder, the arm cylinder, and the bucket In addition to the control valves that control the cylinders, a control valve that collects control valves that control various hydraulic devices provided in the backhoe is housed.

The right vertical plate forms a part of the left side wall of the tank room, and a hose insertion hole for inserting a hydraulic hose is formed above the bottom plate of the right vertical plate. The hose insertion hole There is a backhoe in which hydraulic hoses for an offset cylinder, an arm cylinder, and a bucket cylinder are disposed from a control valve to an excavation work device (see Patent Document 1).
JP 2007-92380 A

In the conventional backhoe, when the hydraulic hoses for the offset cylinder, the arm cylinder, and the bucket cylinder are arranged from the control valve to the excavation work device, the hose insertion hole formed in the vertical plate is inserted. In addition, it is difficult to assemble, and maintenance and work efficiency are deteriorated, and the hydraulic hose may be damaged because an excessive load is applied to the hydraulic hose.
In view of the above problems, an object of the present invention is to provide a turning work machine that facilitates the assembly of a hydraulic hose disposed from a control valve to a working device.

The technical means taken by the present invention in order to solve the technical problem includes a turning frame supported on a traveling body so as to be turnable about a vertical axis, and a hydraulic cylinder is provided at the front of the turning frame. A support portion for supporting a working device having a swinging boom is provided, and the support portion includes a pair of vertical plates opposed to each other in the left-right direction and a bottom plate provided between the vertical plates. The vertical plate is provided with a boom pivot portion that pivotally supports a base portion of the boom inserted between the vertical plates, and the hydraulic cylinder is disposed on the upper side of the bottom plate between the vertical plates and on the front side and the lower side of the boom pivot portion. A cylinder pivot part that pivots one end of the support part is provided, and a control valve is provided on one side of the left and right sides of the support part. A hydraulic hose disposed from the control valve to the working device is located above the bottom plate and is controlled. In front of the vertical plate on the valve side On the side, the rotary working machine is disposed to pass through the said longitudinal plate in the lateral direction,
The front portion of the upper edge portion of the vertical plate on the control valve side is formed so as to be positioned below the arrangement path of the hydraulic hose and the cylinder pivot portion in a side view.

Further, a tank room for accommodating a hydraulic oil tank is provided on the side of the support portion on the control valve side, the control valve is accommodated in the tank room, and the tank room side vertical plate and the support portion side of the tank room are provided. The side plate constituting the side wall of the tank is detachably attached and fixed to the vertical plate on the tank room side, and a hose insertion notch through which the hydraulic hose is inserted is formed on this side plate, and the notch for hose insertion faces downward. It is good that it is formed open.
Moreover, the hose clamp which clamps the said hydraulic hose can be attached and fixed to the stay which protrudes from the surface of the opposing side of a right-and-left vertical board in the position near the base of the said boom.

  According to the present invention, the hydraulic hose that passes from the control valve to the working device through the vertical plate in the left-right direction can be disposed through the vertical plate, so that the hydraulic hose can be easily assembled. Maintenance and work efficiency are good, and the hydraulic hose is not damaged.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
3 and 4, reference numeral 1 denotes an ultra-small turning type backhoe exemplified as a turning working machine (excavation working machine). The backhoe 1 is mainly composed of an upper turning body 2 and a lower traveling body 3. It is configured.
The traveling body 3 includes a crawler traveling device 5 on both the left and right sides of the track frame 4.
Each of the left and right crawler type traveling devices 5 includes a front idler 6, a rear sprocket 7, and a plurality of wheels 8 arranged between the idler 6 and the sprocket 7 around the track frame 4 about the left and right axis. The endless belt-like crawler belt 9 is wound around the idler 6, the sprocket 7, and the plurality of rollers 8, and the sprocket 7 is supported by a traveling motor 10 comprising a hydraulic motor (foil motor). By rotationally driving, a driving force is transmitted from the sprocket 7 to the crawler belt 9, and the crawler belt 9 circulates in the longitudinal direction so that the backhoe 1 can travel in the front-rear direction.

A dozer device 11 is provided at the front of the traveling body 3. The dozer device 11 includes a pair of left and right dozer arms 12 supported by the track frame 4 so as to be swingable up and down, a blade 13 fixed to the front end side of the left and right dozer arms 12, and a hydraulic cylinder that swings the dozer arm 12 up and down. The dozer cylinder 14 is provided.
The swivel body 2 includes a swivel base 15 supported on the track frame 4 of the traveling body 3 so as to be able to swivel around a swivel axis in the vertical direction, a cabin 16 mounted on the swivel base 15, and a front of the swivel base 15. And a work device 17 (excavation work device, ground work device) provided on the section side.

As shown in FIGS. 1, 2, and 5 to 11, the swivel base 15 includes a swivel frame 18 serving as a skeleton (main body portion), a rear surface of the swivel base 15 and left and right sides attached to a rear portion of the swivel frame 18. A weight 19 constituting the rear side of the side surface, a right turning cover 20 covering the right front side and the right front side of the revolving frame 18, a left turning cover covering the left front side and the left front side of the revolving frame 18, and a top surface of the revolving frame 18 And a step 29 covering the front left side.
The swing frame 18 is supported on the track frame 4 of the traveling body 3 through a swing bearing so as to be swingable about a vertical swing axis, and is fixed on the swing substrate 21 by welding or the like. And a member for mounting and supporting equipment, work devices, tanks, and the like on the turning substrate 21.

On the swivel base 15, a cabin 16, an engine 23, a radiator 24, a fuel tank 25, a hydraulic oil tank 26, a control valve 27, and the like are mounted.
The cabin 16 is disposed on the right side of the swivel base 15, and in the cabin 16, an operation device for operating the traveling body 3, the work device 17, the swivel base 15, etc. is provided in addition to the driver's seat 28.
The engine 23 is placed horizontally at the rear of the swivel base 15 (so that the axis of the crankshaft coincides with the left-right direction), and a hydraulic pump P driven by the engine 23 is attached to the left side of the engine 23. .

The radiator 24 is disposed on the right side of the engine 23 such that the radiator core faces in the left-right direction, and a cooling fan 30 driven by the engine 23 is provided between the radiator 24 and the engine 23. The cooling fan 30 is configured such that cooling air flows from the right side of the radiator 24 to the engine 23 side through the radiator core.
An oil cooler 31 is arranged on the right side of the radiator 24.
The fuel tank 25 is disposed in front of the left side of the engine 23 and below the step 29.

The hydraulic oil tank 26 stores hydraulic oil for hydraulic equipment, and is disposed on the front side of the radiator 24. A battery 32 is disposed on the upper right side of the hydraulic oil tank 26.
The control valve 27 is a collection of control valves for controlling the hydraulic equipment provided in the backhoe 1. The control valves are arranged side by side in the vertical direction, and the upper part is fixed to the hydraulic oil tank 26. The bracket 33 is fixed to the bracket 33, and the lower portion is fixed to the bracket 33 fixed to the tank support that supports the hydraulic oil tank 26.

The engine 23, the radiator 24, and the hydraulic oil tank 26 protrude upward from the swivel base 15, and these are covered with a cover body 34.
The cover body 34 mainly includes a bonnet 35 that covers the engine 23, a radiator cover 36 that covers the radiator 24, and a tank cover 37 that covers the hydraulic oil tank 26.
The tank cover 37 constitutes a right side wall, a front wall, and an upper wall of a tank room that houses the hydraulic oil tank 26, the battery 32, and the control valve 27. The tank cover 37 has a front lower portion facing the revolving frame 18 side. It is pivotally supported around the left and right axis, and is swingable back and forth around the pivoted portion (see the solid line and the imaginary line in FIG. 5).

A support portion 39 that supports the working device 17 is provided at the front of the swivel base 15 on the right side of the cabin 16 and on the left side of the tank room (between the cabin 16 and the tank room).
The work device 17 includes a boom 41, an arm 42, and a bucket 43 (work tool).
The boom 41 is constituted by an offset boom, and a main boom 44 whose base side is pivotally supported by the support portion 39 so as to be swingable up and down, and a base side of the main boom 44 is pivotally connected to the distal end side of the main boom 44. An offset boom 45 that is swingable left and right, an arm bracket 46 that is pivotally connected to the distal end side of the offset boom 45 and that can swing left and right, and a front end that is pivotally connected to the arm bracket 46 The rear end side is provided with an offset link 47 pivotally connected to the front end side of the main boom 44.

As shown in FIG. 2, the main boom 44 is provided on the main body portion 44A, a base portion 44B provided on the base end side in the boom longitudinal direction of the main body portion 44A, and on the front end side in the boom longitudinal direction of the main body portion 44A. It is comprised from the front-end | tip part 44C.
The base 44B of the main boom 44 includes a pair of left and right side walls 48 opposed to each other at an interval in the left and right direction, a fixing member 49 at the front end side in the boom longitudinal direction between the left and right side walls 48, and a boom between the left and right side walls 48. It is comprised from the boss | hub 50 of the longitudinal direction base end side, and the adhering member 49 is adhering to the boom longitudinal direction proximal end side of 44 A of main-body parts.

A main boom cylinder 51 provided over the support portion 39 and the front end side of the main body portion 44 </ b> A of the main boom 44 is disposed on the front side of the main boom 44, and the main boom 44 is expanded and contracted by the main boom cylinder 51. Swings up and down.
The offset boom 45 and the offset link 47 are swung to the left and right by the expansion and contraction operation of the offset cylinder 52 provided across the distal end side of the main boom 44 and the distal end side of the offset boom 45, and the offset link 47 and the offset boom 45 are moved. By swinging both left and right, the arm bracket 46 can be translated (offset) to the left and right.

The base side of the arm 42 is pivotally connected to the arm bracket 46 so as to be rotatable about the left-right axis, and the arm 42 is swung back and forth by an expansion / contraction operation of an arm cylinder 53 provided between the arm bracket 46 and the base side of the arm 42. Be moved.
The bucket 43 is pivotally connected to the distal end side of the arm 42 so as to be rotatable around the left and right axis, and is provided across the distal end side of the arm 42 and the link mechanism 54 pivotally connected to the bucket 43 and the base side of the arm 42. Squeezing and dumping operations are enabled by the expansion and contraction operation of the bucket cylinder 55.

The main boom cylinder 51, the offset cylinder 52, the arm cylinder 53, and the bucket cylinder 55 are constituted by double-acting hydraulic cylinders, and the control valve 27 controls these hydraulic cylinders 51, 52, 53, 55. In addition to a main boom control valve, an offset control valve, an arm control valve, and a bucket control valve, a travel control valve that controls the left and right travel motor 10 of the traveling body 3, a dozer control valve that controls the dozer cylinder 14, Control valves such as a turning control valve for controlling a turning motor for turning the turntable 15 are integrated.
The support portion 39 includes a pair of left and right vertical plates 56L and 56R, a rear plate 57 disposed on the rear end side of the left and right vertical plates 56L and 56R, and a bottom plate 58 provided between the left and right vertical plates 56L and 56R. A pair of left and right cylinder brackets 59 is provided.

The left and right vertical plates 56 </ b> L and 56 </ b> R are erected on the turning substrate 21 so that the plate surfaces face the left and right directions, and are opposed to each other in the left and right directions.
The rear plate 57 is erected on the revolving board 21 so that the plate surface faces in the front-rear direction, the right end is fixed to the left side of the right vertical plate 56R, and the left end is fixed to the rear end of the left vertical plate 56L. Has been.
The bottom plate 58 is disposed in an inclined shape so as to move downward as it goes forward. The rear end is fixed to the upper part of the front surface of the rear plate 57 and the front end is fixed to the revolving substrate 21.

Further, the bottom plate 58 is bent in the middle in the front-rear direction, and the front side is inclined more steeply than the rear side.
In order to pass a hydraulic hose or the like disposed over the tank room and the lower side of the step 29 in the swivel base 15 on the front side of the rear plate 57 and the lower side of the bottom plate 58 of the left and right vertical plates 56L and 56R. The opening 60 is formed through.
A first reinforcing plate 61 is provided between the left and right vertical plates 56L and 56R and on the front side of the opening 60. The first reinforcing plate 61 is erected on the turning board 21 so that the plate surface faces in the front-rear direction, and is provided so as to extend from the turning board 21 to the bottom plate 58 and between the left and right vertical plates 56L and 56R. The rotating substrate 21, the bottom plate 58, and the left and right vertical plates 56L and 56R are fixed by welding.

Further, on the left side of the left vertical plate 56L, a second reinforcing plate 62 is located on the left side of the first reinforcing plate 61 (located in a position corresponding to the first reinforcing plate 61 in the left-right direction). Is provided. The second reinforcing plate 62 is formed in a substantially triangular shape, and is erected on the turning substrate 21 so that the plate surface faces in the left-right direction, and is superimposed on the left side surface of the left vertical plates 56L and 56R. Are fixed to the vertical plates 56L and 56R and the swivel board 21 by welding.
A boom pivot portion 63 is provided at the upper part of the middle portion in the front-rear direction of each of the left and right vertical plates 56L and 56R (above the bent portion in the middle in the front-rear direction of the bottom plate 58). The boss 50 of the base portion 44B of the main boom 44 is inserted, and the boom pivot shaft 64 having the left and right axis centers is inserted through the left and right boom pivot support portions 63 and the boss 50 of the main boom base portion 44B. The base portion 44B (the base portion of the offset boom) is supported by the support portion 39 so as to be rotatable around the left and right axes.

The left and right cylinder brackets 59 are disposed between the left and right vertical plates 56L and 56R and on the front lower side of the boom pivot 63, and are fixed to the front portion on the bottom plate 58 by welding.
In addition, a cylinder pivot support 65 for pivotally supporting the main boom cylinder 51 is provided at the upper part of each of the left and right cylinder brackets 59. The cylinder pivot support 65 is located on the front side and the lower side of the boom pivot support 63. doing.
A pivotally supported portion 66 on one end side (bottom side in the present embodiment) of the main boom cylinder 51 is inserted between the left and right cylinder pivot portions 65 and can be rotated around the left and right axes by the cylinder pivot 67. It is pivotally connected to.

The cylinder pivot 67 is constituted by a flange pin (a pin with a flange) composed of a pin 68 and a flange 69 fixed to one end of the pin 68 in the axial center direction. The flange 69 is inserted through the pivoted support 66 on one end side of the boom cylinder 51, and the flange 69 is overlapped with the right side surface of the right vertical plate 56R and is threaded into a screw hole formed in the cylinder bracket 59 through the flange 69. It is fixed to the cylinder bracket 59 with a screw.
The upper edge 71 of the right vertical plate 56R (vertical plate 56R on the control valve 27 side) is formed so that the position on the rear side is high and the position on the front side is low.

The upper edge 71 of the right vertical plate 56R will be described in detail by dividing it into a rear portion 72, an intermediate portion 73, and a front portion 74. First, the rear portion 72 extends from the rear end to above the boom pivot portion 63. It extends so as to extend horizontally.
The intermediate portion 73 is formed in a hanging shape so as to extend downward from the front side of the boom pivot portion 63.
Further, the front portion 74 is formed so as to extend in an inclined direction in which the rear half 74A moves downward as it goes forward, and is bent at a midway portion so that the front half 74B extends in the horizontal direction toward the front. It is formed as follows.

The control valve 27 is arranged on the right side of the intermediate portion 73 of the upper edge 71 of the right vertical plate 56R in the vertical direction along the intermediate portion 73, and is arranged from the control valve 27 to the working device 17. The offset cylinder, arm cylinder and bucket cylinder hydraulic hoses 75 pass from above the control valve 27 to the base 44B of the main boom 44 through the upper half 74A of the front 74 of the upper edge 71 of the right vertical plate 56R. It is arranged to the side.
In the prior art, the upper edge of the vertical plate on the control valve side is located above the hydraulic hose arrangement path for the offset cylinder, arm cylinder, and bucket cylinder. In the present embodiment, the front portion 74 of the upper edge 71 of the right vertical plate 56R is offset while being arranged from the control valve 27 to the base side of the main boom through a hose insertion hole formed through the plate. The hydraulic hose 75 for the offset cylinder, the arm cylinder, and the bucket cylinder is positioned below the arrangement path 76 of the hydraulic hose 75 for the cylinder, arm cylinder, and bucket cylinder. The upper part of the upper edge 71 of the front part 74 of the main boom 44 is extended from the control valve 27 to the base 44B side over the rear half 74A. And it is configured so that it can be disposed with.

Further, in the conventional one, the right side of the cylinder pivot portion of the cylinder bracket is covered by the right vertical plate and the gap between the vertical plate and the cylinder bracket is narrow. In addition, a pin insertion hole is formed in the right vertical plate to pass through the pivot part at one end of the main boom cylinder, and the cylinder pivot is inserted into the cylinder pivot part and the pivot part at one end of the main boom cylinder through the pin insertion hole. Is inserted.
For this reason, although it was difficult to assemble the cylinder pivot, in this embodiment, the front half 74B of the front 74 of the upper edge 71 of the right vertical plate 56R is lower than the cylinder pivot 65 in a side view. The cylinder pivot 65 and the flange 69 of the cylinder pivot 67 are exposed when viewed from the right side, and the cylinder pivot 67 comprising the flanged pin is exposed from the right side of the right vertical plate 56R. The cylinder 56 can be assembled by passing over the vertical plate 56R, and the cylinder pivot 67 can be easily assembled to the cylinder pivot 65 from the side.

The right vertical plate 56R constitutes a part of the left side wall of the tank room, and the right vertical plate 56R includes a side plate constituting a part of the left side wall of the tank room together with the vertical plate 56R. 77 (this is referred to as a first side plate) is detachably attached and fixed by screws.
The first side plate 77 extends upward from the upper edge 71 of the right vertical plate 56 </ b> R and covers the right side of the cylinder pivoting portion 65.
The first side plate 77 is formed with a notch 78 for inserting a hose through which a hydraulic hose 75 for an offset cylinder, an arm cylinder, and a bucket cylinder is passed. The hydraulic hose 75 can be inserted into the hose insertion notch 78 from the open portion of the hose insertion notch 78.

Therefore, after the hydraulic hoses 75 for the offset cylinder, the arm cylinder, and the bucket cylinder are disposed from the control valve 27 to the base 44B side of the main boom 44 over the upper edge 71 of the right vertical plate 56R, The first side plate 77 can be attached and fixed to the right vertical plates 56L and 56R, and the workability of the arrangement of the hydraulic hose 75 and the assembly of the first side plate 77 is good.
A second side plate 79 that constitutes the left side wall of the tank room together with the right vertical plate 56R and the first side plate 77 is attached and fixed to the upper portion of the first side plate 77.

The right vertical plate 56R, the first side plate 77, and the second side plate 79 constitute the left side wall of the tank room.
In the backhoe 1 configured as described above, the cylinder pivot portion 65 is located in the vicinity of the front lower portion of the boom pivot portion 63, and the arrangement path 76 of the hydraulic hose 75 has a boom pivot portion in a side view. 63 and the cylinder pivot 65. In other words, in this embodiment, the arrangement path 76 of the hydraulic hose 75 and the assembly path for inserting the cylinder pivot 67 into the cylinder pivot 65 and the pivot 66 of the main boom cylinder 51 are adjacent to each other in the front-rear direction. ing.

Accordingly, when the front portion of the right vertical plate 56R is viewed from the side with respect to the rear portion, the hydraulic hose 75 is greatly cut out to the position below the arrangement path 76 of the hydraulic hose 75 and the cylinder pivot 65. And easy assembly of the cylinder pivot 67 can be achieved at the same time.
The hydraulic hoses 75 for the offset cylinder, the arm cylinder, and the bucket cylinder are disposed from the control valve 27 over the right vertical plate 56R and between the left and right vertical plates 56L, 56R, and then the base 44B of the main boom 44. From the lower side to the upper surface side of the main boom 44, between the side wall 48 of the main boom base 44B and between the fixing member 49 and the boss 50, and then fixed to the upper surface side of the main boom 44. Connected to the hydraulic pipe 80.

As shown in FIG. 11, a hydraulic hose 75 for an offset cylinder, an arm cylinder, and a bucket cylinder is connected to the main boom 44 on the lower side of the boom pivot 63 on the opposite side of the left and right vertical plates 56L, 56R. A stay 82 for mounting and fixing a hose clamp 81 to be clamped at a position in the vicinity of the lower side of the base portion 44B is provided so as to protrude in the opposing direction from the opposing side surfaces of the left and right vertical plates 56L and 56R.
There are two hydraulic hoses 75 for the offset cylinder, the arm cylinder, and the bucket cylinder, respectively. These hydraulic hoses 75 are arranged in the left-right direction and clamped by a hose clamp 81.

A hose clamp 83 is attached to the stay 82 together with a hose clamp 81.
The hose retainer 83 is superimposed on the front side of the hose clamp 81 and is attached to the stay 82 together with the hose clamp 81, and a retainer 85 that is fixed to the attachment plate 84 and bends the bar. It consists of and.
The pressing member 85 extends upward from the hose clamp 81 and presses the hydraulic hoses 75 for the offset cylinder, the arm cylinder, and the bucket cylinder from the front side in the vicinity of the boom pivot 63.

By passing the hydraulic hoses 75 for the offset cylinder, the arm cylinder and the bucket cylinder through the vicinity of the pivot portion of the main boom base 44B, the amount of change of the hydraulic hose 75 when the main boom 44 swings can be reduced. it can.
In the backhoe 1 of the present embodiment, a hook (not shown) is provided on the base side of the bucket 43 so that crane work can be performed. As shown in FIG. On the lower surface side of the cylinder body 51A, a hold valve 86 is provided for preventing the main boom 44 from descending when a hydraulic line for supplying hydraulic oil to the cylinder 51 is damaged.

As shown in FIG. 12, the hold valve 86 is hydraulically connected to a pilot port 87 for introducing pilot pressure, a drain port 88 connected to the tank 26, and a bottom oil chamber of the cylinder body 51 </ b> A of the main boom cylinder 51. A cylinder port 90 connected via a pipe line 89, an inlet port 93 connected via a hydraulic pipe line 92 to a main boom control valve 91 for controlling the main boom cylinder 51, a switching valve 94, and a shut-off valve 95.
The main boom control valve 91 is constituted by a pilot operation switching valve, and is connected to a pilot valve 96 disposed beside the driver's seat 28 via pilot oil passages 97a and 97b. It is operated by a pilot pressure by 96 operations.

The main boom control valve 91 is connected to an oil chamber on the rod side of the cylinder body 51 </ b> A of the boom cylinder 51 via a hydraulic line 98.
The pilot port 87 is connected to the pilot oil passages 97a and 97b through a pilot pipe line 99.
In the hydraulic circuit having the configuration shown in FIG. 12, when the pilot valve 96 is operated to switch the main boom control valve 91 from the neutral position X to the Y position, the switching valve 94 is simultaneously switched to the F position. The hydraulic oil from the hydraulic pump P is supplied from the inlet port 93 to the shutoff valve 95, the hydraulic oil presses the poppet 100 of the shutoff valve 95 and flows to the hydraulic pipe 101, and further from the cylinder port 90 through the hydraulic pipe 89. Then, the hydraulic oil on the rod side of the boom cylinder 51 is drained to the tank 26.

Thereby, the piston rod 51B of the main boom cylinder 51 is extended and the main boom 44 is raised.
Further, when the pilot valve 96 is operated to switch the main boom control valve 91 to the Z position, the switching valve 94 remains at the F position, and the hydraulic oil from the hydraulic pump P moves to the rod side of the main boom cylinder 51. The hydraulic oil on the bottom side of the main boom cylinder 51 is supplied to the shutoff valve 95 through the hydraulic line 89, the cylinder port 90, and the hydraulic line 101, and presses the poppet 100 to press the hydraulic line 102 and the inlet. It is drained into the tank 26 through the port 93 and the hydraulic line 92.

As a result, the piston rod 51B of the main boom cylinder 51 is retracted and the main boom 44 is lowered.
On the other hand, when the hydraulic line 92 between the inlet port 93 of the hold valve 86 and the main boom control valve 91 is damaged and hydraulic fluid leaks, the pilot valve 96 is operated to the neutral position X, whereby the switching valve 94 is operated. Switches to the E position, and the hydraulic oil on the bottom side of the main boom cylinder 51 reaches the shut-off valve 95 via the hydraulic line 89, the cylinder port 90, and the hydraulic lines 101, 103, 104, and presses the back surface of the poppet 100. Then, the shutoff valve 95 is closed to stop the hydraulic oil from being discharged from the inlet port 93. As a result, the retracting operation of the piston rod 51B of the main boom cylinder 51 is blocked, and the main boom 44 is prevented from being lowered.

In addition, mounting holes 105 for mounting hose joints (not shown) are formed in the lower front portions of the left and right vertical plates 56L and 56R.
One of a pair of hydraulic hoses (not shown) connected to the main boom control valve 91 is connected to the hose joint mounted in the mounting holes 105 of the left and right vertical plates 56L and 56R. And an inlet port 93 of the hold valve 86 are connected by a hydraulic hose 106 constituting a part of the hydraulic line 92.
The other of the pair of hydraulic hoses connected to the main boom control valve 91 is connected to the hose joint mounted in the mounting holes 105 of the other left and right vertical plates 56L and 56R. The bottom side of the boom cylinder 51 is connected by a hydraulic hose 107 constituting a part of the hydraulic pipe line 98.

The hydraulic hoses 106 and 107 are disposed between the vertical plates 56L and 56R and the cylinder bracket 59 on the same side in the left-right direction.
On the other hand, the pilot pipe line 99 is mainly constituted by a pilot hose 99, and the pilot hose 99 is disposed on the rear side of the cylinder bracket 59 between the left and right vertical plates 56L and 56R through the hose insertion notch 78 from the inside of the tank room. Then, the cylinder body 51A of the main boom cylinder 51 passes between the left and right cylinder brackets 59 and passes through the lower side of the pin 68 of the cylinder pivot 67 (below the pivoted support 66 on one end side of the main boom cylinder 51). After that, it is arranged to the hold valve 86 along the lower surface side of the cylinder body 51A of the main boom cylinder 51.

As described above, by passing the pilot hose 99 through the vicinity of the pivot point on the lower side of the main boom cylinder 51, the amount of change in the hose when the main boom 44 is swung up and down can be reduced.
The arm cylinder 53 is also provided with a hold valve that prevents the arm 42 from descending when pressure oil leaks. A pilot hose provided to the hold valve is also a pilot hose 99 of the hold valve 86 for the main boom. It can arrange | position so that it may pass along the same path | route.

  In the above-described embodiment, the arrangement of the members on the turntable 15 may be reversed on the left and right.

It is a side view of a support part. It is a side view of a main boom and a support part. It is a side view of a backhoe. It is a top view of a backhoe. It is a side view of a turntable. It is a top view of a turntable. It is a perspective view of a turning frame. It is a side view of a turning frame. It is a rear view of a turning frame. It is a top view of a turning frame. It is a perspective view of the attachment part of the base part of a main boom. It is a hydraulic circuit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Traveling body 17 Working apparatus 18 Turning frame 26 Hydraulic oil tank 27 Control valve 39 Support part 41 Boom 51 Hydraulic cylinder (main boom cylinder)
56L Left vertical plate 56R Right vertical plate 58 Bottom plate 63 Boom pivot portion 65 Cylinder pivot portion 71 Upper edge portion of right vertical plate 74 Front portion of upper edge portion of right vertical plate 75 Hydraulic hose 76 Hydraulic hose arrangement path 77 Side plate ( First side plate)
78 Notch for hose insertion 81 Hose clamp 82 Stay

Claims (3)

A swing frame (18) is provided on the traveling body (3) so as to be swingable about a vertical axis, and a boom (41) swinging up and down by a hydraulic cylinder (51) is provided at a front portion of the swing frame (18). Is provided with a support portion (39) that supports the working device (17), and the support portion (39) includes a pair of vertical plates (56L, 56R) arranged opposite to each other in the left-right direction, and the vertical plate (56L). , 56R) and a base plate of the boom (41) inserted between the vertical plates (56L, 56R) on the left and right vertical plates (56L, 56R). One end of the hydraulic cylinder (51) is provided above the bottom plate (58) between the vertical plates (56L, 56R) and on the front side and the lower side of the boom pivot portion (63). Cylinder support part (65) for supporting the side is provided, and the support part 39) is provided with a control valve (27) on one side of the left and right sides, and a hydraulic hose (75) disposed from the control valve (27) to the working device (17) is located above the bottom plate (58) and In the turning work machine disposed on the front side of the vertical plate (56R) on the control valve (27) side and passing through the vertical plate (56R) in the left-right direction,
The front part (74) of the upper edge part (71) of the vertical plate (56R) on the control valve (27) side is provided with the arrangement path (76) of the hydraulic hose (75) and the cylinder pivot part (65) in a side view. ), And a swivel work machine characterized by being formed so as to be positioned below.   A tank room for accommodating the hydraulic oil tank (26) is provided on the side of the support portion (39) on the side of the control valve (27), and the control valve (27) is accommodated in the tank room. A side plate (77) that constitutes a side wall on the support portion (39) side of the tank room together with the vertical plate (56R) is detachably attached and fixed to the vertical plate (56R) on the tank room side. The hose insertion notch (78) through which the hydraulic hose (75) is inserted is formed, and the hose insertion notch (78) is formed open toward the lower side. The swivel work machine as described in.   A hose clamp (81) that clamps the hydraulic hose (75) is attached to a stay (82) protruding from the opposing surface of the left and right vertical plates (56L, 56R) at a position near the base of the boom (41). The turning work machine according to claim 1 or 2, wherein the turning work machine is fixedly mounted.

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