JP2007092397A - Excavating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excavating device usable in two modes by inverting a bucket by 180°, in which a mechanism to rotate the bucket is simplified, and manufacturable at low cost. <P>SOLUTION: A working device 243 is supported on a support body 24 pivotally supported at the end of an arm 242 rotatably around a rotating shaft 257 having an axis Y vertical to the work device support surface 256 of the support body 24. The excavating device comprises a rotating means 258 rotating the work device 243 at 180° around the rotating shaft 257 from a first working attitude to a second working attitude and an attitude holding means 273 holding the working device 243 so as to be releasable in the first and second working attitudes. The rotating means 258 comprises a cylinder tube 259 secured to the support body 249, a piston 260 in the cylinder tube 259, and the rotating shaft 257 secured to the working device 243 and inserted into the piston 260. Screws 266, 267 converting the linear motion of the piston 260 to the rotating motion of the rotating shaft 257 are formed on the rotating shaft 257 and the piston 260. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an excavation work apparatus in which a work tool such as a bucket can be turned 180 ° and can be used in two modes.

Conventionally, a support that is rotated around a horizontal axis by a hydraulic cylinder is pivotally supported at the tip of an arm, and a work tool that performs grounding work on this support is rotated perpendicular to the work tool support surface of the support. A pivot motor is pivotally supported around a shaft center, a hydraulic motor is attached to the support, and the rotation of the pinion attached to the output shaft of the hydraulic motor is transmitted to the pivot bearing to rotate the work tool. There is an excavation work device configured to rotate around an axis (see Patent Document 1).
JP-A-4-327611

In the conventional excavation work device, a bucket that can be scooped or scraped is used as a work tool, and the work tool can be used in two modes by rotating the work tool by 180 ° around the rotation axis. However, in the conventional excavation work device, the work tool is supported on the support by the swing bearing, and the work tool is reversed by transmitting the rotation of the pinion attached to the hydraulic motor to the swing bearing. In addition, the hydraulic motor, which is a means for rotating the work tool and maintaining the posture of the work tool, is expensive and expensive.
Therefore, in view of the above problems, the present invention aims to simplify the mechanism for rotating the work tool and to reduce the cost in the excavation work apparatus that can be used in two modes so that the work tool can be turned 180 °. The purpose is to be able to provide.

The technical means taken by the present invention in order to solve the above technical problem is the work of pivoting a support body rotated around a horizontal axis by a hydraulic cylinder at the tip of an arm and performing a ground work on this support body. A tool is supported so as to be rotatable about a rotation axis having an axis perpendicular to the work tool support surface of the support, and the work tool is positioned between the work tool and the support in a first working posture. Rotation means for rotating 180 degrees around the rotation axis from the second work posture, and posture holding means for releasably holding the work tool in the first work posture and the second work posture,
The rotating means includes a cylinder tube fixed to a support, a piston in the cylinder tube, and the rotating shaft fixed to a work tool and inserted into the piston. And a screw for converting linear movement of the piston into rotation of the rotation shaft.

The working tool may be constituted by a bucket that can be scooped in a first working posture and can be scraped in a second working posture.
Further, for example, the posture holding means is supported on the support side so as to be movable along the work tool support surface of the support, and has an engagement member whose tip can be moved back and forth from the outer periphery of the support, and on the work tool side. It is configured by having an engaged portion that is provided at two positions displaced by 180 degrees around the rotation axis and that engages with an engaging member that protrudes from the outer periphery of the support to hold the posture of the work tool.
In addition, a locking portion that rotates integrally with the work tool,
In the first work posture, the engagement is restricted so as to restrict the rotation of the work tool in the direction rotating from the second work posture to the first work posture and to allow the work tool to rotate in the direction opposite to the rotation direction. A first locked portion for locking the locking portion;
In the second working posture, the engagement is restricted so as to restrict the turning of the working tool in the direction of turning from the first working posture to the second working posture and to allow the turning of the working tool in the direction opposite to the turning direction. It is good to provide the 2nd to-be-latched part which latches a stop part.

  Also, a plurality of the locking portions, the first locked portions, and the second locked portions may be provided around the rotating means so as to receive a load acting on the work tool during excavation work. .

  According to the present invention, by rotating the rotating means for rotating the work tool and the posture holding means for holding the work tool in the first and second working postures, the rotating means inverts the work tool by 180 °. It is only necessary to have the function of making it possible to simplify the rotating means and to reduce the cost.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 5, reference numeral 1 denotes an urban-type small wheel-type turning work machine used for gardening, for example. The turning work machine 1 is roughly divided into a lower traveling body 2 and an upper turning body. 3.
The traveling body 2 is a wheel-type traveling body 2 that can be traveled by a pair of left and right front and rear wheels 4 and 5, and is supported by the pair of left and right front and rear wheels 4 and 5 and the front and rear wheels 4 and 5. The vehicle body frame 6, the engine 7 mounted on the vehicle body frame 6, the traveling system power transmission mechanism 8 that transmits power from the engine 7 to the rear wheel 5, and the traveling system power transmission mechanism 8 are branched. A front wheel drive system 33 that transmits power to the front wheels 4 is provided.

  As shown in FIGS. 1 to 13, the fuselage frame 6 is mainly composed of a main frame 9 and a front frame 10 provided on the front side of the main frame 9. The main frame 9 includes an engine 7 and a radiator. 12, a battery 13, a swivel joint 14, a swing motor 15, a swing bearing 16, and the like. The front frame 10 is equipped with a fuel tank 17 for storing fuel for the engine 7, and the rear portion of the main frame 9 is rear left and right. The front portion of the front frame 10 is supported by the wheels 5 and is supported by the left and right front wheels 4 so that the vehicle can run.

The main frame 9 is made of a plate material, and has an upper wall 18, left and right side walls 19 extending downward from left and right side edges of the upper wall 18, and a front fixed to the front ends of the upper wall 18 and the left and right side walls 19. It is mainly composed of a wall 20 and a rear wall 21 that connects lower rear end portions of the left and right side walls 19, and is formed in an open downward shape.
The engine 7 is disposed vertically on the rear side between the left and right side walls 19 of the main frame 9 so that the center of the crankshaft is in the front-rear direction and the output shaft 23 projects forward. A cutout opening 24 is formed in the upper wall 18 so that the upper end side of the engine 7 protrudes upward from the upper wall 18 of the main frame 9, and a cooling fan 25 is provided at the rear of the engine 7. Yes.

The rear part between the left and right side walls 19 of the main frame 9 is an engine placement part 11 for placing the engine 7. A radiator 12 is placed on the left side of the engine 7 and is fixedly attached to the main frame 9. A battery 13 is arranged on the right side of 7 and fixed to the main frame 9.
The left and right sides of the front part of the main frame 9 are covered with side covers 26, and the rear part of the main frame 9 includes a rear wheel fender 27 that covers the left and right rear wheels 5 and connects the front parts of the left and right rear wheel fenders 27. Covered by a fixed cover 28, an open / close cover 29 that is disposed between the rear portions of the left and right rear wheel fenders 27 to cover the upper side of the rear portion of the engine 7 and can be opened and closed, and a rear bumper cover 30 that covers the back side of the main frame 9. ing.

Further, an opening is formed between the rear end of the opening / closing cover 29 and the upper end of the rear bumper cover 30, and air in the engine room is discharged by the cooling fan 25 through the opening or the engine room. Outside air is taken inside.
The front frame 10 is covered with a cover member 31 having a front wheel fender that covers the left and right front wheels 4 and a front bumper cover 41 that covers the front surface of the front frame 10.
The travel system power transmission mechanism 8 includes a travel propulsion shaft 34 to which power from the engine 7 is transmitted, a hydrostatic transmission (hereinafter referred to as HST) 35 to which power is transmitted from the travel propulsion shaft 34, A mechanical transmission device 37 that transmits power to the bevel pinion shaft 36, a rear wheel differential device 38 to which power is transmitted from the bevel pinion shaft 36, and the power transmitted to the rear wheel differential device 38 to the left and right rear axles 39 The travel propulsion shaft 34, the HST 35, the mechanical transmission device 37, the bevel pinion shaft 36, and the rear wheel differential device 38 are disposed on the front side of the engine 7, and the final transmission device 40 is provided. Is arranged from the side of the rear wheel differential device 38 to the front side of the engine 7.

The travel propulsion shaft 34 is arranged in the front-rear direction on the front side of the engine 7, and the rear end side is connected to a flywheel 42 connected to the output shaft 23 of the engine 7.
As shown in FIGS. 7, 8, and 30, the HST 35 includes an input shaft 44 that inputs power from the engine 7 and an output shaft 45 that outputs power to the rear wheel differential device 38 in the casing 43. The hydraulic pump 46 provided in the input shaft 44 and the hydraulic motor 47 provided in the output shaft 45 are accommodated in parallel to the left and right, and sent from the hydraulic pump 46 driven by the input shaft 44. In this mission, the hydraulic motor 47 is driven by pressure oil, and power is output from the output shaft 45 driven by the hydraulic motor 47.

The casing 43 includes a main body 48 having an opening on the rear surface side and a lid body 49 that closes the rear surface side opening of the main body 48, and the input shaft 44 and the output shaft 45 project rearward from the lid body 49.
The input shaft 44 of the HST 35 is disposed concentrically with the propulsion shaft 34 on the front side of the travel propulsion shaft 34 and is coupled to the travel propulsion shaft 34 by coupling.
The hydraulic pump 46 is a variable displacement pump, and the swash plate angle can be changed by the swash plate control actuator 50. By changing the swash plate angle, the flow rate of the pressure oil discharged to the hydraulic motor 47 is changed. Thus, the rotation speed (vehicle speed) of the output shaft 45 can be changed, and the direction of the flow of the pressure oil discharged to the hydraulic motor 47 is changed to change the rotation direction of the output shaft 45 forward (forward rotation) or reverse ( (Reverse rotation).

  The swash plate control actuator 50 is controlled by a forward / reverse switching means 51 comprising a pilot operation switching servo valve operated by a pilot pressure. When a pilot pressure is established at the forward port 52 of the forward / reverse switching means 51, the output shaft 45 is controlled. The swash plate of the hydraulic pump 46 is controlled so as to rotate forward, and the swash plate of the hydraulic pump 46 is controlled so that the output shaft 45 reverses when the pilot pressure is established at the reverse side port 53, and the forward side port 52 or the reverse side. The flow rate of the pressure oil discharged from the hydraulic pump 46 is controlled by the degree of pressure standing at the side port 53, and the rotation speed of the output shaft 45 is controlled.

The hydraulic motor 47 is a variable displacement pump, and the angle of the swash plate can be changed in two stages by the high / low switching actuator 54. By changing the angle of the swash plate, the rotational power output from the output shaft 45 is in a high speed state. And can be switched to a low speed state.
The bevel pinion shaft 36 is disposed parallel to the left side and the lower side of the portion protruding rearward from the lid 49 of the output shaft 45 of the HST 35, and extends rearward from the rear end of the output shaft 45 of the HST 35. A bevel gear portion is formed on the rear end side.
In the present embodiment, the mechanical transmission device 37 includes a drive-side gear 56 that is externally fitted to a portion of the output shaft 45 of the HST 35 that protrudes rearward from the lid 49, and a bevel pinion shaft. The gear 36 is constituted by a gear transmission mechanism that is externally fitted on the front end side of 36 so as to be rotatable together with the driven side gear 56 and meshes with the driving side gear 56, and is also a speed reduction mechanism.

The mechanical transmission device 37 may be a speed increasing mechanism (transmission mechanism) or the same speed mechanism, and may be any device that performs power transmission such as coupling.
The rear wheel differential device 38 is disposed behind the bevel pinion shaft 36 and on the front side on the left side of the engine 7, and projects a differential output shaft 58 on both the left and right sides.
The rear axle 39 is provided behind the differential output shaft 58 of the rear wheel differential device 38 so as to overlap the engine 7 in a side view, and the rear wheel 5 is provided on the outer end side of each of the left and right rear axles 39. It is fixed.

The final transmission 40 includes a drive side gear 59 that is externally fitted to the outer end of the differential output shaft 58 in the left-right direction, and a driven side gear 60 that is externally fitted to the rear axle 39 so as to be freely rotatable. And a speed reduction mechanism.
Note that the final transmission device 40 may be a speed increasing mechanism (transmission mechanism) or the same speed mechanism.
In the traveling system power transmission mechanism 8 configured as described above, the power output forward from the engine 7 is folded back by the HST 35 and transmitted rearward, and is transmitted to the left and right sides by the rear wheel differential device 38 on the front side of the engine 7. It is transmitted and transmitted rearward by the final transmission device 40 to reach the rear axle 39, so that the front-rear direction is made compact.

  A housing 61 that houses the flywheel 42 and the rear wheel differential device 38 and the like is connected and fixed to the front side of the engine 7, and a transmission case 62 that houses a mechanical transmission device 37 and the like is placed on the front side of the housing 61. The casing 43 (the lid 49) of the HST 35 is connected and fixed to the front side of the transmission case 62, and the rear wheel differential device 38, the mechanical transmission device 37, the HST 35, and the like are attached to the engine 7. The housing 61, the transmission case 62, and the casing 43 are disposed between the left and right side walls 19 of the main frame 9, and the front side of the engine placement portion 11 between the left and right side walls 19 of the main frame 9 is attached. A travel power transmission system arrangement unit 63 is provided.

Further, on both the left and right sides of the housing 61, final transmission cases 67 accommodating the final transmission device 40 are fixed. The rear axle 39 is supported by the left and right final transmission cases 67, and the final transmission case 67 is It is fixedly attached to the main frame 9.
The left and right final transmission cases 67 are bolted to the side surfaces of the housing 61 at the front end in the left-right direction, and the rear sides of the left and right final transmission cases 67 are bolted to the upper side of the side wall 19 of the main frame 9. Has been.
On the lower side of the rear part of the left and right side walls 19 of the main frame 9, a case fitting part 64 consisting of an open cut-out part is formed on the lower side so as to be fitted to the upper side of the final transmission case 67 from above. A final transmission case 67 is bolted to the main frame side wall 19 around the fitting portion 64.

The front side of the engine 7 is supported by the main frame 9 via a housing 61 and a final transmission case 67, and the rear side of the engine 7 is a cut-and-raised portion 65 formed on the rear wall 21 of the main frame 9 and the engine. 7 is supported by a connecting plate 66 that connects the lower side surface of 7.
In the configuration described above, the housing 61, the transmission case 62, the casing 43 of the HST 35, and the final transmission case 67 are attached to the engine 7 so as to be integrated (unitized) (the engine 7 includes a rear wheel differential). Since the device 38, mechanical transmission device 37, HST 35, final transmission device 40, and rear axle 39 are attached and integrated), after assembling these, the body frame 6 is attached to the assembly from above the engine 7 or the like. It can be assembled, and the assembly to the body frame 6 becomes easy.

After assembling the housing 61, the transmission case 62, the HST 35, and the final transmission case, the body frame 6 is assembled to these assemblies from above, and then the engine 7 is mounted on the left and right side walls from the upper surface of the upper wall 18 of the main frame 9. The engine 7 may be mounted and fixed to the housing 61 and the rear wall 21 of the main frame 9 after that.
In this case, the notch opening 24 formed in the upper wall 18 of the main frame 9 is formed in a size that allows the engine 7 to be inserted between the left and right side walls 19 from above.
In addition, a rear wheel differential device 38 is provided on the front side of the engine 7, and a rear axle 39 that transmits power from the rear wheel differential device 38 and rotates the rear wheel 5 is positioned at the rear side of the differential output shaft 58 and on the side surface. By providing it so as to overlap with the engine 7 in view, the turning work machine 1 is made compact in the front-rear direction.

In other words, by providing the rear wheel differential device 38 on the front side of the engine 7, the engine 7 can be separated rearward from the turning axis X (the center of the turning bearing 16) of the revolving structure 3. The space of 215 can be taken widely.
Further, when the rear axle 39 is provided concentrically with the differential output shaft 58 of the rear wheel differential device 38, the engine 7 is positioned behind the rear axle 39, and the revolving body 3 is operated rearward. In this case, there is a problem that the distance from the rear axle 39 to the work position behind the engine 7 is longer than in the case of the present embodiment, resulting in poor workability. In the present embodiment, the rear axle 39 is Since it is provided at the rear position of the output shaft 58 and overlaps the engine 7 in a side view, the workability when working with the revolving structure 3 facing backward is good.

Further, when the rear wheel differential device 38 is disposed on the front side of the engine 7, the rear wheel differential device 38 is disposed on the engine 7 side as much as possible because it is disposed at a position disengaged outward from the flywheel 42 in the left-right direction. Accordingly, the distance between the differential output shaft 58 and the rear axle 39 can be shortened, and the final transmission device 40 and the final transmission case 67 can be made compact.
The left and right side frame parts of the machine body frame are formed of square pipes, and when the end transmission case 67 is fixedly attached to the outer side surface of the square pipe in the left and right direction, the left and right width of the turning work machine is widened. If the end transmission case 67 is attached and fixed to the left and right, the left and right width of the turning work machine is not widened, but this time, the height of the traveling body 2 is increased.

On the other hand, in the present embodiment, the main frame 9 of the fuselage frame 6 includes an upper wall 18 and left and right side walls 19 formed of a plate material, and the engine 7 is disposed between the left and right side walls 19. Since the end transmission case 67 is fixedly attached to the left and right side walls 19, the turning work machine 1 can be made compact in the left-right direction, or the upper turning body 3 is arranged low by reducing the vertical dimension. can do.
On the front side of the HST 35, a main pump 68 comprising a double gear pump that is driven in conjunction with the front end side of the input shaft 44 of the HST 35 is attached. Hydraulic fluid is supplied to various equipped actuators.

In the present embodiment, an oil pan 69 provided on the lower end side of the engine 7 is used as a hydraulic oil tank that stores hydraulic oil for hydraulic equipment.
Further, the traveling system power transmission mechanism 8 includes a foot brake means 70 (traveling brake) for braking traveling power transmitted from the HST 35 to the rear wheel differential device 38, and power between the HST 35 and the rear wheel differential device 38. Hydraulic parking brake means 71 for holding the transmission system in a stopped state is provided, and these brake means 70, 71 are arranged behind the drive side gear 56 of the mechanical transmission device 37.

  The foot brake means 70 is housed in a transmission case 62, a brake case 72 fixed to the transmission case 62, and a brake disc 73 externally fitted to the rear end side of the output shaft 45 of the HST 35 so as to be integrally rotatable. And a plate 74 provided on the brake case 72 side, and a piston 75 that press-contacts the brake disc 73 and the plate 74, and the inside of the master cylinder 372 is operated by depressing the brake pedal 364 provided on the revolving body 3 side. When the pressure oil presses the piston 75, the piston 75 moves and the brake disc 73 and the plate 74 are pressed against each other, thereby braking the output shaft 45 of the HST 35.

The parking brake means 71 is disposed on the rear side of the foot brake means 70, is accommodated in the housing 61 and is fixed to the housing 61, and a piston 77 is accommodated in the parking brake case 76. Have
The brake case 72 is opened rearward, the parking brake case 76 is opened forward, and the brake case 72 and the parking brake case 76 are communicated.
The parking brake case 76 houses a spring 78 that presses the piston 77 and presses the brake disc 73 and the plate 74 when the engine 7 is stopped, and is driven by the engine 7 when the engine 7 is started. The hydraulic pressure from the charge pump 79 (see FIG. 30) acts on the piston 77 to move the piston 77 against the urging force of the spring 78, and the pressure contact between the brake disc 73 and the plate 74 is released.

A differential lock device 80 is provided on the left side of the rear wheel differential device 38.
As shown in FIG. 8, the differential lock device 80 moves a differential lock shifter 81 that rotates integrally with the left differential output shaft 58 toward the rear wheel differential device 38 against the return spring by pressure oil. A hydraulic differential lock device 80 that differentially locks the differential action of the rear wheel differential device 38 by engaging the engagement teeth formed in 81 with an engagement tooth provided on the rear wheel differential device 38 side. .
An opening 83 is formed on the upper surface of the upper wall 18 at the front of the main frame 9, and a bearing mounting plate 84 made of a thick plate material is fixed to the upper surface of the upper wall 18 so as to close the opening 83. ing.

The slewing bearing 16 is disposed on the bearing mounting plate 84, and the outer race 85 of the slewing bearing 16 is fixed to the bearing mounting plate 84 by bolting.
The slewing bearing 16 is disposed at a substantially central position between the front and rear wheels 4, 5. The center of the slewing bearing 16 is a slewing axis X, and a bearing mounting plate 84 on the upper surface side of the upper wall 18 of the front portion of the main frame 9. The upper surface side is a bearing arrangement portion 86.
Further, an inner gear 89 is formed on the inner peripheral side of the inner race 87 of the slewing bearing 16, and a pinion 88 meshes with the inner gear 89, and the pinion 88 is fixed to the main frame 9. The rotary motor 15 is fixed to the output shaft of a swing motor 15, and the swing motor 15 can rotate the inner race 87 of the swing bearing 16 about the swing axis X.

A swivel joint 14 is disposed concentrically with the pivot axis X at the front part between the left and right side walls 19 of the main frame 9, and the pressure between the traveling body 2 side and the swivel body 3 side via the swivel joint 14. Oil is distributed.
As shown in FIGS. 9 to 15, the front frame 10 of the fuselage frame 6 is made of a plate material, and includes an upper wall 91 and left and right side walls 92 extending downward from left and right side edges of the upper wall 91. The connecting plate 93 for connecting the front portions of the left and right side walls 92 is mainly configured, and the rear side is formed in an open shape downward.

The upper wall 18 of the main frame 9 and the upper wall 91 of the front frame 10 constitute the upper wall of the body frame 6, and the left and right side walls 19 of the main frame 9 and the left and right side walls 92 of the front frame 10 A wall is constructed.
The left and right widths of the front frame 10 are formed narrower than the main frame 9, and a front wheel arrangement space 94 in which the front wheels 4 are arranged in front of the main frame 9 and on the left and right sides of the front frame 10 is formed.
The dimension of the left and right side walls 92 extending downward from the upper wall 91 is such that the front side is shorter than the rear side, and the left and right side walls 92 are formed so that the vertical width on the front side is narrower than the rear side. An arrangement space for a front axle case 96 and a steering cylinder 97 including a hydraulic cylinder is formed below the front portion of the front frame 10.

The connecting plate 93 extends in a horizontal horizontal wall portion 98 that connects the lower ends of the front portions of the left and right side walls 92 and an inclined direction that moves downward as it goes rearward from the rear end of the horizontal wall portion 98. And an inclined wall portion 99 that connects the middle portions of the left and right side walls 92 in the front-rear direction.
A fuel tank 17 that stores fuel for the engine 7 is disposed at a rear portion between the left and right side walls 92 of the front frame 10.
The fuel tank 17 is inserted between the left and right side walls 92 from below and is fixedly attached to the front frame 10. The front side of the fuel tank 17 is in contact with the inclined wall portion 99 of the connecting plate 93 and positioned. The lower rear end side protrudes toward the main frame 9 via a notch formed on the lower end side of the front wall of the main frame 9.

The upper wall 91 of the front frame 10 is formed with an insertion hole through which the fuel filler port 100 of the fuel tank 17 is inserted. The lower surface side of the fuel tank 17 is the lower surface of the front frame 10 after the fuel tank 17 is mounted. It is covered by a cover (not shown) attached to the side.
On the lower surface side of the horizontal wall portion 98 of the connecting plate 93 of the front frame 10, a front axle case 96 that suspends the left and right front wheels 4 so as to be steerable is disposed along the left-right direction. The front wheel bearings 101 mounted and fixed to the lower surface of the horizontal wall 98 of the connecting plate 93 are disposed on both front and rear sides of the front and rear wheels, and the front axle case 96 is attached to the front and rear front wheel bearings 101 via the center pin 102 in the front and rear direction. It is supported so that it can swing around its center.

Gear cases 103 are provided on the left and right sides of the front axle case 96, and the front wheels 4 are supported by the left and right gear cases 103 so as to be steerable.
On the front side of the front axle case 96, a steering cylinder 97 for steering the front wheel 4 is disposed in the left-right direction and is fixedly attached to the front axle case 96. The steering cylinder 97 is attached to the left and right sides of the cylinder tube. Piston rods projecting from both sides are provided, and the left and right piston rods are linked to the front wheel 4 on the same side in the left-right direction. The steering cylinder 97 is controlled by a power steering controller 367 provided on the revolving body 3 side. Is done.

Since the front wheel 4 is a steered wheel, a large space is required for its arrangement. If the front frame 10 is formed to have the same width as the main frame 9 in the left-right direction, the left-right width of the turning work machine 1 In the present embodiment, the front frame 10 is formed so that the left and right width of the front frame 10 is narrower than the main frame 9, and the front wheels 4 are disposed in front of the main frame 9 and on the left and right sides of the front frame 10. Since the space 94 is provided, the left and right width of the turning work machine 1 is prevented from becoming wide.
A front wheel drive system 33 that transmits power to the front wheels 4 is connected to a driven gear 57 of the mechanical transmission device 37 and protrudes forward from the transmission case 62, and a front wheel case 96. A front wheel differential device 105, a bevel pinion shaft 106 for inputting power to the front wheel differential device 105, a transmission shaft 107 linking the bevel pinion shaft 106 and the front wheel power take-out shaft 104, and a front wheel differential device An unillustrated final reduction mechanism (transmission mechanism) that transmits power from a differential output shaft 108 of 105 to a front wheel drive shaft 109 that drives the front wheels 4 is provided.

The front axle case 96 is provided with an operating body 111 that swings integrally with the front axle case 96, and the front frame case 6 (front frame 10) is controlled by restricting the swinging of the operating body 111. A rocking lock mechanism 112 that restricts the rocking of 96 is provided.
The operating bodies 111 are arranged in a pair in the front-rear direction at the center in the left-right direction of the front axle case 96 and are bolted to attachment portions 113 provided on the front axle case 96, respectively.
The front and rear actuating bodies 111 penetrate upward through the horizontal wall portion 98 of the connecting plate 93, and a fitting portion 114 that is open upward and front and rear is formed on the top of each actuating body 111. Has been.

The rocking lock mechanism 112 closes and closes the two chambers 124A and 124B defined by the lock cylinder 115 disposed between the upper portions of the front and rear operating bodies 111 and the piston 117 in the cylinder tube 116 of the lock cylinder 115. A switching valve 118 for switching to a state (non-communication state) is provided.
The lock cylinder 115 is disposed horizontally in a disposition opening 119 formed in the upper wall 91 of the front frame 10 so that the axis is aligned with the left-right direction, and fluid (oil in the present embodiment) is disposed. A filled cylinder tube 116, a piston 117 accommodated in the cylinder tube 116 so as to be movable in the left-right direction, and a pair of left and right fixed to the left and right sides of the piston 117 and projecting outward in the left-right direction from the cylinder tube 116 Mainly composed of a piston rod 120.

The left and right piston rods 120 are attached to and supported by a support plate 121 on the same side in the left-right direction.
Each of the left and right support plates 121 is erected on the horizontal wall portion 98 of the connecting plate 93 of the front frame 10, and open mounting grooves 122 are formed on the upper and left and right sides of the upper portion in the front-rear direction center. ing.
On the other hand, a mounting bolt 123 made of a headed bolt is screwed in the left-right direction on the outer end side of each of the left and right piston rods 120, and the shaft portion of this mounting bolt 123 is located above the mounting groove 122 of the support plate 121. Then, the left and right piston rods 120 are horizontally fixed to the front frame 10 (airframe frame 6) side in the horizontal direction by tightening the mounting bolts 123.

On both the front and rear sides of the central portion in the left-right direction of the cylinder tube 116, there are provided fitted portions 126 for interlockingly connecting the cylinder tube 116 to the operating body 111 by being fitted into the fitting portion 114 of the operating body 111 from above. Yes.
The fitted portion 126 is composed of a pin having an axial center in the front-rear direction, and is fitted into the fitting portion 114 of the operating body 111 at the same time when the piston rod 120 is attached.
The switching valve 118 includes a two-port two-position switching valve 118, and one port communicates with one chamber 124A in the cylinder tube 116 via a hose or the like, and the other port communicates with the other chamber 124B in the cylinder tube 116. It communicates via a hose or the like, and a fluid (oil) is filled in a path from one chamber 124A of the cylinder tube 116 to the other chamber 124B.

A pair of access ports 125A and 125B for allowing fluid to enter and exit the two chambers 124A and 124B of the cylinder tube 116 are formed on the upper surface side of the cylinder tube 116.
In the rocking lock mechanism 112 having the above-described configuration, when the switching valve 118 is switched to a communication state in which fluid flows from one chamber 124A of the cylinder tube 116 to the other chamber 124B, In a state in which the switching valve 118 is switched to a non-communication state in which the movement is permitted and the swinging of the front axle case 96 is permitted and fluid does not flow from one chamber 124A of the cylinder tube 116 to the other chamber 124B. The horizontal movement of the tube 116 is restricted, and the swinging of the front axle case 96 is restricted (locked).

The lock cylinder 115 of the oscillating lock mechanism 112 having the above-described configuration engages the fitting portion 126 of the cylinder tube 116 with the fitting portion 114 of the operating body 111 from above, and simultaneously attaches the mounting bolt 123 of the piston rod 120 to the support plate. The lock cylinder 115 can be easily attached by fitting in the attachment groove 122 of 121 and then tightening the attachment bolt 123.
As an assembly method, the front axle case 96 to which the operating body 111 is attached may be assembled to the front frame 10, and then the lock cylinder 115 may be assembled. Alternatively, the lock cylinder 115 may be assembled to the front frame 10 first, and then The front axle case 96 to which the operating body 111 is attached may be assembled to the front frame 10.

In the present embodiment, the cylinder tube 116 is disposed horizontally, and the fluid inlet / outlet ports 125A and 125B provided in the cylinder tube 116 are formed on the upper surface side of the cylinder tube 116. When air accumulates in the tube 116, air can be vented through the entry / exit ports 125A and 125B.
The swivel body 3 includes a swivel base 201 that is supported on the body frame 6 so as to be swivel around a swivel axis in the vertical direction, and a traveling control device 202 and a ground work device provided at the front of the swivel base 201. As the excavation work device 203, a driver seat arrangement frame 204 provided in the rear part of the swivel base 201, a driver seat 205 provided in the driver seat arrangement frame 204, and arranged on both left and right sides of the driver seat 205 The excavation work device operating device 206, the excavation work device control valve (switching valve of the operation device 206) 207 and the counterweight 208 provided in the driver seat frame 204, and the LOSS 209. Yes. Further, the turning axis X coincides with an axis perpendicular to the center between the front and rear wheels.

Further, as shown in FIGS. 22 and 23, the swivel base 201 has a flat front part, both left and right sides bulge out from the body frame 6 and extends rearward, and a rear part and left and right side parts are formed in a substantially rectangular shape. Has been.
In addition, the swivel base 201 includes a front frame member 211, a rear frame member 212 disposed behind the front frame member 211, and a front frame member 211 and a rear frame member 212 on both right and left sides. A pair of left and right side frame members 213 to be connected, a lower wall 214 provided between the front and rear frame members 212 on the lower surface side of the swivel base 201, and a step 215 (foot rest) provided on the upper surface side of the lower wall 214 It has.

Further, on the upper surface of the front frame member 211, masts (working device support bodies) 216 are erected on both left and right side portions (left and right sides of the front frame portion), and the excavation work device 203 is attached to the pair of left and right masts 216. ing.
As shown in FIGS. 1 and 16 to 21, the excavation work device 203 includes a pair of left and right booms 241 pivotably connected to the upper portions of the left and right masts 216 around the left and right axes, and the base side is left and right. A pair of left and right arms 242 pivotally connected to the distal end side of each boom 241 about the left and right axis; a bucket 243 provided on the distal end side of the left and right arm 242 as a work tool for ground work; A pair of left and right boom cylinders 244 that swings each boom 241 up and down around the pivot, a pair of left and right arm cylinders 245 that swings each left and right arm 242 back and forth around the pivot, and a bucket 243 that swings 1 Book bucket cylinder 246.

The bucket cylinder 246, the arm cylinder 245 and the bucket cylinder 246 are constituted by hydraulic cylinders.
The base side of the left and right arms 242 is connected by a connecting member 247 made of a pipe material arranged along the left and right direction, and one end side of the bucket cylinder 246 (cylinder) The piston top side of the main body is pivotally connected so as to be rotatable about the left and right axis.
A support body 249 that supports the bucket 243 is provided on the distal end side of the left and right arms 242.

The support 249 is configured by a plate material having a plate surface extending in the left-right direction. A bucket 243 is supported on the front side of the support 249, and mounting brackets 250 are provided on both the left and right sides of the back side of the support 249. The distal end side of the arm 242 on the same side in the left-right direction is pivotally connected to the lower side of each of the left and right mounting brackets 250 via the horizontal shaft 251 so as to be rotatable about the left-right axis.
A support shaft 252 having an axial center in the left-right direction is provided so as to be connected to the left and right arms 242 so as to be connected to the left and right arms 242 at the distal end side of the arm 242. One end side of the first link 253 is connected to the center in the direction, and the second link 254 is pivotally connected to the other end side of the first link 253 so as to be rotatable about the left and right axis. The end side is pivotally connected to a bracket 255 provided at the center in the left-right direction on the back surface of the support 249 so as to be rotatable about the left-right axis.

Further, the other end side (piston rod front end side) of the bucket cylinder 246 is pivotally connected to the middle portion of the first link 253 so as to be rotatable about the left-right axis. By extending and retracting the bucket cylinder 246, the bucket 243 is swung around the horizontal axis 251 (around the horizontal axis), and the bucket 243 can be scooped / dumped or scraped / dumped.
The bucket 243 is supported by the support 249 so as to be rotatable around a rotation shaft 257 having an axis Y perpendicular to the bucket 243 (work tool support surface) 256 of the support 249. 243 is a scraping operation shown in FIG. 18B from the first working posture in which the scooping operation shown in FIG. 18A can be performed by the rotating means 258 provided between the bucket 243 and the support 249. It is possible to rotate 180 ° around the axis Y of the rotation shaft 257 in a possible second working posture.

The rotating means 258 includes a cylinder tube 259 fixed to the support body 249, a piston 260 accommodated in the cylinder tube 259, and the rotation fixed to the bucket 243 side and inserted into the piston 260. And a moving shaft 257.
The cylinder tube 259 is inserted into the support body 249 as a projecting shape before and after the support body 249 with the axis Y of the rotation shaft 257 of the bucket 243 as an axis, and is bolted to the support body 249. The side is open and pressure oil inlet / outlet ports 261A and 261B are formed in the front and rear.

The rotating shaft 257 is inserted into the cylinder tube 259 from the front side, and includes a front mounting portion 262 that closes the front-side opening of the cylinder tube 259, and a midway to rear portion that is formed with a smaller diameter than the mounting portion 262. The mounting portion 262 and the rear end side of the shaft portion 263 are supported by the cylinder tube 259 so as to be rotatable around the shaft center, and the rear end side of the shaft portion 263 is a cylinder tube by a bolt. 259 is attached so as not to move in the axial direction.
A mounting plate 264 is fixed to the mounting portion 262 of the rotating shaft 257 by bolts, and the mounting plate 264 is fixed to the back wall 265 of the bucket 243 by bolts so that the rotating shaft 257 can be mounted to the bucket 243 so as to be integrally rotatable. It is fixed.

The piston 260 is formed in a cylindrical shape and is fitted in the cylinder tube 259 so as to be movable in the axial direction and not rotatable around the axial center, and is moved in the axial direction to the shaft portion 263 of the rotating shaft 257. It is possible to be fitted and externally fitted so as to be rotatable relative to the axis.
Further, the screw that meshes with the outer peripheral side of the shaft portion 263 of the rotating shaft 257 and the inner peripheral side of the piston 260 and converts the linear movement of the piston 260 into the rotation of the rotating shaft 257. 266 and 267 are formed, and by supplying pressure oil into the cylinder tube 259 from one or the other of the access ports 261A and 261B of the cylinder tube 259, the piston 260 moves linearly in the axial direction. When the screw 267 on the inner peripheral side of the 260 and the screw 266 on the outer peripheral side of the shaft portion 263 of the rotation shaft 257 are engaged with each other, the rotation shaft 257 rotates about the axis.

The bucket 243 is configured to rotate 180 ° when the piston 260 moves from one end side to the other end side.
In the illustrated example, the bucket 243 is in the first working posture at a position slightly away from the stroke end on the front end side (one end side) (about 3 mm), and slightly from the stroke end on the rear end side (the other end side). The bucket 243 is set to be in the second working posture at a position (approximately 3 mm) away.
Further, the excavation work device 203 includes a rotation of the bucket 243 (one direction of the bucket 243) in the direction of rotation from the second work posture to the first work posture (the direction indicated by the arrow A in FIG. 21) in the first work posture. The rotation of the bucket 243 in the opposite direction to the rotation A in one direction and the rotation direction from the first work posture to the second work posture in the second work posture. A rotation that restricts the rotation of the bucket 243 (referred to as rotation in the other direction of the bucket 243) in the direction indicated by the arrow B in FIG. 21 and allows rotation of the bucket 243 in the direction opposite to the rotation B in the other direction. A movement restricting means 268 is provided.

The rotation restricting means 268 includes a locking portion 269 that rotates integrally with the bucket 243, a first locked portion 270 that is provided on the support 249 side and locks the locking portion 269, and a second locked portion. And a locking portion 271.
The locking portion 269 is configured by a pin having a horizontal axis, and is fixed to a bracket 272 fixed to the back wall 265 of the bucket 243.
The first locked portion 270 and the second locked portion 271 are formed in a hook shape and are fixed to the front side of the support 249, and the first locked portion 270 is in the other direction of the bucket 243. The engaging portion 269 is engaged so as to restrict the rotation A in one direction of the bucket 243 and allow the rotation B in the other direction of the bucket 243 in the first working posture. The second locked portion 271 is opened in the rotational direction A in one direction of the bucket 243, restricts the rotational B in the other direction of the bucket 243 in the second working posture, and The locking portion 269 is locked so as to allow the rotation A in one direction.

Further, the locking portion 269, the first locked portion 270, and the second locked portion 271 are formed so as to receive a load acting on the bucket 243 during excavation work, and a plurality of them are provided around the rotating means 258. (4 each in this embodiment) are provided, and thereby, it is possible to reduce the load burden acting on the rotating shaft 257 from the bucket 243 during excavation work.
In addition, the excavation work device 203 is provided with posture holding means 273 that holds the bucket 243 in the first work posture and the second work posture.

The posture holding means 273 is disposed on the back side of the support 249 and is supported so as to be movable along the bucket support surface 256 of the support 249 so that the tip can be moved out and out of the outer periphery of the support 249. The bucket in the first and second working postures is engaged with the joint member 276 and the engaging member 276 that is provided at two positions displaced by 180 ° around the rotation shaft 257 on the work tool side and protrudes from the outer periphery of the support 249. And an engaged portion 277 for restricting the rotation of the H.243.
The engaging member 276 is configured by a pin having a tapered tip end side, and a guide tube 278 that guides the engaging member 276 so as to be movable in the retracting direction is attached to a bracket 279 fixed to the back surface of the support 249. The engaging member 276 passes through the bracket 279 and is inserted into the guide cylinder 278.

The engaged portion 277 is formed in a cylindrical shape that engages when the distal end side of the engaging member 276 is inserted, and the inner peripheral side is formed in a tapered shape that matches the tapered shape on the distal end side of the engaging member 276. .
The engaged portion 277 is fixed to an attachment member 280 that is attached and fixed to the back wall 265 of the bucket 243.
A release lever 281 for releasing the engagement by removing the engagement member 276 from the engaged portion 277 is provided on the side of the base side of the engagement member 276.
The release lever 281 is bent in a V shape, and a bent portion of the release lever 281 rotates about an axis parallel to the axis of the rotation shaft 257 on a stepped attachment shaft 282 fixed to the support 249. It is attached freely.

On one end side of the release lever 281, an engagement block 283 is provided that is rotatably attached about an axis parallel to the rotation axis of the release lever 281.
Further, the release lever 281 is rotationally resisted by a biasing force of a spring member 285 including a compression coil spring interposed between the release lever 281 and a spring receiver 284 fitted on the end side of the mounting shaft 282. Is granted.
One end side of the release lever 281 and the base end side of the engaging member 276 are interlocked and connected by an interlocking member 286.

One end side of the interlocking member 286 is pivotally connected to the base end side of the engaging member 276, the other end side of the interlocking member 286 is formed in a rod shape, and the rod portion 287 is provided on one end side of the release lever 281. The engagement block 283 is inserted in a penetrating manner, and a male screw 288 is formed on the end portion side of the rod portion 287 and a nut 289 is screwed.
Further, a spring member 291 made of a compression coil spring is interposed between the spring receiving step 290 provided on one end side of the interlocking member 286 and the engaging block 283 as a fitting shape on the rod portion 287.

Further, in the state where the engaging member 276 is engaged with the engaged portion 277, the release lever 281 is rotated on the support body 249 by the action of the urging force of the spring member 291 fitted on the rod portion 287 ( A contact wall 292 that contacts one end of the release lever 281 is provided so as to restrict the counterclockwise rotation of the release lever 281 in FIG. 20B, and the engagement member 276 is an engaged portion. In the state of being engaged with 277, the spring member 291 fitted into the rod portion 287 urges the engaging member 276 in a direction to engage the engaged portion 277.
Further, in a state where the engaging member 276 is engaged with the engaged portion 277, the other end side of the release lever 281 is rotated clockwise in FIG. 289 is pulled and the interlocking member 286 is pulled, whereby the engaging member 276 is pulled in the removal direction, and the engagement state between the engaging member 276 and the engaged portion 277 is released, and the bucket 243 It can be turned.

Further, the support 249 is provided with a stopper 293 that restricts the rotation of the release lever 281 in the direction in which the engaging member 276 is removed from the engaged portion 277.
The release lever 281 is linked to a remote control lever provided in the vicinity of the driver's seat 205 via an interlocking member 294 such as a push-pull cable, and remote control means constituted by the remote control lever, the interlocking member 294 and the like. Is operated remotely from the driver's seat 205 side, or is operated by a manual lever provided on the support 249.
When a manual lever for operating the release lever 281 is provided on the support 249, the boom 241 is raised and the arm 242 is swung rearward to fold the excavation work device 203 so that the manual operation can be performed from the swivel base 201. The lever can be operated.

In the excavation work device 203 of this embodiment having the above-described configuration, since the load during excavation is not so much applied to the rotation shaft 257, the rotation shaft 257 is thinned to make the cylinder tube 259 (rotation means 258) small. Can be
Further, if the rotation means 258 is constituted by a motor, the cost becomes high. However, by configuring the rotation of the bucket 243 and the rotation restriction and posture maintenance of the bucket 243 by different means, the present embodiment can also be used. In the bucket 243, it is only necessary to change the position between the first working posture and the second working posture, and the rotating means 258 is structured by the cylinder tube 259, the piston 260, and the rotating shaft 257. The rotation means 258 can be configured at a low cost.

Further, by making the rotating shaft 257 a cast product made of a material such as FC, it is possible to eliminate the restriction of manufacturing the leads of the screws 266 and 267.
In the swivel body 3, the lower wall 214 of the swivel base 201 is mounted on the inner race 87 of the swivel bearing 16 of the traveling body 2 and is bolted. The swivel body 3 is supported so as to be pivotable about the pivot axis X. In the present embodiment, the swivel body 3 is capable of swiveling all around the left and right directions.
Here, as shown in FIG. 1, the traveling body 2 has the engine 7 disposed at the rear in order to dispose the swivel base 201 at a lower position even when the engine 7 is mounted, and the traveling system power transmission mechanism. 8 is arranged in front of the engine 7. Thereby, the vertical dimension of the part which opposes the turntable 201 of the traveling body 2 is made small.

As shown in FIG. 1, the swivel body 3 is disposed on the traveling body 2 in a state where the upper surface of the step 215 of the swivel base 201 is lower than the upper surface of the engine 7 on the traveling body 2 side. Thereby, the vehicle height is suppressed while ensuring the height of the operation space of the revolving structure 3, and the entire revolving work machine 1 is configured to be compact in the vertical direction. Further, the center of gravity of the turning work machine 1 is maintained at a low level, thereby improving the stability and reducing the burden of getting on and off the worker getting on and off the turning body 3.
Even when the revolving unit 3 is arranged on the traveling unit 2 with the upper surface of the step 215 slightly higher than the upper surface of the engine 7, the revolving work machine 1 can be made compact in the vertical direction, and at least the swivel base By arranging the swing body 3 on the traveling body 2 in a state where the upper surface of the swing bearing 16 disposed in 201 is lower than the upper surface of the engine 7, the entire swing work machine 1 can be made compact and stable in the vertical direction. Will be improved.

Further, when the revolving structure 3 is in the forward-facing posture, the rear portion of the driver seat arrangement frame body 204 and the counterweight 208 are positioned above the engine 7 provided in the traveling body 2.
As a result, the distance L1 from the turning axis X to the rear end of the revolving body 3 is substantially within the distance L2 from the turning axis X to the rear end of the rear wheel. As a result, even when the revolving unit 3 is turned, a collision with a rear obstacle is avoided.
As shown in FIGS. 24 and 25, the driver's seat arrangement frame 204 is mounted on a support frame 321 fixed to the swivel base 201 and mounted on the support frame 321 so that the driver's seat 205 can be moved forward by a front pivot. A mounting table 322 to be placed and a weight mounting frame 323 for mounting the counterweight 208 are provided.

The support frame 321 is constructed over a pair of left and right connecting portions in which the side frame member 213 is connected to the rear frame member 212 of the swivel base 201, and the pair of left and right extending from the connection portion toward the rear upper side of the swivel base 201. And a connecting portion 225 that connects the rear end portions of the pair of left and right skew portions 324, and is formed in a U-shape. Between the pair of left and right skew portions 324, In addition, a mounting table 322 is provided in front of the connecting portion 225.
The mounting table 322 is erected from the swivel base 201 in a state in which a pair of left and right side walls 326 arranged along a pair of left and right skew portions 324 of the support frame 321 and a front edge of the pair of left and right side walls 326 are connected. A front wall 327, a pair of left and right side walls 326 and an upper edge of the front wall 327 connected to each other, an upper wall 328 extending to a position below the connecting portion 325 of the support frame 321, and an upper surface of the upper wall 328 And a seat base 329 that supports the driver's seat 205.

The seat base 329 is connected to a pair of left and right legs 330 extending along the upper edge of the pair of left and right side walls 326 and the upper ends of the pair of left and right legs 330 and extends toward the front of the swivel base 201. And a flat plate portion 331. As shown in FIG. 22, the flat plate portion 331 includes an opening 332 at a position facing the upper wall 328. Further, as shown in FIG. 25, a pair of left and right support tools 333 for supporting the driver's seat 205 is disposed at a position in front of the turntable 201 with respect to the opening 332, and a small window is provided between the support frames. 333a is established.
The weight mounting frame 323 is supported by the connecting portion 325 of the support frame 321, and includes an upper frame portion 334 that covers the connecting portion 325 from above, and a pair of left and right sides that extend downward from the lower surface side of the upper frame portion 334. A fixture 325a that includes a frame portion 335 and a lower frame portion 336 that connects the lower end portion of the side frame portion 335 and extends to the left and right, and the upper frame portion 334 is welded to the connection portion 325 of the support frame 321. It is attached to the support frame 321 by being fastened via a fastener such as a bolt.

  As shown in FIGS. 1 and 22, the counterweight 208 is connected to the lower frame portion 336 of the weight attachment frame 323 via a fastener, and the rear portion of the skew portion 324 of the support frame 321 and the mounting table 322. The lower weight 208a that covers the rear part from below, the lower frame part 336 of the weight attachment frame 323, and the pair of left and right side frame parts 335 are connected via fasteners to the rear part of the skew part 324 of the support frame 321 and the connection part 325. And an upper weight 208b that covers the rear portion of the mounting table 322 from the rear. These upper and lower weights 208a and 208b are detachable as appropriate according to the work situation and the weight of the excavation work device 203, and can be replaced with, for example, a cover (not shown) made of resin.

Further, as shown in FIGS. 2 and 3, the driver's seat arrangement frame body 204 is covered with a cover body 341 provided from the lower side to the rear side of the driver's seat 205. As shown in FIGS. 22 and 23, the cover body 341 includes a main cover 342 provided from below the pair of left and right operating devices 206 to the rear of the driver's seat 205, and a sub-cover 343 covering the lower portion of the driver's seat 205. And.
The sub cover 343 is opposed to the front wall 327 of the mounting table 322 with a predetermined interval, the lower end edge is in contact with the step 215, and both side edges are opposed to the side edges of the main cover 342. The upper end edge of the seat base 329 covers the front end edge. Further, the sub cover 343 is attached to the step 215, the mounting table 322, and the like via fasteners such as bolts, and can be detached from the attachment position without removing the main cover 342.

Further, the upper surface of the upper frame portion 334 of the weight attachment frame 323 is covered by a thick plate member 345 provided at the upper end portion of the fixture 325a, and angle members are provided at both left and right end portions of the upper surface of the thick plate member 345. 346 is deployed. At the upper end of the rising portion of the angle member 346, a groove-shaped rear lops support portion 347 for supporting the lops 209 is formed.
Further, as shown in FIG. 23, the pair of left and right masts 216 each have a front lops support portion 348 formed in a flat shape at the upper end portion, and a pair of left and right front lops supports positioned before and after these swivel bases 201. The lops 209 are supported by the portion 348 and the rear lops support portion 347.

  As shown in FIGS. 1 and 2, the lops 209 is formed by bending a cylindrical steel pipe into a U shape, and includes a front strut portion 351 extending upward from the front lops support portion 348 and a weight mounting frame 323. And a pair of left and right rear struts 352 extending from the top, the upper ends of the front struts 351 and the upper ends of the rear struts 352, and a pair of left and right rear struts 352. It is connected. In addition, a plurality of connecting rods 354 that connect the pair of left and right beam portions 353 are provided on the LOSS 209, and a canopy (not shown) is attached to the upper portion so as to be able to be shaded.

Further, as shown in FIG. 23, a plate-like connecting piece 351a is fixed to the lower ends of the pair of left and right front struts 351 of the LOSS 209. The connecting piece 351a is fastened to the front lops support portion 348 via a fastener, and the base ends of the left and right rear strut portions 352 are supported by the rear lops support portion 347, whereby the lops 209 is mounted on the swivel base 201. The Rukoto.
The driver's seat 205 includes a seat 355 on which an operator can sit and a seat support portion 356 that supports the seat 355 so that the front and rear positions can be adjusted. A connecting tool 357 connected to the support tool 333 is provided.

The connection tool 357 is pivotally connected to the support tool 333 via a pivot pin (not shown) having an axial center in the left-right direction, whereby the driver's seat 205 is connected to the seat base 329 of the mounting table 322 on the front side. It will be placed on the pivot so that it can be moved forward.
The seat support 356 includes a lid member 358 that closes the opening 332 of the seat base 329 in a state where the driver's seat 205 is placed on the seat base 329. As a result, as shown by a two-dot chain line in FIG. 23, the opening 332 is released from the state closed by the lid member 358 by swinging the driver's seat 205 from the state of being placed on the seat base 329 to the forward position. When the driver seat 205 is swung from the forward position to the state of being placed on the seat base 329, the opening 332 is set from the open state to the closed state by the lid member 358.

Further, the pair of left and right legs 330 of the seat base 329 respectively support an operation lever 361 provided on the side of the driver's seat 205 via a support member (not shown). These operation levers 361L and 361R are the operation devices 206 for the excavation work device, the left operation lever 361L operates the swivel base 201 and the arm 242 of the excavation work device, and the right operation lever 361R is the boom 241. And the bucket 243.
In addition, a bucket rotation lever 361C that can operate the rotation of the bucket 243 is disposed behind the right operation lever 361R.

The traveling system control device 202 includes a control table 362 disposed at the center in the left-right direction of the front part of the swivel base and between the pair of left and right masts 216, and a steering handle 363 and a brake pedal 364 supported by the control table 362. And a forward / reverse switching pedal (accelerator pedal) 365 supported by the swivel base 201.
As shown in FIG. 23, the control 362 includes a handle post 366 that supports the steering handle 363, a power steering controller 367, and a tilt device (not shown) that can adjust the front and rear positions of the steering handle 363. After being assembled as a set of assemblies, the swivel base 201 can be compactly equipped.

Further, as shown in FIGS. 23 and 26, the brake pedal 364 includes a stepped portion 364a having a left and right length substantially the same as or slightly larger than the left and right length of the control table 362 at the rear of the base of the control table 362. It is pivotally supported on a support shaft in the left-right direction provided on the control table 362. Further, the brake pedal 364 is biased so as to be able to return to the position before the depression when the depression is released.
As shown in FIGS. 23 and 27, the forward / reverse switching pedal 365 includes a long swinging body 365a whose middle part is pivotably supported by a support shaft in the left-right direction, and a front end portion of the swinging body 365a. The front stepping portion 365b provided and the rear stepping portion 365c provided at the rear end portion are provided, and when the front stepping or the rear stepping is released, they are urged so as to be returned to the neutral position.

As shown in FIGS. 22 and 23, it is formed below the driver's seat 205 placed on the seat base and by the front wall 327, the upper wall 328, and the seat base 329 of the sub cover 343 and the placement base 322. The operating force relay unit 371 of the control device 202 and the control valve 207 are arranged in the space S.
The operating force relay unit 371 includes a master cylinder 372 for operating the foot brake means 70 and this operating tool, a remote control valve (switching valve) 373 for HST, and this operating tool.

  As shown in FIG. 26, the master cylinder 372 is supported by a mounting member 374 protruding from the swivel base 201 with the longitudinal direction between the front wall 327 and the sub cover 343 in the vertical direction. The brake pedal 364 is connected to the master cylinder 372 via a plurality of link mechanisms, rods, and the like that constitute an operating tool. As a result, when the brake pedal 364 is depressed, the piston of the master cylinder 372 is pushed in and the hydraulic pressure in the master cylinder 372 is increased, and the hydraulic pressure is transmitted to the foot brake means 70 of the traveling body 2 to brake the rear wheels. It is.

A brake oil tank 375 is provided on the side of the master cylinder 372, and an oil injection port 375a of the brake oil tank 375 slightly protrudes upward from the small window 333a of the seat base 329.
The attachment member 374 is provided with a differential lock operating means 377 for operating the differential lock device 80 provided in the traveling body 2. The differential lock actuating means 377 includes a switching valve 378 capable of switching on / off of the differential locking device 80, and a differential lock lever 379 capable of operating the switching valve 378. The differential lock lever 379 has one end connected to the rotary spool of the switching valve 378 and the other end extending to the front of the sub cover 343 through a guide hole (not shown) formed in the sub cover 343. . Then, when the operator seated on the driver's seat 205 steps on the other end of the differential lock lever 379, the differential lock device 80 is turned on and operates. Further, the differential lock lever 379 is biased so as to be able to return to the position before the depression when the depression is released, and by releasing the depression, the differential lock device 80 automatically shifts from the on state to the off state.

  As shown in FIG. 27, the remote control valve 373 for HST is a state where the swash plate of the HST 35 is moved forward by applying a pilot pressure to the forward port 52 or the reverse port 53 of the forward / reverse switching means 51 provided in the traveling body 2. And the reverse traveling state, and the traveling speed of the traveling body 2 can be adjusted. The remote control valve 373 is provided at a position where the swing spool 381 for controlling the pilot pressure is swingable in the front-rear direction of the swivel base 201 and the upper surface side is opposed to the opening 332 of the seat base 329. It is supported by a bracket 382 erected on the upper wall 328 of the mounting table 322.

  The forward / reverse switching pedal 365 is connected to the swing spool 381 of the remote control valve 373 via a plurality of link mechanisms, rods and the like constituting the operating tool. The operating tool includes a cylindrical member 383 that rotates by swinging of the forward / reverse switching pedal 365 between the forward / reverse switching pedal 365 and the remote control valve 373, and the cylindrical member 383 includes a forward / reverse switching pedal 365. A first plate 384 for interlockingly connecting the swinging spool 381 of the remote control valve 373 and a second plate 385 for interlockingly connecting the forward / reverse switching pedal 365 and the damper device 386 are provided so as to protrude in the radially outward direction.

The damper device 386 includes a first damper 386a for front depression and a second damper 386b for rear depression, and is disposed behind the remote control valve 373 and above the upper wall 328. The second plate 385 includes: The first damper 386a and the second damper 386b are connected to the tip divided into two forks.
As a result, when the front stepping portion 365b of the forward / reverse switching pedal 365 is depressed, the swing spool 381 of the remote control valve 373 is swung in one direction via the operation tool, and the remote control valve 373 is operated in the forward depressed state. The Then, the forward / reverse switching pedal 365 returns to the neutral position by releasing the stepping on the front stepping portion 365b, but this return operation is gently performed by the first damper 386a.

Further, by depressing the rear stepping portion 365c of the forward / reverse switching pedal 365, the swing spool 381 of the remote control valve 373 is swung in the other direction via the operation tool, and the remote control valve 373 is operated in the rear stepped state. . Then, the forward / reverse switching pedal 365 returns to the neutral position by releasing the stepping on the rear stepping portion 365c, but this return operation is gently performed by the second damper 386b.
As shown in FIGS. 23 and 27, a control valve 207 is provided at a position behind the HST remote control valve 373 and on the damper device 386 side, and the upper surface of the control valve 207 faces the opening 332. ing.

The control valve 207 controls the hydraulic actuators (the turning motor 15, the boom cylinder 244, the arm cylinder 245, the bucket cylinder 246, and the rotating means 258) provided in the work machine. A plurality of control valves composed of switching valves are connected in a direction perpendicular to the sliding direction of the spool.
In the turning work machine 1 of the present embodiment, as described above, the HST remote control valve 373 serving as the operation force relay unit 371, the operation tool of the remote control valve 373, the damper device 386, the foot, in the space S below the driver's seat 205. A master cylinder 372 for operating the brake means 70, an operating tool for the master cylinder 372, a brake oil tank 375, a differential lock actuating means 377, and a control valve 207 are centrally arranged.

Therefore, the erosion of the operation space by these devices and the operation tools of these devices is as small as possible. Further, since the remote control valve 373, the damper device 386, and the control valve 207 of the HST are disposed at positions facing the opening 332 of the seat base 329, the driver's seat 205 is set in a forward-turned state and the opening 332 is opened. Thus, inspection and maintenance work of these devices can be easily and collectively performed.
Further, by setting the driver's seat 205 forward, the oil injection port 375a of the brake oil tank 375 protruding from the small window 333a of the seat base 329 is also exposed, and oil is injected into the brake oil tank 375. Can also be done.

Further, since the master cylinder 372, the brake oil tank 375, and the differential lock actuating means 377 are provided at a position behind the sub cover 343, the inspection and maintenance work of these devices can be easily performed by removing the sub cover 343. And it can be done together.
30 and 31 show a hydraulic circuit of the swing working machine 1 according to the present embodiment. The hydraulic circuit is separated from the swivel joint 14 by the traveling body side (FIG. 30), the swivel base side (FIG. 31), and FIG. It is divided into.

The power of the engine 7 can drive the charge pump 79 and the main pump 68 at the same time as the hydraulic pump 46 of the HST 35 is driven.
The hydraulic oil from the main pump 68 driven by the power of the engine 7 is also supplied to the control valve 207 via the swivel joint 14 and sent from the control valves V1 to V5 of the control valve 207 to the respective actuators.
In the control valve 207, V1 is a turning control valve that controls the turning motor 15, V2 is an arm control valve that controls the arm cylinder 245, V3 is a bucket turning control valve that controls the turning means 258 of the bucket 243, V4 is a boom control valve for controlling the boom cylinder 244, and V5 is a bucket control valve for controlling the bucket cylinder 246.

The left operation lever 361L of the operation device 206 is provided with a remote control valve 393L for arm and turning, and by swinging the left operation lever 361 back and forth, the arm cylinder is connected via the arm control valve V1. When the 245 is scratched and dumped and the left operating lever 361 is swung left and right, the turning motor 15 is rotated left and right via the turning control valve V2.
The right operation lever 361R is provided with a bucket and boom remote control valve 393R. By swinging the right operation lever 361 back and forth, the bucket 243 is tilted via the work tool control valve V5. By performing the dumping operation and swinging the right operation lever 361 left and right, the boom cylinder 244 is raised and lowered via the boom control valve V4.

Further, the bucket rotation lever 394 disposed behind the right operation lever 361L supplies pressure oil to the rotation means 258 of the bucket 243 via the bucket rotation control valve V3, whereby the bucket 243 rotates. .
In this embodiment, a pilot control switching valve operated by a pilot pressure such as a swing control valve V1, an arm control valve V2, a boom control valve V4, a bucket control valve V5, and the remote control valves 393L and 393R. The bucket rotation control valve V3 is configured by an artificial operation switching valve 378 operated by an artificial operation, but all the control valves V1 to V5 may be configured by pilot operation switching valves.

The hydraulic oil of the main pump 68 is supplied to the steering cylinder 97 via the power steering controller 367.
Further, as shown in FIG. 30, when the swivel base 201 is swung from the forward posture to the rearward posture in the pilot oil passages 395a and 395b connecting the remote control valve 373 for HST and the forward / reverse switching means 51, it is detected. Thus, a forward / reverse conversion means 401 that reverses the switching operation of the forward / reverse switching means 51 by the forward / reverse switching pedal 365 is provided.
As shown in FIGS. 28 and 30, the forward / reverse conversion means 401 switches the pilot oil passages 395 a and 395 b between the HST remote control valve 373 and the forward / reverse switching means 51 to transfer the pressure oil from the remote control valve 373 back and forth. A four-port three-position switching valve 402 that can be supplied to the advance switching means 51, and a detection mechanism 403 that detects the turning state of the swivel base 201 and switches the rotary spool 402a of the switching valve 402 between three positions. .

As shown in FIGS. 28 and 29, the switching valve 402 is formed by a rotary valve having a rotating spool 402 a and is disposed below the upper wall 18 of the main frame 9 of the traveling body 2. Further, an operating piece 404 that protrudes radially outward from the rotating shaft is provided at the upper end of the rotating spool 402a so as to protrude above the upper wall 18, and a pin is provided at the tip of the operating piece 404. 405 protrudes.
In addition, as shown in FIG. 30, the switching valve 402 sets the rotary spool 402a to the A position (forward contact state), whereby the remote control valve 373 and the forward / reverse switching means 51 are connected in the forward contact state. The pressure oil from the forward port 343a of the remote control valve 373 is supplied to the forward port 52 of the forward / reverse switching means 51, and the pressure oil from the reverse port 373b of the remote control valve 373 is the reverse side of the forward / reverse switching means 51. It will be supplied to the port 53. Therefore, the traveling body 2 moves forward by stepping on the front stepping portion 365b of the forward / reverse switching pedal 365, and the traveling body 2 moves backward by stepping on the rear stepping portion 365c of the forward / backward switching pedal 365.

Further, when the rotary spool 402a of the switching valve 402 is set to the B position (neutral state), the supply of pressure oil from the remote control valve 373 to the forward / reverse switching means 51 is cut off, and thereby the forward / reverse switching is performed. The traveling body 2 cannot travel by operating the pedal 365.
Also, by setting the rotary spool 402a of the switching valve 402 to the C position (reverse connection state), the remote control valve 373 and the forward / reverse switching means 51 are connected in a reverse connection state, and from the forward port 373a of the remote control valve 373. Is supplied to the reverse port 53 of the forward / reverse switching means 51, and the pressure oil from the reverse port 373 b of the remote control valve 373 is supplied to the forward port 52 of the forward / reverse switching means 51. . Accordingly, when the front depression portion 365b of the forward / reverse switching pedal 365 is depressed, the traveling body 2 moves backward, and when the rear depression portion 365c of the forward / reverse switching pedal 365 is depressed, the traveling body 2 moves forward.

As shown in FIG. 28, the detection mechanism 403 includes a detection arm 406 provided on the traveling body 2 side and a detection cam 407 provided on the swivel base 201 side to operate the detection arm 406.
The detection arm 406 includes a long swing piece 408, and one end of the swing arm 408 is pivotally supported by the upper wall 18 of the main frame 9 of the traveling body 2 and is long at the other end. A hole 408a is formed, and the pin 405 of the operating piece 404 is inserted into the elongated hole 408a.
As a result, the operating piece 404 swings by swinging the detection arm 406, and the rotary spool 402a rotates as the operating piece 404 swings. In addition, a roller 408 b projects from the detection arm 406 in the longitudinal direction toward the swivel base 201.

Inside the inner race 87 of the swivel bearing 16 disposed on the lower wall 214 of the swivel base 201, a cam forming member 410 is disposed in a state where the center of rotation coincides with the swivel axis X of the swivel base 201. The detection cam 407 is formed in the cam forming member 410 as a cam groove. The cam groove has a shape in which three arcs having different diameters are smoothly connected, and the roller 408b of the detection arm 406 is in contact with the inner surface of the cam groove.
An operating means 411 for operating the rocking lock mechanism 112 is provided between the body frame 6 of the traveling body 2 and the swivel base 201.

As shown in FIGS. 28 and 29, the switching valve 118 of the rocking lock mechanism 112 is formed by a rotary valve having a rotating spool 412a, and is disposed below the upper wall 18 of the main frame 9 of the traveling body 2. Yes. In addition, an operating piece 414 that protrudes radially outward from the rotating shaft is provided at the upper end of the rotating spool 412a so as to protrude above the upper wall 18, and a pin 415 is provided at the tip of the operating piece 414. Is protruding.
When the rotary spool 412a is set to the A position, the switching valve 118 is connected to a communication oil passage that connects the two chambers 124A and 124B formed in the cylinder tube 116 of the swing lock mechanism 112. 124A and 124B are in a communication state. As a result, the fluid in the circuit can freely enter and exit the two chambers. Accordingly, the swing lock mechanism 112 is released, and the front axle case 96 swings according to the road surface condition.

Further, by setting the rotary spool 402a of the switching valve 402 to the B position, the communication oil passage is disconnected and the two chambers 124A and 124B of the cylinder tube 116 are closed. As a result, the pressure oil in the hydraulic circuit cannot move from one chamber 124A to the other chamber 124B. As a result, the swing lock mechanism 112 operates and the front axle case 96 is supported so as not to swing.
The actuating means 411 includes an actuating arm 416 provided on the traveling body side and an actuating cam 417 arranged on the swivel base side to operate the actuating arm 416.

The operating arm 416 has substantially the same configuration as the detection arm 406 and includes a long swing piece 418, and one end of the swing piece 418 is pivotally supported on the upper wall 18 of the main frame 9 of the traveling body 2. In addition, a pin 415 of the operating piece 414 is inserted into a long hole 418a formed at the other end. In addition, a roller 418 b is projected toward the swivel base 201 in the middle in the longitudinal direction of the operating arm 416.
The operating cam 417 is formed by a cam surface formed on the outer peripheral surface of the cam forming member 410, and the cam surface has a shape obtained by smoothly connecting two arcs having different diameters, The roller 418b of the operating arm 416 is in contact with the cam surface.

Further, the operating arm 416 is urged toward the pivot axis X by the pulling spring 419 so as to maintain the state where the roller 418b is in contact with the cam surface.
Further, the operating arm 416 is disposed at a position where the roller 418b is directly opposed to the roller 408b of the detection arm 406 via the rotation axis X. The central axis of the operation arm 416, the rotation axis X The straight line connecting the central axes of the rollers 408b of the detection arm 416 coincides with the central axis extending in the front-rear direction of the traveling body 2.
Here, the operations of the forward / reverse conversion means 401 and the actuating means 411 will be described with reference to FIG.

First, as shown in FIG. 29 (a), when the directions of the traveling body 2 and the turning body 3 coincide with each other and the turning angle of the turning body 3 with respect to the traveling body 2 is 0 ° (forward posture), the forward / reverse conversion means 401 The roller 408b of the detection arm 406 contacts the large-diameter groove portion 421a of the detection cam 407, and the roller 418b of the operation arm 416 of the operation means 411 contacts one large-diameter surface portion 422a of the operation cam 417.
At this time, the detection arm 406 swings in one direction, whereby the rotary spool 402a of the switching valve 402 is set to the A position, and the remote control valve 373 and the forward / reverse switching means 51 are in a forward contact state. Connected. Accordingly, when the front depression portion 365b of the forward / reverse switching pedal 365 is depressed in this state, the traveling body 2 is operated forward, and the traveling body 2 travels forward and, of course, an operator seated in the driver's seat 205. The turning work machine 1 moves forward when viewed from the side.

At this time, the operating arm 416 swings in one direction, so that the rotary spool 412a of the switching valve 118 is set to the A position, so that the two chambers 124A and 124B of the cylinder tube 116 are in a communication state. Thus, the rocking lock mechanism 112 is released. As a result, the front axle case 96 can swing freely, and the pair of left and right front wheels 4 move up and down following the road surface condition, so that the posture of the turning work machine 1 during traveling is stabilized.
Here, the contact state of the detection cam 407 with the large-diameter groove portion 421a by the detection cam 407 and the contact state of the operation cam 417 with the one large-diameter surface portion 422a by the detection cam 407 make the turning angle of the revolving body 3 forward. This is maintained when the vehicle is within the previous turning range given at a predetermined turning angle in the left-right direction from the posture.

Then, the turning body 3 is turned until the turning angle exceeds the previous turning range. For example, as shown in FIG. 29B, the directions of the traveling body 2 and the turning body 3 are orthogonal to each other so When the turning angle is 90 °, the roller 408b of the detection arm 406 comes into contact with the medium-diameter groove portion 421b of the detection cam 407, and the roller 418b of the operation arm 416 comes into contact with the small-diameter surface portion 422b of the operation cam 417.
At this time, the detection arm 406 is swung from a state swung in one direction to a neutral state, whereby the rotary spool 402a of the switching valve 402 is set to the B position, and the remote control valve 373 is moved forward and backward. The connection state with the switching means 51 is cut off. Accordingly, in this state, the traveling body 2 does not travel even when the front stepping portion 365b or the rear stepping portion 365c of the forward / reverse switching pedal 365 is depressed.

  Further, at this time, the operating arm 416 is swung in the other direction, whereby the rotary spool 412a of the switching valve 118 is set to the B position, and the two chambers 124A and 124B of the cylinder tube 116 are in the non-conductive state. As a result, the swing lock mechanism 112 is operated, whereby the front axle case 96 cannot swing. At this time, since the traveling body 2 is in an inoperable state, the front axle case 96 is fixed in a state in which the pair of left and right front wheels receive a ground pressure of substantially the same size and is grounded to the road surface. As a result, the posture of the turning work machine 1 in a state in which it cannot travel is stabilized.

Here, the contact state of the detection cam 407 with the medium-diameter groove portion 421b by the detection arm 406 and the contact state of the operation arm 417 with the small-diameter surface portion 422b by the operation arm 416 indicate that the turning angle of the swing body 3 is within the range of the previous turning. It is maintained when it is within an intermediate turning range given in a predetermined turning angle range.
Then, the turning body 3 is turned until the turning angle exceeds the intermediate turning range. For example, as shown in FIG. 29 (c), the directions of the traveling body 2 and the turning body 3 are made opposite to each other, so When the turning angle is 180 ° (backward posture), the roller 408b of the detection arm 406 comes into contact with the small-diameter groove portion 421c of the detection cam 407, and the roller 408b of the operating arm 416 is relative to the large-diameter surface portion 422a of the operating cam 417. The other large-diameter surface portion 422a comes into contact.

At this time, the detection arm 406 swings in the other direction from the neutral state, whereby the rotary spool 402a of the switching valve 402 is set to the C position, and the remote control valve 373 and the forward / reverse switching means 51 are connected in a reverse connection state. Is done. Accordingly, when the front depression portion 365b of the forward / reverse switching pedal 365 is depressed in this state, the traveling body 2 is operated backward, and the traveling body 2 is moved backward, but the operator seated in the driver's seat 205 The swivel work machine 1 moves forward when viewed from the side.
On the other hand, the operating arm 416 swings in one direction, whereby the rotary spool 412a of the switching valve 118 is set to the A position, and the two chambers 124A and 124B of the cylinder tube 116 are brought into communication with each other to swing. The dynamic lock mechanism 112 is released.

Here, the contact state of the detection cam 407 with the small-diameter groove portion 421c by the detection arm 406 and the contact state of the operation cam 417 with the other large-diameter surface portion 422a by the operation arm 416 cause the turning angle of the revolving body 3 to turn intermediately. It is maintained when it is set within the rear turning range given in a predetermined turning angle range beyond the range.
That is, according to the turning angle of the revolving structure 3, the revolving structure 3 is located in any one of a turning range of a front turning range, a rear turning range, and a pair of intermediate turning ranges provided between these turning ranges. The forward / reverse operation of the forward / reverse switching pedal 65 is switched (reversed) according to the turning range that is positioned, and the swing lock mechanism 112 is switched.

Accordingly, it is not necessary to change the forward / reverse switching pedal 365 according to the case where the revolving body 3 is set to the forward posture and the backward posture, and the operation is performed by depressing the front stepping portion 365b of the forward / reverse switching pedal 365. The turning work machine 1 moves forward as viewed from the worker seated on the seat 205, and the turning work machine 1 moves backward as viewed from the worker by stepping on the rear stepping portion 365c.
Further, the forward contact state of the forward / reverse conversion means 401 and the non-operating state of the operating means 411 of the swing lock mechanism 112 are maintained while the turning angle of the revolving structure 3 is within the forward turning range. For this reason, even when the turning body 3 is turned within a predetermined angle range from the forward posture, the forward / reverse conversion hand 401 stage and the operating means 401 are not switched. The same applies to the case where the revolving structure 3 is set to the rear turning range.

  In addition, there is an intermediate turning range between the front turning angle range in which the switching valve 402 of the forward / reverse conversion means 401 is in the forward contact state and the rear turning angle range in which the switching valve 402 is in the reverse contact state. Even when the swivel base 201 is reciprocated between the forward posture side and the backward posture side, there is no possibility that the forward / reverse operation by the forward / reverse switching pedal 365 is reversed at a certain boundary, and the forward / backward switching pedal 365 is Advance switching is performed through a neutral state in which traveling of the traveling body 2 is disabled, and malfunction caused by forward / reverse operation of the forward / reverse switching pedal 365 during work is prevented.

  Further, when the turning angle of the revolving structure 3 is within the intermediate turning range, the swing lock mechanism 112 is actuated to restrict the swing of the front axle case 96. Therefore, when the work is performed by turning the revolving structure 3, the front axle case 96 does not swing along with the movement of the center of gravity, although the center of gravity moves as the revolving structure 3 turns. The 201 does not swing relative to the axle case, and the stability of the working posture during work is ensured. In addition, by operating the rocking lock mechanism 112, the front and rear wheels 4 and 5 come into contact with the road surface in a state where the ground pressure is substantially equal. For this reason, even when a large lateral force or moment acts on the traveling body 2 as the swivel base 201 turns during work, the front and rear wheels 4 and 5 that support the traveling body 2 must resist these forces. Therefore, the stability of the working posture during work is ensured.

Further, as shown in FIGS. 30 and 31, a steering conversion means 425 having substantially the same structure as the forward / reverse conversion means 401 is disposed between the power steering controller 367 and the steering cylinder 97. The connection state of the power steering controller 367 and the steering cylinder 97 is switched according to the turning angle of the turning body 3. Therefore, when the turning angle of the turning body 3 is within the forward turning range, the steering conversion means 425 is in a forward contact state, and the traveling body 2 turns rightward by turning the steering handle 363 to the right.
When the turning angle of the turning body 3 is within the intermediate turning range, the steering conversion means 425 is in a neutral state, and the traveling body 2 cannot turn regardless of the operation of the steering handle 363.

When the turning angle of the turning body 3 is within the rear turning range, the steering conversion means 425 is in a reverse connection state, and the traveling body 2 turns leftward by turning the steering handle 363 to the right. When viewed from the seated driver, the direction in which the steering handle 363 is turned and the turning direction of the traveling body 2 coincide with each other, and erroneous operation due to the steering operation during the work is prevented.
Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments. For example, when the pair of left and right rear wheels 5 are swingably supported on the traveling body 2 via the axle case like the pair of left and right front wheels 7, and the swing lock mechanism 112 is provided on the axle case, the present embodiment is also implemented. There is an effect similar to the form. That is, the axle case and the rocking lock mechanism 112 according to the present embodiment can be provided on one or both of the pair of left and right front wheels 4 and rear wheels 5.

Further, when the detection arm 406 of the detection mechanism 403 is disposed on the revolving structure 3 side and the detection cam 407 is disposed on the traveling body 2 side, the same effect as that of the present embodiment is obtained. The same applies to the case where the operating arm 416 of the operating mechanism is arranged on the revolving unit 3 side and the operating cam 417 is arranged on the traveling unit 2 side.
It is also possible to arrange a hand accelerator lever in the control device 202 and adjust the number of revolutions of the engine 7 according to the work mode of the ground work device by the hand accelerator lever.

  Further, a travel lock valve that cuts off the supply of pilot pressure from the charge pump to the remote control valve 373 may be provided between the charge pump and the remote control valve 373.

It is a left view of a wheel type turning work machine. It is a front view of a turning work machine. It is a perspective view of a traveling body and a turntable. It is a top view of a traveling body. It is a left view of a traveling body. It is a left side view of a traveling body rear upper part and a revolving structure rear lower part. It is a top view of a traveling system power transmission mechanism and a rear wheel. It is a plane enlarged view of a traveling system power transmission mechanism and its periphery. It is a top view of a body frame. It is a left view of an airframe frame. (A) is a front view of an airframe frame, (b) is a rear view of an airframe frame. It is a left view of a front axle case and a rocking | fluctuation lock mechanism. It is the front view of a front axle case, and the front sectional view of a rocking | fluctuation lock mechanism. It is a front view of a front axle case and a rocking | fluctuation lock mechanism. It is a front view which decomposes | disassembles and shows a front axle case and a rocking | fluctuation lock mechanism. It is a top view of an excavation work apparatus. It is a rear view of a bucket. It is a left view of a bucket and an arm. It is sectional drawing of a rotation means. (A) is a top view of an attitude | position holding means, (b) is a rear view of an attitude | position holding means. (A) is a plan view of the rotation restricting means, (b) is a rear view of the rotation restricting means, (c) is a cross-sectional view taken along line D-D in (b), and (d) is E- in (b). It is an E-line arrow cross section. It is a top view of a driver's seat and its periphery. It is a left view of a driver's seat and its circumference It is a top view of a turntable. It is a left view of a turntable. It is a left view below a driver's seat. It is the other left view below a driver's seat. It is a front view of a pivot axis and its periphery. It is a top view which shows operation | movement of a detection mechanism and an operation means. It is a hydraulic circuit on the traveling body side. It is a hydraulic circuit by the side of a turning body.

Explanation of symbols

242 Arm 243 Bucket (Working tool)
244 Bucket cylinder (hydraulic cylinder)
249 Support body 251 Horizontal shaft 256 Bucket support surface (work implement support surface)
257 Rotating shaft 258 Rotating means 259 Cylinder tube 260 Piston 266 Screw 267 Screw 269 Locking part 270 First locked part 271 Second locked part 273 Posture holding means 276 Engaging member 277 Locked part A Bucket Direction in which the bucket rotates from the second working position to the first working position in the first working position. B direction in which the bucket rotates from the first working position to the second working position in the second working position.

Claims (5)

A work tool (243) for supporting a grounding work on a support (249) pivoted around a horizontal axis (251) by a hydraulic cylinder (244) at the tip of an arm (242). Is supported to be rotatable about a rotation shaft (257) having an axis (Y) perpendicular to the work tool support surface (256) of the support (249). Rotating means (258) for rotating the working tool (243) 180 degrees around the rotating shaft (257) from the first working position to the second working position between the support (249) and the work Posture holding means (273) for releasably holding the tool (243) in the first working posture and the second working posture;
The rotating means (258) is fixed to a cylinder tube (259) fixed to a support body (249), a piston (260) in the cylinder tube (259), and a work tool (243). (260) and the rotation shaft (257) inserted through the rotation shaft (257). The piston (260) is linearly moved between the rotation shaft (257) and the piston (260). An excavation work device characterized by forming a screw (266, 267) for conversion into rotation.   2. The excavation according to claim 1, wherein the work tool (243) is configured by a bucket (243) capable of scooping work in a first work posture and scraping work in a second work posture. Work equipment.   The posture holding means (273) is supported on the support (249) side so as to be movable along the work tool support surface (256) of the support (249), and its tip protrudes from the outer periphery of the support (249). A releasable engagement member (276) and an engagement member (provided from the outer periphery of the support (249) provided at two positions displaced 180 degrees around the rotation shaft (257) on the work tool (243) side) The excavation work device according to claim 1, further comprising: an engaged portion (277) that engages with H.276 and holds the posture of the work tool (243). A locking portion (269) that rotates integrally with the work tool (243);
In the first working posture, the turning of the work tool (243) in the direction (A) rotating from the second working posture to the first working posture is restricted and in the direction (B) opposite to the turning direction (A). A first locked portion (270) for locking the locking portion (269) so as to allow rotation of the work tool (243);
In the second working posture, the turning of the work tool (243) in the direction (B) that turns from the first working posture to the second working posture is restricted, and in the direction (A) opposite to the turning direction (B). The second engagement portion (271) that engages the engagement portion (269) so as to allow rotation of the work tool (243) is provided. The excavation work device according to crab.   The locking portion (269), the first locked portion (270), and the second locked portion (271) are provided with a rotating means (in order to receive a load acting on the work tool (243) during excavation work). 258), a plurality of the excavation work devices according to claim 4.

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