JP6770937B2 - Construction machinery with lift cab - Google Patents

Description

The present invention relates to construction machinery such as hydraulic excavators and hydraulic cranes, and more particularly to construction machinery with a lift cab provided with a cab lifting device for raising and lowering the cab between an ascending position and a descending position.

In general, a hydraulic excavator, which is a typical example of a construction machine, includes a self-propelled lower traveling body (traveling body), an upper rotating body (swivel body) mounted on the lower traveling body so as to be swivel, and an upper traveling body. It is roughly configured by a work device rotatably provided in the vertical direction on the front side of the upper swing body, and a cab constituting the driver's cab is provided on the left side of the front part of the upper swing body. Then, the hydraulic excavator can be used for various purposes such as excavation work of earth and sand using a bucket, dismantling work using a grapple, and scrap sorting work using a magnet by exchanging a work tool attached to the tip of a work device. You can do the work.

By the way, when classifying and loading scrap using a hydraulic excavator, it is necessary to load scrap materials such as construction waste and iron scraps on the truck bed. For example, the circumference of the cargo bed is surrounded by a partition plate or the like. If this is done, it will be difficult for the operator in the cab to see the scrap material piled up on the truck bed.

Therefore, conventionally, as disclosed in Patent Document 1, a cab elevating device is provided between the upper swing body and the cab, and the cab elevating device raises and lowers the cab between the ascending position and the descending position. A hydraulic excavator with a lift cab has been proposed.

The conventional cab elevating device disclosed in Patent Document 1 includes a base provided fixed to an upper swing body, a cab bed supporting the cab, an upper link provided between the base and the cab bed, and an upper link. It is roughly composed of a parallel link mechanism having a lower link and an elevating cylinder that rotates the upper link with respect to the base. One end of the upper link and the lower link are rotatably connected to the cab bed via a bearing device, and the other ends of the upper link and the lower link are rotatably connected to the base via a bearing device, respectively. ing. Of the rods and bottoms that make up the elevating cylinder, the tip of the rod is rotatably connected to the upper link via a bearing device, and the base end of the bottom is rotatable to the base via a bearing device. Is connected to. These bearing devices are used in rotating side structures (upper link, lower link, elevating cylinder, etc.) having through holes, fixed side structures (cab beds, bases, etc.) that sandwich the rotating side structures, and through holes. It is composed of a columnar connecting shaft that is inserted to connect the rotating side structure and the fixed side structure.

In the cab elevating device configured in this way, when the rod of the elevating cylinder is expanded and contracted, the upper and lower links of the parallel link mechanism rotate with the base side as the fulcrum, so that the tips of the upper and lower links The cab bed pivotally supported on the side moves in parallel in the vertical direction while keeping the cab horizontal. As a result, the cab supported on the cab bed can be raised and lowered between the ascending position and the descending position, so that the operator in the cab can accurately grasp the loading state of the scrap material on the truck bed. , Scrap material can be loaded using grapples and magnets.

JP-A-2007-170048

By the way, in this type of hydraulic excavator with a lift cab, in order to allow the operator to easily get on and off the cab, the lowering position of the cab is lowered to maintain good accessibility. Therefore, when the cab is in the lowered position, the gap between the upper link and the lower link of the parallel link mechanism, which is a component of the cab elevating device, the elevating cylinder, the base, and the cab bed is designed to be as small as possible. There is.

Further, the bearing device that rotatably connects the upper link, the lower link, the elevating cylinder, the base, and the cab bed is lubricated with lubricating oil such as grease between the connecting shaft and the through hole of the rotating side structure. To prevent wear and seizure of the sliding surface. Normally, the refueling work for such a bearing device is performed with the cab moved to the lowered position, but as described above, when the cab is in the lowered position, structures such as a parallel link mechanism are densely packed. Therefore, it is difficult to insert a hand into the dense space and directly supply the lubricating oil between the connecting shaft and the through hole.

Therefore, a refueling structure consisting of a grease nipple or the like is provided at an arbitrary position such as an upper swing body or a cab bed located away from the bearing device, and the refueling port and the bearing device are connected by a hose. Has been proposed. If such a lubrication structure is adopted, lubricating oil can be supplied to the bearing device from the lubrication port using a grease pump or the like, but the lubricating oil is supplied from a place where the bearing device cannot be directly seen. There is a problem that the lubricating oil flowing out of the device cannot be visually observed and it cannot be confirmed that the lubricating oil has been sufficiently supplied.

The present invention has been made from the actual situation of such a prior art, and an object of the present invention is to be able to efficiently lubricate a bearing device with lubricating oil and to easily confirm that sufficient lubrication has been achieved. It is to provide construction machinery with a lift cab that can.

In order to achieve the above object, the construction machine with a lift cab of the present invention has a self-propelled traveling body, a swivel body rotatably mounted on the traveling body, and a swivel body rotatable on the swivel body. The cab elevating device includes a work device provided, a cab, and a cab elevating device arranged behind the working device and the cab to elevate the cab between an ascending position and a descending position. A pair of link members rotatably connected to the swing body and the cab via a bearing device, and an elevating cylinder rotatably connected to the swing body and one of the link members via a bearing device, respectively. The cab elevating device has, and the pair of link members are rotated by the expansion and contraction of the elevating cylinder to elevate the cab between the ascending position and the descending position, and at least one of the bearing devices has. , A rotating side structure having a through hole, a fixed side structure sandwiching the rotating side structure, and a columnar connection that is inserted through the through hole to connect the rotating side structure and the fixed side structure. In a construction machine with a lift cab including a shaft, the connecting shaft is provided with a lubricating oil supply flow path leading to a sliding surface with the rotating side structure, and the fixed side structure is provided with the rotating side structure. A lubricating oil return path leading to the sliding surface is provided, and an opening on the inlet side of the lubricating oil supply flow path is connected to an oil filler port provided at a position away from the bearing device via a hose. cage, wherein is the opening of the lubricating oil return outlet side is connected via a discharge port and hose, the fuel supply port and the discharge port is provided to aggregate the viewable positions simultaneously, the rotation A shim ring for adjusting a gap is interposed between the side structure and the sliding surface of the fixed side structure, and the shim ring is characterized in that a slit leading to the return path of the lubricating oil is formed .

According to the construction machine with a lift cab of the present invention, it is possible to efficiently lubricate the bearing device with lubricating oil, and it is possible to easily confirm that sufficient lubrication has been performed. Issues, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

It is external perspective view of the hydraulic excavator with a lift cab which is the object of this invention. It is a side view which shows typically the cab lifting device which concerns on 1st Embodiment. It is a perspective view which looked at the cab lifting device which concerns on 1st Embodiment from one direction. It is a perspective view which looked at the cab lifting device which concerns on 1st Embodiment from another direction. It is an enlarged view of part A of FIG. It is an enlarged view of part B of FIG. It is sectional drawing which shows the bearing device of the cab elevating device which concerns on 1st Embodiment. It is sectional drawing which follows the line VIII-VIII of FIG. It is sectional drawing which shows the bearing device of the cab elevating device which concerns on 2nd Embodiment. It is explanatory drawing of the shim ring provided in the bearing device of FIG. It is sectional drawing which shows the bearing device of the cab elevating device which concerns on 3rd Embodiment.

Hereinafter, a case where the embodiment of the construction machine with a lift cab according to the present invention is applied to a hydraulic excavator will be taken as an example, and will be described in detail with reference to the attached drawings.

First, the configuration of a hydraulic excavator with a lift cab will be described. FIG. 1 is an external perspective view of a hydraulic excavator, which is a typical example of a construction machine. The hydraulic excavator has a self-propelled tracked (crawler type) lower traveling body (running body) 1 and a lower traveling body 1. An upper swivel body (swivel body) 2 mounted so as to be swivel on the top, a boom 3 rotatably provided on the right side of the front portion of the upper swivel body 2 and a boom 3 rotatably provided at the tip of the boom 3. It is roughly composed of an arm 4 connected to the arm 4, and an attachment (not shown) according to the work purpose can be attached to the tip of the arm 4. Further, a cab 5 is arranged on the left side of the front portion of the upper swing body 2, and the cab 5 can be raised and lowered between the ascending position and the lowering position by the cab elevating device 6.

FIG. 2 is a side view schematically showing the cab lifting device 6 according to the first embodiment, FIG. 3 is a perspective view of the cab lifting device 6 as viewed from the left side, and FIG. 4 is a perspective view of the cab lifting device 6 from the right side. A seen perspective view, FIG. 5 is an enlarged view of part A of FIG. 2, and FIG. 6 is an enlarged view of part B of FIG.

As shown in FIGS. 2 to 6, the cab elevating device 6 according to the first embodiment includes a base 7 mounted on the frame 2A of the upper swing body 2, a cab bed 8 for supporting the cab 5, and the cab bed 8. It is outlined by a parallel link mechanism 9 having an upper link 9A and a lower link 9B provided between the base 7 and the cab bed 8 and an elevating cylinder 10 for rotating the parallel link mechanism 9 with respect to the base 7. It is configured. The elevating cylinder 10 is composed of a hydraulic cylinder, the tip end portion on the rod side thereof is connected to the cab bed 8, and the base end portion on the bottom side is connected to the base base 7. In order to make the structure of the cab elevating device 6 easier to see, a part of the base 7 is broken and shown in FIG.

The base 7 includes a bracket body 7A paired in the left-right direction on the frame 2A and a plurality of connecting shafts 20 extending between the bracket bodies 7A, and includes an upper link 9A, a lower link 9B, and an elevating cylinder 10. Each of the rotating side structures such as the above is rotatably supported by a base 7 and a cab bed 8 which are fixed side structures by a bearing device 11 described later. Although not shown, in the gap between each structure and the internal space of the base 7, a hydraulic hose for supplying pressure oil from a hydraulic circuit (not shown) to the elevating cylinder 10 and inside the cab 5 are installed. Power supply to the electric parts, electric harnesses for communication, etc. are routed.

A centralized greasing section 12A is installed in front of the left side surface of the frame 2A of the upper swivel body 2, and another centralized greasing section 12B is installed on the left side surface of the cab bed 8. In the present embodiment, the centralized greasing section 12A and the centralized greasing section 12B are concentrated in the rear side portion of the cab 5 and its vicinity, for example, an operator who is in a position facing the left side surface of the cab 5. These centralized greasing parts 12A and 12B can be visually recognized at the same time. As shown in FIGS. 5 and 6, each of the centralized greasing portions 12A and 12B is provided with a predetermined number of lubrication ports 13 and discharge ports 14, respectively. The oil filler port 13 is composed of a grease nipple that can be connected to a grease gun (not shown), and the oil filler port 13 is connected to a lubricating oil supply flow path 19 of a bearing device 11 described later via a lubrication hose 15. Further, the discharge port 14 is arranged close to the side position of the oil supply port 13, and the discharge port 14 is connected to the lubricating oil return path 22 of the bearing device 11 described later via the drain hose 16. In this way, each of the centralized greasing parts 12A and 12B is provided with a plurality of pairs of the refueling port 13 and the discharging port 14, and the refueling port 13 is provided only by the operator facing each of the centralized greasing parts 12A and 12B. And the discharge port 14 can be visually recognized at the same time.

Further, the refueling hose 15 and the drain hose 16 are arranged at locations that do not interfere with the movement of the parallel link mechanism 9 and the elevating cylinder 10. In FIGS. 3 and 4, the refueling hose 15 connecting the refueling port 13 and the lubricating oil supply flow path 19 is shown by a solid black line, and the drain hose 16 connecting the lubricating oil return path 22 and the discharging port 14 is shown. It is shown by a broken line.

Each bearing device 11 that rotatably connects the rotating side structures such as the upper link 9A, the lower link 9B, and the elevating cylinder 10 to the base 7 and the cab bed 8 which are the fixed side structures has the same structure. It is configured as shown in 7.

As shown in FIG. 7, the bearing device 11 is fixed by sandwiching the rotating side structure 17 having the through hole 17A (corresponding to the upper link 9A, the lower link 9B, and the elevating cylinder 10) and the rotating side structure 17 from both sides. It is roughly composed of a side structure 18 (corresponding to the bracket body 7A of the base 7 and the cab bed 8) and the columnar connecting shaft 20 connecting the rotating side structure 17 and the fixed side structure 18. The connecting shaft 20 has a flange portion 20A on one end side in the axial direction, and the connecting shaft 20 is inserted through a through hole 17A of the rotating side structure 17 into a shaft hole 18A provided in the fixed side structure 18. It is fixed. The connecting shaft 20 is provided with a lubricating oil supply flow path 19 that leads from the flange portion 20A to the sliding surface (through hole 17A) with the rotating side structure 17, and the flange portion 20A side of the lubricating oil supply flow path 19. The above-mentioned refueling hose 15 is connected to the opening of the above via a hose adapter 21.

The fixed side structure 18 is provided with a lubricating oil return path 22 that reaches a sliding surface with the rotating side structure 17, and as shown in FIG. 8, the lubricating oil return path 22 is formed around the shaft hole 18A. It has an annular portion 22A. The drain hose 16 described above is connected to the opening on the outer surface side of the lubricating oil return path 22 via the drain adapter 23, and the discharge port 14 connected to the opposite end of the drain hose 16 is released to the atmosphere. It is supposed to be done. However, it is preferable to attach a plug (not shown) to the discharge port 14 to seal the discharge port 14 except for the lubricating oil supply work described later.

In the present embodiment, the upper link 9A, the lower link 9B, and the lubricating oil supply flow path 19 of the three bearing devices 11 connecting one end side of the elevating cylinder 10 to the base 7 are centrally supplied to the upper swing body 2 side. The three lubrication ports 13 provided in the fat portion 12A are connected to each other via the lubrication hose 15. Then, three discharge ports 14 provided in the same centralized greasing section 12A on the upper swing body 2 side are connected to each of the lubricating oil return paths 22 of these three bearing devices 11 via a drain hose 16.

Further, the upper link 9A, the lower link 9B, and the other end side of the elevating cylinder 10 are connected to the cab bed 8 in each of the lubricating oil supply flow paths 19 of the three bearing devices 11, and in the centralized greasing section 12B on the cab bed 8 side. Each of the three lubrication ports 13 provided is connected via a lubrication hose 15. Then, three discharge ports 14 provided in the same centralized greasing section 12B on the cab bed 8 side are connected to each of the lubricating oil return paths 22 of these three bearing devices 11 via a drain hose 16. However, the number of the refueling ports 13 and the discharge ports 14 provided in the centralized greasing parts 12A and 12B is not limited to three, and for example, the refueling ports 13 and the discharge ports 14 are provided in the centralized greasing part 12A on the upper rotating body 2 side. 6 each, and 6 each of the lubrication port 13 and the discharge port 14 may be provided in the centralized greasing section 12B on the cab bed 8 side. That is, as long as the operator can visually check the refueling port 13 and the discharge port 14 at the same time, the number of the refueling port 13 and the discharge port 14 provided in the centralized greasing portions 12A and 12B does not matter.

When grease (lubricating oil) is supplied to the bearing device 11 configured in this way, the cab 5 is moved to the lowering position by the cab elevating device 6, and the discharge ports of the centralized lubrication sections 12A and 12B are used. Remove the plug from 14. In this state, when a grease gun (not shown) is connected to an arbitrary lubrication port 13 provided in the centralized lubrication section 12A on the upper swivel body 2 side to deliver grease, the grease is supplied from the lubrication hose 15 to the lubricating oil supply flow path 19 Since it flows into the sliding surface between the connecting shaft 20 and the through hole 17A of the rotating side structure 17 through the connecting shaft 20, good lubrication can be obtained for the connecting shaft 20 and the rotating side structure 17. When the grease is further injected, the grease flows into the lubricating oil return path 22 from the annular portion 22A leading to the through hole 17A, and then flows from the discharge port 14 provided in the same centralized greasing portion 12A through the drain hose 16 to the outside. It is discharged.

Similarly, when a grease gun (not shown) is connected to an arbitrary lubrication port 13 provided in the centralized lubrication section 12B on the cab bed 8 side to deliver grease, the grease is discharged from the lubrication hose 15 through the lubricating oil supply flow path 19. Since the oil flows into the sliding surface between the connecting shaft 20 and the through hole 17A of the rotating side structure 17, good lubrication can be obtained for the connecting shaft 20 and the rotating side structure 17. When the grease is further injected, the grease flows into the lubricating oil return path 22 from the annular portion 22A leading to the through hole 17A, and then flows from the discharge port 14 provided in the same centralized greasing portion 12B through the drain hose 16 to the outside. It is discharged.

As described above, the discharge port 14 for discharging the grease to the outside and the refueling port 13 for supplying the grease are the same as the centralized greasing portions 12A and 12B installed on the left side surface of the upper swing body 2 and the cab bed 8. Since it is provided at a location, the state in which grease is discharged from the discharge port 14 can be easily visually recognized while supplying grease. As a result, it is possible to smoothly check whether or not the grease has been sufficiently greased to the bearing device 11 while performing the grease feeding work, and the efficiency of the maintenance work can be improved.

As described above, in the hydraulic excavator with a lift cab according to the first embodiment, a bearing that rotatably supports each structure of the cab lifting device 6 that raises and lowers the cab 5 between the raising position and the lowering position. The device 11 has a rotating side structure 17 having a through hole 17A, a fixed side structure 18 sandwiching the rotating side structure 17 from both sides, and a rotating side structure 17 and a fixed side structure 18 inserted through the through hole 17A. The connecting shaft 20 is provided with a columnar connecting shaft 20 for connecting the above, and the connecting shaft 20 is provided with a lubricating oil supply flow path 19 communicating with a sliding surface with the rotating side structure 17, and is provided with a fixed side structure. The lubricating oil return path 22 leading to the sliding surface with the rotating side structure 17 is provided in 18. Then, centralized grease parts 12A and 12B are installed at positions away from the bearing device 11 of the upper swing body 2 and the cab bed 8, and these centralized grease parts 12A and 12B are connected to the inlet side of the lubricating oil supply flow path 19. Since the refueling port 13 connected to the opening via the refueling hose 15 and the discharge port 14 connected to the opening on the outlet side of the lubricating oil return path 22 via the drain hose 16 are intensively provided. While supplying grease to the bearing device 11 from the oil filler port 13, it is possible to visually recognize how the grease is discharged from the discharge port 14, and it is easy to check whether the grease is sufficiently supplied to the bearing device 11. Can be confirmed in.

FIG. 9 is a cross-sectional view showing a bearing device 30 of the cab elevating device according to the second embodiment, and the parts corresponding to FIG. 7 are designated by the same reference numerals.

In the bearing device 30 according to the second embodiment shown in FIG. 9, a shim ring 24 for adjusting a gap is interposed between the rotating side structure 17 and the sliding surface of the fixed side structure 18, and other than that. The configuration of is basically the same as that of the bearing device 11 according to the first embodiment. The shim ring 24 is an annular thin plate made of resin or metal, and has a central hole 24A through which a columnar connecting shaft 20 is inserted. As shown in FIG. 10, a plurality of arc-shaped slits 24B are formed in the shim ring 24, and these slits 24B are arranged on a concentric circle with the connecting shaft 20 and the central hole 24A at predetermined intervals. The slit 24B faces the annular portion 22A of the lubricating oil return path 22, and the grease that has flowed from the lubricating oil supply flow path 19 onto the sliding surface of the connecting shaft 20 and the rotating side structure 17 is annular from the slit 24B of the shim ring 24. After flowing into the lubricating oil return path 22 through the portion 22A, the oil can be discharged to the outside from the discharge port 14 through the drain hose 16.

Also in the second embodiment configured in this way, while supplying grease from the oil filler port 13 to the bearing device 30, the same centralized supply as the centralized oil supply portions 12A and 12B provided with the oil filler port 13 is also provided. Since it is possible to visually recognize how the grease is discharged from the discharge ports 14 provided in the fat portions 12A and 12B, the efficiency of the maintenance work can be improved as in the first embodiment. Further, since the shim ring 24 makes it possible to fill the gaps between the structures, it is possible to prevent rattling between the structures and the outflow of grease from the gaps. Moreover, since the shim ring 24 is formed with a plurality of slits 24B arranged concentrically with the connecting shaft 20 and the central hole 24A, even if a plurality of shim rings 24 are stacked and used, the slits 24B of each shim ring 24 are closed. It will not come off, and the shim ring 24 will not obstruct the flow of grease from the lubricating oil supply flow path 19 to the lubricating oil return path 22.

FIG. 11 is a cross-sectional view showing a bearing device 40 of the cab lifting device according to the third embodiment, and the parts corresponding to FIG. 7 are designated by the same reference numerals.

In the bearing device 40 according to the third embodiment shown in FIG. 11, a sealing member 25 is attached to one of the two sliding surfaces of the rotating side structure 17 and the fixed side structure 18 to supply lubricating oil. It is cut off from the flow path 19, and the other configurations are basically the same as those of the bearing device 11 according to the first embodiment. The lubricating oil return path 22 leading to the lubricating oil supply flow path 19 is formed only on the fixed side structure 18 that does not have the seal member 25, and is formed on the fixed side structure 18 to which the seal member 25 is attached. The lubricating oil return path 22 is not formed. The seal member 25 prevents grease from flowing out from the sliding surfaces of the rotating side structure 17 and the fixed side structure 18 and the gap between the connecting shaft 20 and the shaft hole 18A. For example, an O-ring is used. be able to. If one seal member 25 cannot satisfy such a function, a plurality of seal members 25 may be used.

In the third embodiment configured as described above, when grease is supplied from the oil filler port 13 to the lubricating oil supply flow path 19 of the bearing device 30, the grease is released from the sliding surface to which the seal member 25 is attached. It does not flow out and flows only into the lubricating oil return path 22 which is not blocked by the seal member 25. As a result, the state in which grease is discharged from the discharge port 14 provided in the same centralized greasing section 12A, 12B as the centralized greasing section 12A, 12B provided with the refueling port 13 can be visually recognized while lubricating. Therefore, the efficiency of the maintenance work can be improved as in the first embodiment. Further, since the sealing member 25 prevents grease from flowing out from one of the two sliding surfaces of the rotating side structure 17 and the fixed side structure 18, fixing corresponding to the sliding surface. It is not necessary to provide the lubricating oil return path 22 in the side structure 18, and the processing cost of the lubricating oil return path 22 and the number of drain hoses 16 and drain adapters 23 can be reduced.

In each of the above embodiments, the upper link 9A, the lower link 9B, and the elevating cylinder 10 which are the rotating side structures of the cab elevating device 6 are all connected to the fixed side structure (base 7 and cab bed 8). The case where the present invention is applied to the bearing device has been described, but if there is a bearing device that can directly feed the lubricating oil (grease), the present invention does not necessarily have to be applied to the bearing device.

Further, in each of the above embodiments, one centralized greasing section 12A is installed on the left side surface of the frame 2A of the upper swing body 2, and the other centralized greasing section 12B is installed on the left side surface of the cab bed 8. As described above, the installation location of the centralized greasing portions 12A and 12B is not limited to this, and can be installed at an arbitrary position of the vehicle body including the lower traveling body 1 and the upper rotating body 2.

Further, in each of the above embodiments, the case where the refueling port 13 and the discharge port 14 corresponding to one bearing device are centrally provided in the same centralized greasing section 12A and 12B has been described, but the discharge port 14 is the refueling port. 13 may be provided at another location as long as it is visible.

Further, by combining the above-described second embodiment and the third embodiment, a seal member 25 is attached to one of the two sliding surfaces of the rotating side structure 17 and the fixed side structure 18 for lubrication. A shim ring 24 for adjusting a gap may be provided on the other sliding surface so as to shut off from the oil supply flow path 19.

In addition, each of the above-described embodiments is an example for the purpose of explaining the present invention, and the scope of the present invention is not limited to those embodiments. One of ordinary skill in the art can practice the present invention in various other aspects without departing from the gist of the present invention.

1 Lower running body (running body)
2 Upper swivel body (swivel body)
2A frame 3 boom 4 arm 5 cab 6 cab lifting device 7 base 7A bracket body 8 cab bed 9 parallel link mechanism 9A upper link 9B lower link 10 lifting cylinder 11, 30, 40 bearing device 12A, 12B centralized lubrication unit 13 lubrication Port 14 Discharge port 15 Refueling hose 16 Drain hose 17 Rotating side structure 17A Through hole 18 Fixed side structure 18A Shaft hole 19 Lubricating oil supply flow path 20 Connecting shaft 20A Bearing part 21 Hose adapter 22 Lubricating oil return route 22A Ring part 23 Drain Adapter 24 Simling 24A Center Hole 24B Slit 25 Sealing Member

Claims (3)

A self-propelled traveling body, a swivel body rotatably mounted on the traveling body, a work device rotatably provided on the swivel body, a cab, the work device, and behind the cab. A pair of cab lifting devices that are arranged to raise and lower the cab between an ascending position and a lowering position, and the cab elevating device is rotatably connected to the swivel body and the cab via bearing devices, respectively. The cab elevating device has the link member, and the elevating cylinder rotatably connected to the swivel body and one of the link members via a bearing device, and the cab elevating device has the pair of links by expanding and contracting the elevating cylinder. The member is rotated to raise and lower the cab between the ascending position and the descending position, and at least one of the bearing devices sandwiches the rotating side structure having a through hole and the rotating side structure. In a construction machine with a lift cab, which comprises a fixed-side structure and a columnar connecting shaft that is inserted through the through hole to connect the rotating-side structure and the fixed-side structure.
The connecting shaft is provided with a lubricating oil supply flow path leading to a sliding surface with the rotating side structure, and the fixed side structure has a lubricating oil return path leading to the sliding surface with the rotating side structure. It is provided,
The opening on the inlet side of the lubricating oil supply flow path is connected to the oil supply port provided at a position away from the bearing device via a hose.
The opening on the outlet side of the lubricating oil return path is connected to the discharge port via a hose.
The refueling port and the discharging port are collectively provided at positions that can be visually recognized at the same time .
A shim ring for adjusting a gap is interposed between the rotating surface of the rotating side structure and the sliding surface of the fixed side structure, and the shim ring is formed with a slit leading to the return path of the lubricating oil. Construction machinery with lift cab. In the construction machine with a lift cab according to claim 1 ,
A construction machine with a lift cab, characterized in that a plurality of slits are formed concentrically with the connecting shaft. In the construction machine with a lift cab according to claim 1,
The lubricating oil supply flow path leads to the lubricating oil return path via one sliding surface of the rotating side structure and the fixed side structure, and the other of the rotating side structure and the fixed side structure. A construction machine with a lift cab, wherein the sliding surface is shielded from the lubricating oil supply flow path by a sealing member.