JPH05295756A - Get-on device of construction machine - Google Patents

Abstract

PURPOSE:To enhance the safety by installing a ladder at the side of an upper revolving member situated under the inlet/outlet of a cab in such a way as rotatable fore and aft round an upper fulcrum, and providing possibility of its being put in a dangling state or horizontally accommodated state. CONSTITUTION:During works, a ladder 12 is detained in the accommodation position by a hydraulic shovel. When the operator in the cab is going to get off, an intra-cab switch 14 is turned into the down-position to feed current to a solenoid-operated selector valve 36, which generates changing-over from the oil path blocking position to the down-position. While a pilot pump 31 is stopped rotating, the pilot primary pressure accumulated in an accumulator 35 is fed to a line 48 and the selector valve 36 down-position via a line 47 and also back to an oil tank 32 via a line 19, swing motor 22, line 50, and the selector valve down-position. The swing motor 22 is thus rotated in regular direction for a certain specified angle to put the ladder 12 in the dangling state, and at the same time, the cab switch 14 is restituted to its neutral position. When the ladder 12 dangling is to be accommodated, an external switch 13 is turned to the up-position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an upper swing type construction machine,
The present invention relates to a boarding device that is provided between a cab of a work vehicle or the like and the ground and that has a ladder for raising and lowering a passenger.

[0002]

2. Description of the Related Art FIG. 5 is a partially cutaway front view of a conventional hydraulic excavator. In the figure, 1 is an upper revolving structure, 2 is a cab mounted on the upper revolving structure 1, 3 is a lower traveling structure, 4 is a crawler frame of the lower traveling structure 3, and 5 is a step fixed to a side portion of the crawler frame 4, 6 is crawler track, 7
Is a handle provided near the entrance of the cab 2.

As shown in FIG. 5, in a hydraulic excavator, an upper revolving structure 1 is rotatably connected to an upper part of a lower traveling structure 3, and the upper revolving structure 1 is equipped with a cab 2 for a driver's cab. There is. Therefore, when the driver climbs up to the cab 2, he grasps the grip 7 with his left hand, hangs one foot on the step 5, and then hangs the other foot on the part of the crawler belt 6 marked with a.

[0004]

As shown in FIG. 5, the step 5 fixed to the side portion of the track frame 4 is provided with a dimension L in the lateral direction in order to prevent the step 5 from colliding with and breaking. It is projected. For that, from step 5 to track 6
There is also a dimension L that is the distance to the outer edge b of. Therefore, when the driver climbed up to the cab 2, not only was it difficult to hook his foot on the step 5, but also the knee of the foot hit the outer end of the crawler track. Also the driver is cab 2
It was difficult to get my foot on step 5 when getting off, so I was jumping off the ground at a stretch from part a of track crawler 6. The above-mentioned raising and lowering operations are not only labor-intensive, but are also unsafe for safety. It is an object of the present invention to provide a boarding device that can solve the above problems.

[0005]

In the boarding device of the present invention,
A ladder is provided on the side of the upper revolving structure below the cab entrance,
Pilot circuit that connects the pilot primary pressure input port of the swing pilot valve for remote control, which is mounted so as to be rotatable in the front-back direction around the upper fulcrum of the ladder, and that controls the switching of the pilot switching valve for swing, and the pilot pump An electromagnetic opening / closing valve is installed in the engine, and an oscillating motor that is a ladder driving means is installed between the pilot primary pressure input port and the oil tank to form an oscillating motor operating circuit. An electromagnetic switching valve for switching the rotation direction of the oscillating motor is arranged in the operating circuit, and an accumulator is provided for the oscillating motor operating circuit, and the pilot primary pressure accumulated in the accumulator is supplied to the swing pilot valve. A check valve is installed in the swing motor operating circuit on the upstream side of the accumulator so that the ladder does not work, while the ladder is stopped at the storage position. An occupant can be installed by providing a limit switch that operates from time to time so that the solenoid on-off valve can be switched by the operation of the limit switch, and operating the switches provided inside and outside the cab to suspend the ladder in the longitudinal direction. To be used for lifting,
When the ladder is not used, the ladder is locked in a substantially horizontal direction so that the ladder can be stored, and when the ladder is not in the storage position, the swing pilot valve cannot be operated.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a side view of a hydraulic excavator having a boarding device according to the present invention. In the figure, 8 is an upper swing body, 9 is a cab mounted on the upper swing body 8, 10 is a door of the cab 9, 11 is a handle provided near the entrance of the cab 9, 12 ladders, 0 ladders 12 Upper fulcrum, 1
3 is an external switch provided outside the cab 9, 14 is a switch inside the cab, 15 is an operation lever for work, 16 is a lower traveling body, and 17 is a turning motor. FIG. 2 is a partially cutaway detailed view showing a state in which the ladder 12 in the portion A of FIG. 1 is stored. In the drawing, 18 is a stopper provided on the upper swing body 8 for positioning the ladder 12 at the storage position,
Reference numeral 9 is a limit switch, and 20 is a contact of the limit switch 19. The arrow F indicates the front direction of the upper swing body 8, and the arrow R indicates the rear direction of the upper swing body 8.

Next, FIG. 3 is a perspective view showing a mounting structure of the ladder 12. In the figure, 21 is a side deck plate on the side of the upper swing body 8, 22 is a swing motor which is a swing type actuator fixedly attached to the side deck plate 21, 2
3 is a drive shaft of the swing motor 22, 24 is an upper fulcrum boss hole of the ladder 12, 25 is a washer, and 26 is a tightening bolt.

Next, FIG. 4 is a circuit diagram of an essential part of the boarding device of the present invention. In the figure, 27 is a turning pilot switching valve, 28 is a hydraulic remote control valve, 29L and 29R are left and right turning pilot valves, 30 is a main pump, 31 is a pilot pump, 32 is an oil tank, 33 is an electromagnetic opening / closing valve, and 34 is A check valve, 35 is an accumulator, 36 is an electromagnetic switching valve, and 37 is a power source.

Next, the construction of the boarding device of the present invention will be described with reference to FIGS.
I will describe. In the boarding device of the present invention, the cab (9)
A ladder 12 is provided on the side of the upper revolving structure (8) below the doorway, and is attached so that it can be rotated by a swing motor 22 in the front-rear direction (direction indicated by arrow C) about the upper fulcrum 0 of the ladder 12. It was In addition, the pilot switching valve for turning 2
An electromagnetic opening / closing valve 33 is provided in a pilot circuit connecting the pilot primary pressure input ports a and b of the orbiting pilot valves 29L and 29R and the pilot pump 31 for performing switching control of 7 (hereinafter referred to as the orbiting switching valve 27). In addition, the pilot primary pressure input ports a and b and the oil tank 32
The rocking motor 22 is provided between the rocking motor 2 and the rocking motor 2 to form a rocking motor operating circuit.
An electromagnetic switching valve 36 for switching the rotation direction of 2 (forward rotation, reverse rotation) is provided, and an accumulator 35 is provided for the swing motor operating circuit, and the pilot primary pressure accumulated in the accumulator 35 is provided. A check valve 34 is provided in the swing motor operating circuit on the upstream side of the accumulator (35) so that does not act on the swing pilot valves 29L and 29R. On the other hand, a limit switch 19 that operates when the ladder 12 is stopped at the storage position is provided, and the electromagnetic switch 33 is switched by the operation of the limit switch 19. Therefore, the in-cab switch 14 or the external switch 13 provided inside and outside the cab, respectively.
The passenger is used to lift the ladder 12 by operating the ladder 12 in the longitudinal direction, and when the ladder 12 is not used, the ladder 12 is locked in a substantially horizontal direction so that the ladder 12 can be stored. At the same time, when the ladder 12 is not in the storage position, the swing pilot valve 2
It was configured to disable the operation of 9L and 29R.

Next, the operation of the boarding device of the present invention will be described. When the hydraulic excavator is engaged in work, the ladder 12 is first locked in the storage position as shown in FIGS. 4 and 2. In this state, the limit switch 19 is turned on and the solenoid 38 of the electromagnetic opening / closing valve 33 is energized, so that the electromagnetic opening / closing valve 33 is switched to the open oil passage position. Further, since the in-cab switch 14 and the external switch 13 are not operated, the electromagnetic switching valve 36 is in the cutoff oil passage position.
In this case, when the operation lever 15 of the hydraulic remote control valve 28 is operated in the L position direction or the R position direction, the pilot primary pressure from the pilot pump 31 is applied to the pipe 39 and the solenoid opening / closing valve 3.
It is input to the turning pilot valve 29L or 29R through the input ports a and b through the open oil passage position 3 and the pipelines 40 and 41. The pilot secondary pressure derived from the swing pilot valve 29L or 29R is supplied through the pipe line 42 or 43 to the pilot port 44L or 44 of the swing switching valve 27.
Acts on R. Since the swing switching valve 27 is switched to the two position or the e position, the swing motor 17 performs normal rotation or reverse rotation. That is, the upper swing body 8 swings, but the ladder 12
Since the vehicle is in the stowed state, there is no possibility that the ladder 12 collides with the undercarriage 16 and is damaged.

When the hydraulic excavator is engaged in work with the ladder 12 stored, that is, when the pilot pump 31 is rotating, the pilot pump 3
The pilot primary pressure from 1 is branched in the pipe line 40, and is accumulated in the accumulator 35 through the pipe line 45, the check valve 34, and the pipe lines 46 and 47. Further, since the pilot pressure accumulated in the accumulator 35 is prevented from flowing backward by the check valve 34, the accumulated pilot primary pressure does not act on the swing pilot valves 29L, 29R.

Next, a case where a passenger inside the cab 9 gets off will be described. When the in-cab switch 14 is operated from the neutral position to the lower position, the electromagnetic switching valve 36 is energized to switch from the oil passage cutoff position to the lower position. When the pilot pump 31 is rotating, the pilot primary pressure from the pilot pump 31 pushes the check valve 34 open to reach the pipe line 46, and when the rotation of the pilot pump 31 is stopped, the pressure is accumulated in the accumulator 35. Pilot primary pressure through line 47, line 4
8. Returning to the lowered position of the electromagnetic switching valve 36 is returned to the oil tank 32 via the pipeline 49, the swing motor 22, the pipeline 50, and the lowered position of the electromagnetic switching valve 36. Since the swing motor 22 rotates forward by a predetermined angle, such as 90 °, the longitudinal direction of the ladder 12 is in a hanging state as shown in FIG. 1, and at the same time, the in-cab switch 14 is in the neutral position (off position). Will be returned. Then, the passenger can open the door 10, hook his / her foot on the ladder 12, and get off in accordance with the ladder steps.

When the passenger getting off the vehicle stores the ladder 12 in the hanging state, the external switch 13
Operate from the neutral position to the raised position. The electromagnetic switching valve 36 is energized to switch from the oil passage cutoff position to the raised position. Assuming that the rotation of the pilot pump 31 is stopped, the pilot primary pressure accumulated in the accumulator 35 is supplied to the swing motor 22 via the raising position of the electromagnetic switching valve 36. Since the swing motor 22 reverses by a predetermined angle, for example, 90 °, the ladder 12 becomes horizontal as shown in FIG. At the same time, the external switch 13 is returned to the neutral position (OFF position), so that the electromagnetic switching valve 36 is returned to the cutoff oil passage position.

Next, a case where a person who gets off the vehicle and is on the ground gets into the cab 9 will be described. Since the ladder 12 is in the stored state, the external switch 13 is operated to the lower position than the neutral position. The electromagnetic switching valve 36 is energized and switches from the oil passage cutoff position to the lowered position. The pilot primary pressure accumulated in the accumulator 35 is supplied to the swing motor 22 via the electromagnetic switching valve 36 in the lowered position. Since the swing motor 22 rotates forward by a predetermined angle, for example, 90 °, the ladder 12 is in a hanging state. There, the passenger can open the door 10 and hook on the ladder 12 to climb into the cab 9 according to the ladder steps.

The passenger climbing up into the cab 9 is
Inadvertently turning the control lever 15
May be operated. However, the contact 20 of the limit switch 19 is not in contact with one end of the ladder 12 because the ladder 12 is not in the storage position. Limit switch 1
Since 9 is off, the solenoid 38 is not energized. The electromagnetic on-off valve 33 is in the cutoff oil passage position by the spring force of its built-in spring. Since the pilot circuit connecting the pilot pump 31 and the swing pilot valves 29L and 29R is cut off, in this case, even if the operation lever 15 is moved, the pilot secondary pressure for controlling the swing changeover valve 27 is not derived. Therefore, since the swing pilot valves 29L and 29R cannot be operated when the ladder 12 is not in the storage position, it is possible to prevent an accident in which the ladder 12 in the hanging state collides with the undercarriage 16 and is damaged, and the safety is improved. Can be made

In the embodiment of the present invention, the oscillating motor 22, which is an oscillating hydraulic actuator, is used as the driving means for rotating the ladder 12, but an electric oscillating motor (not shown) or a manually operated type is also possible. Is. Alternatively, the storage position of the ladder 12 is on the outer surface side of the side deck plate 21 (shown in FIG. 3) on the side of the upper swing body 8, but it may be stored on the inner surface side. In that case, the stored ladder cannot be seen from the side, so that it looks good.

[0017]

According to the hydraulic excavator of the prior art, when the driver tries to get into the cab of the upper swing body from the ground, not only is it difficult for the driver to reach the step fixed to the side portion of the truck frame, Occasionally, the knee of the foot would hit the outer edge of the track. Also, when it was difficult for the driver to get out of the cab, it was difficult for him to step on the step, so he had jumped from the top surface of the track to the ground. Not only was the labor involved in the above-mentioned raising and lowering operations, but the safety was also poor. However, in the boarding apparatus of the present invention, a ladder is provided on the side of the upper revolving structure below the cab entrance, and is attached so as to be rotatable by the swing motor in the front-back direction about the upper fulcrum of the ladder. A switch is provided inside and outside the cab, and the switch is operated as required to suspend the ladder in the longitudinal direction so that the occupant can use it for lifting and lowering the ladder. The ladder is locked in a substantially horizontal direction so that it can be stored. As a result, when the occupant moves up and down, he / she can hook his / her foot on the ladder in a suspended state, and ascend / descend in a normal posture according to the ladder steps, which is safe without undue labor. Also, since the operation of the swing pilot valve was disabled when the ladder was not in the stowed position, it is possible to prevent accidents in which the suspended ladder collides with the undercarriage and is damaged, and it is possible to improve safety. it can.

[Brief description of drawings]

FIG. 1 is a side view of a hydraulic excavator equipped with a boarding device of the present invention.

FIG. 2 is a partially cutaway detailed view showing a state in which a ladder is accommodated in a portion A of FIG.

FIG. 3 is a perspective view showing a mounting structure of a ladder according to the present invention.

FIG. 4 is a circuit diagram of a main part of the boarding device of the present invention.

FIG. 5 is a partially cutaway front view of a conventional hydraulic excavator.

[Explanation of symbols]

 1,8 Upper revolving structure 2,9 Cab 3,16 Lower traveling structure 12 Ladder 13 External switch 14 Cab switch 15 Operating lever 17 Swing motor 19 Limit switch 22 Swing motor 29L, 29R Swiveling pilot valve 31 Pilot pump 33 Electromagnetic opening / closing Valve 34 Check valve 35 Accumulator 36 Electromagnetic switching valve

Claims (3)

[Claims] 1. A boarding device in which an upper revolving structure is equipped with a cab, and a ladder for raising and lowering a passenger is provided at an entrance of the cab, wherein a ladder is provided at a side of the upper revolving structure below the cab entrance. The ladder is attached so that it can rotate in the front-rear direction about the upper fulcrum of the ladder, and the longitudinal direction of the ladder is hung so that it can be used by passengers for lifting and lowering the ladder in a substantially horizontal direction when not in use. A boarding device for a construction machine characterized by being locked and stored. 2. The boarding device for a construction machine according to claim 1, further comprising drive means for rotating the ladder, and switches provided inside and outside the cab, respectively, and the switches are provided as required. A boarding device for a construction machine, characterized in that the ladder can be rotated by operating the ladder. 3. A boarding device for a construction machine according to claim 1, wherein a pilot primary pressure input port of a remote control swing pilot valve for controlling switching of a swing pilot switch valve and a pilot pump are communicated with each other. An electromagnetic opening / closing valve is provided in the pilot circuit, and an oscillation motor operating circuit is formed between the pilot primary pressure input port and the oil tank by providing an oscillation motor as a ladder drive means. An electromagnetic switching valve for switching the rotation direction of the swing motor is arranged in the swing motor operating circuit, and an accumulator is provided for the swing motor operating circuit so that the pilot primary pressure accumulated in the accumulator swings. A check valve is installed in the swing motor operating circuit on the upstream side of the accumulator so that it does not act on the pilot valve, while the ladder is in the stowed position. A limit switch that operates when stopped is provided, the solenoid on-off valve is switched by the operation of the limit switch, and the ladder can be rotated by arbitrarily operating the switches provided inside and outside the cab. In addition, the boarding device for the construction machine is characterized in that the turning pilot valve is disabled when the ladder is in a position other than the storage position.