JP2589734Y2 - Step equipment for aerial work vehicles - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a step device used for getting on and off a bucket of an aerial work vehicle.

[0002]

2. Description of the Related Art In some cases, a step device is installed on a body of an aerial work vehicle in order to allow an operator to get on and off a bucket in a stowed state on the body of an aerial work vehicle.

In this type of step device, the position of the bucket in the stowed state is high above the ground, and the space available for the step device on the vehicle body is small, so that the step device has a steep gradient and narrow stairs. It is,
It is necessary to carefully get on and off the bucket.

[0004]

In order to make it easier for a step device having a steep slope and a narrow stair to get on and off a bucket, it is conceivable to install a handrail near the step device.

[0005] However, since the bucket of the aerial work vehicle is driven by the boom from the retracted state on the vehicle body and is driven up and down, turning, etc., it is necessary to avoid interference between the handrail and the boom. is there.

[0006] The present invention has been made based on such a background, and while avoiding interference between the handrail and the boom,
An object of the present invention is to provide a handrail having good usability in the vicinity of a step device to facilitate getting on and off a bucket.

[0007]

In order to achieve the above object, according to the present invention, there is provided a telescopic boom which is mounted on a vehicle body so as to be pivotable and undulating, and is provided with a bucket at a tip thereof. A step device used for an aerial work vehicle that travels and moves to a retracted position where it is reduced, laid down, and appropriately turned, comprising a step portion formed on a vehicle body near a bucket at the storage position, A handrail mounted on a vehicle body near the vehicle and driven up and down by a hydraulic cylinder driven and controlled by a control valve formed of a switching valve; a storage detection switch for detecting storage of a bucket; An operation switch that outputs an operation signal for instructing reduction, receives signals from the storage detection switch and the operation switch, and outputs a control signal to the control valve. A control device, wherein the control device moves the control valve to the extension side of the handrail in response to an extension and contraction command signal from the operation switch when the storage detection switch detects the storage state. Alternatively, the control valve is switched to the reduction side, and the control valve is switched to the reduction side of the handrail regardless of an operation signal of the operation switch in a state where the storage detection switch detects a non-retracted state. I do.

[0008]

According to the first aspect of the present invention, the getting on and off of the bucket is performed with the bucket stored, so that the handrail can be protruded for convenience of getting on and off, and the telescopic boom can be moved during the operation. The handrail position can be set high regardless of the range, so that the usability is good.

In addition, when performing work at a high place, the telescopic boom is driven to be in the non-retracted state. At this time, the handrail is immersed, and interference between the handrail and the telescopic boom can be avoided. There is no restriction on the range of movement of the boom.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings.

First, an overall outline of an aerial work vehicle will be described with reference to FIGS. 1 and 2, which show a state in which a boom is stored.

In FIG. 1, reference numeral 1 denotes an aerial work vehicle;
Is a self-propelled vehicle body having an outrigger device 3 before and after it.

A turning table (not shown), which is driven to turn around a vertical axis by a hydraulic motor, is provided on the vehicle body 2, and a column 4 is provided integrally with the turning table. I have.

A telescopic boom 5 is pivotally supported on the upper end of the column part 4 via a pivot 4a, and the telescopic boom 5 can be raised and lowered by a raising and lowering cylinder 6 composed of a hydraulic cylinder.

The telescopic boom 5 in this embodiment is one in which a plurality of boom parts are fitted to telescopic and made telescopic by a telescopic cylinder composed of a hydraulic cylinder. A similar implementation is possible.

A bucket 7 is attached to the distal end of the telescopic boom 5 by a mounting bracket.

In the bucket 7 of this embodiment, in order to maintain high electrical insulation inside the bucket 7, a notch portion serving as an entrance for getting into and out of the bucket 7 is not formed on the side surface.
It is made of fiber reinforced plastic and formed into an integral container.

The telescopic boom 5 and the bucket 7 of the aerial work vehicle 1 of this embodiment are connected to the vehicle body 2 as shown in FIG.
The telescopic boom 5 is supported on a boom rest 8 installed on the vehicle body 2 in the retracted state (see FIG. 1).

The space on both sides of the telescopic boom 5 stored on the vehicle body 2 is used as an arrangement space for a tool box or the like.

In the aerial work vehicle 1 of this embodiment, a step portion 11 is formed using the upper surface of a tool box or the like on the front side of the telescopic boom 5 in FIG. A step device 10 is formed by installing a handrail 12 in the vicinity of the upper side of the vehicle and on the side of the vehicle body.

The handrail 12 is mounted so as to be able to protrude and retreat upward from inside a tool box forming a step portion above the stair portion 11, and has a handrail cylinder 23 composed of a hydraulic cylinder for protruding and retracting. Things.

In this embodiment, the handrail 12 is installed at a high position on the stairs 11 and the handrail 12
Is a handrail having a large height in the protruding state, which is particularly useful for convenience of getting on and off (see the phantom line in FIG. 1).

The handrail 12 is driven by a hydraulic circuit 15 shown in FIG. 3, and the hydraulic circuit 15 is operated by a control device 41 shown in FIG.

The hydraulic circuit 15 drives a driving cylinder for driving the telescopic boom 5 such as the outrigger device 3 and the up-and-down cylinder 6 of the aerial work vehicle 1. The hydraulic cylinder 23 for handrails for performing the in / out drive of the handrail is provided.

In the hydraulic circuit 15, reference numeral 24 denotes a hydraulic pump, and an outrigger hydraulic circuit 17 for driving the outrigger device 3 is provided in a discharge line 16 of the hydraulic pump 24.
Is connected. In FIG. 3, reference numeral 24a denotes an emergency hydraulic pump installed in parallel with the hydraulic pump 24.

The outrigger hydraulic circuit 17 has a first directional control valve 25 and a flow path directional control valve 26, and the first directional control valve 25 controls the direction of expansion and contraction of a hydraulic cylinder constituting the outrigger device 3. The flow path switching valve 26
Is used to selectively operate either the overhang cylinder 3a or the jack cylinder 3b of the outrigger device 3.

That is, the first direction switching valve 25 is a 6-port, 3-position switching valve. At the left offset position, the extension cylinder 3a or the jack cylinder 3b of the outrigger device 3 is extended, These are stored at the offset position.

The flow path switching valve 26 has a four-port three
It comprises a position-type switching valve, and operates the overhang cylinder 3a at the left offset position and the jack cylinder 3b at the right offset position.

The supply of the hydraulic pressure to the outrigger device 3 is performed through the discharge pipe 16 through the first directional control valve 2.
5, and the return of the pressure oil from the outrigger device 3 is performed from the flow path switching valve 26 or the first directional switching valve 25 to the oil tank 27 via the pipe 18. ing.

A switching valve 19 is provided between the discharge line 16 and the return line 18, and communicates between the discharge line 16 and the return line 18 in the state shown in FIG. The hydraulic circuit 15 is caused to leak to thereby stop the hydraulic circuit 15, and when the hydraulic circuit 15 is operated, the switching valve 19 is set to the upper offset position to guide the hydraulic oil from the hydraulic pump 24 to the first direction switching valve 25. Things.

The outrigger hydraulic circuit 17
Between the first pipe line 21 branched from the first direction switching valve 25 and the second pipe line 22 branched from the return pipe 18 on the upstream side of the switching valve 19. A hydraulic circuit for the cylinder 6 and a hydraulic circuit for the handrail hydraulic cylinder 23 are connected in parallel.

First, the hydraulic circuit of the undulating cylinder 6 will be described. The first pipe 21 and the second pipe 22
Is connected to a second directional control valve 29, and the undulating cylinder 6 is connected to the first and second conduits 21 and 22 via the second directional control valve 29.

The second directional control valve 29 has a 6 port 3
In the position-type switching valve, the up-and-down cylinder 6 is extended at an offset position on the left side, and is reduced at an offset position on the right side.

The hydraulic circuit of the handrail hydraulic cylinder 23 is connected between the first and second pipes 21 and 22, and the first and second pipes 21 and 22 are connected to the handrail solenoid valve. 31.

The handrail solenoid valve 31 is a four-port, three-position solenoid switching valve. The handrail hydraulic cylinder 23 extends at the left offset position and contracts at the right offset position. The handrail solenoid valve 31 is switched by a power supply current from a control device 41 described below.

In the aerial work vehicle 1 having such a hydraulic circuit 15, only when the switching valve 19 of the hydraulic circuit 15 is at the upper offset position and the first direction switching valve 25 is at the neutral position, The handrail hydraulic cylinder 23 is capable of operating, and does not operate when the switching valve 19 is open as shown in FIG.

The control device 41 comprises an arithmetic device 41a composed of, for example, a microcomputer and the electromagnetic valve 3 for handrails.
Controller 41b for controlling the power supply current to the excitation unit 1
The arithmetic unit 41a receives various signals from the following switches.

Reference numeral 42 denotes a handrail operation mode selection switch, and when it is turned on, the control device 41 performs an operation described later.
Does not work when off.

Reference numeral 43 denotes a handrail lift switch, which switches the handrail 12 when the hydraulic circuit 15 sets the switching valve 19 to the upper offset position and the first direction switching valve 25 to the neutral position as described above. Is moved up and down by manual operation. The handrail lift switch 43 is
It corresponds to the operation switch referred to in the present application, and also corresponds to the manual telescopic command switch.

Reference numeral 44 denotes an upper limit position detection switch of the handrail 12, which detects a position at which the handrail hydraulic cylinder 23 stops the extension operation. Conversely, reference numeral 45 denotes a lower limit position detection switch of the handrail 12, which detects the completion of the storage of the handrail 12 and stops the reduction operation of the handrail hydraulic cylinder 23.

Reference numeral 46 denotes a jack-up switch for detecting from the oil pressure that the jack cylinder 3b of the outrigger device 3 is in a jack-up state. This jack-up switch 46 corresponds to the running state detection switch of the present application.

The driving state detecting switch is not limited to the jack-up switch 46, but may be a switch for detecting output stop from the PTO shaft, release of the parking brake, operation of the traveling transmission, and the like.

Reference numeral 47 denotes a boom storage detection switch for detecting that the telescopic boom 5 has been stored on the boom rest 8, instead of detecting the storage of the bucket 7 itself. It goes without saying that a switch for detecting storage of the bucket 7 itself may be used.

The signals from the respective switches are subjected to a predetermined calculation in a calculation device 41a based on a required program, and the result is output to a controller 41b. The power supply current to the excitation unit is appropriately controlled.

For example, the outrigger device 3 is extended from the running posture shown in FIG.
Is extended to the jack-up state, since the boom storage detection switch 47 is activated, the controller 41 switches the handrail solenoid valve 31 to the left offset position in response to a signal from the jack-up switch 46. The hydraulic oil from the hydraulic pump 24 to the handrail hydraulic cylinder 2
3, the handrail 12 is automatically raised.

The raising of the handrail 12 is stopped when the power supply current from the control unit 41 is stopped when the signal from the upper limit position detection switch 44 is input to the arithmetic unit 41a.

When the telescopic boom 5 stored on the boom rest 8 is separated from the boom rest 8, the detection signal from the boom storage detection switch 47 is not input to the control device 41. The solenoid valve 31 is switched to the right offset position, and the handrail 12 is automatically lowered by the contraction of the handrail hydraulic cylinder 23 to be in the retracted state.

Conversely, when the telescopic boom 5 standing up is stored on the boom rest 8, the boom storage switch 47
The handrail solenoid valve 31 is switched to the left offset position based on the input of the signal from the controller to the control device 41, and the handrail 12 is automatically raised.

Conversely, when the jack cylinder 3b of the outrigger device 3 is contracted to eliminate the jack-up state, the detection signal from the jack-up switch 46 is not input, and the electromagnetic valve 31 for the handrail is turned off. Switching to the right offset position, the handrail 12 automatically descends and enters the stored state. In addition, in these operations, the operation is stopped by stopping the power supply current from the control device 41 when a signal from the upper limit position detection switch 44 or the lower limit position detection switch 45 is input to the arithmetic device 41a. Stopping is similar.

In the above-described embodiment, the operation related to the jack-up switch 46 has been described. However, it is needless to say that the operation related to only the boom storage detection switch 47 may be used.

In the above-described embodiment, the handrail 12 is automatically operated in accordance with the storage of the telescopic boom 5 or the like. However, the present invention is not limited to this, and manual operation of the handrail 12 is prohibited. May be canceled.

When the handrail 12 is installed at a high position of the stairs 11 as in the above-described embodiment, and the handrail 12 is made to protrude greatly, the handrail 12 is located at the uppermost part of the aerial work vehicle 1, and The height of the handrail 12 is determined by the upper end position of the handrail 12. The handrail 12 is immersed by the non-retraction of the telescopic boom 5, jack-up of the outrigger device 3, or the like. Since the height of the aerial work vehicle 1 is not increased except when necessary, there is an advantage that the traveling performance of the aerial work vehicle 1 is not impaired.

[0053]

As described above, according to the first aspect of the present invention, the getting on and off of the bucket is performed with the bucket stored, so that the handrail can be protruded at that time for convenience of getting on and off. In addition, the handrail position can be set high irrespective of the range of movement of the telescopic boom at the time of work, so that convenience is good.

Also, when performing work at a high place, the telescopic boom is driven to be in the non-retracted state. At this time, the handrail is immersed, and interference between the handrail and the telescopic boom can be avoided. There is no restriction on the range of movement of the boom.

Further, according to the present invention, the handrail is immersed when the aerial work vehicle travels, so that the handrail does not increase the height of the aerial work vehicle, and the handrail is the traveling performance of the aerial work vehicle. There is no danger of damage.

[Brief description of the drawings]

FIG. 1 is a side view of an aerial work vehicle.

FIG. 2 is a plan view of the aerial work vehicle.

FIG. 3 is a hydraulic circuit diagram for raising and lowering the handrail.

FIG. 4 is a block diagram of a control device for the handrail solenoid valve.

[Explanation of symbols]

 Reference Signs List 1 aerial work vehicle 2 body 5 telescopic boom 7 bucket 11 step device 12 handrail

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mikio Hazebayashi 1838-17, Mineyama-cho, Takamatsu-shi, Kagawa (58) Field surveyed (Int. Cl. ⁶ , DB name) B66F 9/00-11/04

Claims (4)

(57) [Scope of request for utility model registration] 1. An aerial work vehicle which is provided with a bucket at the tip of a telescopic boom which is mounted on a vehicle body so as to be able to pivot and raise and lower. A step device used, comprising: a stair portion formed on the vehicle body near the bucket at the storage position; and a step device mounted on the vehicle body near the stair portion and driven and controlled by a control valve including a switching valve. A handrail which is driven to expand and contract vertically by a hydraulic cylinder, a storage detection switch for detecting storage of a bucket, an operation switch for outputting an operation signal for instructing expansion or contraction of the handrail, the storage detection switch and the operation switch And a control device for receiving a signal from the control valve and outputting a control signal to the control valve. State, the control valve is switched to the extension side or the reduction side of the handrail in response to the extension and contraction command signals from the operation switch, and the storage detection switch detects the non-storing state. A step device for the aerial work vehicle, wherein the control valve is switched to a reduction side of the handrail regardless of an operation signal of the operation switch. 2. The step device according to claim 1, wherein the operation switch is a manual operation switch. 3. The control device according to claim 1, wherein the operation switch detects a driving state of the vehicle and outputs an operation signal for instructing reduction of a handrail. The control device receives a detection signal from the driving state detection switch. 2. A step device for an aerial work vehicle according to claim 1, wherein a reduction signal of the hour handrail is output. 4. An aerial work vehicle which is provided with a bucket at the tip of a telescopic boom which is mounted on a vehicle body so as to be pivotable and undulateable, and which travels in a retracted position where the telescopic boom is reduced, lowered and appropriately rotated. A step device used, comprising: a stair portion formed on the vehicle body near the bucket at the storage position; and a step device mounted on the vehicle body near the stair portion and driven and controlled by a control valve including a switching valve. A handrail which is driven to expand and contract vertically by a hydraulic cylinder, a storage detection switch for detecting storage of a bucket, an operation switch for outputting an operation signal for instructing expansion or contraction of the handrail, the storage detection switch and the operation switch And a control device that receives a signal from the control valve and outputs a control signal to the switching valve. Command switch and a running state detection switch, and further, the control device, in a state where the storage detection switch detects a storage state, responds to an extension and contraction command signal from the operation switch. The control device switches the handrail to the extension side or the reduction side of the handrail, and the control device controls the control in the state where the traveling state detection switch detects the traveling state regardless of whether the manual type expansion / contraction command switch is operated. A step device for an aerial work vehicle, wherein a valve is switched to a reduction side of a handrail.