JPH0687397U - Boarding control device for aerial work vehicles - Google Patents

Abstract

(57) [Summary] [Purpose] In an aerial work vehicle in which a work platform is provided at the tip of the telescopic boom on the vehicle frame, the work platform in the retracted position is moved to the loading position just before landing by the ups and downs of the telescopic boom and extension control. It has been moved to make it easier for workers to get on and off the workbench. [Structure] When the telescopic boom B in the retracted position stands up slightly, the stand-up detector LS ₁ is activated to stop the standing up and the telescopic boom B is extended downward, so that the workbench 10 is in the loading position just before landing. Then, the telescopic detector LS ₂ is actuated to stop the extension of the telescopic boom B, and the workbench 10 comes to the loading position.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention moves the workbench at the retracted position to the boarding position just before landing by raising and lowering the telescopic boom with the workbench attached to the tip of the vehicle frame, and the extension and contraction control so that the operator can get on and off the workbench. The present invention relates to a boarding control device for an aerial work vehicle, which is made easier.

[0002]

[Prior art]

 Generally, in an aerial work vehicle, a telescopic boom is erected on a swivel base on a vehicle frame so that the telescopic boom can be extended and retracted, and the work platform is attached to the tip of the telescopic boom so that the work platform can always maintain a substantially horizontal position. It is configured so that a worker on a workbench can work at a high place by controlling the turning, undulation and extension / contraction of the.

In such an aerial work vehicle, when the work platform is in the retracted position, it is troublesome for a worker to get on and off the work platform because the work platform is arranged on a vehicle frame far from the ground. There was an inconvenience that the work efficiency deteriorated. Therefore, in order to eliminate such inconvenience, a boarding control device has been proposed in the past, in which the workbench at the retracted position is lowered to near the ground by extension control of the telescopic boom so that a worker can get on and off the workbench. (See, for example, Japanese Utility Model Laid-Open No. 14299/1992).

[0004]

[Problems to be solved by the device]

 In the aerial work vehicle, in order to store the telescopic boom together with the workbench on the vehicle frame as compactly as possible, it is desirable that the retractable boom in the folded and retracted position has a large storage inclination angle with respect to the horizontal plane. If the telescopic boom in such a storage position is extended so that the workbench can be lowered to near the ground as it is, the workbench may interfere with the vehicle frame of the aerial work vehicle or the equipment above it. Actually, the telescopic boom could not be extended, and even if it could be extended, the work platform would drop close to the car frame, but the car frame would be an obstacle even if the work platform was lowered to the ground. However, there is a problem that it is difficult to get on and off the workbench.

The present invention has been made in view of such circumstances, and enables the telescopic boom to be compactly stored on the vehicle frame, and the work platform from the vehicle frame side relatively close to the aerial work vehicle near the ground. A new aerial work that enables one-touch operation to quickly and easily and safely put a worker on and off the workbench, and greatly improve work efficiency at aerial locations. It is intended to provide a boarding control device for a vehicle.

[0006]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, a feature of the present invention is that a swivel base on a vehicle frame is provided with a telescopic boom so that the telescopic boom can be raised and lowered. In a boarding control device for an aerial work vehicle capable of controlling the workbench so that it can take a storage position on the vehicle frame and a boarding position just before landing, an automatic boarding switch provided on the vehicle frame side An undulation detector that can detect the upright movement of the telescopic boom from the retracted position, an telescopic detector that detects extension of the telescopic boom for a predetermined length, and an ON signal for the automatic boarding switch and The control means controls the extension of the telescopic boom slightly based on the detection signals of the undulation and extension / extension detectors, and then extends the workbench until it reaches near the ground.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall side view of an aerial work vehicle equipped with the device of the present invention, FIG. 2 is a plan view taken along the line 2 of FIG. 1, and FIG. 3 is a height view showing a state in which a telescopic boom is slightly raised. FIG. 4 is a side view of the aerial work vehicle, FIG. 4 is a side view of the aerial work vehicle showing a state in which the telescopic boom is extended to the loading / unloading position, FIG. 5 is an electric circuit diagram, and FIG. 6 is a hydraulic circuit diagram.

In FIGS. 1 and 2, a swivel base 2 is mounted on a vehicle frame 1 of an aerial work vehicle V so as to be rotatable about a vertical axis, and a support frame 3 integrally projects on the swivel base 2. It is set up. A telescopic boom B is rotatably supported on the upper part of the support frame 3 with a hinge shaft 4. The extendable / contractible boom B includes a base boom 5 and a tip boom 6 that is telescopically inserted into the base boom 5. A hoisting cylinder 7 is connected between the support frame 3 and the base boom 5, and the telescopic boom B can be hoisted by the telescopic operation of the hoisting cylinder 7. A telescopic cylinder 8 provided inside the base boom 5 and the front boom 6 is connected to each other, and the telescopic boom B 1 can be telescopically operated by the telescopic operation of the telescopic cylinder 8. A workbench mounting portion 9 is provided on the head portion of the tip boom 6, and the workbench 10 can always be held in a horizontal position on the mounting portion 9 and is supported by a conventionally known horizontal supporting mechanism H.

As shown in FIG. 1, in the traveling state of the aerial work vehicle V, the telescopic boom B is folded and stored on the vehicle frame 1. In this case, the telescopic boom B is telescopically mounted on the vehicle frame 1 of the aerial work vehicle V. In order to store the boom B compactly and shorten the total length of the work platform V itself, it is desirable to set a large storage inclination angle θ with respect to the horizontal plane of the telescopic boom B in the storage position. When the inclination angle is large, when the telescopic boom B in the retracted position is extended and the workbench 10 is lowered to near the ground in order to allow a worker to get in and out of the vehicle, the telescopic boom is mounted on the vehicle frame 1 or devices on it. Even if there is no interference, the workbench 10 will get down near the aerial work vehicle V, and even if the workbench 10 is lowered to near the ground, the occupants can get on and off the workbench 10. Not only difficult but dangerous In this embodiment, as will be described later in detail, the telescopic boom in the retracted position is hoisted and extended so that the telescopic boom can be smoothly extended downward even if the storage inclination angle θ is set relatively large. Therefore, the workbench 10 can be safely and reliably lowered to a position away from the aerial work vehicle V.

1 to 4, an automatic boarding switch SW ₁ is mounted on the rear end of the vehicle frame 1, and an automatic boarding release switch SW ₂ is mounted on the workbench 10. The switch base 12 provided on the support frame 3 on the vehicle frame 1 is provided with an undulation detection switch LS ₁ composed of a limit switch as an undulation detector, and this switch LS ₁ is provided by retracting the telescopic boom B in the retracted position. When it is turned on and the telescopic boom B stands up slightly, it is turned off. On the other hand, the telescopic boom B is provided with a telescopic detection switch LS ₂ composed of a limit switch as a telescopic detector. The telescopic detection switch LS ₂ is turned on when the telescopic boom B is fully retracted, and the telescopic boom B is also extended. It is turned off when the workbench 10 extends near the ground after a predetermined amount of extension.

FIG. 5 shows an electric circuit formed by connecting the switch group together with a relay group, a relay switch group, and a standing-up / extending solenoid valve. In this electric circuit, the automatic boarding switch SW ₁ and the automatic boarding release switch SW ₂ are connected in series with the power circuit together with the first relay R _1, and the first relay switch r ₁ is connected in parallel with the automatic boarding switch SW _{1. 1} is connected. Also, the undulation detection switch LS ₁ is connected in series with the upright solenoid valve V ₁ and the power supply circuit with a relay switch r ₁ will be described later, the second relay R ₂ is connected in parallel therewith to the solenoid valve V ₁ for the upright Has been done. Further, the expansion / contraction detection switch LS ₂ is connected in series to the power supply circuit together with an expansion solenoid valve V ₂ , a first relay switch r ₁ and a second relay switch r ₂ which will be described later.

FIG. 6 shows a hydraulic circuit diagram for controlling the operation of the undulating cylinder 7 and the telescopic cylinder 8. The hydraulic pump P and the oil sump T are connected to the undulating cylinder 7 and the telescopic cylinder 8 via a conventionally known valve unit U. The valve unit U is switch-controlled based on the operation signal 14 of the operation unit 13 provided on the workbench 10 to control the supply and discharge of hydraulic oil to the undulating cylinder 7 and the telescopic cylinder 8 to extend and retract those cylinders 7 and 8. By controlling the telescopic boom B, the telescopic boom B is raised and lowered, and the telescopic boom is controlled to perform desired high-altitude work.

The rising solenoid valve V ₁ is provided in the middle of the hydraulic oil passage 16 connecting the extension side oil chamber a of the undulating cylinder 7 and the valve unit U, and the extension side oil chamber of the telescopic cylinder 8 is also provided. The expansion solenoid valve V ₂ is provided in the middle of the hydraulic oil passage 17 connecting the valve b and the valve unit U. When both solenoid valves V ₁ and V ₂ are not energized as shown in FIG. 6, the cutoff state is released and the hydraulic oil passages 16 and 17 are in a conductive state, allowing free flow of hydraulic oil. In this state, the telescopic boom B is freely lifted and retracted as described above.

Next, the operation of this embodiment will be described. When a worker on the workbench 10 carries out normal work at a high place, the operation signal 14 generated by the operation of the operation unit 13 by the operator is the valve unit. The hydraulic oil is supplied to and discharged from the hoisting cylinder 7 and the telescopic cylinder 8 by the switching control of the valve unit U applied to U, and the cylinders 7 and 8 are telescopically controlled. It is possible to perform high-altitude work by a worker on the workbench 10 under control. During the work at height, the automatic boarding switch SW ₁ is turned off and the standing and extending solenoid valves V ₁ and V ₂ are in the cut-off release state as shown in FIG. The supply and discharge of the hydraulic fluid of the above are freely performed.

Next, a description will be given of the loading control of the telescopic boom B for the worker to get on the workbench 10. When the telescopic boom B is in the retracted position as shown in FIG. 1 Rear end automatic boarding switch SW₁ON (Automatic board release switch SW ₂ Keeps the ON state), the first relay R₁Normally open type first relay switch r₁Is turned on. On the other hand, because the telescopic boom B is in the retracted position, the undulation detection switch LS₁Is in the ON state, and the stand-up solenoid valve V₁Is excited and the hydraulic fluid passage 16 is in a communicating state, the telescopic boom B starts to stand up from the retracted position. On the other hand, the second relay R₂Normally closed relay switch r₂Is turned off, so the expansion / contraction detection switch LS₂Solenoid valve for extension V₂Is de-excited to maintain the cutoff state, the hydraulic oil passage 17 is cut off, and the telescopic boom B does not extend.

As shown in FIG. 3, when the telescopic boom B stands up slightly, the up / down detection switch LS ₁ is turned off, the stand-up solenoid valve V ₁ is de-energized, and is switched to the cutoff position to cut off the hydraulic oil passage 16. As a result, the standing cylinder 7 is stopped. On the other hand, the second relay R ₂ is de-energized, the normally-closed second relay switch r ₂ is turned on, and the extension solenoid valve V ₂ is energized, so that the hydraulic oil passage 17 becomes conductive, and FIG. As shown, the telescopic boom B, which is slightly raised, avoids interference with the vehicle frame 1 and starts extending downward, that is, toward the ground.

When the telescopic boom B continues to extend and the workbench 10 is about to come into contact with the ground, the telescopic detection switch LS ₂ is turned off this time, and the hydraulic oil passage 17 is cut off to extend the telescopic boom B. Stops growing. In this state, the workbench 10 is at the landing position just before landing on the ground, and the worker can easily get on the workbench 10.

The hoisting cylinder 7 and the extension cylinder 8 can be retracted even when the stand-up solenoid valve V ₁ and the extension solenoid valve V ₂ are in the shut-off position, so that the telescopic boom B is tilted and retracted. Is possible.

Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various embodiments are possible within the scope of the present invention. For example, the telescopic boom B is composed of the base boom and the front boom in the above embodiment, but may be composed of a multi-stage boom having three or more stages. Further, in the above embodiment, the telescopic boom is controlled so as to extend after the standing up, but it may be extended before the standing up.

[0021]

[Effect of device]

 As described above, according to the present invention, the telescopic boom is provided on the swivel base on the vehicle frame so that the telescopic boom can be raised and lowered, the work platform is attached to the tip of the telescopic boom, and the work platform is mounted on the vehicle frame by the telescopic control of the telescopic boom. In a boarding control device for an aerial work vehicle, which can be controlled so that it can take a stowed position and a boarding position just before landing, an automatic boarding switch provided on the vehicle frame side and the telescopic boom are provided. , An undulation detector capable of detecting a slight upright position from the retracted position, an expansion / contraction detector for detecting extension of the telescopic boom for a predetermined length, an ON signal of the automatic boarding switch, and the undulation / expansion detector. The retractable boom is provided with a control means for controlling the extension until the work platform reaches a position near the ground after the retractable boom is slightly raised based on the detection signal. Even The workbench can reach the boarding / unloading position near the ground by extending it toward the ground at a position away from the car frame without interfering with the frame or the equipment above it, and as a result, the telescopic boom can be moved to the car frame. It can be compactly stored on the top, and it is extremely easy for a worker to get on and off the elevator, which improves work efficiency.

[Brief description of drawings]

FIG. 1 is an overall side view of an aerial work vehicle equipped with the device of the present invention.

FIG. 2 is a plan view taken along the line 2 of FIG.

FIG. 3 is a side view of an aerial work vehicle showing a state where the telescopic boom is slightly raised.

FIG. 4 is a side view showing a state in which the telescopic boom is extended to the loading position.

[Fig. 5] Electric circuit diagram

[Fig. 6] Hydraulic circuit diagram

[Explanation of symbols]

1 ・ ・ Car frame 2 ・ ・ ・ ・ ・ Swivel base 10 ・ ・ ・ ・ ・ Work platform B ・ ・ ・ ・ ・ ・ Extendable boom C ・ ・ ・ ・ Control means (relay electric circuit) LS ₁・ ・ ・ ・ Elevation detector (elevation detection switch) LS ₂・ ・ ・ ・ Expansion detector (extension detection switch) SW ₁・ ・ ・ ・ Automatic boarding switch

Claims (1)

[Scope of utility model registration request] 1. A telescopic boom (B) is movably provided on a swivel base (2) on a vehicle frame (1), and a workbench (10) is attached to the tip of the telescopic boom (B) to attach the telescopic boom (B). In the boarding control device for an aerial work vehicle, the workbench (10) can be controlled so as to take a storage position on the vehicle frame (1) and a boarding position on the verge of landing by controlling the expansion and contraction of Automatic boarding switch (SW) provided on the side of the vehicle frame (1)
₁ ), an undulation detector (LS ₁ ) capable of detecting a slight rise of the telescopic boom (B) from the retracted position, and an telescopic detector for detecting extension of the telescopic boom (B) by a predetermined length. (LS ₂ ), after slightly raising the telescopic boom (B) based on the ON signal of the automatic boarding switch (SW ₁ ) and the detection signals of the undulation and telescopic detectors (LS ₁ , LS ₂ ), A boarding control device for an aerial work vehicle, comprising: a control means (C) for controlling extension until the workbench (10) reaches near the ground.