JPS6131716B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a crane with a work platform.

Conventionally, crane trucks and aerial work vehicles have been separate cargo handling devices, and there has been no such device that can be used in combination. Furthermore, in the case of aerial work vehicles, as in Utility Model Publication No. 48-26801, the leveling of the work platform was done manually, and the levelness was determined by the operator's intuition, which was inefficient and lacked safety. . Furthermore, there is a device, such as Special Publication No. 54-33421, which maintains the work platform horizontally regardless of the ups and downs of the boom, but this only has the function of working at heights.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a crane with a work platform that can be used for both crane work and high-altitude work, and furthermore, to be constructed so that it can be used as a stand-alone crane work vehicle.

The drawings will be explained below.

Reference numeral 1 is a vehicle-mounted crane mounted on a truck or the like, and has a base 2 fixed to the body of the truck, and a column 3 rotatably mounted on the base 2. Reference numeral 4 denotes a telescoping boom which is pivotally supported by a column 3 and is movable up and down by a derrick cylinder 5, and consists of a base boom 4a and a tip boom 4b.
The telescopic cylinder 6 extends and retracts the distal end boom 4b with respect to the proximal boom 4a. A hook 7 is suspended from the tip of the tip boom 4b, and crane work is performed using this hook. Reference numeral 8 denotes a telescoping ladder which is pivotally supported by a bracket 9 fixed to the column and extends in the boom axis direction on the upper surface side of the boom 4. The expandable portion 8b is expanded and contracted relative to the base portion 8a. Note that 11 is a handrail provided on this telescoping ladder 8. Next, the distal end of the telescopic boom 4 and the distal end of the telescopic ladder 8 are connected by pivots I and J, respectively, with members 12, and a workbench 13 is fixed to this member 12. The workbench 13 is provided with a frame 14, which can be folded or erected as required. Further, the pivot points G, H, I, and J are connected to the telescopic boom 4 and the telescopic ladder 8.
The working platform 13 is configured to form a parallelogram in its most contracted state, and therefore, the work platform 13 is configured to remain horizontal regardless of the ups and downs of the telescopic boom 4. Further, the telescopic cylinder 6 for extending and contracting the telescopic boom 4 and the balance cylinder for extending and contracting the telescopic ladder 8 are configured to cooperate with each other. That is, the telescopic cylinder 6
The contraction side oil chamber 6b of the expansion cylinder 6 and the expansion side oil chamber 10a of the balance cylinder 10 are made to communicate with each other, and the pressure receiving areas of these oil chambers are made equal. Small side oil chamber 10
b is connected to the oil supply/discharge circuit via the operation switching valve 15. Therefore, by switching the operation switching valve 15, the telescopic cylinder 6 and the balance cylinder 10
expand and contract at the same time and by the same amount. This means that the telescoping boom 4 and the telescoping ladder 8 extend and contract at the same time and by the same amount, and the shape of the parallelogram formed by the pivot points G, H, I, and J is maintained regardless of the extension or contraction of the telescoping boom 4. means no change.

Note that a switching valve 16 is provided in the middle of the pipe that communicates the contraction side oil chamber 6b of the telescopic cylinder 6 with the expansion side oil chamber 10b of the balance cylinder 10 (see FIG. 2), and the E position of this switching valve 16 is As mentioned above, the telescopic cylinder 6, the balance cylinder 6, and the balance cylinder 10 are configured to expand and contract at the same time and by the same amount, and when switched to position F, the telescopic cylinder 6
To switch to the F position, pull out the pivot pin 17 from the pivot point J, and as shown in FIG. 17, it engages with the switching lever 19 of the switching valve 16, and the normal E
If the switching valve 16 located at the position is configured to be switched to the F position, only the telescopic boom 4 can be extended and contracted independently and safely. This is because, if the telescopic boom 4 is extended and retracted with the switching valve 16 switched to the F position and the pivot pin 17 pivoted to the pivot point J, the circuit will connect the telescopic cylinder 6 and the balance cylinder. 10, but the telescopic boom 4 and the telescopic ladder 8 are mechanically connected by the pivot pin 17, so the telescopic ladder 8 is forcibly moved by the expansion and contraction of the telescopic boom 4, and the telescopic ladder 8 is This is because the balance cylinder 10 etc. may be damaged.

Since the present invention is configured as described above, (1) When used as an aerial work vehicle or a crane vehicle (Fig. 4), the telescopic cylinder 6 is extended and retracted by operating the operation switching valve 15. When the boom 4 is extended, the telescoping ladder is also extended by the same amount by the balance cylinder 10, and the shapes of the parallelograms G, H, I, and J do not change, and the work platform remains unchanged regardless of the ups and downs of the telescoping boom 4. 13 is held constant. Telescopic boom 4
The same applies to the case of reducing . When used as an aerial work vehicle, the frame 14 attached to the work platform 13 is raised, and a worker climbs onto the work platform 13 along the ladder 8 to perform work. When used as a crane vehicle, there is no need to raise the frame 14.

(2) When used alone as a crane vehicle (No. 5)
In Figure), if the pivot pin 17 is pulled out from the pivot point J and the pivot pin 17 is inserted into the guide 18 of the switching valve 16 to switch the switching valve 16 to the position F, the telescopic cylinder 6 and the balance cylinder 10 are separated. When the work switching valve 15 is operated, the telescopic cylinder 6 is operated independently, and only the telescopic boom is extended and retracted.

If you forget to insert the pivot pin 17 into the guide 18 of the switching valve 16 after pulling it out from the pivot point J, the switching valve 16 will be in position E, and when the telescopic boom 4 is extended or retracted, The telescoping ladder 8 also expands and contracts at the same time and by the same amount, making the user aware of his or her carelessness. Only when the pivot pin 17 is pulled out from the pivot point J and inserted into the guide 18 of the switching valve 16, only the telescopic boom 4 is activated. That is, since the pulling out of the pivot pin 17 from the pivot point J is associated with the switching of the switching valve 16, the switching valve 16 is in the F position even though the pivot pin 17 is pivotally attached to the pivot point J. We were able to prevent erroneous operations and ensure work safety.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the present invention, FIG. 2 is a hydraulic circuit diagram, FIG. 3 is an explanatory diagram of main parts, and FIGS. 4 and 5 are explanatory diagrams of working conditions. 3... Column, 4... Telescopic boom, 6... Telescopic cylinder, 8... Telescopic ladder, 10... Balance cylinder, 13... Workbench, 15... Operation switching valve, 16
...Switching valve, 17...Pivot pin.

Claims (1)

[Scope of Claims] 1. A telescopic boom 4, which has a hook 7 suspended from its tip and is extendable and retractable by a telescopic cylinder 6, is pivotally supported on a column 3 so as to be able to rise and fall freely, and a bracket 9 is provided on the column. 9, one end side of the telescopic ladder 8 which is extended and contracted by the balance cylinder 10 is pivoted H.
The telescopic ladder 8 is provided extending in the axial direction on the upper surface side of the boom, and the other end side of the telescopic ladder 8 and the tip of the telescopic boom 4 are pivotally connected by members I and J, and the member 1
A workbench 13 is attached to 2, and the pivot points G, H,
I and J are configured in the shape of a parallelogram, and the pressure receiving areas of the expansion side oil chamber of the balance cylinder 10 and the contraction side oil chamber of the telescopic cylinder 6 are equalized, and these oil chambers are communicated through the switching valve 16. However, when the switching valve 16 is in one position, the balance cylinder 10 and the telescopic cylinder 6 simultaneously expand and contract by the same amount, and the boom 4 and the ladder 8 simultaneously expand and contract by the same amount,
A crane with a work platform characterized in that when it is in the other position, only the telescopic cylinder 6 is extended and contracted, and only the boom 4 is extended and contracted. 2. A telescopic boom 4, which has a hook 7 hanging from its tip and can be extended and retracted by a telescopic cylinder 6, is pivotally supported on a column 3 so as to be able to rise and fall freely. One end side of the telescoping ladder 8 is pivoted H
The telescopic ladder 8 is provided extending in the axial direction on the upper surface side of the boom, and the other end side of the telescopic ladder 8 and the tip of the telescopic boom 4 are pivotally connected by members I and J, and the member 1
A workbench 13 is attached to 2, and the pivot points G, H,
I and J are configured in the shape of a parallelogram, and the pressure receiving areas of the expansion side oil chamber of the balance cylinder 10 and the contraction side oil chamber of the telescopic cylinder 6 are equalized, and these oil chambers are communicated through the switching valve 16. However, when the switching valve 16 is in one position, the balance cylinder 10 and the telescopic cylinder 6 simultaneously expand and contract by the same amount, and the boom 4 and the ladder 8 simultaneously expand and contract by the same amount,
When in the other position, only the telescopic cylinder 6 expands and contracts, and only the boom 4 expands and contracts.Furthermore, a guide 18 is provided near the switching valve 16, and a pivot pin 17 of the pivot point J is provided on this guide 18. A crane with a workbench characterized in that the pivot pin 17 and the switching lever 19 of the switching valve 16 engage with each other by inserting the switching valve 16 to switch the switching valve 16 to the other position.