JPH0597391A - Extensible/contractible boom equipped with trolley - Google Patents

Abstract

PURPOSE:To prevent a boom from extending/contracting when a trolley shifts and efficiently carry out the crane work in the vicinity of the basic edge part of the boom when an obstacle exists in the above or in the boom extension/ contraction direction. CONSTITUTION:A trolley boom 20 which is constituted so that a trolley 30 supporting a suspending tool 7 is mounted in shiftable manner on the extension/ contractible boom 1 for crane is installed so as to be positioned outside a basic edge boom 11 when the extension/contractible boom 1 is shortened, and a limit switch LSI for trolley and an electromagnetic selecting valve which select a cylinder for extension/contraction from an inoperative state to an operation- enabled state when the trolley 30 shifts to a prescribed position at the top edge part of the trolley boom 20 are installed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telescopic boom with a trolley in which a trolley for supporting a lifting tool is movably provided on a telescopic boom for a crane.

[0002]

2. Description of the Related Art Generally, a crane equipped with a telescopic boom has a hoist attached to the tip of the boom so as to lift a load located near the base end of the boom or close to the base end of the boom. It is necessary to raise the boom when performing crane work to unload the load to the position. Therefore, such crane work is restricted where there are obstacles above the crane or indoors where the ceiling is low.

Therefore, in order to enable crane work near the base end portion of the boom without raising the boom, a trolley for supporting the lifting device is movably provided on the outer boom which is extendably attached to the inner boom. In addition, a crane having a telescopic boom with a trolley has been proposed (Japanese Patent Publication No. 51).
-45369, 51-45370).

[0004]

However, such a telescopic boom with a trolley is constructed so that the trolley moves toward the distal end side and the proximal end side as the boom expands and contracts. Therefore, when the trolley is moved from the base end side to the tip end side of the boom, the outer boom on the tip end side is extended in the tip end direction at the same time as the movement of the trolley, so it is extended where there is an obstacle in the extension direction. There is a risk that the boom will collide and hinder work, and the moment on the boom tip side will increase, and the lifting performance will decrease accordingly. Moreover, although it can be applied to a telescopic boom having a two-stage boom structure, it is difficult to apply the wire rope to a multi-stage boom having three or more stages because the wire rope is complicated to hang around.

The present invention solves such a problem in the telescopic boom with trolley. Thus, the present invention is
When the trolley is moved, the boom does not expand and contract, and it is possible to efficiently perform crane work near the base end of the boom in places where there are obstacles in the upper direction or the boom expansion and contraction direction, or in a room with a low ceiling. An object is to provide a telescopic boom with a trolley that can be applied to a multi-stage telescopic boom.

[0006]

According to the present invention, in a telescopic boom for a crane in which a telescopic cylinder is mounted on a plurality of stages of booms including a base end boom and a tip boom, a trolley supporting a lifting device can be moved. With the mounted trolley boom,
It is installed along the tip boom so that it is located outside the base boom when the telescopic boom is shortened, and it switches the telescopic cylinder from the inoperative state to the operable state when the trolley moves to the predetermined position on the tip of the trolley boom. The above problem is solved by providing means.

[0007]

When the load near the base end of the boom is lifted, the telescopic boom is shortened and the trolley is moved to the base end to lift the load. Since there is no need to raise the boom, there are no restrictions on the work when there is an obstacle above the crane or inside a room with a low ceiling. When moving the hoisted load, the trolley is moved to the tip side of the trolley boom, but at this time the telescopic boom does not extend and contract. When the trolley moves to the predetermined position of the tip of the trolley boom, the telescopic cylinder is switched from the inoperative state to the operable state by the switching means, and therefore the telescopic boom may be extended by a necessary distance thereafter. Therefore, work can be performed without obstacle even in a place where there is an obstacle in the extending direction of the boom.

In order to unload the load at a position close to the base end of the boom, the trolley may be moved to the base end after shortening the telescopic boom.

[0009]

1 is a front view showing a state in which a telescopic boom with a trolley according to an embodiment of the present invention is shortened, and FIG. 2 is shown in FIG.
2 is a sectional view taken along line II-II of FIG. 3, FIG. 3 is a sectional view taken along line III-III of FIG. 1, FIG. 4 is a sectional view taken along line IV-IV of FIG. 1, and FIGS. 5A to 5D are explanatory views of an operating state of the telescopic boom with a trolley. is there. Here, the telescopic boom 1 is a three-stage telescopic boom in which an intermediate boom 12 and a tip boom 13 are sequentially slidably fitted in the proximal boom 11 and the intermediate boom 12, respectively. Boom 11
And the intermediate boom 12 between the telescopic cylinder 14, and the intermediate boom 12 and the tip boom 13 between the telescopic cylinder 15
Is provided. This telescopic boom 1 is a base boom 1
1 is pivotally supported on a column 2 by a foot pin 3, and is hoisted by a hoisting cylinder 4 provided between it and the column 2.
A trolley boom 20 is provided outside the tip boom 13 so as to be located outside the base boom 11 when the telescopic boom 1 is shortened. The tip of the trolley boom 20 is attached with a mounting bolt 21. It is fixed to the tip of the tip boom 13.

Guide rails 22T, 2 having an L-shaped cross section are formed on the inner surfaces of both sides of the trolley boom 20 with a slight vertical distance therebetween.
2B is laid in the axial direction of the trolley boom 20, and a guide piece 23 is attached to the lower surface of the base end portion of the guide rail 22T. Guides 16 having a rectangular cross section that engage with the guide pieces 23 are laid on both outer surfaces of the base boom 11 in the axial direction of the base boom 11, and guide rails 22T are provided at the tip of the intermediate boom 12. A guide 17 that engages with the lower surface of the is provided. Therefore, when the telescopic boom 1 is extended, the intermediate boom 12 first extends from the base end boom 11, and at this time, the trolley boom 2 is extended.
The guide piece 23 of 0 is guided by the guide 16 of the base boom 11, the trolley boom 20 moves on the base boom 11, and then the tip boom 13 extends from the intermediate boom 12. At this time, the guide rail 22T moves on the intermediate boom 12 while being guided by the guide 17 of the intermediate boom 12. During this time, the guide rail 22B prevents the trolley boom 20 from jumping upward. Telescopic boom 1
When the length is shortened, the tip boom 13 and then the intermediate boom 12 are shortened in the reverse order. At this time, the trolley boom 20 is guided by the guides 16 and 17 smoothly as in the extension. You can move.

The trolley boom 20 is provided with trolley rails 24 each having a rectangular cross section at the lower ends of both outer surfaces in the axial direction of the trolley boom 20. The trolley boom 20 is provided with rollers 36 and shoes 37 that engage with the trolley rails 24. A trolley 30 is installed. A trolley hydraulic motor 31 is installed at the tip of the tip boom 13, and a drive sprocket 33 attached to the output shaft 32 of the trolley hydraulic motor 31 and a driven sprocket 34 attached to the base end side of the trolley boom 20. A chain 35 having one end fixed to the tip end of the upper portion of the trolley 30 is hung between and, and the other end of the chain 35 is fixed to the upper base end side of the trolley 30. By driving the hydraulic motor 31 forward and backward, the trolley 30 can be moved along the trolley rail 24 from the base end side to the tip end side of the trolley boom 20 or from the tip end side to the base end side. A pulley 38 is pivotally supported on the lower end of the center of the trolley 30, a wire rope 6 of a winch 5 installed on the column 2 passes through the pulley 38, and a lifting tool 7 is connected to the tip thereof. Therefore, the wire rope 6 is wound up by the winch 5 and unwound to raise and lower the suspending tool 7.

The trolley boom 20 is provided with a trolley limit switch LS1 for detecting the movement of the trolley 30 to a predetermined position on the tip end portion thereof, and the base end boom 1 is also provided.
1, a boom limit switch LS2 for detecting shortening of the telescopic boom 1 is provided. FIG. 6 shows a trolley hydraulic motor 31 and a telescopic cylinder 1 of this embodiment.
It is a hydraulic circuit diagram of 4,15. Here, the discharge pipe line 41 of the hydraulic pump 40 and the return pipe line 46 to the tank 45 extend from the operation switching valve 42 to the forward rotation drive side pipe line 43N of the trolley hydraulic motor 31 and the expansion and contraction cylinders 14 and 15. Via an electromagnetic switching valve V1 for switching between the driving side pipeline 44N and an electromagnetic switching valve V2 for switching between the reverse rotation driving side pipeline 43R of the trolley hydraulic motor 31 and the shortening driving side pipeline 44R of the extension / contraction cylinders 14 and 15. , Is connected to the operating circuit 43 of the trolley hydraulic motor and the operating circuit 44 of the telescopic cylinder. The solenoid of the electromagnetic switching valve V1 is connected to the trolley limit switch LS1, and the solenoid of the electromagnetic switching valve V2 is connected to the boom limit switch LS2. Further, a check valve C1 that communicates with the return line 46 at the time of reverse drive is connected in parallel to the electromagnetic switching valve V1 to the forward rotation drive side pipe line 43N of the trolley hydraulic motor 31, and the expansion / contraction cylinders 14 and 15 are connected. A check valve C2, which communicates with the return conduit 46 during extension driving, is connected to the shortening drive side conduit 44R in parallel with the electromagnetic switching valve V2.

When lifting a load located near the base end of the boom, the telescopic boom 1 is shortened as shown in FIG. 5A and the trolley 30 is on the base end side. At this time, the trolley limit switch LS1 and the boom limit switch L
S2 is both OFF as shown in FIG. Here, when the operation switching valve 42 is switched to the A position, the pressure oil discharged from the hydraulic pump 40 is transferred to the trolley hydraulic motor 31.
Is supplied to the normal rotation driving side pipe line 43N, the trolley hydraulic motor 31 rotates in the normal direction, and the trolley 30 moves to the front end side.
As shown in FIG. 5B, the trolley 30 has a trolley boom 2.
When the tip end portion of 0 is moved to a predetermined position, the trolley limit switch LS1 is turned on and the electromagnetic switching valve V1 is switched. It is supplied to 44N and the expansion and contraction cylinders 14 and 15 start expansion. Telescopic boom 1
When is extended, the trolley boom 20 also moves to the tip side, so that the boom limit switch LS2 is also turned on, the electromagnetic switching valve V2 is switched, and the trolley 30 is stopped. After that, the telescopic boom 1 may be extended by the required distance.
The operation circuit 44 of the telescopic cylinder is provided with a known sequential operation switching valve 47. First, the telescopic cylinder 14 extends and the intermediate boom 12 extends as shown in FIG. 5C, and then the telescopic cylinder 15 extends. Is extended and the tip boom 13 is extended as shown in FIG. 5D.

When the telescopic boom 1 is shortened, when the operation switching valve 42 is switched to the C position, the pressure oil discharged from the hydraulic pump 40 is supplied to the shortening drive side pipe line 44R of the telescopic cylinders 14 and 15. Telescopic cylinders 14 and 15
Is shortened, and the trolley boom 20 also moves to the base end side. When the trolley boom 20 returns to the position shown in FIG. 5A, the boom limit switch LS2 is turned off and the electromagnetic switching valve V2
Is switched to, the pressure oil discharged from the hydraulic pump 40 is supplied to the reverse rotation drive side pipe line 43R of the trolley hydraulic motor 31, and the trolley 30 starts moving to the base end side. Then, the trolley limit switch LS1 is also turned off, the electromagnetic switching valve V1 is switched, and the telescopic cylinder 1 is deactivated.

FIG. 7 is a front view of another embodiment, and FIG. 8 is a view of FIG.
It is a VIII-VIII sectional view taken on the line. In this embodiment, the winch 5 includes a winch drum 51 around which a wire rope 6 to which a lifting device 7 is connected, a winch hydraulic motor 53 that drives the winch drum 51, and a winch speed reducer 52.
The winch drum 51 is pivotally supported on the lower end of the center of the trolley 30 instead of the pulley 38 of FIG. A hose reel 54 is pivotally supported on a bracket 56 provided on the base end boom 11 side, and a hose 57 that supplies pressure oil to the winch hydraulic motor 53 is a hose reel 5.
It is wound around 4. The hose reel 54 is always the hose 5
The trolley 30 is biased in the winding direction so that the trolley 30 does not loosen at any position.

In the embodiment in which the winch 5 is installed in the column 2, the hoisting tool 7 uses the wire rope 6 of the winch 5 as a pulley 38.
Since it is suspended from the trolley 30 and the height of the telescopic boom 1 changes due to expansion and contraction of the telescopic boom 1, it is difficult to use. Although it is necessary to wind and unwind the winch 5 in accordance with the expansion and contraction, the control is troublesome, but in this embodiment, the lifting device 7 is also used when the trolley 30 is moved or when the telescopic boom 1 is expanded or contracted.
Crane work is easier because the height of the crane does not change.

[0017]

As described above, the telescopic boom with trolley of the present invention does not expand or contract when the trolley is moved, so that it can be used in places where there is an obstacle above or in the direction of boom expansion and contraction, or where the ceiling is narrow and the room is narrow. Also, the crane work near the base end of the boom can be efficiently performed. It can also be applied to multi-stage telescopic booms.

[Brief description of drawings]

FIG. 1 is a front view showing a shortened state of a telescopic boom with a trolley that is an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is an explanatory diagram of an operating state of a telescopic boom with a trolley.

FIG. 6 is a hydraulic circuit diagram of a trolley hydraulic motor and a telescopic cylinder.

FIG. 7 is a front view of another embodiment of the present invention.

8 is a sectional view taken along line VIII-VIII of FIG.

[Explanation of symbols]

 1 Telescopic Boom 2 Column 5 Winch 7 Lifting Tool 11 Base Boom 12 Middle Boom 13 Tip Boom 14 Telescopic Cylinder 15 Telescopic Cylinder 20 Trolley Boom 30 Trolley 31 Hydraulic Motor for Trolley 38 Pulley 40 Hydraulic Pump 42 Operation Switching Valve 43 Trolley Hydraulic motor operating circuit 44 Telescopic cylinder operating circuit 51 winch drum 52 winch reducer 53 winch hydraulic motor 54 hose reel 57 hose V1 electromagnetic switching valve V2 electromagnetic switching valve LS1 trolley limit switch LS2 boom limit switch

Claims (3)

[Claims] 1. A telescopic boom for a crane, comprising a telescopic cylinder equipped with a plurality of booms including a proximal boom and a distal boom, wherein a trolley boom movably mounted on a trolley for supporting a lifting device is used. It is provided along the tip boom so as to be located outside the base boom when the boom is shortened, and when the trolley moves to a predetermined position of the tip of the trolley boom, the telescopic cylinder is operable from the inoperative state. Telescopic boom with trolley, characterized by having switching means for switching to. 2. A limit switch for detecting a movement of the trolley to a predetermined position of the tip portion of the trolley boom, and a solenoid switch valve for connecting a hydraulic circuit with an operating circuit of the telescopic cylinder by a detection signal of the limit switch. A telescopic boom with a trolley according to claim 1, comprising: 3. The telescopic boom with trolley according to claim 1 or 2, wherein the trolley is provided with a winch for raising and lowering a lifting tool.