JPS627119B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sequential extension/retraction device for a multi-stage boom used in a crane or the like, and particularly to a sequential extension/retraction device for a multi-stage boom that sequentially extends/contracts using a wedge device.

The applicant had previously filed Japanese Patent Application No. 54-16520 (Japanese Unexamined Patent Publication No. 55-111391) as a three-stage telescopic boom using a wedge device.
No.) was filed.

By the way, in this application, the tip boom is locked with respect to the intermediate boom when the wedge provided at the tip of the intermediate boom rides on a stepped portion provided at an appropriate position at the tip of the tip boom.

Therefore, at the beginning of the extension of the tip boom, the frictional restraining force due to this wedge acts, which becomes a burden on the extension force of the cylinder. For this reason, there was a problem in that the output of the cylinder had to be increased to provide a margin for the extension force of the cylinder.

Therefore, the present invention aims to provide a multi-stage sequentially telescopic boom that solves these problems, and its gist is to provide a base end boom, at least one intermediate boom, and a distal end boom that are slidable in order. In a multi-stage telescopic boom in which a multi-action cylinder device is installed between a proximal boom and a distal boom, the first wedge locks each intermediate boom to the boom on the proximal side of each intermediate boom. A second wedge is always biased in the locking direction by a spring and is provided at the base of each intermediate boom, and locks the boom on the tip side adjacent to each intermediate boom with respect to each intermediate boom. and is provided at the tip of each intermediate boom, and the first wedge is such that the boom on the tip side adjacent to each intermediate boom collides with the engaging portion provided on the first wedge at the end position of its retracting operation. 1st
By moving the wedge against the spring, the lock becomes unlocked, and the second wedge is located at the end position of the extension operation of each intermediate boom, and the engaging portion provided on the second wedge is on the proximal end side adjacent to each intermediate boom. The second wedge is moved against a spring by colliding with a member provided at an appropriate location on the boom, thereby making the lock unlocked.

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

FIG. 1 shows the case of a three-stage boom, which is an example embodiment of the multi-stage telescopic boom according to the present invention, and shows the most contracted state. 1 is a base end boom, 2 is an intermediate boom that is slidably inserted into the base end boom 1, and 3 is a tip boom that is slidably inserted into the intermediate boom 2. Reference numeral 4 denotes a three-stage cylinder device disposed between the base end boom 1 and the tip boom 3, and as shown in FIG. 4, this three-stage cylinder device consists of a first cylinder 4a, a second cylinder 4b, and a piston rod 4c.
In a conventionally known cylinder device in which each extension side oil chamber and each contraction side oil chamber are communicated with each other, the expansion and contraction order is as follows:
In reality, it seems to be determined by the difference in pressure receiving area, but in the usage mode of the present invention, either of them may expand or contract first.

A first wedge 5 is provided at the base of the intermediate boom 2 and is always biased by a spring 6 in the direction of locking the intermediate boom 2 with respect to the base end boom 1. When the first wedge is in the position where the tip boom 3 is stored in the intermediate boom 2, the engaging portion 5a provided on the first wedge collides with the base 3a of the tip boom 3, and the first wedge is placed in the unlocked position. It is configured so that

A second wedge 7 is provided at the tip of the intermediate boom 2, and is always biased by a spring 8 in the direction of locking the tip boom 3 with respect to the intermediate boom 2. This second wedge 7 is provided with an engaging rod 7a, which is guided toward the base end of the intermediate boom, and an engaging portion 7b is provided at the end thereof. On the other hand, this engaging portion 7b is placed at a suitable location on the base end boom 1.
A member 9 that abuts against the intermediate boom is fixedly installed, and the engaging portion 7b and this member 9 abut each other at the most extended position of the intermediate boom, thereby placing the second wedge in the unlocked position.

Note that 10a is a sliding member provided at the front and rear ends of each boom so that each boom can extend and contract smoothly and to eliminate play between each boom.

FIG. 5 shows the schematic configuration of the telescoping device of the present invention for a 5-stage boom in an expanded state, but the configuration also applies to an n-stage boom in which each wedge is
The basic configuration is the same as that of the three-stage boom described above except that there are two multi-cylinder devices in n stages.

Figure 6 shows a suitable shape for the wedge to fully demonstrate its function.As shown in Figure A, it should be self-aligning (R or spherical) so that it makes sufficient contact with the contact surface of the boom. This makes it possible to correct dimensional deviations due to increased gaps between the booms caused by wear of the boom sliding members, etc., and to ensure sufficient contact pressure. In addition, the figure B shows a self-aligning shape on the boom side.

Next, the operation of the multi-stage boom configured as described above will be explained for a three-stage boom.

In FIG. 1, when the cylinder device 4 is extended (in this case, the second cylinder 4b and the piston rod 4C may be extended at the same time or either of them may be extended first), the tip boom 3 is in the retracted position, so the first wedge 5 is unlocked and therefore intermediate boom 2
expands. When the intermediate boom reaches its maximum extension position, the engaging portion 7b of the second wedge 7 abuts against the member 9, and the second wedge 7 becomes unlocked (FIG. 2). As a result, the tip boom 3 begins to extend. The intermediate boom 2 is blocked at its extended end by a flange 1a provided at the tip of the proximal boom, and does not extend any further. When the tip boom 3 extends, the engagement portion 5a of the first wedge 5 and the base portion 3a of the tip boom 3 no longer collide, and the first wedge 5 becomes locked (the third
figure).

Next, to explain the retraction operation, in each boom maximum extension state, when the cylinder device 4 is retracted (in this case, the second cylinder 4b and the piston rod 4c may be retracted at the same time or either may be retracted first). Since the first wedge 5 is in a locked state and the second wedge 7 is in an unlocked state, only the tip boom 3 is retracted (FIG. 3). When this state continues and the tip boom 3 moves to the retracted position, the end 3c of the tip boom 3 and the engaging portion 5a of the first wedge 5 abut each other, and the first wedge 5 becomes unlocked (FIG. 2). The intermediate boom 2 therefore begins to retract. When the intermediate boom 2 is retracted, the engagement portion 7b of the second wedge 7 and the member 9 no longer collide, and the second wedge 7 becomes locked. This state continues, resulting in the reduced state shown in FIG.

Although the operation of the three-stage boom has been described above, even in the case of a multi-stage boom with three or more stages, the same is true in that the boom extends sequentially from the base boom side and contracts sequentially from the distal boom side.

In the present invention, a multiple cylinder device is used as a means for extending and contracting the boom, but as mentioned above, each cylinder may be extended and contracted at the same time or either one first. Not limited to equipment,
For example, a conventional so-called single-type cylinder device may be disposed between each boom, and the extension side oil chambers and the contraction side oil chambers of this cylinder device may be communicated with each other so that they can expand and contract at the same time.

As described above, the present invention is configured to sequentially extend and retract the multi-stage boom using the simplest structure of the multiple cylinder device and the wedge device, so the structure is simple and its practical value is further enhanced.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a three-stage boom, which is an example embodiment of a multi-stage sequential telescopic boom according to the present invention;
FIG. 3 is an explanatory diagram of its operation, FIG. 4 is a configuration diagram of the multi-cylinder device 4 used in FIG. , FIG. 6 is a preferred configuration diagram of the wedge of the locking device. 1... Proximal boom, 2... Intermediate boom, 3...
Tip boom, 4...multi-cylinder device, 5...first wedge, 7...second wedge.

Claims (1)

[Claims] 1 a proximal boom; at least one intermediate boom;
In a multi-stage telescopic boom in which a multi-cylinder device is installed between the proximal boom and the proximal boom, each intermediate boom is slidably inserted into the proximal boom in sequence, and each intermediate boom is connected to the boom on the proximal side of each intermediate boom. A first wedge is always biased by a spring in the locking direction and is provided at the base of each intermediate boom, and a second wedge is provided at the base of each intermediate boom to lock the boom on the tip side adjacent to each intermediate boom. The first wedge is always biased by a spring in the direction and is provided at the tip of each intermediate boom, and the first wedge is engaged with the first wedge when the boom on the tip side adjacent to each intermediate boom is in the final position of its final operation. The locking state is achieved by moving this first wedge against the spring, and the engaging portion provided on the second wedge is at the end position of the extension operation of each intermediate boom. A multi-stage sequential telescopic boom configured to be brought into an unlocked state by moving this second wedge against a spring by colliding with a member provided at an appropriate position on a proximal boom adjacent to each intermediate boom.