JPS582189A - Multistage successive extensible boom - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sequential extension/retraction device for a multi-stage boom used in cranes, etc. Conventionally, multi-stage booms used in cranes, etc. have a special sequential operating mechanism in the cylinder device for extending/retracting the boom. It is necessary to incorporate a valve or provide other valves that operate sequentially, making the structure complicated and expensive. In particular, when a multi-stage boom is sequentially expanded and contracted using a multi-cylinder device, the structure thereof is extremely complicated.

Therefore, the present invention aims to provide a multi-stage telescopic boom with a simple sequential operation mechanism, the gist of which is to provide a base end boom, at least one intermediate boom, and a distal boom that can be slidably moved in order. In a multi-stage telescopic boom in which a multiple cylinder device is installed between a base boom and a tip boom, a first wedge for locking each intermediate boom is provided at the base of each intermediate boom, and a first wedge is provided adjacent to each intermediate boom. A second wedge for locking the boom on the tip side is provided at the tip of each intermediate boom, and the first wedge is in an unlocked state at a retracted position of the boom on the tip side adjacent to each intermediate boom, and
The wedge is configured so that each intermediate boom is in an unlocked state at its most extended position.

An example embodiment of the present invention will be explained 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. 2 is a base end boom, 2 is an intermediate poom that is slidably inserted into the base end boom 1, and %3 is a tip end boom that is slidably inserted into the intermediate boom 2. 4 is a three-stage cylinder device disposed between the base boom 1 and the tip boom 3, and as shown in FIG. 4, this three-stage cylinder device includes a first cylinder 4a,
This is a conventionally known cylinder device in which the second cylinder 4b, the piston rod 4C, the oil chamber on the expansion side, and the oil chambers on the contraction side are connected to each other, and the order of expansion and contraction is actually determined by the difference in the pressure receiving area. However, in the usage mode of the present invention, either of them may expand or contract first.

Reference numeral 5 denotes a first wedge provided at the base of the intermediate boom 2, which is always biased by a spring 6 in a direction to lock 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 pool 2, the retaining portion provided on the first wedge and the base 3a of the tip boom 3 abut against each other, and the tip boom 3 is placed in the unlocked position. It is configured so that

Reference numeral 7 denotes a second wedge provided at the tip of the intermediate pool 2, which is always biased by a spring 8 in the direction of locking the tip pool 3 with respect to the intermediate pool 2. This second wedge 7 has an engaging rod 7a.
is provided and guided to the base end side of the intermediate boom, and a retaining portion 7b is provided at the end thereof. On the other hand, a member 9 that abuts with this retaining portion 7b is fixed at a proper location of the base end pool 1, and the retaining portion 7b is
This member 9 is configured to abut against each other at the most extended position of the intermediate pool to place 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 looseness between each boom.

Fig. 5 shows the schematic configuration of the telescopic device of the present invention for a 5-stage boom in an expanded state, but the configuration for an 8-stage boom also includes n-2 wedges, multiple cylinders, and n-stage carrier devices. Other than that, the basic configuration is the same as the three-stage boom described above.

Figure 6 shows a suitable shape for the wedge to fully perform its functions. By doing so, it is possible to correct dimensional deviations due to an increase in the gap between the booms caused by wear of the sliding members of the booms, etc., and to ensure sufficient contact pressure. In addition, figure (b) shows the boom side with a self-aligning shape.

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 poom 3 is in the retracted position, so the first wedge 5 is in the unlocked state, so the intermediate pool 2 is extended. When the intermediate pool 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 pool 3 begins to expand. Intermediate f.

- The boom 2 has a flange 1 provided at the tip of the proximal boom at its extended end.
It is blocked by a and does not extend any further. When the tip arm 3 extends, the engagement portion 5a of the first wedge 5 and the base portion 3a of the tip boom 3 are no longer in contact with each other, and the first wedge 5 becomes locked (FIG. 3).

Next, to explain the retraction operation, when the cylinder device 4 is retracted in the maximum extension state of each boom (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). ), the first wedge 5 is in the locked state and the second wedge 7 is in the unlocked state, so only the tip pool 3 is reduced (FIG. 3). When this state continues and the tip pool 3 reaches the retracted position, the end 3C of the tip pool 3
and the engaging portion 5a of the first wedge 5 collide, and the first wedge 5
is in the unlocked state (Fig. 2), so the intermediate pool 2 begins to contract. When the intermediate pool 2 contracts, the engagement portion 7b of the second wedge 7 and the member 9 no longer collide with each other, and this second
Wedge 7 becomes locked. This state continues, resulting in the reduced state shown in FIG.

The operation of the three-stage boom has been described above, but even in the case of a multi-stage boom with three or more stages, the same is true in that the boom is extended sequentially from the base boom side and contracted 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. It is not limited to the type of equipment, but for example, a normal so-called single-type cylinder device may be installed between each boom, and each extension side oil chamber and each contraction side oil chamber of this cylinder device may be communicated with each other. It may also be configured to 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, Figs. 2 and 3 are explanatory diagrams of its operation, and Fig. 4 is a multi-cylinder used in Fig. 1. family'
The configuration diagram of R4, FIG. 5 is a configuration diagram in an extended state in the case of a five-stage boom, which is an example embodiment of the present invention. l... Base end boom, 2... Intermediate boom, 3... Tip boom, 4... Multiple cylinder device, 5... First wedge, 7... Second wedge. Patent applicant: UNIC Co., Ltd.

Claims (1)

[Scope of Claims] 1. A proximal end boom, at least one intermediate boom, and a distal end boom, each of which is slidably fitted in this order. - In a multi-stage telescopic boom in which multiple cylinder devices are arranged between the boom and the tip boom, the first boom locks each intermediate boom.
A wedge is provided at the base of each intermediate boom, a second wedge is provided at the tip of each intermediate frame for locking the boom on the tip side adjacent to each intermediate boom, and the r-th wedge is provided at the tip of each intermediate boom. - a multi-stage sequential telescopic boom configured such that the boom is in an unlocked state at a retracted position on the tip side adjacent to the boom, and the second wedge is in an unlocked state at a maximum extension position of each intermediate boom;