JPH0444546Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a boom device for a crane.

Conventional technology When using a crane to transport materials to a place of varying size or depth on the ground, cranes with different specification capacities are used depending on the weight of the material, lifting height, installation location of the crane, etc. It is necessary to select the work equipment.

When making this selection, it may be necessary to use a crane operating device with specifications that exceed the required capacity.

For example, when a crane must be installed close to a building, it may not be possible to reach the transport depth due to contact between the boom and the building. It is a must.

The higher the lift above the ground, the larger the crane working equipment, and the larger the vehicle to transport it. Therefore, if there is no road or place where a crane vehicle equipped with such a large crane working equipment can enter, use a crane. make work impossible.

As a solution to the above-mentioned problem, there is a method of attaching an auxiliary jib to the tip of the boom of the crane at an angle and increasing the depth of the boom working range, or the method of
A method of increasing the depth of the boom working range by attaching a bendable and telescopic auxiliary boom to the tip of the crane boom as seen in No. 55-119693, or a method of bending as seen in Utility Model Application No. 58-87789. A known method is to increase the depth of the boom working range by using a boom.

The above-mentioned auxiliary jib means is usually a method in which the auxiliary jib is stored and equipped in the base boom, and is connected to the top boom and swung out as necessary, or as disclosed in Japanese Patent Application Laid-open No. 58-92289 and Utility Model Application No. 57. -120590, there is a method of building an auxiliary jib inside the boom and pulling it out and extending it as needed.

In the former case, when the auxiliary jib is oscillated and extended, it is difficult to avoid contact with obstacles when swinging in a narrow space, and the same is true when storing the auxiliary jib, and sometimes it is not even possible to extend the auxiliary jib. The latter method of pulling out the auxiliary jib is better than the swinging method of the former, but since the inclination angle of the auxiliary jib cannot be changed when the auxiliary jib is pulled out, it is necessary to adjust the depth by changing the boom hoisting angle. It is also inconvenient in that the depth and width cannot be changed by changing the inclination angle of the auxiliary jib.

The method of using a foldable and extendable auxiliary boom as disclosed in Japanese Patent Application Laid-open No. 55-119693 has the same problems as the auxiliary jib mentioned above because the auxiliary boom must be oscillated and extended. There are problems in terms of bulk, weight, and cost.

In the method of using a refracting boom as in Utility Model Application No. 58-87789, since the boom on the hanging hook side is fixed in a bent position, the lift height cannot be increased by swinging the boom on the hanging hook side. cannot be made higher.

Problems to be Solved by the Invention The present invention was developed in view of the above circumstances, and its purpose is to extend and retract the boom 20 in synchronization with the telescopic movement of the main boom structure A, and to refract the boom 20. To easily extend a boom even in a narrow place by making it possible to freely change the depth and width of a boom working radius, and to enable lifting work in a deep width range.

Means and Effects for Solving the Problems The present invention provides a multi-stage main boom structure A in which the top boom 11 is telescopically supported in the front and rear directions relative to the base boom 10 side, and connected via a telescoping cylinder 12. A bracket 14 is provided at the tip of the top boom 11 of the main boom structure A so as to be rotatable in the vertical direction.
An overhanging boom 20 located above the main boom structure A is slidably supported in the front and rear direction, and a cylinder is connected to the upper side of the rear end of the base boom 10 of the main boom structure A via a trunnion 26. A device 27 is provided, the piston rod 2 of the cylinder device 27
A third pulley 29 is provided at the tip of the boom 8 with its axis of rotation facing up and down, and a pair of first pulleys 23a, 23b are provided on both sides of the rear end of the boom 20 for extension. A second pulley 24 is provided at the rear end of the extending boom 20 with its rotational axis facing in the horizontal direction, and a second pulley 24 is provided on the bracket 14 with its rotational axis facing in the vertical direction.
A pair of fifth pulleys 18 and 19 located on both sides of the boom 20 for extension are provided with their rotation axes in the horizontal direction, and one of the first pulleys is connected from the third pulley 29 to the other.
An endless wire 22 for extension extends across the pulley 23a, the fifth pulley 18 on one side, the second pulley 24, the other fifth pulley 19, the first pulley 23b on the other side, and the third pulley 29. The fourth pulleys 33a, 3 are wrapped around the top boom 11 and
3b with its axis of rotation facing the horizontal direction, and pulleys 16 and 17 are provided on the pivot shaft of the bracket 14, and one end is attached to the fourth pulley 33a, 33b and the sixth pulley 16, 17. A shortening wire 30 is connected to the tip of the base boom 10, and the other end is connected to the tip of the boom 20 for extension. The boom 20 for extension is moved to extend by the wire 22, and the boom 20 for extension is moved to be shortened by the shortening wire 30 in synchronization with the shortening operation of the main boom structure A. When the boom 20 for overhanging is extended,
By moving the third pulley 29 forward, the extension wire 22 is loosened, and the extension boom 20 is rotated downward together with the bracket 14 and bent.

Embodiments The present invention will be described below with reference to embodiments. 1
0 is a base boom, and a top boom 11 is extendably provided on the base boom 10, and these constitute a main boom structure A. A gate-shaped bracket 14 is attached to the tip of the top boom 11 so as to be rotatable in the vertical direction by a support shaft 15. This support shaft 15 has a sixth pair of pulleys 16,1
7 are positioned and supported on both sides of the top boom 11, and the bracket 14 has boom holding parts 2.
1 is provided, and a fifth pair of pulleys 18 and 19 are positioned on the left and right sides of this boom holding portion 21 and are pivotally supported with their rotational axes oriented in the horizontal direction. A boom 20 for extending is slidably held in the boom holding part 21, and a rolling roller 21' is provided at the rear end of the boom 20 for extending.
The rolling roller 21' is in contact with the upper surface of the base boom 10.

A first pair of pulleys 23a and 23b are provided on both sides of the rear end of the boom 20 for overhanging, and a second pair of pulleys 23a and 23b are provided at the rear end of the boom 20 for overhanging. A pulley 24 is provided with its axis of rotation facing in the vertical direction. A bracket 25 is fixed to the rear end of the base boom 10, and a cylinder device 27, which is a double-acting cylinder, is attached to the bracket 25 via a trunnion 26. A third pulley 29 is pivotally supported. Then, the third pulley 29, the first left pulley 23a,
The fifth left pulley 18 of the bracket 14, the second pulley 24, the fifth right pulley 19 of the bracket 14, the first right pulley 23b, the third pulley 29, and an endless extension wire in this order. A rope 22 is wound around the boom operating mechanism C.

A base end of a telescopic cylinder 12 is connected to the top boom 11, and a piston rod 12' of the telescopic cylinder 12 is connected to the base boom 10. A fourth pair of pulleys 33a, 33b are pivotally supported on both sides of the rear end of the top boom 11, and a pair of shortening wire ropes 30, one end of which is latched to both sides of the tip of the base boom 10. 30 are each engaged with an engaging portion 32 of a bracket 31 at the tip of the boom 20 via a fourth pair of pulleys 33a, 33b and a sixth pulley 16, 17 of the bracket 14, and these engage the boom telescoping mechanism B. It consists of

Reference numeral 34 in the drawings indicates an auxiliary jib, and the auxiliary jib 34 is provided so that it can be moved in and out of the boom 20 for overhanging, and is pulled out by hand when in use.

Next, the operation will be explained.

In the retracted state (see FIG. 1), when the telescopic cylinder 12 is extended, the top boom 11 slides to the left in the drawing. This causes the bracket 14 to also move, pulling the wire rope 22 for extension via the fifth pulleys 18 and 19. Since one side of the wire rope 22 is fixed by a third pulley 29 whose position is fixed by a cylinder device 27, the wire rope 22 is connected to the boom 20 for extension via the wire portion hooked to the second pulley 24. is pushed out to the left in synchronization with the extension of the top boom 11 (indicated by a two-dot chain line in FIG. 2). Note that the auxiliary jib 34 is pulled out by hand and fixed to the tip of the boom 20 in advance.

When the cylinder device 27 is extended, one fixed end of the wire rope 22 for extension is displaced, and the boom 20 for extension is bent around the support shaft 15 of the bracket 14, thereby increasing the depth of the boom working radius. Can be changed freely.

When retracting, the telescopic cylinder 12 is retracted. As a result, the top boom 11 moves to the right, and the shortening wire rope 30 pulls the extending boom 20 in synchronization with the contraction side, so that the state shown in FIG. 1 can be returned.

At this time, the wire rope 22 for extending the extending boom 20 is shortened by the movement caused by the retreating of the extending boom 20 via the second pulley 24.

In addition, the auxiliary jib 34 is attached to the boom 20 for extending.
Since it is a built-in and pull-out type, unlike the conventional swinging extension, it can be easily extended even in narrow spaces.

In addition, since the bending means for the boom 20 for extending is simply changing the fixed position of the wire rope 22 for extension, there is no bending cylinder between the bending part that expands and contracts and the fixed part, so the bending part is provided at a high position. In combination with the auxiliary jib 34, it is possible to carry out lifting work in a deep and wide range.

Effects of the invention Since the invention is as described above, the boom 20 is extended and extended in synchronization with the telescopic movement of the main boom structure A, and the boom 20 is bent around the fulcrum of the bracket 14 to increase the depth of the boom working radius. You can change the width.

For this reason, unlike the conventional swinging boom, the boom can be easily extended even in narrow spaces, and it is possible to carry out lifting operations in a deep and wide range. Further, according to the present invention, the boom 20 that is further extended than the top boom 11 and performs a digging and folding operation can be stored along the upper side of the main boom structure A, and this storage and extension can be performed in conjunction with the top boom 11. By being able to do this, the boom 20 for overhanging can be stored in a small space, and the boom 20 for overhanging can be easily stored without manual intervention.

[Brief explanation of the drawing]

FIG. 1 is a side view of an embodiment of the present invention in a boom retracted state, FIG. 2 is a side view of the same boom in an extended state, and FIG. 3 is a sectional view taken along the line of FIG. 1. 11 is the top boom, 14 is the bracket, 20
is the boom, A is the main boom structure, B is the boom extension mechanism, and C is the boom operating mechanism.

Claims (1)

[Scope of claim for utility model registration] Top boom 11 against base boom 10 side
A multi-stage main boom structure A is constructed by supporting the main boom structure A in a multi-stage type main boom structure A, and a bracket 14 is attached in the vertical direction to the tip of the top boom 11 of the main boom structure A. The bracket 14 supports an overhanging boom 20 located above the main boom structure A so as to be slidable in the front and rear direction, and a rear end of the base boom 10 of the main boom structure A. The cylinder device 2 is connected to the upper side via the trunnion 26.
7, and a third pulley 29 is provided at the tip of the piston rod 28 of the cylinder device 27, with its rotational axis directed in the vertical direction, and both sides of the rear end of the boom 20 for extension are provided. A pair of first pulleys 23a and 23b are provided with their rotational axes oriented in the horizontal direction, and at the rear end of the boom 20 for extension,
A second pulley 24 is provided with its axis of rotation facing up and down, and a pair of fifth pulleys 1 are provided on the bracket 14, which are located on both sides of the boom 20 for extension.
8 and 19 with their rotational axes in the horizontal direction, and one of the first pulleys 23 from the third pulley 29
a, one fifth pulley 18, second pulley 24, fifth other pulley 19, other first pulley 23b,
An endless extension wire 22 is wound around the third pulley 29, and fourth pulleys 33a and 33b are provided on the side surface of the rear end of the top boom 11 with their rotation axes oriented in the horizontal direction. Also, a sixth pulley 1 is attached to the pivot shaft of the bracket 14.
6, 17 are provided, and the fourth pulleys 33a, 33b and the sixth pulleys 16, 17 are connected at one end to the tip of the base boom 10 and the other end to the tip of the boom 20 for extension. A crane boom device characterized in that a shortening wire 30 is connected.