JPH02233497A - Overhead crane - Google Patents

Abstract

PURPOSE:To reduce the load to a host and its size by traveling respective mobile masts provided between the fixed mast and the lowest layer mast of a telescopic multiple-stage mast at the same time, and allocating the hall of its dead weight with the fixed mast for supporting. CONSTITUTION:When a work 11 is lifted up, a wire 10 is pulled up by driving hoist winding to pull up the mast 4 of the lowest layer connected to the wire 10. For this pulling-up, a wire B2 connected to it is rotated counter-clockwise, and the mobile mast M3 of the lower stage is moved upwards at the same time, taking a mobile mast M2 as a fixing point, through a sprocket installed on the mobile mast of lower stage. Through the operation of the lower stage mobile mast M3 moving upwards, the mobile mast M2 of upper stage is lifted up, taking a fixed mast M1 as a fixing point. At this time, the half of the dead weight of the upper stage mobile mast M2 is supported by the fixed mast M1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an overhead crane, and particularly to an overhead crane configured to be telescopically telescopic. [Conventional technology] As an overhead crane installed in a factory, etc., a telescopic (folding method) is used in which multi-stage masts are sequentially slid relative to each other.
An overhead crane is known in which a hanging wire is connected to a movable mast for a workpiece at the lowest end, and the wire is hoisted up and lowered. The multi-stage mast of this type of overhead crane has upper and lower stoppers provided at the upper and lower ends of a cylindrical frame.

However, the fixed mast fixed to the overhead crane body has a stopper only at the lower end. When each mast is lowered by these vertical stoppers, the uppermost movable mast is extended, and the extension operation is sequentially transferred to the lower masts, and when the masts are raised, the uppermost masts are sequentially extended from the lowest movable mast to the lower masts. It was a structure that could be pulled up.

[Problem to be solved by the invention]

In the above conventional technology, a hanging wire is connected to the movable mast at the lowest end. For example, when each mast is operated from an extended state to a direction of contraction (to lift an "article"), the hanging wire is The dead weight of the movable mast for the lowest workpiece is added to the weight of the workpiece. Then, when this lowest movable mast is pulled up to the upper limit position,
The upper limit stopper engages with the mast located above it and is pulled up with the weight of this mast added to it, and the lifting is performed with the weight of each mast added in sequence.

Therefore, for example, if the weight of each mast is Wl, W2, W3, the weight of the workpiece (article) is Wo, and the load on the hoist is TO, then the maximum value is To=W1 +W
2 +W3 +Wo.

Similarly, when lowering a workpiece from a suspended state with each mast retracted, the entire weight of the movable mast is applied to the hoist from the beginning, and the mast adjacent to the fixed proximal mast reaches its lowering limit. Once reached, the weight of this mast is supported by the proximal mast, and then, when each mast reaches its lowering limit, the weight of the entire movable mast is supported through each mast to the proximal mast, but during the extension process. In this case, the weight of each mast is on the hoist. Therefore, the load applied to the hoist 1 at the beginning of the descent becomes the maximum load shown in the above equation.

As a result of the weight of each mast being applied to the hoist, there is a drawback that performance must take into account the weight of each mast 1 in addition to the workpiece weight, and extra energy is consumed each time the crane is operated. The problem becomes more pronounced as the number of stages increases.

[Means to solve the problem]

In order to solve the above problems, the overhead crane according to the present invention has a telescopic structure in which at least two stages of cylindrical movable masses 1 are sequentially slid relative to a cylindrical fixed mast fixed to the overhead crane main body. A sprocket is rotatably provided at the lower end of each mast except the fixed mast and the lowest mast, a cable is wound around the sprocket, and both ends of the cable are connected. It is fixed at a predetermined position on the mast adjacent to the inside and outside.

(Function) According to the present invention, taking the case of lifting the workpiece 11 as an example, when the wire 10 is pulled up by the winding drive of the hoist 4 from the fully extended state of each movable mast, the wire 10 The lowest connected mast is raised.

That is, in the state shown in FIG. 6, when the lowest mast moves upward, the cable-shaped body connected thereto rotates counterclockwise in the drawing. Then, since the other side of this cable-shaped body is connected to the movable mast, this movable mast is set as a fixed point.Actually, it moves as described later, but here we will assume that it is fixed for relative explanation. The lower movable mast is simultaneously moved upward via the sprocket provided with the movable mast (see FIG. 7).

In other words, half of the weight of the lower movable mast is applied to the upper movable mast as a reaction force via the cable. Similarly, the upper movable mast has a cable wound around a sprocket, and both ends of the cable are connected to the fixed mast and the lower movable mast, respectively, so that the upper movable mast cannot be moved upwardly as described above. By operating the lower movable mast, the upper movable mast is then lifted upward using the fixed mast as a fixed point. At this time, half of the weight of the upper movable mast is supported by the fixed mast.

Here, if the weight of the lower movable mast is WL, the weight of the upper movable mast is W2, the weight of the bottom mast is W3, and the weight of the workpiece 11 is Wo, then the tension applied to the hoist 4 is T.
is, T = 1 / 3 W 1 + 2 / 3 W 2
+ W 3 + W o, and compared to the equation of the conventional example described above, the amount of reduction in the load applied to the hoist 4 is: 1/3W1 + 2/3W2 of the To-T scheme. [Example] Hereinafter, an example of the overhead crane according to the present invention will be described in detail based on the drawings.

FIG. 1 shows an overall front view of an overhead crane according to the present invention. A bridge 6 is provided on a rail 2 provided on a factory structure 1 so as to be movable in the horizontal direction, and an overhead crane main body 3 is attached to the bridge 6. The overhead crane main body 3 is installed to be movable in a horizontal direction orthogonal to the moving direction of the bridge 6, and is equipped with a hoist 4 for raising and lowering a workpiece. 5
is an operation box that controls the overhead crane main body 3 and hoist 4. The following description will be given with reference to FIGS. 2 to 9. A fixed mast M1 is fixed to the overhead crane main body 3. This fixed mast M1 and each of the movable masts described below have a cylindrical shape with a substantially square cross section, and the fixed mast M1 has the largest diameter.

A movable mast M2 whose diameter is temporarily smaller than that of the fixed mast M1. M3 is fitted in order to be able to slide relative to each other. A workpiece movable mast M4 as a lowermost mast having a smaller diameter is similarly fitted into the movable mast M3. An electromagnetic carrier 8 for holding and releasing the workpiece 7 is provided at the lower end of the workpiece movable mast M4.

The electromagnetic carrier 8 may be replaced with a simple hook, a negative pressure carrier, or the like, and may also be provided with electric control means for tilting or turning the workpiece 11.

These fixed masses I-M! , and movable mast M2
, M3 and each movable mast M2 . M3
A load divider lateral LDM is provided to allow the mast Ml to share and support substantially half of its own weight. The above-mentioned load division mechanism LDM connects the cylindrical fixed mast Ml to the overhead crane main body 3.
The cylindrical movable masts M2, M3 and the lowermost workpiece movable mast M4 are sequentially slid relative to the fixed mass Ml so as to be telescopically extendable and retractable, and Mast M1 and movable mast M for workpiece
Sprocket 31 on each movable mast M2, M3 except 4.
S2.33, S4 are provided rotatably at intervals vertically, and the first and second cable members Bl, B2 are wound between these sprockets, and the first cable member B1, B2 is wound between these sprockets. The fixed mast M1 is connected to one side of the endless body B1 using a fitting 9, and the third movable mast M is connected to the other side of the endless body B1.
3 are connected using a mounting bracket 9, and a hanging wire 10 (or chain block) is connected to the movable mast M4 for the workpiece on the lowest layer. The above sprocket St, 32. S3 and S4 are arranged as a pair symmetrically around the centers of the movable masts M2 and M3, respectively, and the sprockets Sl. S2 is arranged with a phase shift of 90 degrees from the other sprockets }33 and S4 in plan view.

Although chains are used for the first and second cable members B1 and B2, wires or belts may also be used, and wheels may be used instead of sprockets accordingly. Each of the fixed masts and the movable mast M1. M2
, M3, and M4 are provided with guide rollers 12, 13, and 14 for assisting mutual sliding. As shown in FIGS. 2 and 5, these guide rollers 12, 13, and 14 are arranged at four locations so that each one contacts the outer corner of each movable mast M2, M3, M4, and one roller 12, as shown in FIG. 5, is composed of a pair of upper and lower rollers.

Therefore, when lifting the workpiece 11, when the workpiece 11 is held by the carrier 8, each movable mast M2. M:1
．． And from the fully extended state of the workpiece movable mast M4,
When the wire 10 is pulled up by the winding drive of the hoist 4, the workpiece movable mass l-M4 connected to the wire lO is pulled up. That is, in the state shown in FIG. 6, when the workpiece movable mass l-M4 moves upward, the second endless body B2 connected thereto rotates counterclockwise in the drawing. Then, since the other side of this second endless body B2 is connected to the movable mass l-M2, this movable mass M2 is fixed at a fixed point (actually it moves as described later, but here it is fixed as a relative explanation) )
As a result, the movable mast M3 is moved upward via the sprocket $2 provided with the movable mast M3 (
(See Figure 7). In other words, as the workpiece movable mast M4 moves upward, it pushes the movable mass M3 upward, but half of the weight of the movable mast M3 is applied to the movable mass M2 as a reaction force via the second endless body B2. It joins. Similarly, the movable mast M2 has a first endless body B1 wound around the sprocket Sl, and one side of the first endless body B1 is connected to the fixed mast M1 and the other side is connected to the movable mast M3. By the operation of the movable mast M3 that has been moved upward, the movable mast M2 is now lifted upward using the fixed mast M1 as a fixing point. On this occasion,
Half of the weight of the movable mast M2 is supported by the fixed mast Ml.

Therefore, the second and third movable masts M mounted on the hoist 4
2. The weight of M3 will be halved. [Effects of the Invention] According to the overhead crane of the present invention, each movable mast provided between the fixed mast and the lowest mast of the telescopic multi-stage mast can be moved simultaneously, and approximately half of its own weight can be fixed. By having the mast share the support, the load on the hoist can be reduced, which not only allows the hoist to be made smaller, but also has the effect of eliminating wasted operating energy.

[Brief explanation of the drawing]

The drawings show an embodiment of the overhead crane according to the present invention, in which FIG. 1 is an overall front view, FIG. 2 is a schematic plan view of each mast, and FIG. Line arrow sectional view, 4th
The figure is a sectional view taken along the line B-B' in Fig. 2, and Fig. 5 is a sectional view taken along the line BB'
FIG. 8 is a vertical cross-sectional side view taken along line c-c' in the figure; FIG. 8 is a perspective view of the main parts showing the relationship between the fixed mast and the second mast;
The figure is a perspective view of the main parts showing the relationship between the third mast and the movable workpiece mast. In the figure, 3...overhead crane body, M1...fixed mast, M2. M3, M4...movable mast, Sl, S2. S3, 34... Sprocket, Bl, B
2... Cable body. Figure 2

Claims (1)

[Claims] (1) At least two or more stages of cylindrical movable masts are sequentially slid relative to a cylindrical fixed mast fixed to the overhead crane main body, and telescopically extendable and retractable. A sprocket is rotatably provided at the lower end of each mast except for the movable mast, a cable-shaped body is wound around the sprocket, and both ends of the cable-shaped body are fixed at predetermined positions on adjacent masts inside and outside. An overhead crane.