JP6668909B2 - Chain sheave - Google Patents

Description

  The present invention relates to a chain sheave for guiding a chain for suspending a heavy object.

At a steel mill, hot metal discharged from a blast furnace is decarburized by a converter and refined into steel, and then, as secondary refining, the molten steel is transferred to a vessel such as a ladle to remove powder containing Ca and alloy components. It is mainly used for desulfurization and component adjustment.
In this secondary refining, the molten steel container such as a ladle is covered to keep the molten steel warm.

  Since this lid is used by being lifted and lowered under the harsh environment of the position directly above the container filled with molten steel, it is a heavy object with a refractory lining inside the iron body, and as a suspension means, , Chains are used.

  The chain is moved up and down by winding and rewinding a wire portion connected to the end opposite to the lid through a chain sheave for turning and guiding, onto a drum.

  The conventional chain sheave is a structure that guides the chain with a groove formed in the center part in the axial direction cross section, and the groove shape seen from the axial direction of the sheave is also circular, so the part that supports the chain link is As a result, the line link was in effect, and a strong bending stress was applied to the central portion in the longitudinal direction of the chain link. As a result, breakage of the chain link was sporadic.

Also, in the lifting operation in normal secondary refining, only the chain portion of the suspension means passes through the chain sheave, but if the refractory of the lid is consumed by melting or the like, the lid Since the body is lowered to the work floor level and the refractory lining is repaired, it is necessary to lower the lid over the operation stroke.
At this time, the wire portion connected to the chain end that does not pass through the chain sheave during normal operation also passes through the chain sheave, and a different stress is applied to the chain sheave than when passing through the chain link.

  Patent Literature 1 discloses a wheel (corresponding to a chain sheave) main body which is formed in a polygon having a protrusion at a vertex and which is engaged with a chain lateral link, and each surface of which is a guide surface of the chain lateral link. There is disclosed a chain wheel comprising: a guide groove for accommodating and engaging a chain longitudinal link formed between the projections on a peripheral surface of the wheel body.

  Further, in Patent Document 2, in a towing hoist, a load sheave (corresponding to a chain sheave) that rotates while suspending a load chain includes a main body portion that abuts and supports an outer peripheral surface of a long side of a chain link. Discloses a sheave configured in a polygonal shape and configured by a load receiving portion inserted into an opening of a chain link adjacent to the sheave.

  Each of these wheels or sheaves receives most of the load received from the chain link that suspends the heavy object to be raised and lowered on the outer peripheral side of one of the long sides of the link, and enters the opening formed in each chain link. , Because it is designed to insert the projecting part of the sheave, it is difficult to apply it to chain sheaves for lifting and lifting extremely large heavy objects, such as the lid of a secondary smelting vessel in a steel mill, and Neither of the chains was suspended.

JP-A-50-130160 JP-A-7-157289

The present invention has been made in view of the above circumstances, and has as its object to provide a chain sheave that can safely and securely lift a heavy object even under severe conditions such as a high-temperature environment such as a lid for secondary refining. And
Further, it is possible to provide a sheave capable of reliably guiding not only the chain but also a wire portion continuous thereto.

  The present inventors have studied a chain sheave that can safely wind a chain link in order to solve the above-mentioned problem, and as a result, by adopting a structure in which two long sides of the chain link are supported by the peripheral surface of the chain sheave. By avoiding that the bending stress that causes breakage is applied to the chain link, and by being able to support the load of the suspended heavy object with a larger area, the lid of the secondary refining vessel, etc. The present invention has been conceived which can safely and reliably lift a heavy object, and can reliably suspend and guide a wire portion.

The specific gist of the present invention is as follows.
(1) A sheave that guides a chain on an outer peripheral surface, wherein a first groove formed in the sheave and supporting the chain is a horizontal link among links constituting the chain when viewed from the sheave axial direction. And the outer peripheral surface on the sheave shaft side of the vertical link forming the chain fits into the center of the first groove in the sheave shaft direction. A chain sheave, wherein a second groove to be obtained is formed.

(2) The chain sheave according to claim 1, wherein a length Ls of one side of the regular polygon is represented by the following equation (1).
{Σ _al πd ³ (L _l −d) / (16F)} ≦ Ls ≦ (L _l −4d)
Where σal: allowable bending stress of the chain link
d: Chain link diameter
F: Load on the chain link

(3) The chain sheave according to (1) or (2), wherein a radius is provided at a corner of the regular polygon, that is, a ridge formed by a plane forming an adjacent first groove. .

(4) The chain sheave according to any one of (1) to (3), wherein the bottom of the second groove is circular as viewed from the sheave axis direction.

(5) In any of the above (1) to (4), a taper is provided at an entrance of the second groove in a cross-sectional shape of the second groove in a direction orthogonal to a sheave axis. Chain sheave described in Crab.

(6) The chain sheave according to any one of (1) to (5), wherein the depth of the second groove is {(Bd) / 2} or more.

(7) The chain sheave according to any one of (1) to (6), wherein the width of the second groove is d or more and B or less.

(8) The chain sheave according to any one of (1) to (7), wherein the width of the first groove is B or more.

(9) The chain sheave as described in any one of (1) to (8) above, wherein the bottom of the second groove has a shape capable of surface-supporting a wire connected to the chain.

According to the present invention, in the cross section orthogonal to the rotation axis, the bottom surface of the first groove of the chain sheave forming a regular polygon is formed by the long side of every other chain link (lateral link) among the links in the chain. The two sides are contacted and supported, and the chain link (longitudinal link) located between these links is configured to fit into the second groove formed at the corner of the chain sheave, so that the chain is suspended. Since the load of the heavy object to be bridged is applied to the chain sheave by the two long sides of the horizontal link of the chain, the additional load per unit area at the contact surface between the chain sheave and the chain link is reduced, and the chain link is bent. No load is applied and breakage trouble is greatly reduced.
Further, by giving a radius to a ridge formed by a plane forming the adjacent first groove, even if the horizontal link of the chain link is shifted with respect to the first groove of the chain sheave, The horizontal link slides smoothly on the ridge line of the first groove, so that it can be settled at the original position.
Furthermore, by setting the cross-sectional shape of the second groove to an appropriate shape, it is possible to form a chain sheave that can stably support the wire portion connected to the chain end.

It is the side view of the chain sheave seen from the rotation axis direction concerning the present invention, and the sectional view of the diameter side including the rotation axis. It is a side view in the state where the chain link was wound around the chain sheave concerning the present invention. FIG. 1 shows a sketch when a chain sheave according to the present invention is applied to a lifting device for a lid of a molten steel pot, and an enlarged view of a connection portion between a chain and a wire. It is a dimension drawing of a chain link.

  Hereinafter, the case where the chain sheave according to the present invention is applied to a chain for raising and lowering a lid of a molten steel pot used for secondary refining during steelmaking will be described in detail as an example.

FIG. 3 shows the chain sheave 3 around which the chain 1 for suspending the lid 12 of the molten steel pot 11 is bridged. The circular lid 12 as viewed from above is suspended by two chains 1 at two points on the diameter with the center thereof interposed therebetween.
A wire 13 is connected to the other end of the chain 1 that is connected to the lid 12, and the other end of the wire is wound around a lifting drum 14. The pair of chains 1 that suspend the lid 12 across the center of the lid 12 and the wire 13 connected thereto are wound around a common elevating drum 14 and moved up and down, so that they are automatically synchronized. Can take.

  After the molten steel pot 11 is filled with molten steel and a desulfurizing agent or the like is added, the lid 12 descends and covers the upper surface of the molten steel pot to prevent an excessive temperature drop of the molten steel. In raising and lowering the lid during normal operation, only the chain 1 is engaged with and interlocked with the chain sheave 3 for hanging the lid.

  However, due to long-term use, the refractory lining the lid is damaged, and when repairing it, it is necessary to lower the lid 12 to the work floor level and perform repair work.

  At this time, since the wire 13 wound around the elevating drum 14 is largely unwound, the wire portion is also guided by the chain sheave 3.

  The chain sheave 3 according to the present invention has, as shown in FIG. 2, a horizontal link 1 a in contact with the chain sheave 3 on two long sides of the link among the links constituting the chain 1, each having a regular polygonal shape. Designed to be in contact with the sides.

  The longitudinal link 1b located before and after the horizontal link 1a has its longitudinal center located on the ridge line of the regular polygonal first groove 3a of the chain sheave 3, and is formed at the axial center of the chain sheave 3. It fits in the second groove 3b.

Since the bottom of the second groove 3b is formed so as not to contact the outer periphery of the vertical link, bending stress does not act on the center of the vertical link.
On the other hand, when lowering the lid to the work floor level for repairing the lining of the lid 12, the wire 13 connected to the drum side end of the chain 1 is rewound until the wire 13 is hooked on the chain sheave 3. However, at this time, the bottom of the second groove 3b of the chain sheave 3 supports the inner side surface of the wire 13 hanging on the chain sheave 3, so that the wire 13 is securely guided to the second groove 3b of the chain sheave. Thus, the lid 12 can be smoothly lowered.
The end of the chain 1 on the connection side with the wire 13 is a horizontal link 1a, and an annular portion 13b corresponding to a vertical link is formed at the end of the wire 13 on the side of the chain 1 to form a joint between the chain 1 and the wire 13. 2 can also pass over the sheave smoothly.

The second groove 3b formed at the bottom of the first groove 3a having a regular polygonal shape when viewed from the rotation axis direction is formed in a circular shape as a whole when viewed from the rotation axis direction of the chain sheave 3. In addition, when viewed from a cross section including the rotation axis, the first link from the bottom of the second groove 3b is inserted from the bottom of the second groove 3b so that the vertical link and the wire forming the chain are securely fitted into the second groove 3b. It is desirable to provide a divergent taper toward the groove 3a.
Due to this taper, the long side of the vertical link 1b of the chain 1 and the wire 13 are reliably guided into the second groove 3b, so that the chain link is hooked on the side surface of the second groove 3b and is asymmetric with respect to the chain sheave 3. Applying stress can be prevented.

A chain consisting of the chain link shown in FIG. 4 is designed.
Each link of the chain 1 is formed to have a diameter d, a length L of a long side, and a width B of a short side of the link.
When the first groove 3a of the regular sheave of the chain sheave is located on the paper surface of FIG. 4, the chain link 1a, which shows the entirety at the center, corresponds to the horizontal link, and both sides correspond to the vertical link 1b.
In the vertical links 1b on both sides, the plane length Ls of the first groove forming the regular polygon is (L-4d) at the maximum so that the portion closest to the horizontal link does not hit the first groove. I do.

The longer the length Ls of one side of the regular polygon in the above-mentioned range is, the more advantageous in terms of the load per unit area, but the minimum length is ｛σ _al πd3 ( Ld) / (16F)} or more.
That is, it is desirable to design so as to satisfy the following expression (1).
{Σ _al πd ³ (L−d) / (16F)} ≦ Ls ≦ (L−4d) (1)
Where σ _{al is} the allowable bending stress of the chain link
d: Chain link diameter
F: Load on the chain link
L: Length of the long side of the chain link.

The width of the bottom surface of the first groove 3a is set to be equal to or greater than the width B of the link so that the horizontal link is surely dropped to the bottom surface of the first groove.
The width of the second groove 3b is not less than d and not more than B so that the vertical link 1b of the chain 1 can be fitted and the horizontal link 1a of the chain 1 is not fitted. It is preferable to set {(Bd) / 2} so that the side of the chain sheave 3 of the vertical link 1b does not contact the bottom surface of the second groove 3b.
The side wall forming the second groove 3b is provided with the above-described taper so that the vertical link 1b does not abut on the side wall portion of the second groove 3b and does not fit into a regular position. Is preferred.
The bottom of the second groove 3b may be flat in the shape viewed from the cross section including the rotation axis shown in FIG. 1B, but it is assumed that the wire 13 connected to the chain 1 passes through the chain sheave 3. If it is formed into a curved surface and has a shape that increases the contact area with the wire 13, a portion where the engagement portion with the chain sheave 3 shifts from the chain 1 to the wire 13 due to the drop of a heavy object. In addition, it is possible to reliably obtain a frictional force that does not cause a slip phenomenon, thereby contributing to improvement of work safety and stable lowering of a heavy object.

According to the present invention, in a chain sheave around which a chain supporting a heavy object represented by a lid of a molten steel pot so as to be able to ascend and descend can be prevented from acting on bending stress on a chain link constituting the chain, It is possible to prevent a heavy object from falling due to breakage of the chain link, to increase the safety of work, and to greatly improve the life of the chain and the chain sheave.
In addition, even when the chain and the wire pass, the suspended object can always be stably moved up and down.

1: Chain link 1a: Horizontal link 1b: Vertical link 2: Joint part (between chain and wire) 3: Chain sheave 3a: First groove 3b: Second groove 11: Molten steel pot 12: Lid 13: Wire 14: Winding drum

Claims (8)

A sheave that guides a chain on an outer peripheral surface, wherein a first groove formed in the sheave and supporting the chain is configured such that when viewed from the sheave axial direction, a horizontal link of a link constituting the chain has a length. The first groove is a regular polygon having sides that are in contact with and supported in the vertical direction, and the outer peripheral surface of the longitudinal link that constitutes the chain on the sheave shaft side can be fitted into the central portion of the first groove in the sheave axis direction. grooves have been formed in the chain sheave bottom of the second groove, the contact area between the wire connected to the chain, characterized in curved der Rukoto capable face supporting to increase. The chain sheave according to claim 1, wherein the length Ls of one side of the regular polygon is represented by the following equation (1).
{Σ _al πd ³ (L−d) / (16F)} ≦ Ls ≦ (L−4d) (1)
Where σ _{al is} the allowable bending stress of the chain link
d: Chain link diameter
F: Load on the chain link
L: Length of long side of chain link   3. The chain sheave according to claim 1, wherein a radius is provided at a corner of the regular polygon, that is, a ridge formed by a plane forming the adjacent first groove. 4.   The chain sheave according to any one of claims 1 to 3, wherein a bottom portion of the second groove is circular when viewed from a sheave axis direction.   The cross-sectional shape of the second groove in a direction orthogonal to a sheave axis is provided with a taper at an entrance portion of the second groove. Chain sheave. The depth of the said 2nd groove | channel is {(Bd) / 2} or more, The chain sheave of any one of Claim 2 and Claim 3-5 characterized by this .
B: Width of short side of chain link The chain sheave according to claim 6 , wherein the width of the second groove is d or more and B or less. The chain sheave according to any one of claims 6 to 7, wherein the width of the first groove is B or more.

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