JP2012171774A - Telescopic mast fall prevention mechanism of crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a telescopic mast fall prevention mechanism of a crane capable of preventing fall of a mast in process of extension and contraction.SOLUTION: This telescopic mast fall prevention mechanism 100 of the crane includes: a cylindrical lower mast 1 extending in a vertical direction; and an upper mast 2 which is telescopically inserted into the lower mast 1 and constitutes a telescopic mast mechanism together with the lower mast 1. The telescopic mast fall prevention mechanism 100 includes: a base 12 provided at a top 1a of the lower mast 1; a bar-shaped bolt 14 retractable from the base 12 toward the inside of the lower mast 1; a guide fixed to the base 12 to guide the movement of the bolt 14; an elastic member interposed between the bolt 14 and the guide to energize the bolt 14 in a direction to the inside of the lower mast 1; and a bolt receiver 18 provided on an outer periphery of the upper mast 2 to be locked at an end portion of the bolt 14 drawn from the base 12.

Description

  The present invention relates to a telescopic mast drop prevention mechanism for a crane including a multistage telescopic mast.

  Conventionally, floor cranes equipped with multi-stage telescopic masts are used in building formwork and the like. As shown in FIG. 10 (1), when the beam formwork is installed in the ground, the mast is extended to a lift corresponding to the floor height. After attaching the beam formwork, as shown in FIGS. 10 (2) and 10 (3), the mast is reduced and the crane is folded to a height that allows it to pass under the beam bottom, and travels to the next construction position. To do.

  Here, the telescopic mast is composed of cylindrical masts 1 to 4 arranged in multiple stages, as shown in FIG. A mast 2 is stored in the lowermost mast 1, a mast 3 is stored in the mast 2, and a mast 4 is stored in the mast 3.

  A wire 6 a is wound around the telescopic winch 5 provided in the lowermost mast 1, and one end side of the wire 6 a includes a sheave 7 a provided on the top 1 a of the mast 1 and a sheave 7 b provided on the lower portion of the mast 2. It is fixed to the mast 1 after being wound around. When the wire 6 a is wound up by the winch 5, the lower sheave 7 b of the mast 2 is lifted and the mast 2 rises from the mast 1.

  Further, both ends of the wire 6b are fixed to the top portion 1a of the mast 1 and are wound around the top sheave 7c of the mast 2 and the lower sheave 7d of the mast 3, and the mast 3 rises at the same time as the mast 2 rises. It is supposed to be. By a similar mechanism, the mast 4 is also connected to the mast 3 via the wire 6c, and rises at the same time as the mast 3 rises.

  On the other hand, as shown in FIG. 12 and FIG. 13, as a mechanism for preventing the fall of the expansion / contraction mast, a through hole 8 for inserting kanuki is provided on the upper side of the mast 1. The lower end of the mast 2 is supported by inserting the cannula 9. This prevents the wire 6a from being cut and the mast 2 from falling when the mast 2 is raised and the crane is operated.

  The present inventor has already proposed a crane having a high lift and a light weight as shown in Japanese Patent Application No. 2010-128243 regarding a crane having such a multistage telescopic mast.

  By the way, in the conventional expansion / contraction mast drop prevention mechanism, the cannula 9 cannot be inserted into the through hole 8 unless the mast 2 is fully extended. For this reason, it is difficult to prevent the mast 2 from falling during expansion and contraction.

  Therefore, in order to enable support of the mast 2 in the middle of expansion and contraction, as shown in FIG. 14, it is conceivable to provide a plurality of through holes 8 with the height changed to the lowest mast 1. However, in the case of such a penetrating cannula, the cannula 9 cannot be inserted unless the mast 2 inside the mast 1 rises to a height that passes through the through hole 8, and lacks flexibility.

  Further, since the mast 2 is supported by the cannula 9, it does not fall even if the wire 6a (see FIG. 11) is cut, but the mast 3 and the mast 4 are cut when the wires 6b and 6c (see FIG. 11) are cut. It will fall. For this reason, there was a problem that it was not possible to prevent individual masts from falling.

  This invention is made | formed in view of the above, Comprising: It aims at providing the expansion / contraction mast fall prevention mechanism of the crane which can prevent the fall of the mast in the middle of expansion / contraction.

  In order to solve the above-described problems and achieve the object, a telescopic mast drop prevention mechanism for a crane according to claim 1 of the present invention is provided with a cylindrical lower mast extending in the vertical direction and the lower mast. A crane telescopic mast fall prevention mechanism comprising an upper mast that is telescopically inserted and constitutes a telescopic mast mechanism together with a lower mast, and a base provided on the top of the lower mast, and a lower mast from the base A rod-shaped kanuki that can be moved in and out toward the interior of the base, a guide that is fixed to the base and guides the movement of the kanuki, and is interposed between the kanuki and the guide, and the kanuki is placed inside the lower mast. It is composed of an elastic member that urges in the direction of the head, and a cannula receiver that is provided on the outer periphery of the upper mast and is engaged with the end of the cannula that is extended from the base. It is characterized in.

  According to a second aspect of the present invention, the crane's telescopic mast drop prevention mechanism according to the first aspect described above is characterized in that the guide has a hole through which the cannula passes, and is arranged on the base. A guide, a second guide disposed on the side closer to the kanuki receiver than the first guide, and a third guide disposed on the side farther from the kanuki receiver than the first guide, the kanuki receiving the kanuki receiver Projecting on the outer periphery on the side close to the first guide and the second guide, and a flange that cannot be inserted into the hole, and projecting on the outer periphery on the side farther from the first guide than the kanuki support. A pin that can pass through a groove provided in the third guide, and the elastic member is assembled to the outer periphery of the cannula between the collar and the first guide, and the cannula is directed in the direction toward the inside of the lower mast. With Characterized by comprising the coiled spring to be.

  Moreover, the expansion / contraction mast drop prevention mechanism for a crane according to claim 3 of the present invention is characterized in that, in claim 1 or 2, the kanuki support is provided at a plurality of locations in the height direction of the outer periphery of the upper mast. To do.

  Moreover, the expansion-and-contraction mast fall prevention mechanism of the crane which concerns on Claim 4 of this invention is based on this detection in the any one of Claims 1-3 which detected the appearance of the said Kanuki from the said base. It has an interlock mechanism for stopping the lowering operation of the upper mast.

  The crane's telescopic mast drop prevention mechanism according to claim 5 of the present invention is the crane according to any one of claims 1 to 4, wherein the telescopic mast mechanism is telescopic with respect to the cylindrical upper mast. A connecting mast comprising a third mast that is freely inserted, having one side connected to the lower mast and the other side connected to the lower part of the third mast via a sheave provided on the top of the upper mast. It is characterized by having two.

  According to the present invention, the expansion and contraction of a crane including a cylindrical lower mast that extends in the vertical direction and an upper mast that is inserted into the lower mast so as to be extendable and constitutes an expandable mast mechanism together with the lower mast. A mast fall prevention mechanism, a base provided at the top of the lower mast, a rod-shaped kanuki that can be moved in and out from the base toward the inside of the lower mast, and fixed to the base to guide the movement of the kanuki And a guide that is interposed between the guide and the guide, and is provided on an outer periphery of the upper mast, and is provided on the outer periphery of the upper mast. Since it is composed of a cannula receiver that locks to the end of the cannula, the cannula receiver is provided at an arbitrary height position on the outer periphery of the upper mast, and the upper mast can If the key received to lock the Kannuki end of the lower mast top, capable of supporting the weight of the upper mast bottom mast. Therefore, there is an effect that it is possible to prevent the mast from dropping during expansion and contraction.

FIG. 1 is a schematic side view showing an embodiment of a telescopic mast drop prevention mechanism for a crane according to the present invention. FIG. 2 is a schematic top view of the expansion / contraction mast drop prevention mechanism of the crane according to the present invention. FIG. 3 is a side view taken along line AA of FIG. FIG. 4 is a side view taken along line BB in FIG. FIG. 5 is a side view of the kanuki receiver. FIG. 6 is a schematic side view showing a state in which the crane's telescopic mast drop prevention mechanism according to the present invention is not operated. FIG. 7 is a schematic top view showing a state in which the crane's telescopic mast drop prevention mechanism according to the present invention is not operated. FIG. 8 is a diagram for explaining the operation of the crane of the crane's telescopic mast drop prevention mechanism according to the present invention. FIG. 9 is a sectional view showing another embodiment of the telescopic mast drop prevention mechanism of the crane according to the present invention. FIG. 10 is a diagram illustrating an example of a deformation mode of a conventional crane. FIG. 11 is a cross-sectional view showing a multistage telescopic mast of a conventional crane. FIG. 12 is a side view of a conventional mast drop prevention mechanism using a penetrating cannula. FIG. 13 is a cross-sectional view of a conventional mast dropping prevention mechanism using a penetrating cannula. FIG. 14 is a side view of a mast when a plurality of conventional penetrating cannulas are provided.

  Hereinafter, embodiments of a telescopic mast drop prevention mechanism for a crane according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

  As shown in FIG. 1, a crane mast mechanism 10 includes a cylindrical lowermost mast 1 (lower mast) extending in the vertical direction, and a mast 2 (upper mast) inserted into the mast 1 so as to be stretchable. ). The mast mechanism 10 further includes a mast 3 that is inserted into the mast 2 to be extendable and an uppermost mast 4 that is inserted into the mast 3 to be extended.

  As shown in FIGS. 1 and 2, a telescopic mast drop prevention mechanism 100 for a crane according to the present invention includes a base plate 12 (base) provided at the top 1 a of the mast 1, and the base plate 12 toward the inside of the mast 1. A rod-shaped cannula 14 that can be moved freely, a first to third guides 16 a to 16 c that are fixed on the base plate 12 and guide the movement of the cannula 14, and a cannula 14 that is provided on the outer periphery of the mast 2 and is extended from the base plate 12. It is comprised from the cannula receptacle 18 latched to the edge part 14a.

  As shown in FIGS. 2 to 5, the first to third guides 16 a to 16 c are plate members with holes having holes 20 through which the kanuki 14 passes. The second guide 16b is disposed on the side closer to the cannula receiver 18 than the first guide 16a disposed at the center, and the third guide 16c is disposed on the side farther from the cannula receiver 18 than the first guide 16a. It is.

  The cannuki 14 has a flange 22 and a pin 24 on its outer periphery. The flange 22 protrudes from the outer periphery on the side close to the cannula receiver 18 and is located between the first guide 16a and the second guide 16b and cannot be inserted through the holes 20. The pin 24 protrudes from the outer periphery on the side farther from the cannula receiver 18 than the first guide 16a, and can pass through a groove 26 provided in the third guide 16c. Further, a grip portion 14b bent in an L shape is formed on the outer end side of the cannula 14.

  In addition, a coiled spring 28 (elastic member) is assembled on the outer periphery of the cannula 14 between the collar 22 and the first guide 16a, and the cannula 14 is attached in a direction toward the inside of the mast 1 (X direction in FIG. 2). It is fast.

  In the above configuration, the cannula receiver 18 is provided at an arbitrary height position optimal for crane work. The weight of the mast 2 can be supported by the mast 1 if the cannula receiver 18 of the mast 2 in the middle of ascending is locked to the end part 14a of the cannula 14 at the top 1a of the mast 1. Accordingly, it is possible to prevent the mast 2 from falling during expansion and contraction. In particular, if the cannula receiver 18 is provided at a plurality of positions in the height direction of the outer periphery of the mast 2, it is possible to prevent the mast 2 from dropping at each stage during the expansion. In addition, when a kanuki proof stress is insufficient, it can respond by increasing the installation number of the kanuki 14, etc.

  Here, each state at the time of kanuki operation and non-operation will be described.

[State when kanuki operates]
First, the state at the time of a kanuki operation | movement is demonstrated.
As shown in FIGS. 2 to 4, when the cannula is operated, the collar 22 of the cannula 14 is pushed out in the X direction by the urging force of the spring 28 supported by the first guide 16 a, and the end 14 a of the cannula 14 is Inserted into. As a result, the cannula 14 can support the cannula receiver 18 and the mast 2 can be prevented from falling.

[When kanuki is not operating]
Next, the state when Kanuki is not operated will be described.
As shown in the top view of FIG. 8A and the side view of FIG. 8B, the pin 24 projecting from the outer periphery of the cannula 14 remains in a state where it can pass through the groove 26 of the third guide 16c. Is pulled in the Y direction to contract the spring 28. Then, when the pin 24 has passed the third guide 16c, the grip 14b is operated to rotate the cannula 14 and stop the pin 24 on the outside of the third guide 16c, so that the end 14a of the cannula 14 can be It is released from the receptacle 18 and held. By doing so, the state when the kanuki is not operated as shown in FIGS. 6 and 7 is obtained.

Therefore, according to the telescopic mast drop prevention mechanism of the present invention, the following effects are obtained.
The mast can be prevented from dropping at any height during expansion and contraction. For this reason, it is possible to perform the crane operation while preventing the mast from dropping at a desired mast height. In addition, since it is not necessary to extend the mast extra, the waiting time for mast expansion is shortened.

  In addition, the cannuki 14 is provided at the top 1a of the mast 1 and attached to the mast 1, so that it is not necessary to store it separately when the cannuki is not used. For this reason, it is possible to prevent the kanuki from being lost.

  In the above embodiment, a wire (connecting cord) is connected to the top of the mast 1 on one side and connected to the lower part of the mast 3 (third mast) through a sheave provided on the top of the mast 2 on the other side. You may make it have at least two. For example, as shown in FIG. 9, the wires 30a and 30b for expanding and contracting the mast 3 are connected to the lower portions 36a and 36b of the mast 3 via the top sheaves 34a and 34b of the mast 2, respectively. In this way, by configuring two wires, even if one of the wires 30a and 30b is cut, the mast 3 can be supported by one of the wires that is not cut, and the mast 3 can be prevented from falling. it can.

  Similarly, for the mast 4, wires 32 a and 32 b for expanding and contracting the mast 4 are connected to the lower portions 40 a and 40 b of the mast 4 via the top sheaves 38 a and 38 b of the mast 3, respectively. By doing so, even if any one of the wires 32a and 32b is cut, the mast 4 can be supported by one of the wires that is not cut. As described above, the mast 3 and the mast 4 are not dropped unless the two wires are cut at the same time, so that the safety can be improved.

  Moreover, in said embodiment, you may make it have the interlock mechanism which detects the appearance of the cannulas 14 from the baseplate 12, and stops the descent | fall operation | movement of the mast 2 based on this detection. For example, an interlock circuit is incorporated in the electric telescopic winch 5 for operating the raising and lowering of the mast 2, and the presence or absence of the cannula 14 is detected by a limit switch or the like. When it is detected that the cannula 14 is inserted into the cannula receiver 18, the driving of the telescopic winch 5 is stopped by the action of the interlock circuit. By doing so, it becomes possible to avoid an artificial erroneous operation such as lowering the mast 2 while the cannula 14 is inserted into the cannula receiver 18.

  In the above-described embodiment, other mast drop prevention mechanisms such as a conventional penetrating kanuki can be used in combination.

  As described above, according to the present invention, a cylindrical lower mast extending in the vertical direction, and an upper mast that is telescopically inserted into the lower mast and constitutes an expandable mast mechanism together with the lower mast. A crane telescopic mast fall prevention mechanism comprising: a base provided at the top of the lower mast; a rod-shaped kanuki that can be projected and retracted from the base toward the inside of the lower mast; and fixed to the base. A guide for guiding the movement of the kanuki, an elastic member interposed between the kanuki and the guide, for biasing the kanuki in a direction toward the inside of the lower mast, and provided on an outer periphery of the upper mast, Since it is composed of a cannula receiver that locks to the end of the cannula that is taken out from the base, the cannula receiver is provided at an arbitrary height position on the outer periphery of the upper mast, If the yoke receiving the upper mast to lock the Kannuki end of the lower mast top, capable of supporting the weight of the upper mast bottom mast. Therefore, it is possible to prevent the mast from dropping during expansion and contraction.

  As described above, the expansion / contraction mast drop prevention mechanism for a crane according to the present invention is useful for a crane including a multistage expansion / contraction mast, and is particularly suitable for preventing the mast from falling during expansion / contraction.

1 mast (lower mast)
2 Mast (upper mast)
3 mast (third mast)
4 Mast 5 Telescopic winch 10 Mast mechanism 12 Base plate (base)
14 Kanuki 16a First Guide (Guide)
16b Second guide (guide)
16c Third guide (guide)
18 Cannuki receiving 20 hole 22 flange 24 pin 26 groove 28 spring (elastic member)
30a, 30b, 32a, 32b Wire (connecting cord)
34a, 34b, 38a, 38b Sheaves 36a, 36b Lower part of mast 3 40a, 40b Lower part of mast 4 100 Expansion and contraction mast drop prevention mechanism of crane

Claims (5)

A crane's telescopic mast drop prevention mechanism comprising a cylindrical lower mast that extends in the vertical direction and an upper mast that is inserted into the lower mast in a telescopic manner and forms a telescopic mast mechanism together with the lower mast. There,
A base provided at the top of the lower mast; a rod-shaped cannula that can be moved in and out from the base toward the inside of the lower mast; a guide that is fixed to the base and guides the movement of the cannula; the cannula and the guide An elastic member interposed between and for biasing the kanuki in the direction toward the inside of the lower mast;
An extension mast drop prevention mechanism for a crane, comprising: a cannula receiver provided on an outer periphery of an upper mast and engaged with an end of the cannula that is extended from the base. Each of the guides has a hole for passing the cannula, a first guide disposed on the base, a second guide disposed closer to the cannula receiver than the first guide, and a first guide And a third guide arranged on the far side of the cannula receiver,
The kanuki protrudes from the outer periphery on the side close to the kanuki receiver, is located between the first guide and the second guide, and is not able to be inserted into the hole, and is farther from the kanuki receiver than the first guide. Projecting on the outer periphery of the side, having a pin that can pass through a groove provided in the third guide,
The said elastic member is assembled | attached to the outer periphery of the said cannula between the said collar and a 1st guide, and consists of a coiled spring which urges | biases the said cannula in the direction which goes inside a lower mast. The expansion / contraction mast fall prevention mechanism of the described crane.   3. The expansion / contraction mast drop prevention mechanism for a crane according to claim 1, wherein the cannula receiver is provided at a plurality of locations in the height direction on the outer periphery of the upper mast.   The crane according to any one of claims 1 to 3, further comprising an interlock mechanism that detects the appearance of the kanuki from the base and stops the lowering operation of the upper mast based on the detection. Telescopic mast drop prevention mechanism. The telescopic mast mechanism is configured to include a third mast that is telescopically inserted into the cylindrical upper mast,
5. The connection cable according to claim 1, further comprising at least two connection cords, one side of which is connected to the lower mast and the other side of which is connected to the lower part of the third mast via a sheave provided on the top of the upper mast. The crane's telescopic mast drop prevention mechanism according to claim 1.

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