JP6052552B2 - Telescopic mast retention mechanism - Google Patents

Description

  The present invention relates to a holding mechanism for a multistage expandable mast (hereinafter referred to as an expandable mast), and more particularly to a hold mechanism for an expandable mast provided in a floor crane or the like.

  In recent years, there is a movement to improve the productivity of formwork by building a beam formwork in construction work for small and medium RC (steel reinforced concrete) structures, especially hospitals and schools with high floors. In such a construction, a floor crane equipped with a telescopic mast may be installed on the floor. In this case, as shown in FIG. 10 (1), when the ground beam formwork is attached, the mast is extended to a lift exceeding the floor height, and after all the beam formwork has been attached, ), (3), it is necessary to reduce the mast so that it can pass under the beam, and the expansion and contraction of the mast is an important function.

  FIGS. 11 to 14 show an example of a conventional mast telescopic mechanism. FIGS. 11 to 13 show a mast telescopic mechanism (A system), and FIG. 14 shows a mast telescopic mechanism (B system). Show.

First, the expansion / contraction mechanism (A method) of the mast will be described with reference to FIGS.
FIG. 11 shows a mast contraction limit state, FIG. 12 shows a mast extension state, and FIG. 13 shows a mast extension limit state. In each figure, (1) is a front sectional view and (2) is a side sectional view. As shown in FIGS. 11 to 13, the telescopic mast includes a cylindrical top mast 1, an intermediate mast A, an intermediate mast B, and a lower mast 2 arranged in multiple stages. An intermediate mast B is accommodated in the lowermost mast 2 at the lowermost stage, an intermediate mast A is accommodated in the intermediate mast B, and a top mast 1 is accommodated in the intermediate mast A.

  A hydraulic cylinder 3 is arranged on the outer peripheral side of the lowermost mast 2 at the lowermost stage so as to extend in the vertical direction. The hydraulic cylinder 3 is disposed at the upper end of a base 4 projecting from the upper outer peripheral surface of the lower mast 2. It is fixed. A rod 5 is disposed in the hydraulic cylinder 3 so as to be able to protrude and retract, and an upper end of the rod 5 is fixed to a base 6 protruding from an upper outer peripheral surface of the intermediate mast B.

  Sheaves 7a and 7b and mounts 8a and 8b for supporting the sheaves are provided on the left and right sides of the upper outer peripheral surfaces of the intermediate masts A and B, respectively. Locking portions 9a, 9b, and 9c for locking the wire ropes are provided on the left and right sides of the lower outer peripheral surface of the top mast 1 and the intermediate mast A and on the left and right both sides of the upper outer peripheral surface of the lower mast 2, respectively. is there. The wire rope 10a is wound around the sheave 7a, and both ends thereof are fixed to the gantry 8b and the locking portion 9a. The wire rope 10b is wound around the sheave 7b and both ends thereof are fixed to the locking portions 9b and 9c.

  As described above, in the mast expansion / contraction mechanism (A method), the top mast 1, the intermediate mast A, the intermediate mast B, and the lower mast 2 are connected to each other via the two wire ropes 10a and 10b so as to expand and contract. In this configuration, when the rod 5 of the hydraulic cylinder 3 is expanded and contracted, the intermediate mast B expands and contracts, and the other masts (the top mast 1 and the intermediate mast A) also move through the wire ropes 10a and 10b in conjunction with the movement of the intermediate mast B. To expand and contract.

  Next, the expansion / contraction mechanism (B system) of the mast will be described with reference to FIG. FIG. 14A is a front sectional view of the telescopic mast, and FIG. 14B is a side sectional view. As shown in FIG. 14, the telescopic mast includes a cylindrical top mast 1, an intermediate mast A, an intermediate mast B, and a lower mast 2 arranged in multiple stages. An intermediate mast B is accommodated in the lowermost mast 2 at the lowermost stage, an intermediate mast A is accommodated in the intermediate mast B, and a top mast 1 is accommodated in the intermediate mast A.

  This mast expansion / contraction mechanism (B method) employs a wire winch 11 instead of the hydraulic cylinder 3 in the mast expansion / contraction mechanism (A method), and is similar to the mast expansion / contraction mechanism (A method). In addition, in conjunction with the movement of the intermediate mast B, the other masts (the top mast 1 and the intermediate mast A) expand and contract via the wire rope.

  That is, a wire rope 12a is wound around the wire winch 11 provided on the outer peripheral side of the lowermost mast 2 at the lowest stage, and one end of the wire rope 12a is connected to the sheave 13a provided on the upper part of the lower mast 2 and the intermediate mast B. It is fixed to the lower mast 2 after being wound around a sheave 13b provided at the lower part. When the wire rope 12 a is wound up by the winch 11, the lower sheave 13 b of the intermediate mast B is lifted and the intermediate mast B rises from the lower mast 2.

  Further, both ends of the wire rope 12b are fixed to the upper part of the lower mast 2 and the lower part of the intermediate mast A via the upper sheave 13c of the intermediate mast B. The intermediate mast A is adjusted according to the rise of the intermediate mast B. It rises at the same time. By the same mechanism, the top mast 1 is also connected to the intermediate mast A via the wire rope 12c and the sheave 13d, and rises simultaneously with the rise of the intermediate mast A.

Next, a conventional extension mast holding mechanism will be described with reference to FIG.
As shown in FIG. 14, this telescopic mast holding mechanism is configured such that a cannula 16 can be inserted and removed from the outside with respect to the through holes 14 and 15 provided on the outer peripheral surfaces of the lower mast 2 and the intermediate mast B. . By inserting the cannula 16 into the through hole 14 (or the through holes 14, 15), the intermediate mast B, the intermediate mast A, and the top mast 1 are prevented from dropping to the lowest part of the lower mast 2. In the example of FIG. 14, the lower end of the intermediate mast B is supported by inserting the cannula 16 into the through hole 14 in a state where the intermediate mast B is fully raised. By doing so, when the intermediate mast B is raised and the crane work is performed, the wire rope is cut and the intermediate mast B is prevented from falling. Such a holding mechanism for the expansion / contraction mast can be applied to the expansion / contraction mechanism (A method) of the mast illustrated in FIGS.

  The present inventor has already proposed a crane telescopic mast drop prevention mechanism shown in Patent Document 1 and a high lift and lightweight crane apparatus shown in Patent Document 2 for the technology related to such an extendable mast.

JP 2012-171774 A JP 2011-251834 A

  By the way, in the conventional mast expansion / contraction mechanism (A method and B method), if the wire rope is cut due to overload, deterioration, etc., the mast falls and the suspended load may hit the operator and be damaged. Moreover, even if there is a cannula only in the lower mast and another mast stops at the level of the cannula, there is a possibility that a suspended load suspended by a hoisting wire rope hits a worker in the vicinity.

  This invention is made | formed in view of the above, Comprising: It aims at providing the holding mechanism of the expansion / contraction mast which can hold | maintain all the masts of each step in the middle of expansion / contraction.

  In order to solve the above-described problems and achieve the object, a telescopic mast holding mechanism according to the present invention is inserted into a cylindrical lower mast extending in the vertical direction, and is telescopically inserted into the lower mast. A telescopic mast holding mechanism comprising an intermediate mast that constitutes a telescopic mast mechanism together with a lower mast, and a top mast that is telescopically inserted into the intermediate mast and constitutes an telescopic mast mechanism together with the intermediate mast. Provided on the outer peripheral side of the top of each of the lower mast and the intermediate mast, and has a cannula that can be freely inserted into and removed from the inside of each of the masts. A cannula mechanism that operates so as not to retain the intermediate mast or the top mast when the cannula is taken out from the inside of each mast. A switching mechanism for switching the operating state of each cannula mechanism, the switching mechanism extending vertically along the outer peripheral side of the lower mast and the intermediate mast, and extending and retracting to follow the expansion and contraction operation of the mast mechanism A sheath tube is included, and the operation state of each of the cannula mechanisms can be switched in conjunction with each other by rotating the sheath tube around the tube axis.

  According to another aspect of the present invention, there is provided a telescopic mast holding mechanism according to the present invention, wherein the cross-sectional shape of the sheath tube is a square cross-sectional shape.

  According to another aspect of the present invention, there is provided a mechanism for holding the telescopic mast according to the above-described invention, wherein an operating portion for rotating the sheath tube around a tube axis is provided at a lower end of the sheath tube. .

  According to another aspect of the present invention, in the above-described invention, the cannula mechanism moves in the left-right direction and can be moved in and out of the mast, and the outside of the cannula. A link member that is rotatably fixed to the arm member and an arm member that operates the link member by moving in the left-right direction, and the arm member moves in the left-right direction by rotating the sheath tube. Features.

  Further, the other telescopic mast holding mechanism according to the present invention is the above-described Kanuki mechanism provided on the top of the lower mast in the above-described invention, wherein an elastic body is provided on the lower side of the Kanuki, and the base is provided via this elastic body. The kanuki is supported by a member.

  In addition, in the above-described invention, another telescopic mast holding mechanism according to the present invention detects the insertion / extraction of the kanuki with respect to the inside of each mast, and stops the raising / lowering operation of the intermediate mast or the top mast based on this detection. It has an interlock mechanism.

  According to the telescopic mast holding mechanism according to the present invention, a cylindrical lower mast extending in the vertical direction and an intermediate that is telescopically inserted into the lower mast and constitutes the telescopic mast mechanism together with the lower mast. A telescopic mast holding mechanism comprising a mast and a top mast that is telescopically inserted into the intermediate mast and constitutes a telescopic mast mechanism together with the intermediate mast, the outer periphery of each top of the lower mast and the intermediate mast Provided on the side and having a cannula that can be taken in and out toward the inside of each mast, and when the cannula is placed inside each mast, the intermediate mast or the top mast is held, while the cannuki is placed inside each mast. Switch the operation state of each kanuki mechanism and the kanuki mechanism that operates so as not to hold the intermediate mast or the top mast when removed from A switching mechanism, and the switching mechanism includes an extendable shear tube that extends in the vertical direction along the outer peripheral side of the lower mast and the intermediate mast and follows the expansion and contraction operation of the mast mechanism. Since the operation state of each of the cannula mechanisms can be switched in conjunction with each other by rotating the tube around the tube axis, the cannula mechanisms provided in each stage can be operated in conjunction with the rotation of the sheath tube. Since it operates, it has the effect that all the masts (intermediate mast and top mast) of each stage in the middle of expansion and contraction can be efficiently held.

  Further, according to the other telescopic mast holding mechanism according to the present invention, since the cross-sectional shape of the Saya tube is a square cross-sectional shape, the rotational force due to the rotation operation of the Saya tube is effectively transmitted in the vertical direction. There is an effect that the cannula mechanism provided in each stage can be operated in a more reliable manner.

  Further, according to the other telescopic mast holding mechanism according to the present invention, since the operating portion for rotating the Saya tube around the tube axis is provided at the lower end of the Saya tube, There is an effect that the sheath tube can be easily rotated manually.

  Further, according to the other telescopic mast holding mechanism according to the present invention, the kanuki mechanism moves in the left-right direction and can be moved in and out of the mast, and can be rotated to the outside of the kanuki. A link member fixed to the arm and an arm member that actuates the link member by moving in the left-right direction, and the arm member moves in the left-right direction by the turning operation of the sheath tube. If the turning operation is performed, the arm member moves in the left-right direction to operate the link member, and the kanuki can be moved in the left-right direction so that it can be easily put in and out of each mast.

  Further, according to the other telescopic mast holding mechanism according to the present invention, in the kanuki mechanism provided at the top of the lower mast, an elastic body is provided on the lower side of the kanuki, and the base member is interposed by the elastic member. Since the kanuki is supported, there is an effect that the load of each stage mast including the intermediate mast can be smoothly and surely transferred to the lower mast.

  Further, according to the other telescopic mast holding mechanism according to the present invention, the interlock mechanism that detects the loading and unloading of the kanuki with respect to the inside of each mast and stops the raising / lowering operation of the intermediate mast or the top mast based on this detection Therefore, it is possible to prevent the occurrence of a disaster due to a mast expansion / contraction operation error or the like.

FIG. 1 is a side sectional view (mast elongation limit state) showing an embodiment of a holding mechanism for a telescopic mast according to the present invention. FIG. 2 is a side cross-sectional view (mast shrinkage limit state) showing an embodiment of the holding mechanism for the telescopic mast according to the present invention. FIG. 3 is a schematic perspective view showing an image example of a mast at each stage applied to the present invention. FIG. 4 is a top cross-sectional view illustrating an example of a kanuki mechanism, and is a diagram when the kanuki operates. FIG. 5 is a top cross-sectional view showing an example of a kanuki mechanism, and is a view when kanuki is released. FIG. 6 is a side cross-sectional view (step 1) showing an embodiment of the holding mechanism for the telescopic mast according to the present invention. FIG. 7 is a view (step 2) showing an embodiment of a holding mechanism for a telescopic mast according to the present invention, where (1) is a side sectional view and (2) is a front sectional view. FIG. 8 is a view (step 3) showing an embodiment of a holding mechanism for a telescopic mast according to the present invention, where (1) is a side sectional view and (2) is a front sectional view. FIG. 9 is a view (step 4) showing an embodiment of a holding mechanism for a telescopic mast according to the present invention, where (1) is a side sectional view and (2) is a front sectional view. FIG. 10 is a diagram illustrating an example of a deformation mode of a conventional floor crane. FIG. 11 is a cross-sectional view (mast shrinkage limit state) showing a conventional mast expansion / contraction mechanism (A method). FIG. 12 is a cross-sectional view (mast extending state) showing a conventional mast expansion / contraction mechanism (A method). FIG. 13 is a cross-sectional view (mast elongation limit state) showing a conventional mast expansion / contraction mechanism (A method). FIG. 14 is a cross-sectional view showing a conventional mast expansion / contraction mechanism (B system).

  Embodiments of a telescopic mast holding mechanism according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

First, a mast expansion / contraction mechanism (mast mechanism) applied to the present invention will be described.
As shown in FIG. 1, FIG. 2 and FIG. 7, the mast telescopic mechanism applied to the present invention is of the above-described A system, and is a multi-stage cylindrical top mast 1, intermediate mast A, intermediate It consists of a mast B and a lower mast 2. An intermediate mast B is accommodated in the lowermost mast 2 at the lowermost stage, an intermediate mast A is accommodated in the intermediate mast B, and a top mast 1 is accommodated in the intermediate mast A. In this embodiment, the case where the intermediate mast is composed of the intermediate mast A and the intermediate mast B will be described. However, the intermediate mast may be only one of the intermediate mast A or three in addition to the intermediate masts A and B. An intermediate mast of the eyes may be provided.

  A hydraulic cylinder 3 is arranged on the outer peripheral side of the lowermost mast 2 at the lowermost stage so as to extend in the vertical direction. The hydraulic cylinder 3 is disposed at the upper end of a base 4 projecting from the upper outer peripheral surface of the lower mast 2. It is fixed. A rod 5 is disposed in the hydraulic cylinder 3 so as to be able to protrude and retract, and an upper end of the rod 5 is fixed to a base 6 protruding from an upper outer peripheral surface of the intermediate mast B.

  Sheaves 7a and 7b and mounts 8a and 8b for supporting the sheaves are provided on the left and right sides of the upper outer peripheral surfaces of the intermediate masts A and B, respectively. Locking portions 9a, 9b, and 9c for locking the wire ropes are provided on the left and right sides of the lower outer peripheral surface of the top mast 1 and the intermediate mast A and on the left and right both sides of the upper outer peripheral surface of the lower mast 2, respectively. is there. The wire rope 10a is wound around the sheave 7a, and both ends thereof are fixed to the gantry 8b and the locking portion 9a. The wire rope 10b is wound around the sheave 7b and both ends thereof are fixed to the locking portions 9b and 9c.

  Thus, in the mast telescopic mechanism applied to the present invention, the top mast 1, the intermediate mast A, the intermediate mast B, and the lower mast 2 are connected to each other via the two wire ropes 10a and 10b so as to expand and contract. Yes. In this configuration, when the rod 5 of the hydraulic cylinder 3 is expanded and contracted, the intermediate mast B expands and contracts, and the other masts (the top mast 1 and the intermediate mast A) also move through the wire ropes 10a and 10b in conjunction with the movement of the intermediate mast B. To expand and contract. In the present embodiment, the intermediate mast B is configured to be extendable / contractable by the hydraulic cylinder 3, but may be configured to be extendable / contractable using a wire winch as in the above-described B system.

  In addition, as shown in FIG. 3, the image of the mast at each stage is provided with a plurality of horizontal members at predetermined intervals in the vertical direction, and a plurality of through holes are formed in the portion sandwiched between the upper and lower sides. Thus, the lateral member also serves as a cannula receiver.

Next, the elastic mast holding mechanism according to the present invention will be described.
As shown in FIG. 1 and the like, the expansion / contraction mast holding mechanism 100 according to the present invention includes, in the above-described expansion / contraction mast, a cannuki mechanism 20 provided on the outer peripheral side of each of the tops of the lower mast 2 and the intermediate masts A and B; And a switching mechanism 22 for switching the operating state of each kanuki mechanism 20.

  The cannuki mechanism 20 has a base member 24 fixed to the top of each mast, and a cannuki 26 that is provided on the base member 24 and can be inserted into and removed from the inside of each mast. The cannuki mechanism 20 holds each mast 1, A, or B when the cannula 26 is placed inside each mast 1, A, or B and engaged with each mast cannula receiver 32a, 32b, or 32c. When the mast 1, A or B is pulled out from the inside of the mast 1 to release the engagement with the cannula receivers 32a, 32b or 32c, the mast 1, A or B is operated so as not to be held.

  The switching mechanism 22 extends in the vertical direction along the outer peripheral side of the lower mast 2 and the intermediate masts A and B so as to connect the kanuki mechanisms 20, and is an extendable shear tube 28a that follows the expansion and contraction operation of the mast mechanism. 28b, and the upper sheath tube 28a is accommodated in the lower sheath tube 28b. Note that the number of sheath tubes is not limited to two, 28a and 28b, and can be configured with a larger number of tubes, but in any case, it is preferable to configure the number of sheath tubes according to the number of mast stages. .

  The switching mechanism 22 is configured to be able to switch the operating state of each of the cannula mechanisms 20 by rotating the sheath tubes 28a and 28b around the tube axis. Therefore, if the sheath pipes 28a and 28b are rotated, the cannula mechanism 20 provided in each stage operates in conjunction with each other, so that all the masts in the middle of expansion and contraction (the intermediate masts A and B and the top mast 1). ) Can be held efficiently. In particular, according to the present invention, the mast can be mechanically supported by the cannula 26 during crane work, the possibility of dropping is eliminated, and the work safety can be further improved as compared with the prior art.

  Here, each cross-sectional shape of the Saya tubes 28a and 28b is a square cross-sectional shape. A Saya tube rotation lever 30 (for rotating the Saya tube 28b around the tube axis) is provided at the lower end of the Saya tube 28b. An operation unit) is provided. For this reason, the operator who exists below can rotate the sheath pipe 28b manually easily by rotating this lever 30.

  In particular, since the cross-sectional shape of the sheath pipes 28a and 28b is a square cross-sectional shape, the rotational force due to the turning operation of the lower sheath pipe 28b is effectively transmitted to the upper sheath pipe 28a, and the sheath pipe 28b. Since the Saya tube 28a also rotates synchronously, the cannula mechanism 20 provided in each stage can be operated in a more reliable manner.

  Next, each state when the kanuki mechanism is activated and when it is released (not activated) will be described with reference to FIGS. 4 and 5 by taking the ganuki mechanism 20 provided at the top of the lower mast 2 as an example.

First, the detailed configuration of the kanuki mechanism 20 will be described.
As shown in FIG. 4, the kanuki mechanism 20 includes a pair of kanukis 26 that move in the left-right direction and can be inserted into and removed from the intermediate mast B, a base member 24 that guides and supports the kanukis 26, The link members 34a and 34c are rotatably fixed to the outer side, and the arm members 36 that actuate the link members 34a and 34c by moving in the left-right direction. The arm member 36 is an L-shaped member, and the right end portion in the drawing is rotatably connected to the link member 34a via the shaft portion 42b. The link member 34a is rotatably fixed to a fixing member 46a provided on the top of the lower mast 2 via a shaft portion 44a, and is rotatably connected to the right cannula 26 via the shaft portion 42a.

  On the other hand, the left end portion of the arm member 36 in the drawing is rotatably connected to the link member 34b via the shaft portion 42e. The link member 34b is rotatably connected to the link member 34c via the shaft portion 42f. The central portions of the link member 34b and the link member 34c are rotatably fixed to a fixing member 46b provided on the top of the lower mast 2 via shaft portions 44c and 44b. The link member 34c is rotatably connected to the left kanuki 26 via a shaft portion 42g.

  In addition, a spring 52 is interposed between the regulating member 54 fixed to the arm member 36 and the fixing member 56 fixed to the outer peripheral surface of the top of the lower mast 2 to urge them in a direction to separate them from each other. The central portion of the arm member 36 is rotatably connected to the cam member 38 via the shaft portion 42c. The cam member 38 is rotatably connected to the individual operation lever 40 via the shaft portion 42. The individual operation lever 40 is connected to the sheath tube 28b (and also the sheath tube 28a) of the switching mechanism 22.

  In the above configuration, the arm member 36 moves in the left-right direction via the individual operation lever 40 by the turning operation of the sheath pipes 28a, 28b. Therefore, when the sheath member 28a, 28b is turned, the arm member 36 moves. The link members 34a to 34c are moved by moving in the left-right direction, and the cannula 26 is moved in the left-right direction so that it can be easily put in and out of each mast.

[When operating Cannuki]
Next, a description will be given of when the kanuki operates.
As shown in FIG. 4, if the sheath tube 28 b is rotated around the tube axis so that the direction of the individual operation lever 40 is in the left-right direction in the drawing, the inner end portion of the cannula 26 is located in the middle of the lower mast 2. Get inside mast B. In this case, the intermediate mast B can be held if the cannula 26 enters and engages with the through hole below the cannula receiver 32c.

[When canceling Kanuki]
Next, a description will be given of when kanuki is released (when not activated).
As shown in FIG. 5, when the sheath tube 28b is rotated clockwise by a predetermined angle (for example, 90 °) around the tube axis, the individual operation lever 40 connected to the sheath tube 28b is rotated. In this case, the inner end portion of the cannuki 26 is pulled out from the inside of the intermediate mast B inside the lower mast 2 so that the intermediate mast B is not held.

  Next, an example of the operation of the telescopic mast holding mechanism according to the present invention will be described with reference to FIGS.

  FIG. 6 shows step 1 of the operation of the holding mechanism for the telescopic mast. As shown in FIG. 6, the extension of the mast is in a limit state, and the cannula 26 of each stage is inserted into each mast by rotating the sheath pipe rotation lever 30 by a predetermined angle (for example, 90 °). . In this case, it arrange | positions so that the clearance dimension a, b, c with the cannula 26 of each step | paragraph in the cannula receivers 32a, 32b, 32c may become a magnitude relationship of a <b <c. Here, for example, the dimensional ratio of a, b, and c may be considered as a: b: c = 1: 2: 3.

  Next, the rod 5 of the hydraulic cylinder 3 is contracted and the intermediate mast B is lowered. FIG. 7 shows this step 2. As shown in FIG. 7, the telescopic mast is in a state where the amount corresponding to the gap dimension a (= 1) is lowered. At this time, the top mast 1 is in a state in which the mast A attached to the intermediate mast A is in contact, and the wire ropes 10a and 10b for expansion and contraction of each mast are in a tensioned (tensed) state. Note that h1 in FIG. 7 corresponds to 3 in the above dimensional ratio.

  When the intermediate mast B is further lowered by the dimension b1, as shown in FIGS. 7 to 8, the intermediate masts A and B are lowered by the dimension b1, and the intermediate mast A is attached to the intermediate mast B as shown in FIG. It will be in the state contact | abutted to Kanuki 26.

  Since the relative position relationship (dimension L1) between the top mast 1 and the intermediate mast A is not changed by the cannula 26, the wire rope 10a is loosened as much as the intermediate mast A is lowered, and the weight of the top mast 1 is supported only by the cannula 26. become. Note that h2 in FIG. 8 corresponds to 2 in the above dimensional ratio.

  When the intermediate mast B is further lowered by the dimension c2, as shown in FIGS. 8 to 9, the intermediate mast B is lowered by the dimension c2, and the intermediate mast B is attached to the lower mast 2 as shown in FIG. It will be in a state of touching.

  Since the relative positional relationship (dimension L2) of the intermediate mast A and the intermediate mast B does not change due to the stopper action by the cannula 26, the wire rope 10b is loosened by the amount of the intermediate mast B being lowered. It comes to be supported. On the other hand, the upper wire rope 10a is further loosened as the intermediate mast B is lowered. Note that h3 in FIG. 9 corresponds to 1 in the above dimensional ratio.

  Here, in the cannula mechanism 20 provided on the top of the lower mast 2, a spring 48 as an elastic body and a regulating member 50 for regulating the spring 48 are provided below the cannula 26, and the base member is interposed via the spring 48. It is assumed that 24 supports the ganuki 26. In this way, the load of the mast at each stage including the intermediate mast B can be smoothly and reliably transferred to the lower mast 2.

  Now, the intermediate mast B is slightly lowered from the state shown in FIG. 9 so that the lower spring 48 attached to the lower mast 2 is contracted, and the mast load at each stage is smoothly applied to each cannula 26. And make sure to migrate. When the crane operation is performed in that state, the load applied to the mast is mechanically supported by each cannula 26, and the mast does not fall even if the wire ropes 10a and 10b for mast expansion and contraction are cut.

  Further, a state where the crane can be operated and a state where the crane cannot be operated are defined by detecting the limit switch or the like with respect to the operation of inserting and removing the cannula 26 by the switching mechanism 22 and the contraction operation of the spring 48, and based on this detection, the lifting operation of the mast is stopped. If the interlock mechanism is employed, it is possible to prevent the occurrence of a disaster due to a mast expansion / contraction operation error or the like.

  Further, in the above-described embodiment, the mast reduction operation can be performed in the reverse procedure to the above-described expansion operation procedure. In addition, while relying on wire ropes during mast expansion and contraction, disasters at the time of cutting are assumed, but selection of wire ropes and sheaves is performed with a mast support load during crane work that is larger than during unloaded mast expansion and contraction. It is possible to ensure safety by configuring the stepped wire rope as two separate left and right bodies and taking measures such as being able to be supported by the remaining wire rope even if one is cut.

  Moreover, this invention is applicable not only to the expansion-contraction mast with which a crane is equipped, but with respect to the general expansion-contraction mast which is not provided with a crane.

  As described above, according to the telescopic mast holding mechanism according to the present invention, the cylindrical lower mast extending in the vertical direction and the telescopic mast are telescopically inserted into the lower mast. A telescopic mast holding mechanism comprising an intermediate mast constituting a mast mechanism and a top mast that is inserted into the intermediate mast in a telescopic manner and constitutes a telescopic mast mechanism together with the intermediate mast. The cannula is provided on the outer peripheral side of each top of the mast and has a cannula that can be freely inserted and removed toward the inside of each mast. When the cannula is inserted into each mast, the intermediate mast or the top mast is held. A cannula mechanism that operates so as not to hold the intermediate mast or the top mast when the mast is taken out from the inside of each mast; And a switching mechanism that switches a moving state, and the switching mechanism includes a telescopic sheath tube that extends in the vertical direction along the outer peripheral side of the lower mast and the intermediate mast and follows the telescopic operation of the mast mechanism. Since the operation state of each of the cannula mechanisms can be switched in conjunction by rotating this sheath tube around the tube axis, the cannula mechanism provided at each stage if the sheath tube is operated to rotate. Are operated in conjunction with each other, so that all masts (intermediate mast and top mast) at each stage in the middle of expansion and contraction can be efficiently held.

  Further, according to the other telescopic mast holding mechanism according to the present invention, since the cross-sectional shape of the Saya tube is a square cross-sectional shape, the rotational force due to the rotation operation of the Saya tube is effectively transmitted in the vertical direction. The cannula mechanism provided in each stage can be operated in a more reliable manner.

  Further, according to the other telescopic mast holding mechanism according to the present invention, since the operating portion for rotating the Saya tube around the tube axis is provided at the lower end of the Saya tube, The shear tube can be easily rotated manually.

  Further, according to the other telescopic mast holding mechanism according to the present invention, the kanuki mechanism moves in the left-right direction and can be moved in and out of the mast, and can be rotated to the outside of the kanuki. A link member fixed to the arm and an arm member that actuates the link member by moving in the left-right direction, and the arm member moves in the left-right direction by the turning operation of the sheath tube. If the rotation operation is performed, the arm member moves in the left-right direction to actuate the link member, and the kanuki can be moved in the left-right direction to be easily put in and out of each mast.

  Further, according to the other telescopic mast holding mechanism according to the present invention, in the kanuki mechanism provided at the top of the lower mast, an elastic body is provided on the lower side of the kanuki, and the base member is interposed by the elastic member. Since the cannula is supported, the load of the mast of each stage including the intermediate mast can be smoothly and reliably transferred to the lower mast.

  Further, according to the other telescopic mast holding mechanism according to the present invention, the interlock mechanism that detects the loading and unloading of the kanuki with respect to the inside of each mast and stops the raising / lowering operation of the intermediate mast or the top mast based on this detection Therefore, it is possible to prevent a disaster from occurring due to a mast expansion / contraction operation error or the like.

  As described above, the telescopic mast holding mechanism according to the present invention is useful for a crane including a multi-stage telescopic mast, and is particularly suitable for holding all the masts in each stage during expansion and contraction.

DESCRIPTION OF SYMBOLS 1 Top mast A, B Middle mast 2 Lower mast 3 Hydraulic cylinder 4, 6 Base 5 Rod 7a, 7b, 13a, 13b Sheave 8a, 8b Mount 9a, 9b, 9c Locking part 10a, 10b, 12a, 12b Wire rope 11 Wire winch 14,15 Through hole 16 Cannuki 20 Cannuki mechanism 22 Switching mechanism 24 Base member 26 Cannuki 28a, 28b Saya tube 30 Saya tube rotation lever (operation unit)
32a, 32b, 32c Cannula receiver 34a, 34b, 34c Link member 36 Arm member 48 Spring (elastic body)
100 Retractable mast retention mechanism

Claims (6)

A cylindrical lower mast that extends in the vertical direction, and an intermediate mast that is telescopically inserted into the lower mast and forms a telescopic mast mechanism together with the lower mast, and is telescopically inserted into the intermediate mast. A retractable mast holding mechanism comprising an intermediate mast and a top mast that constitutes a telescopic mast mechanism,
It is provided on the outer peripheral side of each top of the lower mast and the intermediate mast, and has a cannula that can be freely inserted and removed toward the inside of each mast, and holds the intermediate mast or the top mast when the cannula is inserted into each of the masts. On the other hand, a kanuki mechanism that operates so as not to hold the intermediate mast or the top mast when the kanuki is taken out from the inside of each mast,
A switching mechanism for switching the operating state of each of the kanuki mechanisms,
The switching mechanism includes an extendable shear tube that extends in the vertical direction along the outer peripheral side of the lower mast and the intermediate mast, and follows the expansion and contraction operation of the mast mechanism, and the sheath tube rotates around the tube axis. An expansion / contraction mast holding mechanism characterized in that the operation state of each of the cannula mechanisms can be switched in conjunction with the operation.   The holding mechanism for the telescopic mast according to claim 1, wherein a cross-sectional shape of the sheath tube is a square cross-sectional shape.   The telescopic mast holding mechanism according to claim 1 or 2, wherein an operation portion for rotating the sheath tube around a tube axis is provided at a lower end of the sheath tube.   The kanuki mechanism moves in the left-right direction so that it can move in and out of the mast, a link member that is rotatably fixed to the outside of the kanuki, and the link by moving in the left-right direction. The holding of the expansion / contraction mast according to any one of claims 1 to 3, wherein the arm member moves in a left-right direction by a rotation operation of the sheath tube. mechanism.   5. The kanuki mechanism provided on the top of the lower mast, wherein an elastic body is provided below the kanuki, and the kanuki is supported by a base member via the elastic body. The holding mechanism of the expansion-contraction mast as described in one.   6. An interlock mechanism for detecting the insertion / removal of the kanuki with respect to the inside of each mast and stopping the raising / lowering operation of the intermediate mast or the top mast based on the detection. A mechanism for holding the telescopic mast as described in 1.

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