JP2021046324A - Crane wire hooking number switching device - Google Patents

Abstract

To provide a crane wire hooking number switching device that can easily switch the number of wire hooking number with a simple structure.SOLUTION: A crane wire hooking number switching device 28 comprises a sheave 45 provided at a tip 20 of the boom and around which a hanging wire 17 is hung, a floating sheave block 50 having a sheave 53 around which the hanging wire 17 extending from the sheave 45 is hung, a sheave 47 provided at the tip 20 and around which the hanging wire 17 extending from the sheave 53 is hung, a hook block 60 to which the hanging wire 17 extending from the sheave 47 is connected, and a connecting pin that connects the hook block 60 and the floating sheave block 50 so that they can be disconnected. n×m>M is satisfied, where n is the number of hanging wires 17 of the floating sheave block 50, m is the mass of the hook block 60, and M is the mass of the floating sheave block 50.SELECTED DRAWING: Figure 1

Description

The present invention relates to a wire hook number switching device that switches a so-called "wire hook number" in crane work.

For crane work by a crane vehicle equipped with a boom, a fixed pulley mechanism provided at the tip of the boom and a moving pulley mechanism suspended via the fixed pulley mechanism are generally used. These pulley mechanisms include a plurality of sheaves around which wires are hung, and the moving pulley mechanism is provided with hooks that engage the suspended load. The number of sheaves around which the wire is hung, the so-called "wire hang number", is determined according to the weight of the suspended load. When the number of wires to be hung is large, the maximum weight of the suspended load that can be lifted can be increased, but it takes a long time to raise and lower the suspended load.

When the weight of the suspended load is not so heavy and quick crane work is required, the number of wire hooks may be set small, and when operating a heavy load, the number of wire hooks may be set large. desirable. Conventionally, means for changing the number of wires hooked have been proposed (see, for example, Patent Document 1 and Patent Document 2). In Patent Documents 1 and 2, the sheave unit configured as a separate body is selectively connected to the fixed pulley mechanism side or the moving pulley mechanism side in the preparatory stage of the crane work, so that the wire is hung around. It discloses a structure in which the number of sheaves is increased or decreased.

Japanese Unexamined Patent Publication No. 8-34590 Japanese Unexamined Patent Publication No. 7-228475

By the way, in the crane disclosed in Patent Documents 1 and 2, the wire is wound and the sheave unit is relatively pressed against the fixed pulley mechanism from below, so that the sheave unit is connected to the fixed pulley mechanism and at the same time. The connected state is maintained. Further, when the wire is wound while the sheave unit is connected to the fixed pulley mechanism side, the moving pulley mechanism pushes the sheave unit against the fixed pulley mechanism side, whereby the connection is released and the sheave unit is released. It is connected to the moving pulley mechanism side. In this way, the number of wires hooked changes depending on whether the sheave unit is connected to the fixed pulley mechanism side or the moving pulley mechanism side.

Therefore, the wire hooking number switching device disclosed in Patent Documents 1 and 2 needs to be provided with a sheave unit, and further includes a mechanism for connecting the sheave unit to the fixed pulley mechanism side and a mechanism for maintaining the connection. In addition, it is necessary to provide a mechanism for breaking the connection, which causes a problem that the structure becomes complicated.

The present invention has been made based on such a background, and an object of the present invention is to provide a wire hooking number switching device for a crane capable of easily switching the wire hooking number with a simple structure. ..

(1) The wire hook number switching device for a crane according to the present invention is a device applied to a crane having a boom and a hanging wire, and is a device for switching the wire hooking number in the lifting work. The wire hooking number switching device of the crane according to the present invention is provided at the tip of the boom, and the first sheave on which the hanging wire is hung and the hanging wire extending from the first sheave are hung. A floating sheave block having a second sheave to be turned, a third sheave provided at the tip of the boom and to which the suspending wire extending from the second sheave is hung, and extending from the third sheave. The hanging wire that has come out is connected, and a hook block provided with a hook and a connecting mechanism that connects the hook block and the floating sheave block so as to be disconnectable are provided. The wire hook number switching device of the crane according to the present invention satisfies n × m> M (Equation 1). In Equation 1, n is the number of hanging wires of the floating sheave block, m is the mass of the hook block, and M is the mass of the floating sheave block.

When the hook block is connected to the floating sheave block, the number of wires hooked is the number of hanging wires between the first sheave and the second sheave and the number of hanging wires between the third sheave and the hook block. Is the total of. On the other hand, when the hook block is not connected to the floating sheave block, the number of wires hooked is the number of hanging wires between the third sheave and the hook block. In this way, the number of wires can be easily switched depending on whether or not the hook block and the floating sheave block are connected.

As long as Equation 1 holds, the hanging wire is unwound or wound while the hook block is not connected to the floating sheave block and the floating sheave block is in contact with the boom tip from below. In this case, the hook block moves up and down while the floating sheave block is in contact with the tip of the boom. That is, this configuration does not require a complicated mechanism for maintaining the floating sheave block in contact with the boom tip.

Further, as long as Equation 1 holds, the floating sheave block moves downward when the hanging wire is unwound while the hook block is not connected to the floating sheave block and the hook block is grounded. ..

(2) The number of the first sheave and the second sheave is plural and the same. The hanging wire is alternately hung around the first sheave and the second sheave.

Increasing the number of first sheaves and second sheaves increases the number of wires.

(3) A fourth sheave on which the suspension wire extending from the third sheave is hung is provided at the tip of the boom. The fourth sheave is provided at a position away from the third sheave so as to avoid contact between the suspended load wires. The hanging wire hung around the fourth sheave is connected to the hook block.

Since the third sheave and the fourth sheave are separated from each other, it is less likely that the floating sheave block located directly below the third sheave and the hook block located directly below the fourth sheave interfere with each other.

(4) The connecting mechanism is provided on the floating sheave block with respect to a first engaging portion that engages with the hook block that is relatively displaced with respect to the floating sheave block and the first engaging portion. The hook block is provided on the floating sheave block and the fixed claw that is elastically urged so as to be able to move forward and backward and always enter, and engages with the hook block engaged with the first engaging portion. A fixing release member for retracting the fixing claw engaged with the first engaging portion from the first engaging portion is provided.

The connection and disconnection of the floating sheave block and the hook block can be automated.

(5) The fixed claw is slidably supported by the floating sheave block and receives a predetermined urging force by an elastic member, and when the hook block comes into contact with the hook block, it opposes the urging force. A drag surface that receives an external force in a predetermined direction is formed. The fixing release member is provided so as to be slidable with respect to the floating sheave block by coming into contact with the boom tip portion as the floating sheave block is displaced, and the slide of the fixing release member is slid on the fixing claw. It is equipped with a gear mechanism that converts the slide into the above-mentioned anti-predetermined direction.

In the crane disclosed in Patent Documents 1 and 2, the sheave unit is pressed against the fixed pulley mechanism from below to connect the sheave unit to the fixed pulley mechanism, and the sheave unit is further pressed against the fixed pulley mechanism to cause the fixed pulley mechanism. The connection with is released. That is, both the connection of the sheave unit to the fixed pulley mechanism and the release of the connection are executed by pressing the sheave unit from below to the fixed pulley mechanism. Therefore, it is not easy to distinguish between the connection with the fixed pulley mechanism and the release of the connection. In order to facilitate the determination, it is necessary to provide a sensor or the like.

On the other hand, in this configuration, the hook block can be connected to the floating sheave block by the floating sheave block coming into contact with the hook block from above, and the hook block can be released from the connection with the floating sheave block. , The floating sheave block connected to the hook block can be implemented by abutting the boom tip from below. Therefore, it is easy to distinguish between the connection of the hook block to the floating sheave block and the release of the connection without providing a sensor or the like.

(6) The floating sheave block includes a guide arm that guides the hook block to a connecting position with the floating sheave block by rotating in a state of being engaged with the hook block.

The hook block can be guided to the connection position with the floating sheave block simply by engaging the guide arm with the hook block and rotating the hook block.

(7) The guide arm hangs by its own weight in a state where it can rotate around a rotation shaft extending in parallel with the axial direction of the second sheave, and engages with the hook block. Have. The hook block includes an engaged portion that can be engaged with the second engaging portion. The rotating shaft is located on the opposite side of the connecting position with respect to the second engaging portion with the guide arm hanging down.

The rotating shaft is located on the opposite side of the connecting position with respect to the second engaging portion. Therefore, by bringing the floating sheave block and the hook block closer to each other while the second engaging portion and the engaged portion are engaged, the guide arm can be rotated in the direction in which the hook block approaches the connecting position.

(8) In a state where the floating sheave block and the hook block are suspended from the boom tip portion, the second engaging portion of the guide arm is located directly above the engaged portion.

According to this configuration, the second engaging portion of the guide arm and the engaged portion of the hook block can be engaged with each other simply by moving the floating sheave block and the hook block relative to each other in the vertical direction and bringing them closer to each other.

(9) The hook block is connected to the hanging wire extending from the third sheave, and is connected to a connecting portion that can be moved to a plurality of positions in the axial direction of the second sheave and the connecting portion. A holding portion for holding each of the plurality of positions is provided.

According to this configuration, the position of the connecting portion can be set directly below the third sheave by changing the position of the connecting portion according to the position of the third sheave. As a result, in the state where the floating sheave block and the hook block are connected, the hanging wire extending from the third sheave and connected to the hook block can be in a state along the vertical direction.

Further, by changing the position of the connecting portion according to the position of the third sheave, it is possible to correct the misalignment between the floating sheave block and the hook block. As a result, it is possible to prevent the floating sheave block and the hook block from interfering with each other at the time of connection and hindering the connection.

(10) The hook block includes a pair of plate members of the second sheave facing in the axial direction. The connecting portion can be moved to the first position and the second position between the pair of plate members. The holding portion is sandwiched between the connecting portion and one of the pair of plate members when the connecting portion is in the first position, and when the connecting portion is in the second position, the connecting portion and the connecting portion are described. A spacer sandwiched between the pair of plate members and the other.

According to this configuration, it is possible to realize a function of holding the connecting portion at the first position or the second position with a simple configuration.

(11) The floating sheave block includes a pair of support members facing each other in the axial direction of the second sheave. The hanging wire extending from the third sheave is connected to the hook block through between the pair of support members. The number of wire hooks of the crane according to any one of claims 1 to 11, wherein the floating sheave block includes a guide sheave on which the suspension wire extending from the third sheave and connected to the hook block is hung. Switching device.

The guide sheave can prevent the hanging wire extending from the third sheave and connected to the hook block from coming out from between the pair of support members.

Further, a hanging wire extending from the third sheave and connected to the hook block is hung on the guide sheave. Therefore, even when the floating sheave block and the hook block are not connected, the suspended load wire can be stabilized, so that the swing of the suspended load wire and the hook block can be reduced.

(12) The second sheave is supported by the floating sheave block between the pair of support members. The guide sheave is located on the opposite side of the second sheave with respect to the suspension wire extending from the third sheave.

The hanging wire extending from the third sheave and connected to the hook block can be sandwiched by the guide sheave and the second sheave. As a result, the suspended load wire can be stabilized.

(13) The floating sheave block is arranged to face the guide sheave, and includes an opposed sheave that sandwiches the suspension wire extending from the third sheave with the guide sheave.

Since the guide sheave and the opposed sheave extend from the third sheave and sandwich the suspended load wire connected to the hook block, the suspended load wire can be further stabilized as compared with the configuration without the opposed sheave. it can.

(14) The connecting mechanism is provided on the floating sheave block, and includes a stopper that abuts on the hook block connected to the floating sheave block to position the hook block.

The position of the hook block when connected to the floating sheave block can be stabilized.

According to the present invention, it is possible to easily switch the number of wires with a simple structure.

FIG. 1 is a side view of a work vehicle 11 in which a crane 10 including a wire hook number switching device 28 according to an embodiment of the present invention is adopted. FIG. 2 is a side view of the vicinity of the wire hook number switching device 28 in the crane 10. FIG. 3A is a front view of a part of the fixed sheave block 40 and the floating sheave block 50, FIG. 3B is a front view of the hook block 60, and FIG. 3C is a connection. It is a front view of the floating sheave block 50 and the hook block 60. FIG. 4 is a side view of the boom device 14 and the wire hook number switching device 28. FIG. 4A shows a state in which the connected floating sheave block 50 and the hook block 60 are in contact with the ground, and FIG. 4B shows a floating sheave block. Indicates a state in which the 50 and the hook block 60 are disconnected. 5A and 5B are side views of the boom device 14 and the wire hook number switching device 28. FIG. 5A shows a state in which the hook block 60 is in contact with the ground and the floating sheave block 50 is located in the air, and FIG. 5B shows a state in which the floating sheave block 50 is located in the air. The state where the hook block 60 is in contact with the ground and the floating sheave block 50 is in contact with the lower surface 34 of the rotating member 36 is shown. FIG. 6 is a side view of the boom device 14 and the wire hook number switching device 28. In (A), the hook block 60 is located in the air and the floating sheave block 50 is in contact with the lower surface 34 of the rotating member 36. A state is shown, and (B) shows a state in which the connected floating sheave block 50 and the hook block 60 are located in the air. FIG. 7 is a front view of a part of the fixed sheave block 40, the floating sheave block 50, and the hook block 30. FIG. 8A is a front view of the connected floating sheave block 50 and the hook block 30, and FIG. 8B is a front view of the disconnected floating sheave block 50 and the hook block 30. 9A and 9B are side views of the boom device 14 and the wire hook number switching device 28, FIG. 9A shows a state in which the connected floating sheave block 50 and the hook block 30 are located in the air, and FIG. 9B shows the connected state. The state in which the floating sheave block 50 and the hook block 30 are in contact with the lower surface 34 of the rotating member 36 is shown. 10A and 10B are side views of the boom device 14 and the wire hook number switching device 28. In FIG. 10A, the hook block 30 is located in the air and the floating sheave block 50 is in contact with the lower surface 34 of the rotating member 36. The state is shown, and (B) shows the state where the hook block 30 is in contact with the ground and the floating sheave block 50 is in contact with the lower surface 34 of the rotating member 36. 11A and 11B are side views of the boom device 14 and the wire hook number switching device 28. FIG. 11A shows a state in which the hook block 60 is in contact with the ground and the floating sheave block 50 is located in the air, and FIG. 11B shows a state in which the floating sheave block 50 is located in the air. The state where the connected floating sheave block 50 and the hook block 60 are in contact with each other is shown. FIG. 12A is a front view of the floating sheave block 50 and the hook block 30 when the inclined surface 85 of the fixing claw 82 is in contact with the upper surface 32 of the hook block 30, and FIG. 12B is a fixed view. It is a front view of the floating sheave block 50 and the hook block 30 when the claw 82 is in contact with the side surface 33 of the hook block 30. FIG. 13 is a perspective view of the floating sheave block 50 in the modified example. FIG. 14 is a left side view of the floating sheave block 50 in the modified example. FIG. 15 is a front view of a part of the fixed sheave block 40, the floating sheave block 50, and the hook block 60 in the modified example. FIG. 16 is a front view of a part of the fixed sheave block 40, the floating sheave block 50, and the hook block 60 in the modified example. FIG. 17 is a front view of the hook block 60 in the modified example, showing a state in which the slider 141 and the connecting plate 142 are in the right position. FIG. 18 is a plan view of the hook block 60 in the modified example. FIG. 19 is a front view of the hook block 60 in the modified example, showing a state in which the slider 141 and the connecting plate 142 are in the left position. FIG. 20 is a perspective view of the spacer 144. FIG. 21 is a perspective view of the hook block 60 in the modified example. FIG. 22 is a left side surface of the floating sheave block 50 and the hook block 60 in the modified example. FIG. 23 is the left side surface of the floating sheave block 50 and the hook block 60 in the modified example. FIG. 24 is a left side surface of the floating sheave block 50 and the hook block 60 in the modified example.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as appropriate. Needless to say, the present embodiment is only one aspect of the crane provided with the wire hook number switching device according to the present invention, and the embodiment may be changed without changing the gist of the present invention.

FIG. 1 is a side view of a work vehicle 11 in which the crane 10 according to the embodiment of the present invention is adopted. FIG. 1 schematically shows a work vehicle 11 and a crane 10. Hereinafter, the front-rear direction of the work vehicle 11 is defined with reference to the state shown in FIG. That is, the left side of the paper in FIG. 1 is the front, and the right side of the paper in FIG. 1 is the rear. Further, the left-right direction is defined based on the right side and the left side when the work vehicle 11 is viewed from the rear. That is, the direction from the front to the back of the paper in FIG. 1 is the right, and the direction from the back to the front of the paper in FIG. 1 is the left. Further, the direction orthogonal to the front-rear direction and the left-right direction is defined as the vertical direction.

[Aerial work platform]

As shown in FIG. 1, the work vehicle 11 is typically a crane vehicle. In the present embodiment, the work vehicle 11 includes a self-propelled device including a traveling engine and a steering mechanism, an actuator drive device including a hydraulic pump, and a ground safety device including an outrigger device 15.

[crane]

As shown in FIG. 1, the crane 10 includes a swivel base 13 and a boom device 14. The swivel base 13 is mounted on the work vehicle 11. The swivel base 13 swivels with respect to the work vehicle 11 via a swivel actuator (not shown).

The boom device 14 is expandable and contractible in the longitudinal direction 101 as described later. The boom device 14 is connected to the swivel base 13 via an undulating cylinder 18 in an undulating state. A winch 16 for suspending is provided on the swivel base 13. The suspension winch 16 includes a drum and a suspension wire 17 of a required length. The suspension wire 17 is wound around and held by the drum. The hanging wire 17 drawn out from the drum is wound around the wire hooking number switching device 28 and suspended. A hook block 60 is connected to the tip of the suspended load wire 17. When the suspension winch 16 is operated while the suspension is suspended from the hook 61 provided on the hook block 60, the drum is driven and the suspension wire 17 is unwound or wound up from the drum, so-called suspension. Work is done.

[Swivel stand]

As shown in FIG. 1, the swivel base 13 is connected to the work vehicle 11 via the swivel actuator (typically, a turntable and a hydraulic motor). Although not shown, the actuator drive device is arranged on the swivel base 13, and a counterweight or the like can also be mounted on the swivel base 13.

[Boom device]

As shown in FIG. 1, the boom device 14 has a telescopic structure, and includes a boom body 25 and a telescopic cylinder (not shown) that expands and contracts the boom body 25. The boom body 25 is an example of the "boom" described in the claims. The boom body 25 includes a plurality of booms. The plurality of booms are a top boom 21, an intermediate boom 22, and a base boom 23. The plurality of booms consist of a tubular member having a so-called closed cross section, and are assembled in a so-called nested shape. The intermediate boom 22 is inserted and accommodated in the accommodating space of the base boom 23, and the top boom 21 is inserted and accommodated in the accommodating space of the intermediate boom 22. The intermediate boom 22 is slidable in the longitudinal direction 101 with respect to the base boom 23, and this relationship is also established between the intermediate boom 22 and the top boom 21.

The base end portion of the base boom 23 is connected to the swivel base 13. The base end portion of the base boom 23 is rotatably supported by the swivel base 13 via an undulating center pin (not shown). As shown in the figure, the undulating cylinder 18 is interposed between the swivel base 13 and the base boom 23. As the undulating cylinder 18 expands and contracts, the base boom 23 and thus the boom body 25 undulate.

[Wire hook number switching device]

The wire hooking number switching device 28 shown in FIG. 1 is a device for switching the wire hooking number (the number of hanging wires 17) in the hanging load work.

As shown in FIG. 1, the wire hook number switching device 28 includes a fixed sheave block 40, a floating sheave block 50, a hook block 60, and a connecting mechanism 70 (see FIG. 3C).

[Fixed sheave block]

As shown in FIG. 1, the fixed sheave block 40 is fixed to the tip portion 20 of the top boom 21. The tip portion 20 is an example of the “boom tip portion” described in the claims. As shown in FIG. 2, the fixed sheave block 40 is located outside the intermediate boom 22 in a state where the top boom 21 is inserted into the accommodation space of the intermediate boom 22.

As shown in FIG. 2, the fixed sheave block 40 includes a first portion 41 extending vertically and a second portion 42 extending in a predetermined direction (obliquely forward and downward in FIG. 2) from the lower end portion of the first portion 41. I have. The first portion 41 is fixed to the tip portion 20.

As shown in FIGS. 2 and 3 (A), the fixed sheave block 40 rotatably supports the sheaves 43, 44, 45, 46, 47. Specifically, as shown in FIG. 3A, the fixed sheave block 40 includes a pair of plate-shaped members 48 facing each other in the left-right direction. The sheaves 43, 44, 45, 46, 47 are rotatably supported by a pair of plate-shaped members 48 between the pair of plate-shaped members 48. Note that, in FIG. 3A, only the sheaves 44, 45, 46 rotatably supported around the shaft 39 by the pair of plate-shaped members 48 are shown, and the sheaves 43, 47 are omitted. Both ends of the shaft 39 are connected to a pair of plate-shaped members 48. As shown in FIG. 2, the shaft 37 of the sheave 43 and the shaft 38 of the sheave 47 are also connected to the pair of plate-shaped members 48.

As shown in FIG. 2, the sheave 43 is supported by one end of the first portion 41. One end of the first portion 41 is the upper end of the first portion 41 when the longitudinal direction 101 of the boom body 25 is horizontal (see FIG. 2). The sheaves 44, 45, 46 are supported by the other end (lower end in FIG. 2) of the first portion 41. As shown in FIG. 3A, the sheaves 44, 45, and 46 are arranged side by side in the left-right direction. In the left-right direction, the sheave 46 is arranged between the sheaves 44 and 45. The diameter of the sheave 46 is shorter than the diameter of the sheaves 44 and 45. As shown in FIG. 2, the sheave 47 is supported by a second portion 42.

The suspension wire 17 extending from the drum of the suspension winch 16 is hung around the sheaves 43, 44, 45, 46, 47. The routing of the suspended load wire 17 to the sheaves 43, 44, 45, 46, 47 will be described in detail later.

The sheaves 44 and 45 are examples of the "first sheave" described in the claims. Sheave 46 is an example of the "third sheave" described in the claims. Sheave 47 is an example of the "fourth sheave" described in the claims.

The fixed sheave block 40 includes a rotating body 49. The rotating body 49 is rotatably supported by the first portion 41. The rotating body 49 sandwiches the suspended load wire 17 between the rotating body 49 and the sheave 43.

The fixed sheave block 40 includes a flat plate-shaped rotating member 36. The rotating member 36 is connected to the shaft 39 via the connecting member 35 and is rotatable around the shaft 39. The lower surface 34 of the rotating member 36 faces vertically downward due to the weight of the rotating member 36 regardless of the undulation angle of the boom body 25.

[Floating sheave block]

As shown in FIG. 1, the floating sheave block 50 is connected to the fixed sheave block 40 via a suspending wire 17. The floating sheave block 50 is suspended from the fixed sheave block 40 by a suspending wire 17. The floating sheave block 50 is located below the fixed sheave block 40.

As shown in FIGS. 2 and 3A, the floating sheave block 50 includes a pair of plate-shaped members 51 facing each other in the left-right direction, and sheaves 52 and 53. The sheaves 52 and 53 are examples of the "second sheave" described in the claims.

The sheaves 52 and 53 are located between the pair of plate-shaped members 51. The sheaves 52 and 53 are rotatably supported around a shaft 54 by a pair of plate-shaped members 51. Both ends of the shaft 54 are connected to a pair of plate-shaped members 51.

The pair of plate-shaped members 51 have two through holes 55 below the sheaves 52 and 53. As shown in FIG. 2, the two through holes 55 of each plate-shaped member 51 are formed side by side in the front-rear direction. As shown in FIG. 3A, the through holes 55 on the front side of each plate-shaped member 51 face each other in the left-right direction. The through holes 55 on the rear side of each plate-shaped member 51 face each other in the left-right direction.

The pair of plate-shaped members 51 are connected by a plate-shaped member 56.

[Hook block]

As shown in FIG. 1, the hook block 60 is connected to the fixed sheave block 40 via a hanging wire 17. The hook block 60 is suspended from the fixed sheave block 40 by a hanging wire 17. That is, the hook block 60 is located below the fixed sheave block 40. The hook block 60 is located in front of the floating sheave block 50. In the line of sight along the vertical direction, the hook block 60 and the floating sheave block 50 do not overlap.

As shown in FIGS. 2 and 3B, the hook block 60 includes a pair of plate-shaped members 62, plate-shaped members 63 and 64, and a hook 61.

As shown in FIG. 3B, the pair of plate-shaped members 62 face each other in the left-right direction. The plate-shaped member 63 connects a pair of plate-shaped members 62. The plate-shaped member 64 is located between the pair of plate-shaped members 62. The plate-shaped member 64 is connected to the plate-shaped member 63.

The pair of plate-shaped members 62 and the plate-shaped members 64 have two through holes 65 each. As shown in FIG. 2, the two through holes 65 included in each plate-shaped member 62 and the plate-shaped member 64 are formed side by side in the front-rear direction. As shown in FIG. 3B, the plate-shaped members 62 and the through holes 65 on the front side of the plate-shaped members 64 are arranged along the left-right direction. The through holes 65 on the rear side of each plate-shaped member 62 and the plate-shaped member 64 are arranged along the left-right direction.

As shown in FIGS. 2 and 3B, the hook 61 is rotatably supported around the shaft 66 by a pair of plate-shaped members 62.

[Connecting mechanism]

As shown in FIG. 3C, the connecting mechanism 70 includes a through hole 55 provided in the floating sheave block 50, a through hole 65 provided in the hook block 60, and a connecting pin 71.

The connecting pin 71 is a rod-shaped member. As described in detail below, the connecting pin 71 can be inserted through the through holes 55 and 65. As shown in FIG. 3A, a space in which the sheaves 52 and 53 do not exist is formed in the lower part of the floating sheave block 50. The upper part of the hook block 60 can be inserted into this space. When the upper part of the hook block 60 is inserted into the lower part of the floating sheave block 50, the through hole 55 and the through hole 65 are arranged in the left-right direction. In this state, as shown in FIG. 3C, the connecting pin 71 is inserted into the through holes 55 and 65. As a result, the floating sheave block 50 and the hook block 60 are connected. When the connecting pin 71 is pulled out, the floating sheave block 50 and the hook block 60 are disconnected from each other.

In this embodiment, two connecting pins 71 are provided. One of the connecting pins 71 is inserted through the through holes 55 and 65 on the front side. The other end of the connecting pin 71 is inserted through the through holes 55 and 65 on the rear side.

[Hanging wire]

As shown in FIG. 1, the suspension wire 17 extending from the drum of the suspension winch 16 extends along the longitudinal direction 101 from the base end portion of the base boom 23 toward the tip end portion of the top boom 21. There is. As shown in FIGS. 1 and 2, the suspended load wire 17 is hung around the sheave 43 at the tip portion 20 of the top boom 21.

As shown in FIG. 2, the suspended load wire 17 (suspended load wire 171) extending from the sheave 43 is hung around the sheave 44 (see FIG. 3A). As shown in FIG. 3A, the suspended load wire 17 (suspended load wire 172) extending from the sheave 44 is hung around the sheave 52. The suspension wire 17 (suspension wire 173) extending from the sheave 52 is hung around the sheave 45. The suspension wire 17 (suspension wire 174) extending from the sheave 45 is hung around the sheave 53. From the above, the suspended load wire 17 is alternately hung around the first sheave (sheaves 44 and 45) and the second sheave (sheaves 52 and 53).

As shown in FIG. 3A, the suspended load wire 17 (suspended load wire 175) extending from the sheave 53 is hung around the sheave 46. The suspension wire 17 (suspension wire 176) extending from the sheave 46 is hung around the sheave 47 (see FIG. 2). As shown in FIG. 2, the suspended load wire 17 (suspended load wire 177) extending from the sheave 47 is connected to the hook block 60. That is, the wire extending from the sheave 46 is connected to the hook block 60 via the sheave 47.

As mentioned above, the sheave 47 is supported by the second portion 42. On the other hand, the sheaves 44, 45, 46 are supported by the first portion 41. That is, the sheave 47 is provided at a position away from the sheaves 44, 45, and 46. As a result, the suspended load wire 177 extending from the sheave 47 and the suspended load wire 172 to 176 extending downward from the sheaves 44, 45, 46 are positioned apart from each other. As a result, the possibility of interference between the suspended load wire 177 and the suspended load wire 172 to 176 can be reduced.

As described above, since the hanging wire 17 is hung around each sheave, the drum of the hanging wire 17 is in a state where both the floating sheave block 50 and the hook block 60 are in the air (see FIG. 1). The floating sheave block 50 is displaced (ascended or lowered) relative to the hook block 60 when the wire is unwound from the hook block or the wire is wound onto the drum. At this time, which of the floating sheave block 50 and the hook block 60 preferentially moves will be described later.

[Relationship between multiplication and mass]

Between the number n of the hanging wires 17 of the floating sheave block 50, the mass m (kg) of the hook block 60, and the mass M (kg) of the floating sheave block 50, the following (Equation 1) is used. The relationship is satisfied.

The number n of the suspended load wires 17 of the floating sheave block 50 is the number of the suspended load wires 17 hung between the floating sheave block 50 and the fixed sheave block 40. In the present embodiment, as shown in FIG. 3A, there are four suspension wires 17 (suspension wires 172, 173, 174) hung between the floating sheave block 50 and the fixed sheave block 40. 175). Therefore, in the present embodiment, the number n of the suspension wires 17 of the floating sheave block 50 is 4. The number n of the suspended load wires 17 of the floating sheave block 50 is not limited to 4. For example, when the floating sheave block 50 includes only one sheave, there are two suspension wires 17 extending from the one sheave to the fixed sheave block 40. In this case, the number n of the suspended load wires 17 of the floating sheave block 50 is 2.

Hereinafter, the derivation of the above (Equation 1) will be described. As shown in FIG. 1, when the floating sheave block 50 and the hook block 60 are both in the air and the hanging wire 17 is unwound from the drum, the hook block 60 lowers preferentially over the floating sheave block 50. The mass m (kg) of the hook block 60 and the floating so that the floating sheave block 50 rises preferentially over the hook block 60 when the hanging wire 17 is wound around the drum. The mass M (kg) of the sheave block 50 is determined.

In the state shown in FIG. 1, the equation of motion shown by the following (Equation 2) holds.

In (Equation 2), T (N) is the tension of the suspended load wire 17, α (m / s ² ) is the acceleration of the hook block 60, and g (m / s ² ) is the gravitational acceleration. (Equation 2) is a system of equations for α and T. When the simultaneous equations of (Equation 2) are solved to obtain the acceleration α of the hook block 60, the following (Equation 3) is obtained.

Here, as shown in FIG. 1, when the floating sheave block 50 and the hook block 60 are both in the air and the hanging wire 17 is unwound from the drum, the hook block 60 has priority over the floating sheave block 50. In order for the floating sheave block 50 to rise preferentially over the hook block 60 when the hanging wire 17 is wound around the drum, the acceleration α of the hook block 60 α
Must be a positive number. That is, as described in (Equation 3), α> 0 needs to be satisfied. N, m, M, and g, which are elements other than α constituting (Equation 3), are all positive numbers. Therefore, in order to satisfy α> 0, the numerator in (Equation 3) must be larger than zero in parentheses. That is, it is necessary to satisfy nm-M> 0. When this equation is transformed, it becomes (Equation 1). In addition, in (Equation 2) and (Equation 3), the description of the multiplication symbol "x" is omitted.

Since the relationship of (Equation 1) derived as described above is satisfied, as shown in FIG. 1, the hanging wire from the drum is provided with the floating sheave block 50 and the hook block 60 both in the air. The hook block 60 descends preferentially over the floating sheave block 50 when the 17 is unwound, and the floating sheave block 50 takes precedence over the floating sheave block 60 when the suspending wire 17 is wound around the drum. Ascends.

[Switching operation of the number of hanging wires]

Hereinafter, the operation of switching the number of hanging wires 17 will be described with reference to FIGS. 4 to 6. In the crane 10 according to the present embodiment, the number of hanging wires 17 can be switched between 1 and 5.

When the hook block 60 is connected to the floating sheave block 50 (see FIG. 3C), as shown in FIG. 4A, the hook block 60, the floating sheave block 50, and the fixed sheave block 40 are It is connected by five hanging wires 17. At this time, the number of hanging wires 17 is five.

On the other hand, as shown in FIG. 1, when the hook block 60 is not connected to the floating sheave block 50, the hook block 60 and the fixed sheave block 40 are connected by one hanging wire 17. At this time, the number of hanging wires 17 is one.

First, the operation when the number of hanging wires 17 is switched from 5 to 1 will be described.

In a state where the floating sheave block 50 and the hook block 60 are connected, the hanging wire 17 is unwound from the drum. As a result, the hook block 60 descends integrally with the floating sheave block 50. The lifting wire 17 is unwound from the drum until the hook block 60 comes into contact with the ground, as shown in FIG. 4 (A).

Next, the connecting pin 71 (see FIG. 3C) is pulled out of the through holes 55 and 65 by the operator. As a result, as shown in FIG. 4B, the connection between the floating sheave block 50 and the hook block 60 is released.

Next, the hanging wire 17 is wound around the drum. As a result, as shown in FIG. 5A, the floating sheave block 50 rises. This is because the floating sheave block 50 rises preferentially over the hook block 60 because the relationship of (Equation 1) is satisfied.

As shown in FIG. 5B, when the floating sheave block 50 comes into contact with the lower surface 34 of the rotating member 36 from below, the floating sheave block 50 stops rising. As described above, the lower surface 34 faces vertically downward due to the weight of the rotating member 36 regardless of the undulation angle of the boom body 25. Therefore, the posture of the floating sheave block 50 in contact with the lower surface 34 is the same regardless of the undulation angle of the boom body 25 (as shown in FIG. 3, a pair of plate-shaped members 51 extend in the vertical direction). Is.

In the state shown in FIG. 5 (B), when the suspended load wire 17 is wound around the drum, the hook block 60 is raised as shown in FIG. 6 (A). Since the relationship of (Equation 1) is satisfied, the floating sheave block 50 originally rises preferentially over the hook block 60, but the floating sheave block 50 cannot rise because it is blocked by the rotating member 36. Therefore, the hook block 60 is raised. When the floating sheave block 50 is in contact with the rotating member 36 from below and the hook block 60 is located in the air, the hook block 60 is lowered when the hanging wire 17 is unwound from the drum. This is because the hook block 60 descends preferentially over the floating sheave block 50 because the relationship of (Equation 1) is satisfied.

As described above, in a state where the floating sheave block 50 is in contact with the lower surface 34 of the rotating member 36 from below, the hook block 60 is lowered by the feeding of the suspension wire 17 from the drum, and the suspension wire 17 The hook block 60 is raised by winding on the drum. At this time, the hook block 60 and the fixed sheave block 40 are connected by one hanging wire 17. That is, the number of hanging wires 17 is one. That is, in a state where the floating sheave block 50 and the hook block 60 are disconnected and the floating sheave block 50 is in contact with the lower surface 34 of the rotating member 36 from below, the crane 10 is the suspension wire 17. It functions as one with one multiplication number.

Next, the operation when the number of hanging wires 17 is switched from 1 to 5 will be described.

As shown in FIG. 6A, the suspended load is in a state where the floating sheave block 50 and the hook block 60 are disconnected and the floating sheave block 50 is in contact with the lower surface 34 of the rotating member 36 from below. When the wire 17 is unwound from the drum, the hook block 60 is lowered by itself. The lifting wire 17 is unwound from the drum until the hook block 60 comes into contact with the ground, as shown in FIG. 5 (B).

As shown in FIG. 5B, when the hook block 60 comes into contact with the ground, the hook block 60 stops descending. In this state, when the suspended load wire 17 is unwound from the drum, the floating sheave block 50 is lowered as shown in FIG. 5 (A). Originally, the hook block 60 descends preferentially over the floating sheave block 50 because the relationship of (Equation 1) is satisfied, but the hook block 60 is blocked by the ground and cannot descend, so that it floats. The sheave block 50 descends.

As shown in FIG. 4B, when the floating sheave block 50 descends to the vicinity of the ground, the upper part of the hook block 60 is inserted into the lower part of the floating sheave block 50 by the operator. At this time, the through hole 55 and the through hole 65 are arranged in the left-right direction. Next, the connecting pin 71 (see FIG. 3C) is inserted into the through holes 55 and 65 by the operator. As a result, the floating sheave block 50 and the hook block 60 are connected (see FIG. 4A).

In the state shown in FIG. 4 (A), when the suspended load wire 17 is wound around the drum, the hook block 60 rises integrally with the floating sheave block 50 (see FIG. 6 (B)). In the state shown in FIG. 6B, when the suspending wire 17 is unwound from the drum, the hook block 60 descends integrally with the floating sheave block 50. At this time, the hook block 60, the floating sheave block 50, and the fixed sheave block 40 are connected by five hanging wires 17. That is, the number of hanging wires 17 is five. That is, in a state where the floating sheave block 50 and the hook block 60 are connected, the crane 10 functions as having five hanging wires 17.

[Action and effect of the embodiment]

When the hook block 60 is connected to the floating sheave block 50, the number of wires hooked is the number of the suspending wires 17 between the sheaves 44 and 45 and the sheaves 52 and 53, and the suspension between the sheave 47 and the hook block 60. It is the total with the number of wires 17. On the other hand, when the hook block 60 is not connected to the floating sheave block 50, the number of wires hooked is the number of hanging wires 17 between the sheave 47 and the hook block 60. In this way, the number of wires hooked can be easily switched depending on whether or not the hook block 60 and the floating sheave block 50 are connected.

As long as (Equation 1) is established, the hanging wire 17 is in a state where the hook block 60 is not connected to the floating sheave block 50 and the floating sheave block 50 is in contact with the tip portion 20 from below. When the floating sheave block 50 is unwound or wound up, the hook block 60 moves up and down while the floating sheave block 50 is in contact with the tip portion 20. That is, in the present embodiment, a complicated mechanism for maintaining the floating sheave block 50 in a state of being in contact with the tip portion 20 is unnecessary.

Further, as long as (Equation 1) is established, when the hanging wire 17 is unwound while the hook block 60 is not connected to the floating sheave block 50 and the hook block 60 is grounded, the floating sheave Block 50 moves downward.

Further, according to the above embodiment, the number of wires is increased by increasing the number of the first sheave (the sheaves 44 and 45 in the above embodiment) and the second sheave (the sheaves 52 and 53 in the above embodiment).

Further, according to the above embodiment, since the sheave 46 and the sheave 47 are separated from each other, there is a possibility that the floating sheave block 50 located directly below the sheave 46 and the hook block 60 located directly below the sheave 47 interfere with each other. Will be low.

[Modification 1]

In the above embodiment, the connecting mechanism is composed of a through hole 55 provided in the floating sheave block 50, a through hole 65 provided in the hook block 60, and a connecting pin 71. However, the configuration of the connecting mechanism is not limited to the configuration provided with the connecting pin 71 as in the above embodiment, and various known configurations can be adopted.

For example, as shown in FIGS. 7 and 8, the connecting mechanism may include an engaging portion 81, a fixing claw 82, a fixing release member 83, and a coil spring 84. The engaging portion 81 is an example of the “first engaging portion” described in the claims. The coil spring 84 is an example of the "elastic member" described in the claims. In the following, the parts having the same configuration as the above-described embodiment are designated by the same reference numerals as those in the above-described embodiment, and the description thereof will be omitted, and the parts having a configuration different from the above-described embodiment will be described.

As shown in FIG. 7, the engaging portion 81 is a portion of the space between the pair of plate-shaped members 51 of the floating sheave block 50, which is lower than the sheaves 52 and 53. The upper part of the hook block 30 can be inserted and removed from the engaging portion 81. That is, the engaging portion 81 is a space occupied by the inserted hook block 30. Specifically, the engaging portion 81 is a space surrounded by a virtual broken line 72 in FIG. 7. The hook block 30 and the engaging portion 81 are engaged with each other by inserting the upper portion of the hook block 30 into the engaging portion 81.

The fixed claw 82 is slidably supported by a pair of plate-shaped members 51, a plate-shaped member 56, and the like along the opposite direction (left-right direction) of the pair of plate-shaped members 51. Two fixing claws 82 are provided. Each fixing claw 82 is connected to each of the pair of plate-shaped members 51 via a coil spring 84. The two fixing claws 82 face each other in the left-right direction.

The fixed claw 82 has an approach position (position shown in FIGS. 7 and 8 (A)) at which the tip thereof has entered the engaging portion 81 and a retracted position (FIG. 8 (B)) withdrawn from the engaging portion 81. Position) and can be moved to. That is, the fixed claw 82 can move forward and backward with respect to the engaging portion 81. The fixing claw 82 is urged by the coil spring 84 so as to constantly enter the engaging portion 81. In other words, each fixed claw 82 receives an urging force of a predetermined direction 106 from the retracted position to the approached position in the direction approaching the other fixed claw 82 facing itself by the coil spring 84.

The fixed claw 82 has an inclined surface 85 on the lower surface of the tip end portion thereof. The inclined surface 85 is an example of the “drag surface” described in the claims. The inclined surface 85 is inclined so as to move away from the fixing claw 82 of the other party facing itself, that is, toward the counter-predetermined direction 107 from the approach position to the evacuation position.

The fixing release member 83 is provided on the floating sheave block 50. The fixing release member 83 includes a gear mechanism. The gear mechanism includes a first rack gear 86, a pinion gear 87, and a second rack gear 88.

The first rack gear 86 is slidably supported in the vertical direction with respect to the floating sheave block 50 by a pair of plate-shaped members 51, plate-shaped members 56, and the like. The first rack gear 86 is slidable to the upper position shown in FIG. 8 (A) and the lower position shown in FIG. 8 (B). The first rack gear 86 is urged to an upper position by an urging member (for example, a coil spring) (not shown). When the first rack gear 86 is in the upper position, the upper end portion of the first rack gear 86 projects upward from the floating sheave block 50. The first rack gear 86 is provided corresponding to each fixed claw 82. That is, two first rack gears 86 are provided. A gear is formed on the surface 89 of each of the first rack gears 86 facing the opposite predetermined direction 107.

The pinion gear 87 is rotatably supported by a pair of plate-shaped members 51, plate-shaped members 56, and the like. The pinion gear 87 is provided corresponding to each first rack gear 86 and each fixed claw 82. That is, two pinion gears 87 are provided. Each pinion gear 87 meshes with a corresponding first rack gear 86.

The second rack gear 88 is integrated with the fixing claw 82. The second rack gear 88 is a gear formed on the upper surface of each fixed claw 82. Each second rack gear 88 meshes with a corresponding pinion gear 87.

In the first modification, the boom device 14 includes a hook block 30 instead of the hook block 60. The hook block 30 includes two recesses 31. The two recesses 31 are formed one on each of the two side surfaces 33 facing the anti-predetermined direction 107. In the first modification, the mass of the hook block 30 is m (kg).

In the first modification, the suspended load wire 17 (suspended load wire 176) extending from the sheave 46 is connected to the hook block 30 as shown in FIG. 7. That is, in the first modification, the hanging wire 176 passes between the pair of plate-shaped members 51 in the floating sheave block 50 and is attached to the hook block 30 without being hung around the sheave 47 (see FIG. 1). It is connected. In this case, the fixed sheave block 40 does not have to include the sheave 47.

Hereinafter, the operation of switching the number of hanging wires 17 in the first modification will be described with reference to FIGS. 9 to 12. In the crane 10 according to the first modification, the number of hanging wires 17 can be switched between 1 and 5 as in the above embodiment. That is, the number of hanging wires 17 when the hook block 30 is connected to the floating sheave block 50 is 5, and the hanging wire when the hook block 30 is not connected to the floating sheave block 50. The number of multiplications of 17 is one.

First, the operation when the number of hanging wires 17 is switched from 5 to 1 will be described.

When the hook block 30 is connected to the floating sheave block 50, as shown in FIG. 8A, the fixed claw 82 at the approach position enters the recess 31 of the hook block 30 engaged with the engaging portion 81. ing. As a result, the fixed claw 82 and the hook block 30 are engaged with each other, and the hook block 30 and the floating sheave block 50 are connected to each other.

In a state where the floating sheave block 50 and the hook block 30 are connected (the state shown in FIG. 8A), the hanging wire 17 is wound around the drum. By winding the suspending wire 17 around the drum, the hook block 30 rises integrally with the floating sheave block 50, as shown in FIG. 9 (A). As shown in FIG. 9B, the floating wire 17 is wound around the drum by the floating sheave block 50 from below at the tip portion 20 of the top boom 21 (specifically, the lower surface 34 of the rotating member 36). It is executed until it comes into contact with.

Immediately before the floating sheave block 50 abuts on the lower surface 34 of the rotating member 36 from below, the upper end of the first rack gear 86 (see FIG. 8A) in the upper position abuts on the lower surface 34. As a result, the first rack gear 86 is pushed by the lower surface 34 and slides from the upper position to the lower position with respect to the floating sheave block 50 (see FIG. 8B). The downward slide of the first rack gear 86 causes the pinion gear 87 to rotate. Due to the rotation of the pinion gear 87, the fixing claw 82 moves from the approach position to the retract position against the urging force of the coil spring 84 (see FIG. 8B). That is, the fixing release member 83 converts the downward slide of the first rack gear 86 into a slide of the fixing claw 82 in the opposite predetermined direction 107, and retracts the fixing claw 82 engaged with the hook block 30 from the engaging portion 81. Let me. As a result, the engagement between the fixed claw 82 and the hook block 30 is released, and the connection between the hook block 30 and the floating sheave block 50 is released. That is, the hook block 30 can be displaced relative to the floating sheave block 50. After that, the hook block 30 comes into contact with the lower surface 34 of the rotating member 36 from below (see FIG. 9B).

In the state shown in FIG. 9 (B), when the suspended load wire 17 is unwound from the drum, the floating sheave block 50 does not move and only the hook block 30 descends (see FIG. 10 (A)). This is because the hook block 30 descends preferentially over the floating sheave block 50 because the relationship of (Equation 1) is satisfied. In the state shown in FIG. 10A, when the suspended load wire 17 is wound around the drum, the floating sheave block 50 does not move and only the hook block 30 descends. Since the relationship of (Equation 1) is satisfied, the floating sheave block 50 originally rises preferentially over the hook block 30, but the floating sheave block 50 cannot rise because it is blocked by the rotating member 36. Therefore, the hook block 30 is raised.

As described above, in a state where the floating sheave block 50 is in contact with the lower surface 34 of the rotating member 36 from below, the hook block 30 is lowered by the feeding of the suspension wire 17 from the drum, and the suspension wire 17 The hook block 30 is raised by winding on the drum. At this time, the hook block 30 and the fixed sheave block 40 are connected by one hanging wire 17. That is, the number of hanging wires 17 is one. That is, in a state where the floating sheave block 50 and the hook block 30 are disconnected from each other and the floating sheave block 50 is in contact with the lower surface 34 of the rotating member 36 from below, the crane 10 is the suspension wire 17. It functions as one with one multiplication number.

Next, the operation when the number of hanging wires 17 is switched from 1 to 5 will be described.

In the state shown in FIG. 10A, the suspended load wire 17 is unwound from the drum. As a result, the hook block 30 is lowered. The lifting wire 17 is unwound from the drum until the hook block 30 comes into contact with the ground, as shown in FIG. 10 (B).

When the hook block 30 comes into contact with the ground, the descent of the hook block 30 stops. In this state, when the suspended load wire 17 is unwound from the drum, the floating sheave block 50 is lowered as shown in FIG. 11 (A). Originally, the hook block 30 descends preferentially over the floating sheave block 50 because the relationship of (Equation 1) is satisfied, but the hook block 30 is blocked by the ground and cannot descend, so that the hook block 30 floats. The sheave block 50 descends. As shown in FIG. 11B, the lifting wire 17 is unwound from the drum until the floating sheave block 50 engages with the hook block 30 from above.

When the floating sheave block 50 approaches the hook block 30 from above, the inclined surface 85 of the fixed claw 82 at the approach position comes into contact with the upper surface 32 of the hook block 30 from above, as shown in FIG. 12 (A). Then, the inclined surface 85 receives an external force in the anti-predetermined direction 107 from the upper surface 32. By this external force, the fixing claw 82 moves from the approach position to the retract position against the urging force of the coil spring 84.

As a result, the floating sheave block 50 is further lowered, so that the upper portion of the hook block 30 is inserted into the engaging portion 81. At this time, the fixed claw 82 at the retracted position is in contact with the side surface 33 of the hook block 30 by the urging force of the coil spring 84 (see FIG. 12B).

When the floating sheave block 50 is further lowered and the fixed claw 82 becomes the same height as the recess 31 and faces the predetermined direction 106, the fixed claw 82 moves from the retracted position to the approached position by the urging force of the coil spring 84. Engage with the recess 31 (see FIG. 8 (A)). As a result, the hook block 30 is engaged with the engaging portion 81, in other words, the hook block 30 and the floating sheave block 50 are connected to each other.

In the state shown in FIG. 11B, when the hanging wire 17 is wound around the drum, the hook block 30 rises integrally with the floating sheave block 50 (see FIG. 9A). In the state shown in FIG. 9A, when the suspending wire 17 is unwound from the drum, the hook block 30 descends integrally with the floating sheave block 50. At this time, the hook block 30, the floating sheave block 50, and the fixed sheave block 40 are connected by five hanging wires 17. That is, the number of hanging wires 17 is five. That is, in a state where the floating sheave block 50 and the hook block 30 are connected, the crane 10 functions as having five hanging wires 17.

According to the first modification, the connection between the floating sheave block 50 and the hook block 30 and the disconnection thereof can be automated.

In the crane disclosed in Patent Documents 1 and 2, the sheave unit is pressed against the fixed pulley mechanism from below to connect the sheave unit to the fixed pulley mechanism, and the sheave unit is further pressed against the fixed pulley mechanism to cause the fixed pulley mechanism. The connection with is released. That is, both the connection of the sheave unit to the fixed pulley mechanism and the release of the connection are executed by pressing the sheave unit from below to the fixed pulley mechanism. Therefore, it is not easy to distinguish between the connection with the fixed pulley mechanism and the release of the connection. In order to facilitate the determination, it is necessary to provide a sensor or the like.

On the other hand, in the first modification, the hook block 30 can be connected to the floating sheave block 50 by the floating sheave block 50 coming into contact with the hook block 30 from above, and the hook block 30 can be connected to the floating sheave block 30. The disconnection with the 50 can be executed by the floating sheave block 50 connected to the hook block 30 coming into contact with the tip portion 20 from below. Therefore, it is easy to distinguish between the connection of the hook block 30 to the floating sheave block 50 and the release of the connection without providing a sensor or the like.

[Modification 2]
In the above embodiment, as shown in FIG. 2, the hanging wire 176 extending from the sheave 46 (see FIG. 3A) is hung around the sheave 47, and the hanging wire 177 extending from the sheave 47 is hung. Was connected to the hook block 60 through the outside of the floating sheave block 50. On the other hand, in the first modification, as shown in FIG. 7, the suspension wire 176 is not hung around the sheave 47 (see FIG. 9), but is sandwiched between the pair of plate-shaped members 51 in the floating sheave block 50. It passed through and was connected to the hook block 30. Of course, also in the above embodiment shown in FIG. 2, the suspension wire 176 is not hung around the sheave 47, and is between the pair of plate-shaped members 51 (see FIG. 3A) in the floating sheave block 50. It may be connected to the hook block 60 through the hook block 60. When the suspension wire 176 is connected to the hook blocks 30 and 60 through the pair of plate-shaped members 51 in the floating sheave block 50, the floating sheave block 50 is shown in FIGS. 13 and 13. As indicated by 14, the guide sheave 130 and the opposed sheave 131 may be provided.

In the following description of the modified example 2, the parts having the same configuration as that of the above embodiment are designated by the same reference numerals as those of the above embodiment, and the description thereof is omitted, and the parts having a configuration different from that of the above embodiment are described. To. Further, in the following description of the modified example 2, the configuration in which the floating sheave block 50 of the above embodiment includes the guide sheave 130 and the opposed sheave 131 will be described, but the floating sheave block 50 of the modified example 1 includes the guide sheave 130 and An opposed sheave 131 may be provided.

As shown in FIGS. 13 and 14, the floating sheave block 50 of the second modification includes a guide sheave 130, an opposed sheave 131, a shaft 132, and a shaft 133.

The shafts 132 and 133 extend in the left-right direction between the pair of plate-shaped members 51 facing each other in the left-right direction (the direction in which the shaft 54 extends). That is, the shafts 132 and 133 are parallel to the shaft 54. The right end of the shafts 132 and 133 is fixed to the right plate-shaped member 51 of the pair of plate-shaped members 51. The left end of the shafts 132 and 133 is fixed to the left plate-shaped member 51 of the pair of plate-shaped members 51. The shafts 132 and 133 face each other in the front-rear direction. The shaft 132 is located in front of the shaft 133. The shaft 132 is located in front of the sheaves 52 and 53. The shaft 133 is located between the front ends of the sheaves 52 and 53 and the shaft 54. The left-right direction is an example of the "axial direction of the second sheave" described in the claims. The pair of plate-shaped members 51 is an example of the "pair of support members" described in the claims.

The guide sheave 130 is rotatably supported around the shaft 132 by the shaft 132. That is, the guide sheave 130 is rotatably supported around the shaft 132 by a pair of plate-shaped members 51. The opposing sheave 131 is rotatably supported around the shaft 133 by the shaft 133. That is, the opposed sheave 131 is rotatably supported around the shaft 133 by a pair of plate-shaped members 51.

The configuration in which the guide sheave 130 and the opposing sheave 131 are rotatably supported by the pair of plate-shaped members 51 is not limited to the above configuration, and various known configurations can be adopted. For example, the guide sheave 130 and the opposing sheave 131 are integrally formed with the shaft 132 and 133, respectively, and the left and right ends of the shaft 132 and 133 penetrate through the through holes formed in the pair of plate-shaped members 51. , The guide sheave 130 and the opposing sheave 131 may be rotatably supported by a pair of plate-shaped members 51.

As shown in FIGS. 14 and 15, the suspension wire 176 extending from the sheave 46 and connected to the hook block 60 without being hung around the sheave 47 is formed between the pair of plate-shaped members 51. It is sandwiched by the guide sheave 130 and the opposing sheave 131. As shown in FIG. 14, a predetermined gap G is formed between the rear end of the guide sheave 130 and the front end of the opposite sheave 131. The predetermined gap G is set to be smaller than the diameter of the suspended load wire 176. As a result, the suspended load wire 176 sandwiched between the guide sheave 130 and the opposing sheave 131 is prevented from coming out from between the guide sheave 130 and the opposing sheave 131.

As shown in FIG. 15, the guide sheave 130 is located to the left of the sheaves 52 and 53. In FIG. 15, the opposing sheave 131 is located on the back side of the paper surface of the guide sheave 130 and is not visible, but the opposing sheave 131 is also located to the left of the sheaves 52 and 53.

In the second modification, the fixed sheave block 40 includes sheaves 44, 45, and 46, but does not include sheave 47 (see FIG. 1). Further, the arrangement order of the sheaves 44, 45, and 46 in the left-right direction is different from that of the above-described embodiment and the first modification. That is, in the above embodiment and the first modification, the sheaves 44, 46, 45 are arranged in the order from the right (see FIGS. 3A and 7), but in the second modification, the sheaves 44, 45 are arranged from the right. , 46 (see FIG. 15). Further, in the above embodiment and the first modification, the diameter of the sheave 46 is shorter than the diameters of the sheaves 44 and 45 (see FIGS. 3A and 7), but in the second modification, the diameter of the sheave 46 is the sheave. It has the same diameter as 44 and 45 (see FIG. 15).

Hereinafter, with reference to FIG. 15, the hanging wire 17 in the second modification will be described.

The suspension wire 17 (suspension wire 171) extending from the sheave 43 (see FIG. 1) is hung around the sheave 44. The suspension wire 17 (suspension wire 172) extending from the sheave 44 is hung around the sheave 52. The suspension wire 17 (suspension wire 173) extending from the sheave 52 is hung around the sheave 45. The suspension wire 17 (suspension wire 174) extending from the sheave 45 is hung around the sheave 53. The suspension wire 17 (suspension wire 175) extending from the sheave 53 is hung around the sheave 46.

The suspension wire 17 (suspension wire 176) extending from the sheave 46 passes between the pair of plate-shaped members 51 and is connected to the hook block 60. The suspension wire 176 passes between the guide sheave 130 and the opposing sheave 131 between the pair of plate-shaped members 51 (see FIG. 14). That is, the suspended load wire 176 is hung on the guide sheave 130 and the opposed sheave 131. Further, the guide sheave 130 is located on the opposite side of the sheaves 52 and 53 with respect to the suspension wire 176.

The guide sheave 130 can prevent the suspension wire 176 extending from the sheave 46 and being connected to the hook block 60 from coming out from between the pair of plate-shaped members 62.

A hanging wire 176 extending from the sheave 46 and connected to the hook block 60 is hung on the guide sheave 130. Therefore, even when the floating sheave block 50 and the hook block 60 are not connected, the suspended load wire 176 can be stabilized, so that the swing of the suspended load wire 176 and the hook block 60 can be reduced. Can be done.

Since the guide sheave 130 and the opposed sheave 131 extend from the sheave 46 and sandwich the suspended load wire 176 connected to the hook block 60, the suspended load wire 176 is further provided as compared with the configuration without the opposed sheave 131. It can be stabilized.

The floating sheave block 50 does not have to include the opposed sheave 131. In this case, the suspended load wire 176 is not sandwiched by the guide sheave 130 and the opposing sheave 131. However, the forward movement of the suspended load wire 176 can be regulated by the guide sheave 130.

Further, the positions of the guide sheave 130 and the opposite sheave 131 in the left-right direction are not limited to the positions shown in FIG. For example, the guide sheave 130 and the opposing sheave 131 may be in the same position as the sheave 52 in the left-right direction. In this case, even if the floating sheave block 50 is not provided with the facing sheave 131, the guide sheave 130 and the sheave 52 face each other in the front-rear direction, so that the lifting wire 176 can be moved forward. It can be regulated by 130 and the rearward movement of the suspended load wire 176 can be regulated by the sheave 52.

That is, the suspension wire 176 extending from the sheave 46 and connected to the hook block 60 can be sandwiched by the guide sheave 130 and the sheave 52. As a result, the suspended load wire can be stabilized.

Further, the guide sheave 130 does not have to be located on the opposite side of the sheaves 52 and 53 with respect to the suspension wire 176. For example, the guide sheave 130 may be located coaxially with the sheaves 52 and 53.

[Modification 3]
In the above-described embodiment and the first modification, the connection portion of the hook block with the suspension wire is fixed. However, as described in detail below, the connection portion of the hook block with the suspension wire may be configured to be movable.

In the following description of the third modification, the parts having the same configuration as the above-described embodiment are designated by the same reference numerals as those in the above-described embodiment, and the description thereof is omitted, and the parts having a configuration different from the above-described embodiment will be described. To. Further, in the following description of the modified example 3, a configuration in which the connection portion with the suspended load wire 17 in the hook block 60 of the above embodiment can be moved will be described, but for suspended loads in the hook block 30 of the modified example 1. The connection point with the wire 17 may be configured to be movable.

As shown in FIGS. 17 and 18, the hook block 60 of the third modification includes a shaft 140, a slider 141, a connecting plate 142, a convex portion 143, a spacer 144, and a pin 145. The connection plate 142 is an example of the “connection portion” described in the claims. The spacer 144 is an example of the "holding portion" described in the claims.

The shaft 140 extends in the left-right direction between the pair of plate-shaped members 62. The right end of the shaft 140 is fixed to the right plate-shaped member 62 of the pair of plate-shaped members 62. The left end of the shaft 140 is fixed to the left plate-shaped member 62 of the pair of plate-shaped members 62. The pair of plate-shaped members 62 is an example of the "pair of plate members" described in the claims.

The slider 141 is a cylindrical member. The slider 141 is fitted on the shaft 140. The slider 141 is shorter than the axis 140 by a length L (see FIG. 17) in the left-right direction. As a result, the slider 141 can move relative to the shaft 140 in the left-right direction by a length L between the pair of plate-shaped members 62. That is, the slider 141 can move between the pair of plate-shaped members 62 in the left-right direction between the right position shown in FIG. 17 and the left position shown in FIG. When the slider 141 is in the right position, the right end of the slider 141 is in contact with the left surface of the plate-shaped member 62 on the right side. When the slider 141 is in the left position, the left end of the slider 141 is in contact with the right surface of the left plate-shaped member 62. The right position is an example of the "first position" described in the claims. The left position is an example of the "second position" described in the claims.

As shown in FIGS. 17 and 18, the connecting plate 142 is fixed to the slider 141. Specifically, a groove (not shown) is formed on the outer peripheral surface of the slider 141, and the connection plate 142 is fixed to the slider 141 by being fitted into the groove. As a result, the connecting plate 142 can be moved to the right position (see FIG. 17) and the left position (see FIG. 19) integrally with the slider 141 between the pair of plate-shaped members 62. The means for fixing the connection plate 142 to the slider 141 is not limited to the above means, and for example, the connection plate 142 and the slider 141 may be integrally molded.

As shown in FIG. 17, the connecting plate 142 projects from the outer peripheral surface of the slider 141 in the radial direction of the shaft 140 (upward in FIG. 17). A through hole 146 in the left-right direction is formed in a portion of the connection plate 142 that protrudes from the outer peripheral surface. As shown in FIG. 15, the suspended load wire 176 extending from the sheave 46 is inserted into the through hole 146 (see FIG. 17) and connected to the connecting plate 142. That is, the hanging wire 17 is connected to the hook block 60.

As shown in FIG. 17, when the slider 141 is in the right position, the connecting plate 142 is located between the pair of plate-shaped members 62 in the left-right direction. As shown in FIG. 19, when the slider 141 is in the left position, the connecting plate 142 is positioned to the left between the pair of plate-shaped members 62 (the distance between the connecting plate 142 and the left plate-shaped member 62 in the left-right direction is the right plate). It is located at a position shorter than the lateral distance from the shape member 62).

As shown in FIG. 18, two convex portions 143 are provided on each of the pair of plate-shaped members 62. The two convex portions 143 on the right side project from the left surface of the plate-shaped member 62 on the right side to the left. The two convex portions 143 on the left side project to the right from the right surface of the plate-shaped member 62 on the left side. The two convex portions 143 on the right side face each other in the front-rear direction, and the two convex portions 143 on the left side also face each other in the front-rear direction.

As shown in FIG. 17, each convex portion 143 is located above the shaft 140. As shown in FIG. 18, each convex portion 143 has a through hole 147 in the front-rear direction.

As shown in FIGS. 17 and 19, the spacer 144 is fitted in the gap between 141 and the pair of plate-shaped members 62 on the shaft 140. The spacer 144 selectively holds the slider 141 and the connecting plate 142 in either the left or right position.

As shown in FIG. 20, the spacer 144 includes a pair of side plates 73 and a flat plate 74.

The pair of side plates 73 are arranged at intervals. The interval is the same as the diameter of the shaft 140 (see FIG. 17). The interval may be slightly smaller than the diameter of the shaft 140.

The flat plate 74 is located between the pair of side plates 73. One end of the flat plate 74 is connected to one of the pair of side plates 73. The other end of the flat plate 74 is connected to the other of the pair of side plates 73. The pair of side plates 73 is composed of a first portion 731 projecting from the flat plate 74 to one side and a second portion 732 projecting from the flat plate 74 to the other side. The pair of side plates 73 have a through hole 75 in the first portion 731.

The spacer 144 is attached to and detached from the hook block 60 as described in detail below.

First, the slider 141 and the connecting plate 142 are moved to the right position (see FIG. 17) or the left position (see FIG. 19). Here, the case where the slider 141 and the connecting plate 142 are moved to the right position (see FIG. 17) will be described.

Next, as shown in FIG. 17, the spacer 144 is fitted into the shaft 140 from above. The spacer 144 is fitted into the portion of the shaft 140 between the slider 141 and the left plate-shaped member 62 (in other words, the portion where the slider 141 is not located in the left-right direction and the shaft 140 is exposed). .. Further, the spacer 144 is fitted into the shaft 140 from above in a posture in which a pair of side plates 73 sandwich the shaft 140 from the front and rear and the second portion 732 is located below. As a result, the spacer 144 is in a posture in which the second portion 732 of the pair of side plates 73 sandwiches the shaft 140 from the front and rear, and the flat plate 74 is in contact with the shaft 140 from above. Here, the length of the second portion 732 in the left-right direction when the spacer 144 is in the posture is the same as the length L. Therefore, by fitting the spacer 144 into the shaft 140, the movement of the slider 141 and the connecting plate 142 to the left is restricted, and the slider 141 and the connecting plate 142 are held in the right position.

As shown in FIG. 18, in a state where the spacer 144 is fitted to the shaft 140, the through hole 75 of the first portion 731 and the through hole 147 of the convex portion 143 face each other in the front-rear direction. Further, the diameter of the through hole 75 and the diameter of the through hole 147 are substantially the same. Then, the rod-shaped pin 145 is inserted into the through hole 75 and the through hole 147. As a result, the spacer 144 is fixed to the hook block 60.

As shown in FIG. 19, when the slider 141 is moved to the left position, the spacer 144 is fitted in the portion of the shaft 140 between the slider 141 and the plate-shaped member 62 on the right side. As a result, the movement of the slider 141 and the connecting plate 142 to the right is restricted, and the slider 141 and the connecting plate 142 are held in the left position.

As in the above embodiment (see FIG. 3A) and modification 1 (see FIG. 7), the hanging wire 17 hung in the fixed sheave block 40 and the floating sheave block 50 is the fixed sheave block 40. In the case of a configuration in which the sheave 46 arranged in the center in the left-right direction of the three sheaves 44, 45, 46 extends toward the hook block, the slider 141 and the connecting plate 142 are held in the right position as shown in FIG. By doing so, the connecting plate 142 of the hook block 60 is located directly below the sheave 46 of the fixed sheave block 40 (the sheave located in the middle of the three sheaves 44, 45, 46 in the left-right direction). In this case, the suspended load wire 17 extending from the sheave 46 extends vertically downward and is connected to the connecting plate 142 of the hook block 60.

On the other hand, as in the second modification, the hanging wire 17 hung around the fixed sheave block 40 and the floating sheave block 50 is arranged on the leftmost side of the three sheaves 44, 45, 46 of the fixed sheave block 40. In the case of a configuration extending from the sheave 46 toward the hook block, as shown in FIG. 15, the slider 141 and the connecting plate 142 are positioned at the left positions, so that the connecting plate 142 of the hook block 60 is fixed to the fixed sheave block 40. It is located directly below the sheave 46 (the leftmost sheave of the three sheaves 44, 45, 46). Also in this case, the suspending wire 17 extending from the sheave 46 extends vertically downward and is connected to the connecting plate 142 of the hook block 60.

That is, the connection plate 142 of the hook block 60 is changed by changing the positions of the slider 141 and the connection plate 142 according to the order in which the suspension wire 17 of the fixed sheave block 40 and the floating sheave block 50 is hung on each sheave. , The suspension wire 17 extending toward the hook block 60 can be positioned directly below the sheave 46 around which the suspension wire 17 is hung.

The hook block 60 may be configured such that the connection plate 142 can be moved to three or more positions in the left-right direction. For example, the connecting plate 142 has a position in the middle of the pair of plate-shaped members 62 in the left-right direction and a position on the left side between the pair of plate-shaped members 62, as well as a position on the right side between the pair of plate-shaped members 62. It may be movable to a position (a position where the left-right distance from the right plate-shaped member 62 is shorter than the left-right distance from the left plate-shaped member 62).

Further, the configuration for holding the connection plate 142 at each position such as the left position and the right position is not limited to the spacer 144. For example, a plurality of integrally molded members in which the shaft 140 and the connecting plate 142 are integrally molded are prepared, and the left and right directions of the connecting plate 142 of each integrally molded member are different positions. Then, the position of the connecting plate 142 may be changed by selectively attaching the integrally molded member to the hook block. In this case, the plurality of integrally molded members are both the "connecting portion" and the "holding portion" described in the claims.

According to the third modification, the position of the connecting plate 142 can be set directly below the sheave 46 by changing the position of the connecting plate 142 according to the position of the sheave 46. As a result, in the state where the floating sheave block 50 and the hook block 60 are connected, the hanging wire 17 extending from the sheave 46 and connected to the hook block 60 can be brought into a state along the vertical direction.

Further, according to the third modification, by changing the position of the connecting plate 142 according to the position of the sheave 46, it is possible to correct the misalignment between the floating sheave block 50 and the hook block 60. As a result, it is possible to prevent the floating sheave block 50 and the hook block 60 from interfering with each other at the time of connection and hindering the connection.

Further, according to the third modification, it is possible to realize a function of holding the connection plate 142 at the right position or the left position with a simple configuration using the spacer 144.

[Modification example 4]
As shown in FIGS. 13 and 14, the floating sheave block 50 may include a stopper 160. The stopper 160 positions the hook block at a connection position described later by abutting the hook block connected to the floating sheave block 50 from above.

The stopper 160 is provided on each of the pair of plate-shaped members 51. Specifically, two stoppers 160 are provided on the left side of the plate-shaped member 51 on the right side and two on the right side of the plate-shaped member 51 on the left side. The two stoppers 160 on each surface are formed at intervals in the front-rear direction. Each stopper 160 extends in the front-rear direction. Each stopper 160 is located below the sheaves 52 and 53 and above the lower ends of the pair of plate-shaped members 51. The specific shape of the stopper 160 is not limited to the above-mentioned shape as long as the hook block is positioned at the connecting position.

According to the fourth modification, the position of the hook block 60 when connected to the floating sheave block 50 can be stabilized.

[Modification 5]
As shown in FIG. 13, the floating sheave block 50 may include a guide arm 110, and as shown in FIGS. 17 and 21, the hook block 60 may include a protrusion 120.

In the following description of the modified example 5, the same components as those in the above embodiment are designated by the same reference numerals as those in the above embodiment, and the description thereof is omitted, and the parts having the same configurations as those in the above embodiment are described. To. Further, in the following description of the modified example 5, the configuration in which the hook block 60 is provided with the protrusion 120 will be described, but the hook block 30 of the modified example 1 may be provided with the protrusion 120.

As shown in FIG. 13, the guide arm 110 includes a rotating shaft 111 and a pair of rotating pieces 112.

The rotating shaft 111 is rotatably supported by a pair of plate-shaped members 51. More specifically, the pair of plate-shaped members 51 have through holes in the front lower end portion along the left-right direction, and the rotation shaft 111 is penetrated through the through holes.

As shown in FIG. 15, the rotating shaft 111 extends parallel to the shafts 54 of the sheaves 52 and 53, that is, in the left-right direction. The right end portion of the rotating shaft 111 slightly protrudes to the right from the plate-shaped member 51 on the right side. The left end portion of the rotating shaft 111 slightly protrudes to the left from the plate-shaped member 51 on the left side.

As shown in FIGS. 13 and 15, the pair of rotating pieces 112 are fixed to the right end portion and the left end portion of the rotating shaft 111. As a result, the guide arm 110 is supported by the pair of plate-shaped members 51 so that the pair of rotating pieces 112 can rotate around the rotating shaft 111. The pair of rotating pieces 112 face each other in the left-right direction. The pair of rotating pieces 112 extend in the same direction. In the modified example 5, the pair of rotating pieces 112 hang down due to their own weight in a state where no force is applied to the guide arm 110 from the outside. At this time, the pair of rotating pieces 112 project downward from the pair of plate-shaped members 51. The pair of rotating pieces 112 have a recess 114 in the rotating tip portion 113. The recess 114 is an example of the "second engaging portion" described in the claims.

As shown in FIG. 17, the hook block 60 includes two protrusions 120. One protrusion 120 projects from the left surface of the left plate-shaped member 62 to the left. The other protrusion 120 projects to the right from the right surface of the plate-shaped member 62 on the right side. The protrusion 120 is an example of the "engaged portion" described in the claims. In the modified example 5, the protrusion 120 is located coaxially with the shaft 140, but the position of the protrusion 120 is not limited to coaxial with the shaft 140.

Hereinafter, an example of the connection operation between the floating sheave block 50 and the hook block 60 in the modified example 5 will be described. In this example, the floating sheave block 50 includes the guide sheave 130 and the opposed sheave 131 of the modified example 2, and the stopper 160 of the modified example 4.

As shown in FIG. 22, when the floating sheave block 50 and the hook block 60 are suspended from the tip portion 20 (see FIG. 1), no external force is applied to the guide arm 110. Therefore, the rotating piece 112 of the guide arm 110 hangs down due to its own weight. At this time, the rotating tip 113 of the rotating piece 112 is located directly above the protrusion 120. In this state, the rotating tip portion 113 of the rotating piece 112 may be located at a position deviated from directly above the protrusion 120.

When the hanging wire 17 is unwound from the drum while the hook block 60 is grounded, the floating sheave block 50 descends and approaches the hook block 60. Here, the guide sheave 130 and the opposed sheave 131 are provided at the front portion of the floating sheave block 50. Therefore, as shown in FIG. 22, the hook block 60 is in a position shifted forward with respect to the floating sheave block 50.

In the state shown in FIG. 22, when the hanging wire 17 is unwound from the drum, the floating sheave block 50 is lowered, and the rotating tip 113 of the rotating piece 112 comes into contact with the protrusion 120 of the hook block 60 from above. .. At this time, the protrusion 120 engages with the recess 114 formed in the rotation tip 113 (see FIG. 23). When the rotating tip portion 113 of the rotating piece 112 is located at a position deviated from directly above the protrusion 120, for example, the protrusion 120 and the recess 114 are moved and engaged by an operator.

In the state shown in FIG. 23, when the suspending wire 17 is unwound from the drum, the floating sheave block 50 is lowered. Here, the rotation shaft 111 of the guide arm 110 is located in front of the rotation tip portion 113. Therefore, at this time, the rotating piece 112 rotates in the direction in which the rotating tip portion 113 moves rearward, that is, in the direction of the arrow 102. The floating sheave block 50 slides forward in conjunction with the rotation of the rotating piece 112. That is, the floating sheave block 50 descends diagonally forward and downward. The floating sheave block 50 slides forward so that it is located directly above the hook block 60. In this state, when the floating sheave block 50 is lowered, the upper portion of the hook block 60 is inserted into the lower portion of the floating sheave block 50 (see FIG. 24).

As shown in FIG. 24, the upper end 511 of the pair of plate-shaped members 51 of the hook block 60 inserted and connected to the lower part of the floating sheave block 50 abuts on the stopper 160 of the floating sheave block 50 from below and hooks. The block 60 is positioned at the position (connecting position) shown in FIG. 24. This prevents the hook block 60 from interfering with the sheaves 52 and 53 of the floating sheave block 50 from below. As the mechanism for connecting the floating sheave block 50 and the hook block 60, the mechanism of the above embodiment or the first modification is adopted.

The connecting position is a position when the hook block 60 is connected to the floating sheave block 50. For example, in the modified example 5, as shown in FIG. 24, when the hook block 60 is in the connecting position, the center of the hook block 60 in the front-rear direction is the same position as the center of the floating sheave block 50 in the front-rear direction, and the hook block 60 The center of the floating sheave block 50 in the left-right direction is at the same position as the center of the floating sheave block 50 in the left-right direction, and the suspension wire 17 extending from the sheave 46 extends vertically downward and is connected to the connecting plate 142 of the hook block 60. There is. The connecting position is not limited to the position shown in FIG. 24.

As described above, the guide arm 110 guides the hook block 60 to the connection position with the floating sheave block 50 by rotating in a state of being engaged with the hook block 60.

Further, as described above, the rotation shaft 111 of the guide arm 110 is located in front of the rotation tip portion 113 shown in FIG. On the other hand, the connecting position (the position of the hook block 60 shown in FIG. 24) is located behind the rotating tip portion 113 shown in FIG. 22. That is, the rotating shaft 111 is located on the opposite side of the connecting position with respect to the rotating tip 113 (rotating tip 113 shown in FIG. 22) with the guide arm 110 hanging under its own weight.

In the above-described configuration, the guide arm 110 has a recess 114 in the rotating tip portion 113 of the rotating piece 112, and the hook block 60 has the protrusion 120, so that the guide arm 110 and the hook block 60 are engaged with each other. However, the configuration for engaging the guide arm 110 and the hook block 60 is not limited to this. For example, contrary to the above-described configuration, the guide arm 110 has a protrusion 120 on the rotating tip 113 of the rotating piece 112, and the hook block 60 has the recess 114, so that the guide arm 110 and the hook block 60 May engage. In this case, the protrusion 120 corresponds to the "second engaging portion" described in the claims, and the recess 114 corresponds to the "engaged portion" described in the claims.

Further, the guide arm 110 is not limited to the one that hangs down by its own weight, and may be urged to the position shown in FIG. 22 by, for example, a spring.

According to the modified example 5, the hook block 60 can be guided to the connection position with the floating sheave block 50 only by engaging the guide arm 110 with the hook block 60 and rotating the guide arm 110.

Further, according to the modified example 5, the rotating shaft 111 is located on the opposite side of the connecting position with respect to the recess 114. Therefore, by bringing the floating sheave block 50 and the hook block 60 closer to each other in a state where the recess 114 and the protrusion 120 are engaged, the guide arm 110 can be rotated in a direction in which the hook block 60 approaches the connecting position.

Further, according to the modified example 5, in a state where the floating sheave block 50 and the hook block 30 are suspended from the tip portion 20, the recess 114 of the rotating piece 112 of the guide arm 110 is the true of the protrusion 120 of the hook block 60. Located on top. Therefore, the recess 114 of the rotating piece 112 of the guide arm 110 and the protrusion 120 of the hook block 60 can be engaged with each other simply by moving the floating sheave block 50 and the hook block 60 relative to each other in the vertical direction and bringing them closer to each other.

[Other variants]

In the above embodiment and the first modification, the first sheaves are two sheaves 44 and 45, and the second sheaves are two sheaves 52 and 53. That is, the number of the first sheave and the second sheave was a plurality and the same number. However, the number of the first sheave and the second sheave may be three or more or one. Also, the number of first sheaves and the number of second sheaves may be different.

For example, when the first sheave and the second sheave are each three sheaves, the number of hanging wires 17 hung between the floating sheave block 50 and the fixed sheave block 40 is six. That is, the number n of the suspended load wires 17 of the floating sheave block 50 is 6. Therefore, when the hook block 60 is connected to the floating sheave block 50, the hook block 60, the floating sheave block 50, and the fixed sheave block 40 are connected by seven hanging wires 17. At this time, the number of hanging wires 17 is seven. From the above, in this case, in the crane 10, the number of hanging wires 17 can be switched between 1 and 7.

In the above embodiment, the fixed sheave block 40 does not have to include the sheave 47. In this case, also in the above embodiment, the hanging wire 17 (hanging wire 176) extending from the sheave 46 is connected to the hook block 30 without passing through the sheave 47, as in the first modification.

In the first modification, the suspended load wire 17 (suspended load wire 176) extending from the sheave 46 may be connected to the hook block 30 via the sheave 47.

10 ... Crane 11 ... Work vehicle 13 ... Swing table 14 ... Boom device 15 ... Out trigger device 16 ... Suspended load winch 17 ... Suspended load wire 18 ... Undulating Cylinder 20 ... Tip 21 ... Top boom 22 ... Intermediate boom 23 ... Base boom 25 ... Boom body 28 ... Wire hook number switching device 30 ... Hook block 31 ... Recessed portion 32 ... Top surface 33 ... Side surface 34 ... Bottom surface 35 ... Connecting member 36 ... Rotating member 37 ... Shaft 38 ... Shaft 39 ... Shaft 40 ... Fixed sheave Block 41 ... 1st part 42 ... 2nd part 43 ... Sheave 44 ... Sheave 45 ... Sheave 46 ... Sheave 47 ... Sheave 48 ... Plate-shaped member 49 ...・ Rotating body 50 ・ ・ ・ Floating sheave block 51 ・ ・ ・ Plate-shaped member 52 ・ ・ ・ Sheave 53 ・ ・ ・ Sheave 54 ・ ・ ・ Shaft 55 ・ ・ ・ Through hole 56 ・ ・ ・ Plate-shaped member 60 ・ ・ ・ Hook Block 61 ... Hook 62 ... Plate-shaped member 63 ... Plate-shaped member 64 ... Plate-shaped member 65 ... Through hole 66 ... Shaft 70 ... Connecting mechanism 71 ... Connecting pin 72 ... Virtual broken wire 73 ... Side plate 74 ... Flat plate 75 ... Through hole 81 ... Engagement part 82 ... Fixing claw 83 ... Fixing release member 84 ... Coil spring 85 ...・ Inclined surface 86 ・ ・ ・ 1st rack gear 87 ・ ・ ・ Pinion gear 88 ・ ・ ・ 2nd rack gear 89 ・ ・ ・ Surface 101 ・ ・ ・ Longitudinal direction 102 ・ ・ ・ Arrow 106 ・ ・ ・ Predetermined direction 107 ・ ・ ・ Anti-predetermined Direction 110 ... Guide arm 111 ... Rotation shaft 112 ... Rotation piece 113 ... Rotation tip 114 ... Recess 120 ... Protrusion 130 ... Guide sheave 131 ... Opposite Sheave 132 ... Axis 133 ... Axis 140 ... Axis 141 ... Slider 142 ... Connection plate 143 ... Convex 144 ... Spacer 145 ... Pin 146 ... Through hole 147 ... Through hole 160 ... Stopper 171 ... Suspended load wire 172 ... Suspended load wire 173 ... Suspended load wire 174 ... Suspended load wire 175 ... Suspended load wire 176 ... Suspended load wire 177 ... Suspended load wire 511 ... Upper end 731 ... First part 732 ... Second part

Claims (14)

It is a wire hooking number switching device that is applied to cranes with booms and hanging wires and switches the wire hooking number in the lifting work.
The first sheave provided at the tip of the boom and around which the above-mentioned hanging wire is hung,
A floating sheave block having a second sheave around which the hanging wire extending from the first sheave is hung, and
A third sheave provided at the tip of the boom and around which the hanging wire extending from the second sheave is hung,
The hook block to which the hanging wire extending from the third sheave is connected and provided with a hook, and
It is provided with a connecting mechanism for connecting the hook block and the floating sheave block so that they can be disconnected.
A crane wire number switching device that satisfies the following equation 1.
n × m> M ... (Equation 1)
n: Number of hanging wires of the floating sheave block m: Mass of the hook block M: Mass of the floating sheave block The number of the first sheave and the second sheave is plural and the same.
The wire hooking device for a crane according to claim 1, wherein the suspended load wire is alternately hung around the first sheave and the second sheave. A fourth sheave on which the hanging wire extending from the third sheave is hung is provided at the tip of the boom.
The fourth sheave is provided at a position away from the third sheave so as to avoid contact between the suspended load wires.
The wire hook number switching device for a crane according to claim 1 or 2, wherein the suspended load wire hung around the fourth sheave is connected to the hook block. The above connection mechanism
A first engaging portion that is provided on the floating sheave block and engages with the hook block that is displaced relative to the floating sheave block.
A fixing claw that is elastically urged to move forward and backward with respect to the first engaging portion and always enters the first engaging portion, and engages with the hook block engaged with the first engaging portion.
The number of wire hooks of the crane according to any one of claims 1 to 3, further comprising a fixing release member provided on the floating sheave block and retracting the fixing claw engaged with the hook block from the first engaging portion. Switching device. The fixed claw is slidably supported by the floating sheave block and receives a predetermined urging force by an elastic member, and when the hook block comes into contact with the hook block, the fixed claw opposes the urging force and is oriented in the opposite direction. A drag surface that receives external force is formed,
The fixing release member is provided so as to be slidable with respect to the floating sheave block by coming into contact with the boom tip portion as the floating sheave block is displaced, and the slide of the fixing release member is slid on the fixing claw. The wire hook number switching device for a crane according to claim 4, further comprising a gear mechanism for converting the slide into the anti-predetermined direction. The floating sheave block according to any one of claims 1 to 5, further comprising a guide arm that guides the hook block to a connecting position with the floating sheave block by rotating in a state of being engaged with the hook block. Crane wire hook switching device. The guide arm has a second engaging portion that hangs around a rotating shaft extending parallel to the axial direction of the second sheave by its own weight in a rotatable state and engages with the hook block.
The hook block includes an engaged portion that can be engaged with the second engaging portion.
The wire hook number switching device for a crane according to claim 6, wherein the rotating shaft is located on the opposite side of the connecting position with respect to the second engaging portion with the guide arm hanging down. According to claim 7, the second engaging portion of the guide arm is located directly above the engaged portion in a state where the floating sheave block and the hook block are suspended from the boom tip portion. The described crane wire hook switching device. The above hook block
The hanging wire extending from the third sheave is connected to the connecting portion that can be moved to a plurality of positions in the axial direction of the second sheave.
The wire hook number switching device for a crane according to any one of claims 1 to 8, further comprising a holding portion that holds the connecting portion at each of the plurality of positions. The hook block includes a pair of plate members facing each other in the axial direction of the second sheave.
The connecting portion can be moved between the pair of plate members to the first position and the second position.
The holding portion is sandwiched between the connecting portion and one of the pair of plate members when the connecting portion is in the first position, and when the connecting portion is in the second position, the connecting portion and the connecting portion are described. The wire hook number switching device for a crane according to claim 9, which is a spacer sandwiched between the pair of plate members and the other. The floating sheave block includes a pair of support members facing each other in the axial direction of the second sheave.
The hanging wire extending from the third sheave is connected to the hook block through between the pair of support members.
The number of wire hooks of the crane according to any one of claims 1 to 10, wherein the floating sheave block includes a guide sheave on which the suspension wire extending from the third sheave and connected to the hook block is hung. Switching device. The second sheave is supported by the floating sheave block between the pair of support members.
The wire hooking device for a crane according to claim 11, wherein the guide sheave is located on the opposite side of the second sheave with respect to the suspended load wire extending from the third sheave. The eleventh or twelfth aspect of claim 11 or 12, wherein the floating sheave block is arranged to face the guide sheave, and includes an opposed sheave that sandwiches the suspension wire extending from the third sheave with the guide sheave. Crane wire number switching device. The crane according to any one of claims 1 to 13, wherein the connecting mechanism is provided on the floating sheave block and includes a stopper that abuts on the hook block connected to the floating sheave block to position the hook block. Wire hook number switching device.

Images