The content of Japanese Patent Application No. 2018-142844, on the basis of which priority benefits are claimed in an accompanying application data sheet, is in its entirety incorporated herein by reference.
Certain embodiment of the present invention relates to a crane on which the hook device is mounted.
In the related art, a hook block combining a plurality of hooks is used in a crane. The hook block including the plurality of hooks has an advantage that it can be used for a wide range of applications such as lifting a low load cargo by some hooks or lifting a high load cargo by all hooks.
As an example of the hook block, a hook block including a sheave housing which is connected to a wire suspended from a boom of a crane, a pair of plates which is supported by the sheave housing so as to be rotatable around a horizontal axis, and two dual-key hooks which are supported by the pair of plates so as to be rotatable around the horizontal axis and a vertical axis is disclosed in the related art.
According to an embodiment of the present invention, there is provided a hook device including: a central shaft which extends in a first direction; and a first locking portion and a second locking portion which are disposed such that the central shaft is interposed therebetween, in a second direction orthogonal to the first direction, in which the first locking portion and the second locking portion are connected to the central shaft in a state where the first locking portion and the second locking portion are not rotatable independently around an axis extending in the first direction and are rotatable around an axis extending in a third direction different from the first direction and the second direction.
In the related art, it is assumed that a cargo is hung on one dual-key hook. In this case, it is necessary to perform a hooking operation such that a center of gravity of the cargo is positioned immediately below a shaft portion of the dual-key hook. However, a high level of technology is required so as to appropriately adjust a relative position between the dual-key hook and the center of gravity of the cargo, and thus, the adjusting the relative position is particularly difficult to be used in a field where personal and time limits are large.
In addition, if the cargo is lifted in a state where the position of the center of gravity is shifted from immediately below the shaft portion of the dual-key hook, a bending load acts on the dual-key hook, and thus, the dual-key hook and a thrust bearing are strongly rubbed. As a result, a smooth rotation of the dual-key hook is hindered, and thus, there is a possibility that the shaft of the dual-key hook cannot withstand the bending load and thus, the shaft of the dual-key hook is broken.
It is desirable to provide a hook device having a plurality of locking portions and a structure capable of automatically adjusting a relative position between the hook device and the center of gravity of the cargo.
According to the present invention, it is possible to automatically adjust a relative position between a hook device and a center of gravity of a cargo in the hook device including a plurality of locking portions. In addition, objects, configurations, and effects except for the above-described those are clarified in description of the following embodiment.
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The crawler crane 1 includes a lower traveling body (crawler) 10 which can travel and an upper turning body 20 which is turnably supported by the lower traveling body 10 via a turning bearing 20a. The lower traveling body 10 includes a pair of endless tracks 11a and 11b (in
Each of the endless tracks 11a and 11b1 mainly includes a drive wheel 12 which is disposed on a rear end, a driven wheel 13 which is disposed on a front end, a plurality of rollers 14 which are disposed between the drive wheel 12 and the driven wheel 13, and a shoe 15 which is wound around the drive wheel 12, the driven wheel 13, and the rollers 14. A driving force of the engine is transmitted to the drive wheels 12 and the endless tracks 11a and 11b are rotated, and thus, the lower traveling body 10 travels. In addition, instead of the lower traveling body 10 having the endless tracks 11a and 11b, the lower traveling body 10 may be a wheeled type lower traveling body.
The boom 21 includes a tower boom 21a, a tower jib 21b, a mast 21c, a front strut 21d, and a rear strut 21e. A proximal end of the tower boom 21a is supported by a front end of the upper turning body 20 and extends forward and upward of the upper turning body 20. The tower jib 21b is supported by a distal end of the tower boom 21a and extends forward and upward of the upper turning body 20.
The mast 21c is supported by the upper turning body 20 near a connection position between the tower boom 21a and the mast 21c and extends rearward and upward of the upper turning body 20. The front strut 21d and the rear strut 21e are provided near a connection portion between the tower boom 21a and the tower jib 21b. In addition, a length of each of the tower boom 21a and the tower jib 21b can be appropriately changed. Moreover, a derricking motion of the boom 21 is performed by winches 22a and 22b.
The winch 22a is supported by the upper turning body 20. A wire 22c extending from the winch 22a is connected to a distal end of the mast 21c. In addition, distal ends of the mast 21c and the tower boom 21a are connected by a wire 22d. In addition, the winch 22a lets out the wire 22c, and thus, the tower boom 21a is lowered. The winch 22a winds the wire 22c, and thus, the tower boom 21a is raised.
The winch 22b is disposed on a proximal end portion of the tower boom 21a. The wires 22e and 22f extending from the winch 22b are connected to a distal end of the tower jib 21b via a distal end of the rear strut 21e and a distal end of the front strut 21d. In addition, the winch 22b lets out the wires 22e and 22f, and thus, the boom 21 is lowered. The winch 22b winds the wires 22e and 22f, and thus, the boom 21 is raised. That is, the tower boom 21a and the tower jib 21b are supported by the upper turning body 20 in a state where derricking motions of the tower boom 21a and the tower jib 21b can be performed.
The boom 21 includes a wire 27, a winch 29, and a hook block (hook device) 30. The wire 27 extends along the tower boom 21a and tower jib 21b from the winch 29 and is suspended from the distal end of the tower jib 21b. The winch 29 is provided near the proximal end of the tower boom 21a to let out or wind the wire 27. The hook block 30 is hung on the wire 27 suspended from the distal end of the tower jib 21b.
The winch 29 lets out the wire 27, and thus, the hook block 30 is lowered. In addition, the winch 29 winds the wire 27, and thus, the hook block 30 is raised. However, the tower jib 21b may be omitted such that the hook block 30 is hung on the wire 27 suspended from the distal end of the tower boom 21a.
In the cabin 23, an internal space on which an operator who operating the crawler crane 1 rides is formed. An operation device (steering, pedal, lever, switch, or the like) is disposed in the internal space of the cabin 23. The operation device receives an operation of the operator to travel the lower traveling body 10, turn the upper turning body 20, performs the derricking motion of the boom 21, or raise or lower the hook block 30 (that is, cause the winch 29 to let out or wind the wire 27). That is, the operator who rides on the cabin 23 operates the operation device, and thus, the crawler crane 1 is operated.
Next, details of the hook block 30 according to the present embodiment will be described with reference to
The hook block 30 mainly includes a sheave block 31, a central shaft 32, a connection member 33, a first single-hook 34, and a second single-hook 35.
The sheave block 31 includes a plurality of sheaves 31a around which the wire 27 suspended from the distal end of the boom 21 is wound, a thrust bearing 31b which rotatably supports the central shaft 32 around an axis extending in the upward-downward direction, and a trunnion 31c which fixes the thrust bearing 31b to the sheave block 31.
The central shaft 32 includes a columnar small-diameter portion 32a, a large-diameter portion 32b which is provided on one end (upper end) of the small-diameter portion 32a, and an eye end 32c which is provided on the other end (lower end) of the small-diameter portion 32a. An inner diameter of the thrust bearing 31b is larger than a diameter of the small-diameter portion 32a and is smaller than a diameter of the large-diameter portion 32b. That is, if the small-diameter portion 32a is inserted into the thrust bearing 31b, an end face of the large-diameter portion 32b is supported by the thrust bearing 31b. The eye end 32c is opened below a lower end of the sheave block 31 in the forward-rearward direction.
The connection member 33 includes a first shaft 33a, a second shaft 33b, and a third shaft 33c which respectively extend in the forward-rearward direction, and a pair of support plates 33f and 33g which supports the first shaft 33a, the second shaft 33b, and the third shaft 33c. The connection member 33 is a member which connects the central shaft 32, the first single-hook 34, and the second single-hook 35 to each other.
The first shaft 33a and the second shaft 33b are disposed at positions separated from each other in the right-left direction. More specifically, the first shaft 33a and the second shaft 33b are disposed on sides opposite to each other such that the third shaft 33c is interposed therebetween, in the right-left direction. The first shaft 33a and the second shaft 33b are disposed at a position separated from the third shaft 33c in the upward-downward direction. That is, when the connection member 33 is viewed in the forward-rearward direction, a triangle which connects centers of the first shaft 33a, the second shaft 33b, and the third shaft 33c is an isosceles triangle with a central position of the third shaft 33c as an apex angle. In addition, preferably, the apex angle is 90° or less.
The pair of support plates 33f and 33g is disposed to be separated from each other in the forward-rearward direction by a distance L1. In addition, the support plate 33f supports one end of each of the first shaft 33a, the second shaft 33b, and the third shaft 33c, and the support plate 33g supports the other end of each of the first shaft 33a, the second shaft 33b, and the third shaft 33c. That is, the first shaft 33a, the second shaft 33b, and the third shaft 33c are disposed between the pair of support plates 33f and 33g.
When viewed in the forward-rearward direction, an appearance of each of the support plates 33f and 33g exhibits an isosceles triangle in which each vertex is chamfered. More specifically, when the support plates 33f and 33g are viewed in the forward-rearward direction, each of the support plates 33f and 33g includes a first side 33x along an imaginary line connecting the centers of the first shaft 33a and the third shaft 33c to each other, a second side 33y along an imaginary line connecting the centers of the second shaft 33b and the third shaft 33c to each other, and a third side 33z along an imaginary line connecting the first shaft 33a and the second shaft 33b to each other. An angle α between the first side 33x and the second side 33y is set to 90° or less.
The first single-hook 34 includes a shaft portion 34a, an eye end 34b which is provided on one end (upper end) of the shaft portion 34a, a locking portion (first locking portion) 34c which is curved from the other end (lower end) of the shaft portion 34a and extends upward, and a stopper 34d which prevents dropping of the wire hooked to the locking portion 34c. The second single-hook 35 has the same shape as that of the first single-hook 34, and includes a shaft portion 35a, an eye end 35b, a locking portion (second locking portion) 35c, and a stopper 35d. Each of the eye end 34b and 35b is opened in the forward-rearward direction.
Each of the first single-hook 34 and the second single-hook 35 is a so-called “single-key hook” having only one locking portion. In addition, when viewed in the right-left direction, a thickness dimension L2 of each of the first single-hook 34 and the second single-hook 35 is set smaller (L1>L2) than the separation distance L1 of the pair of support plates 33f and 33g. In addition, for example, each of the first single-hook 34 and the second single-hook 35 can hang a cargo of about 80 tons. That is, the entire hook block 30 has the same performance as that of a dual-key hook capable of hanging a cargo of about 160 tons.
The first shaft 33a is inserted into the eye end 34b of the first single-hook 34, the second shaft 33b is inserted into the eye end 35b of the second single-hook 35, and the third shaft 33c is inserted into the eye end 32c of the central shaft 32. That is, the central shaft 32, the first single-hook 34, and the second single-hook 35 are indirectly connected to each other via the connection member 33.
In addition, the first single-hook 34 and the second single-hook 35 are disposed on sides opposite to each other such that the central shaft 32 is interposed therebetween, in the right-left direction. In other words, the central shaft 32 is disposed between the first single-hook 34 and the second single-hook 35 in the right-left direction. In addition, the first single-hook 34 and the second single-hook 35 (more specifically, locking portions 34c and 35c) are separated from each other in the right-left direction.
Moreover, the first single-hook 34 and the second single-hook 35 are connected to the connection member 33 in a state where the locking portions 34c and 35c facing outward. That is, the first single-hook 34 and the second single-hook 35 are connected to the connection member 33 with a mirror symmetric positional relationship with respect to the imaginary line V1 extending in the upward-downward direction through the central shaft 32.
In addition, each of the first single-hook 34 and the second single-hook 35 can be independently rotated around an axis extending in the forward-rearward direction (that is, an extension direction of each of the first shaft 33a and the second shaft 33b). Meanwhile, each of the first single-hook 34 and the second single-hook 35 cannot rotate independently around an axis extending in the upward-downward direction. Therefore, it is not necessary to interpose thrust bearings between the connection member 33 and the first single-hook 34 and between the connection member 33 and the second single-hook 35.
Moreover, the central shaft 32 is connected to the connection member 33 so as to be relatively rotatable around an axis extending in the forward-rearward direction (that is, an extending direction of the third shaft 33c). Meanwhile, the central shaft 32 cannot rotate around an axis extending in the upward-downward direction with respect to the connection member 33. Furthermore, the central shaft 32 is supported by the thrust bearing 31b of the sheave block 31 in a state of being rotatable about an axis extending in the upward-downward direction. That is, the central shaft 32, the connection member 33, the first single-hook 34, and the second single-hook 35 cannot rotate independently and can integrally rotate around the axis extending in the upward-downward direction.
Next, a movement in a case where a long cargo 36 is hung on the hook block 30 will be described with reference to
First, as shown in
In this case, each of the central shaft 32, the connection member 33, the first single-hook 34, and the second single-hook 35 relatively rotates on a virtual plane including the upward-downward direction and the right-left direction such that the center of gravity G of the cargo 36 moves to immediately below the central shaft 32. In other words, each of the central shaft 32, the connection member 33, the first single-hook 34, and the second single-hook 35 rotates around the axis extending in the forward-rearward direction such that the center of gravity G of the cargo 36 is positioned on the imaginary line V1.
More specifically, the connection member 33 rotates with respect to the central shaft 32 about the third shaft 33c such that the first single-hook 34 is positioned below the second single-hook 35 (in the counterclockwise direction in
Next, as shown in
More specifically, the connection member 33 rotates with respect to the central shaft 32 until the centers of the first shaft 33a and the third shaft 33c are aligned with each other in the upward-downward direction. In addition, the hook block 30 according to the present embodiment is configured to satisfy the following relationship in the state where the connection member 33 is largely inclined as described above.
First, the first single-hook 34 and the second single-hook 35 do not come into contact with each other. That is, the first single-hook 34 and the second single-hook 35 are connected to the connection member 33 with a positional relationship in which the first single-hook 34 and the second single-hook 35 do not contact with each other regardless of the rotation angle of the connection member 33. In other words, the first single-hook 34 and the second single-hook 35 are separated from each other in the right-left direction regardless of the rotation angle of the connection member 33.
In addition, a portion of the second single-hook 35 enters between the pair of support plates 33f and 33g. That is, the second single-hook 35 does not come into contact with the pair of support plates 33f and 33g regardless of the rotation angle of the connection member 33. Furthermore, the second side 33y of the pair of support plates 33f and 33g is approximately parallel to an imaginary line extending in the right-left direction through the center of the third shaft 33c. That is, the connection member 33 does not come into contact with the sheave block 31 regardless of the rotation angle of the connection member 33.
The crawler crane 1 has the above-described configuration, and thus, for example, the following operation and effect are exerted.
In a case where the long cargo 36 is lifted by the hook block 30 according to the present embodiment, the cargo 36 is locked to the locking portions 34c and 35c in a state where a longitudinal direction of the cargo 36 faces the right-left direction. In this case, as shown in
In addition, according to the present embodiment, since the first single-hook 34 and the second single-hook 35 cannot rotate around the axis extending in the upward-downward direction, and thus, it is not necessary to interpose a thrust bearing between the first single-hook 34 and the second single-hook 35, and the connection member 33. As a result, as compared to the hook block having the thrust bearing described in the related art, it is possible to shorten an entire length of the hook block 30 in the upward-downward direction. That is, if this hook block 30 is mounted, a work near a limit height of the crawler crane 1 is possible.
Further, in the hook block 30 according to the present embodiment, if the locking portions 34c and 35c face the inside and are attached to the connection member 33, it is necessary for a worker to put hands into a portion between the first single-hook 34 and the second single-hook 35 so as to perform the hooking. Therefore, as shown in
Moreover, according to the present embodiment, as shown in
In addition, as shown in
In addition, the hook block 30 according to the present embodiment is configured and disposed such that the connection member 33 and the sheave block 31 do not come into contact with each other regardless of the rotation angle of the connection member 33. Therefore, it is possible to shorten a length of the central shaft 32. As a result, if this hook block 30 is mounted, a work near a limit height of the crawler crane 1 is possible.
The hook block according to the present invention is not limited to the configuration shown in
First, the hook block 40 shown in
The shackle 45 has a U-shaped appearance. In addition, an inside of the U shape functions as a locking portion for locking the wire 36b. That is, the shape of the locking portion is not limited to the locking portions 34c and 35c. In addition, a pair of through-holes 46 and 47 penetrating the shackle 45 in the forward-rearward direction is formed on both end portions of the shackle 45.
As shown in
Next, the hook block 50 shown in
The connection member 53 includes a first shaft 53a, a second shaft 53b, a third shaft 53c, a fourth shaft 53d, and a fifth shaft 53e which respectively extend in the forward-rearward direction, and a pair of support plates 53f and 53g (the support plate 53g is not shown) which supports the first shaft 53a, the second shaft 53b, the third shaft 53c, the fourth shaft 53d, and the fifth shaft 53e.
The first shaft 53a, the second shaft 53b, the fourth shaft 53d, and the fifth shaft 53e are disposed to be separated from each other in the right-left direction. In addition, the third shaft 53c is disposed between the first shaft 53a and the fourth shaft 53d, and the second shaft 53b and the fifth shaft 53e in the right-left direction. In other words, the first shaft 53a and the fourth shaft 53d, and the second shaft 53b and the fifth shaft 53e are disposed on sides opposite to each other such that the third shaft 53c is interposed therebetween, in the right-left direction.
When viewed in the forward-rearward direction, each of the pair of support plates 53f and 53g has an approximately fans-shaped appearance. In addition, the third shaft 53c is disposed at a main position of the fan shape, and the first shaft 53a, the second shaft 53b, the fourth shaft 53d, and the fifth shaft 53e are disposed along an arc. That is, the shape of the connection member is not limited to the example of
First, the number of the connection members is not limited to one. As another example, a second connection member (not shown) may be connected to the first shaft 33a of the connection member 33 (first connection member) of
In addition, the shape of the connection member is not limited to the examples of
Moreover, the connection member 33, the first single-hook 34, and the second single-hook 35 may be integrally formed with each other. That is, in a state where the locking portions 34c and 35c cannot rotate independently around an axis extending in the upward-downward direction and can integrally rotate around the axis extending in the forward-rearward direction, the locking portions 34c and 35c may be connected to the central shaft 32. That is, for example, the “locking portions 34c and 35c being connected to the central shaft 32” includes both an indirect connection case where the locking portions 34c and 35c are connected to the central shaft 32 via the connection member 33 as described in the embodiment, and a direct connection case where a member obtained by integrally forming the connection member 33, the first single-hook 34, and the second single-hook 35 is connected to the central shaft 32.
In addition, a specific example of the crane is not limited to the crawler crane 1, and may be a wheel crane, a rough terrain crane, an all-terrain crane, or the like. In addition, each of the hook blocks 30, 40, and 50 can be applied not only to a mobile crane having a traveling body but also to a ceiling crane or the like.
It should be understood that the invention is not limited to the above-described embodiment, but may be modified into various forms on the basis of the spirit of the invention. Additionally, the modifications are included in the scope of the invention.
Number | Date | Country | Kind |
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2018-142844 | Jul 2018 | JP | national |