Patent Description:
Conventionally, in assembling and disassembling work for a work machine such as a crane, structure members such as a jib, a boom, and a strut included in the crane are lifted up by an auxiliary crane (accompanying machine) and attached to other parts of the crane. For example, Patent Literature <NUM> discloses lifting work of lifting up a strut of a crane by an auxiliary crane in order to attach the strut to a distal end portion of a boom (<FIG>, paragraphs <NUM> and <NUM> of Patent Literature <NUM>).

In such lifting work, a plurality of slings are used as suspending members. Each of the plurality of slings is made of a wide tape-shaped rope provided with rings at both ends. The structure member includes a plurality of protrusions (suspending rings) for attaching the plurality of slings. Each of the plurality of slings is attached to any one of the plurality of protrusions and a hook of the auxiliary crane by conducting the following attaching work. First, a worker conducting the slinging work hangs both rings of the sling on the hook of the auxiliary crane. This causes the sling to form a loop. Next, the worker hooks a part near a lower end of the loop on the protrusion of the structure member. As a result, the sling is attached to the hook and the protrusion. The worker conducts the above-described attaching work for each of the plurality of slings.

When the attaching work for the plurality of slings is completed, each of the plurality of slings is in a loosened state between the hook and the protrusion. Therefore, an operator who operates the auxiliary crane conducts operation (hook raising operation) for gradually raising the hook of the auxiliary crane so that the plurality of slings change from the loosened state (relaxed state) to a taut state (tensioned state).

However, since the sling is in the relaxed state, the part near the lower end of the loop hooked on the protrusion of the structure member may come off from the protrusion in a raising process of the hook by the hook raising operation. Therefore, the worker who conducts the slinging work needs to conduct assisting work to prevent each of the plurality of slings from coming off the protrusion in the raising process of the hook. In addition, the operator who operates the auxiliary crane needs to carefully conduct the hook raising operation so as to gradually raise the hook in cooperation with the worker so that each of the plurality of slings does not come off the protrusion. Lifting work accompanied by the assisting work and the hook raising operation described above require a lot of labor by the worker who conducts the slinging work, and it takes long time to complete the lifting work. Therefore, it is desired to reduce worker's labor in the lifting work and shorten time required for the lifting work.

The present invention has been made in view of the above problems, and an object thereof is to provide a work machine suspension device, a retention device, and a method for suspending a structure member which enable reduction in worker's labor in lifting work of lifting up a structure member included in a work machine, and enable reduction in time required for the lifting work.

With respect to the retention device, the above object is solved by a retention device having the features of claim <NUM>.

A work machine suspension device having the retention device is stated in claim <NUM>. Further developments are stated in the dependent claims.

A method for suspending a structure member is stated in claim <NUM>.

In the following, work machine suspension devices will be described with reference to the drawings.

<FIG> is a side view showing lifting work for lifting up a structure member included in a crane <NUM> by using a work machine suspension device <NUM> according to an example not forming part of the invention. <FIG> is a perspective view showing the work machine suspension device <NUM>. <FIG> is a perspective view showing a retention device <NUM> of the work machine suspension device <NUM>, the view illustrating a state in which a support member <NUM> of the retention device <NUM> is disposed at a retention position. <FIG> is a front view showing the retention device <NUM> of the work machine suspension device <NUM>, the view being for explaining a retention position and an entry allowed position of the support member <NUM> of the retention device <NUM>. <FIG> is a perspective view showing the retention device <NUM> of the work machine suspension device <NUM>, the view illustrating a state in which the support member <NUM> of the retention device <NUM> is disposed at the entry allowed position. <FIG> is a perspective view showing the retention device <NUM> of the work machine suspension device <NUM>. Hereinafter, the work machine suspension device <NUM> will be simply referred to as a suspension device <NUM>.

"Up", "down", "left", "right", "front" and "rear" directions illustrated in the drawings are indicated for convenience to explain structures of suspension devices <NUM> according to a plurality of embodiments, and do not limit the structure and usage of the suspension device. In addition, the "up", "down", "left", "right", "front" and "rear" directions shown in the drawings are indicated to correspond to the respective directions seen from a driver's seat of the crane <NUM>.

As shown in <FIG>, the suspension device <NUM> is attached to a hook <NUM> of an auxiliary crane (lifting equipment) not shown, and is used for lifting work for lifting up a structure member included in the crane <NUM> from the ground. The auxiliary crane is another work machine different from the crane <NUM> shown in <FIG>.

The structure member is not particularly limited and may be any member as long as it is included in the crane <NUM> (an example of a work machine). The structure member may be, for example, a raising and lowering member such as a boom, a jib, or a strut, but is not limited thereto. In a case where the raising and lowering member is configured with a plurality of members, each of the plurality of members is the structure member to be lifted up by the suspension device <NUM>. In the following, description will be made of a case where the structure member is a boom member (specifically, a second intermediate boom member <NUM> to be described later) included in the boom as an example.

The crane <NUM> includes a lower traveling body <NUM>, an upper slewing body <NUM> slewably supported on the lower traveling body <NUM>, and a boom <NUM>. The boom <NUM> is supported by the upper slewing body <NUM> so as to be raised and lowered. The boom <NUM> is configured with a plurality of boom members. The plurality of boom members include a lower boom member <NUM>, a first intermediate boom member <NUM>, the second intermediate boom member <NUM>, and an upper boom member (not shown). The boom <NUM> is assembled by coupling the plurality of boom members to each other on the ground.

<FIG> shows a state where the first intermediate boom member <NUM> is coupled to the lower boom member <NUM> attached to the upper slewing body <NUM>, and further, the second intermediate boom member <NUM> is coupled to the first intermediate boom member <NUM>. As shown in <FIG>, the suspension device <NUM> attached to the hook <NUM> of the auxiliary crane is connected to the second intermediate boom member <NUM>, and the second intermediate boom member <NUM> is lifted up from the ground. In the following, the second intermediate boom member <NUM> exemplified as the structure member to be lifted up by the suspension device <NUM> will be simply referred to as the intermediate boom member <NUM>.

As shown in <FIG> and <FIG>, the suspension device <NUM> includes an attachment part <NUM> and four retention devices <NUM>. The attachment part <NUM> is attached to the hook <NUM> of the lifting equipment in the lifting work, and is lifted up by the lifting equipment. The attachment part <NUM> includes a wire suspension portion <NUM>, four suspension wires <NUM>, a base member <NUM>, and four cylinders <NUM>.

The wire suspension portion <NUM> is attached to the hook <NUM> of the auxiliary crane. Upper end portions of the four suspension wires <NUM> are connected to the wire suspension portion <NUM>, and lower end portions of the four suspension wires <NUM> are connected to the base member <NUM>.

The base member <NUM> extends along a horizontal direction below the four suspension wires <NUM>, and has a rectangular parallelepiped shape in the present embodiment. As an example, when each member of the boom <NUM> is lifted up by the suspension device <NUM>, the base member <NUM> is disposed so that one side of the base member <NUM> extends in a front-rear direction, and the other side of the base member <NUM> orthogonal to the one side extends in a right-left direction. The base member <NUM> is supported by the hook <NUM> of the auxiliary crane via the wire suspension portion <NUM> and the four suspension wires <NUM>.

The lower end portions of the four suspension wires <NUM> are fixed to members provided at the four corners of an upper surface of the base member <NUM>. The four suspension wires <NUM> connect the wire suspension portion <NUM> and the base member <NUM> to each other such that the base member <NUM> maintains a horizontal attitude in a state where the wire suspension portion <NUM> is lifted up by the hook <NUM> of the auxiliary crane. The number of the suspension wires <NUM> is not limited to four. Further, although in the present embodiment, the base member <NUM> has a rectangular parallelepiped shape, i.e., a quadrangle shape in a plan view, the present invention is not limited thereto. For the base member <NUM>, various shapes can be adopted such as a shape having a polygon other than a quadrangle in a plan view, a circular shape or an ellipse shape in a plan view, and a combination of these shapes.

Each of the four cylinders <NUM> is an actuator that is configured with a hydraulic cylinder that expands and contracts upon reception of supply of hydraulic oil, and that operates so as to cause the corresponding retention device <NUM> to move up and down. Each of the four cylinders <NUM> has a cylinder main body <NUM>, a cylinder rod <NUM>, and a cylinder bracket <NUM>. The four cylinders <NUM> are fixed to members provided at the four corners of a lower surface portion of the base member <NUM>. The cylinder bracket <NUM> is fixed to an upper portion of the cylinder main body <NUM>. The cylinder bracket <NUM> is rotatably attached to the base bracket <NUM> of the base member <NUM>. As a result, each of the four cylinders <NUM> is rotatably supported by the base member <NUM>.

In the present embodiment shown in <FIG>, the suspension device <NUM> includes a switching valve 1A, a drive source 1B, a base portion supply path 1C, and four cylinder supply paths 1D. The drive source 1B includes an oil tank (not shown). The switching valve 1A switches supply and shut-off of a hydraulic oil supplied from the drive source 1B such as a hydraulic pump to the four cylinders <NUM>. The base portion supply path 1C is an oil path connecting the switching valve 1A and the drive source 1B. The cylinder supply path 1D is an oil path connecting the switching valve 1A and each cylinder <NUM>. According to such a configuration, each retention device <NUM> can be moved up and down. This enables height positions of the four retention devices <NUM> to be adjusted according to a shape and a lifting attitude of the structure member, and enables each retention device <NUM> to be easily connected to the structure member. As a result, workability of the lifting work can be improved. The cylinder <NUM> may be an electric cylinder, and in this case, the drive source 1B is configured with a power source.

As shown in <FIG>, the four retention devices <NUM> are supported by the four cylinders <NUM> of the attachment part <NUM>, respectively. The four retention devices <NUM> are attached to four retained portions <NUM> of the intermediate boom member <NUM>, respectively. The four retention devices <NUM> have the same structure. Therefore, one of the four retention devices <NUM> will be described below.

As shown in <FIG> and <FIG>, the retention device <NUM> includes a proximal end portion <NUM> connected to a lower end portion of the cylinder rod <NUM> of the cylinder <NUM>, a first leg portion <NUM>, a second leg portion <NUM>, the support member <NUM>, a support member moving mechanism <NUM>, and a drive part <NUM>. The proximal end portion <NUM> has an attachment bracket <NUM> (attachment part <NUM>).

Although in the present embodiment, the proximal end portion <NUM> is located in an upper portion of the retention device <NUM> and has a substantially rectangular parallelepiped shape, the shape is not limited to such a shape. The attachment bracket <NUM> is located on an upper portion of the proximal end portion <NUM> and is rotatably attached to the lower end portion of the cylinder rod <NUM>.

The first leg portion <NUM> extends downward from one end portion in a horizontal direction of the proximal end portion <NUM> and is supported by the proximal end portion <NUM>. The first leg portion <NUM> includes a first leg portion main body 21A disposed below the proximal end portion <NUM>. In the present embodiment, the first leg portion <NUM> is configured with only the first leg portion main body 21Abecause the entire first leg portion <NUM> is located below the proximal end portion <NUM>. The first leg portion <NUM> may include not only the first leg portion main body 21Abut also other member, for example, as in a third embodiment to be described later which is shown in <FIG>.

The second leg portion <NUM> extends downward from the other end portion in the horizontal direction of the proximal end portion <NUM> and is supported by the proximal end portion <NUM>. The second leg portion <NUM> is disposed at an interval in the horizontal direction from the first leg portion <NUM>. The second leg portion <NUM> includes a second leg portion main body 22A disposed below the proximal end portion <NUM>. In the present embodiment, the second leg portion <NUM> is configured with only the second leg portion main body 22A because the entire second leg portion <NUM> is located below the proximal end portion <NUM>. The second leg portion <NUM> may include not only the second leg portion main body 22A but also other member, for example, as in the third embodiment to be described later which is shown in <FIG>.

As shown in <FIG>, a first lower end portion of the first leg portion <NUM> and a second lower end portion of the second leg portion <NUM> have such a first inclined surface <NUM> and a second inclined surface <NUM>, respectively, that makes a distance between the lower end portions increases downward. At the time of relative displacement of the retained portion <NUM> in an up-down direction with respect to the retention device <NUM>, the retained portion <NUM> can be guided by one or both of the first inclined surface <NUM> and the second inclined surface <NUM> so as to relatively move. This enables the retained portion <NUM> to smoothly enter between the first leg portion main body 21A and the second leg portion main body 22A.

Of the first leg portion <NUM>, the first lower end portion may be integrally molded with a portion other than the first lower end portion, and may be configured to be removable from a portion other than the first lower end portion. Similarly, of the second leg portion <NUM>, the second lower end portion may be integrally molded with a portion other than the second lower end portion, and may be configured to be removable from a portion other than the second lower end portion.

Further, although in the present embodiment, the proximal end portion <NUM>, the first leg portion <NUM>, and the second leg portion <NUM> are integrally molded, the present invention is not limited thereto. After each of the proximal end portion <NUM>, the first leg portion <NUM>, and the second leg portion <NUM> is individually molded, these members may be coupled to each other.

As shown in <FIG> and <FIG>, the support member <NUM> is supported by the first leg portion main body 21A so as to be movable between the entry allowed position and the retention position.

As shown in <FIG>, the entry allowed position is a position where the support member <NUM> retracts from the second leg portion main body 22A to allow the retained portion <NUM> of the intermediate boom member <NUM> to enter between the first leg portion main body 21A and the second leg portion main body 22A. Specifically, in the present embodiment, when the support member <NUM> is disposed at the entry allowed position, the plurality of retention devices <NUM> are moved downward to cause the corresponding retained portion <NUM> to enter between the first leg portion main body 21A and the second leg portion main body 22A of each retention device <NUM>.

As shown in <FIG> and <FIG>, the retention position is a position where the retained portion <NUM> of the intermediate boom member <NUM> can be retained on the support member <NUM> while the support member <NUM> is supported by the first leg portion main body 21A and the second leg portion main body 22A.

At the retention position, the support member <NUM> straddles between the first leg portion main body 21A and the second leg portion main body 22A to couple the first leg portion main body 21A and the second leg portion main body 22A. When the support member <NUM> is disposed at the retention position, the proximal end portion <NUM>, the first leg portion main body 21A, the second leg portion main body 22A, and the support member <NUM> form a housing portion A1 in which the retained portion <NUM> is housed. The housing portion A1 is a region surrounded by the proximal end portion <NUM>, the first leg portion main body 21A, the second leg portion main body 22A, and the support member <NUM>.

When the support member <NUM> is disposed at the retention position, the retained portion <NUM> retained on the support member <NUM> is prevented from moving downward relative to the support member <NUM>, and is retained in the housing portion A1.

When the support member <NUM> goes away from the second leg portion main body 22A to be disposed at the entry allowed position, an entry path A2 for the retained portion <NUM> to enter the housing portion A1 is formed between the support member <NUM> and the second leg portion main body 22A. The entry path A2 is a region between the support member <NUM> and the second leg portion main body 22A.

In the present embodiment, the first leg portion main body 21A has a first through hole <NUM> that horizontally penetrates the first leg portion main body 21A, and the second leg portion main body 22A has a second through hole <NUM> that horizontally penetrates the second leg portion main body 22A. As shown in <FIG>, the support member <NUM> is supported by the first leg portion main body 21A at both the entry allowed position and the retention position because of being inserted into the first through hole <NUM> at both positions. When the support member <NUM> moves from the entry allowed position to the retention position, an end portion of the support member <NUM> is inserted into the second through hole <NUM>, so that the support member is supported by the first leg portion main body 21A and the second leg portion main body 22A.

Although in the present embodiment, a movement direction of the support member <NUM> is the horizontal direction, the direction is not limited thereto and may be a direction inclined with respect to the horizontal direction.

In the present embodiment, when the support member <NUM> is disposed at the entry allowed position, the support member <NUM> is not disposed between the first leg portion main body 21A and the second leg portion main body 22A. As a result, when the retained portion <NUM> relatively moves with respect to the retention device <NUM> from an opening between a lower end <NUM> of the first leg portion main body 21A and a lower end <NUM> of the second leg portion main body 22A toward the housing portion A1, the support member <NUM> does not interfere with the movement of the retained portion <NUM>. However, when the support member <NUM> is disposed at the entry allowed position, a portion including the end portion (distal end portion) of the support member <NUM> may be disposed between the first leg portion main body 21A and the second leg portion main body 22A. In this case, a distance (a distance in the horizontal direction) between the distal end portion of the support member <NUM> disposed between the first leg portion main body 21A and the second leg portion main body 22A and the second leg portion main body 22A is set to a size that allows the retained portion <NUM> to pass in the up-down direction between the distal end portion of the support member <NUM> and the second leg portion main body 22A. Further, in this case, the distal end portion of the support member <NUM> preferably has such an inclined surface that makes the distance in the horizontal direction between the distal end portion and the second leg portion main body 22A increase downward. This enables the retained portion <NUM> to smoothly enter between the first leg portion main body 21A and the second leg portion main body 22A while being guided by the inclined surface of the support member <NUM>.

As shown in <FIG> and <FIG>, the retained portion <NUM> of the intermediate boom member <NUM> to which the retention device <NUM> is attached is a connection part at which a pair of inclined pipes P2, P2 are connected to a main pipe P1 in the intermediate boom member <NUM>. In this embodiment, the intermediate boom member <NUM> has a lattice structure. Specifically, the intermediate boom member <NUM> includes four main pipes P1 and the plurality of inclined pipes P2. Each of the four main pipes P1 is disposed along a longitudinal direction of the boom <NUM>. Each of the plurality of inclined pipes P2 connects two adjacent main pipes P1 to each other. As shown in <FIG>, among the plurality of inclined pipes P2, upper end portions of two adjacent inclined pipes P2, P2 are connected to one main pipe P1 so as to be adjacent to each other. Of the two inclined pipes P2, P2, the inclined pipe P2 on the front side is inclined so as to have a lower end portion located in front of the upper end portion, and the inclined pipe P2 on the rear side has a lower end portion located behind the upper end portion.

As shown in <FIG>, the support member <NUM> has a shape corresponding to a shape of a lower portion of the retained portion <NUM> that is retained on the support member <NUM>. Specifically, the support member <NUM> has a pair of inclined surfaces <NUM> and <NUM> (an example of a contact surface) inclined along surfaces of the two inclined pipes P2, P2 in the retained portion <NUM>. The pair of inclined surfaces <NUM> and <NUM> are formed in an upper portion of the support member <NUM>. As shown in <FIG>, when the support member <NUM> is viewed in a longitudinal direction thereof, one inclined surface <NUM> (the inclined surface on the left side in <FIG>) is inclined in the same direction as the surface of one inclined pipe P2 (the inclined pipe on the left side in <FIG>) with respect to a vertical direction, and the other inclined surface <NUM> (the inclined surface on the right side in <FIG>) is inclined in the same direction as the surface of the other inclined pipe P2 (the inclined pipe on the right side in <FIG>) with respect to the vertical direction. The pair of inclined surfaces <NUM> and <NUM> are in contact with the surfaces of the two inclined pipes P2, P2 in the retained portion <NUM>. Since the support member <NUM> only needs to be capable of retaining the retained portion <NUM>, it does not necessarily have to have the pair of inclined surfaces <NUM> and <NUM> as shown in <FIG>, and one or both of the inclined surfaces <NUM> and <NUM> can be omitted.

The support member <NUM> includes a rigid member main body <NUM> made of metal, for example, steel, and a pair of cushioning members <NUM> and <NUM> attached to the member main body <NUM>. The pair of inclined surfaces <NUM> and <NUM> form surfaces of the pair of cushioning members <NUM> and <NUM>, respectively. The pair of cushioning members <NUM> and <NUM> are formed of a material having hardness lower than that of the member main body <NUM>. This suppresses the retained portion <NUM> of the intermediate boom member <NUM> from being scratched. The pair of cushioning members <NUM> and <NUM> preferably have cushioning properties. The pair of cushioning members <NUM> and <NUM> preferably have a frictional resistance that makes them less slippery with respect to a surface of the retained portion <NUM>. It is also possible to omit one or both of the pair of cushioning members <NUM> and <NUM>.

The support member moving mechanism <NUM> operates so as to move the support member <NUM> between the entry allowed position and the retention position. The drive part <NUM> drives the support member moving mechanism <NUM>.

As shown in <FIG> and <FIG>, in the present embodiment, the drive part <NUM> is configured with an electric motor <NUM>, and the support member moving mechanism <NUM> is configured with a mechanism having a plurality of gears rotated by the electric motor <NUM>. The electric motor <NUM> and the plurality of gears are housed in a case <NUM>, and the case <NUM> is attached to a side surface of the first leg portion main body 21A. The drive part <NUM> is not limited to the electric motor <NUM>, and may be configured by other drive mechanism such as a hydraulic motor.

The plurality of gears include a first gear 26A, a second gear 26B, and a third gear 26C. The first gear 26A is connected to a rotation shaft of the electric motor <NUM> to rotate with rotation of the electric motor <NUM>. The second gear 26B circumscribes the first gear 26A and rotates with rotation of the first gear 26A. The third gear 26C is disposed at a position deviated from the second gear 26B in an axial direction of a rotation shaft thereof and is connected to the rotation shaft of the second gear 26B to rotate with rotation of the second gear 26B.

A rack portion 24A that meshes with the third gear 26C is formed on a surface of the support member <NUM> (a lower surface of the support member <NUM> in <FIG>). The rack portion 24Ais a part in which a plurality of teeth are formed on a flat lower surface of the support member <NUM>. Therefore, a rotational force of the electric motor <NUM> is transmitted to the first gear 26A, the second gear 26B, and the third gear 26C in this order, and is converted into a linear movement of the rack portion 24A. In other words, since the support member <NUM> is allowed to move in a direction corresponding to a rotation direction of the electric motor <NUM>, the support member can move between the retention position and the entry allowed position.

The support member moving mechanism <NUM> is not limited to a mechanism having a plurality of gears, and may be configured by a mechanism having only a single gear. In this case, for example, the drive part <NUM> such as the electric motor <NUM> directly causes a single gear (for example, the third gear 26C) to rotate, and a rotational force of the single gear is converted into a linear movement of the rack portion 24A that meshes with the single gear.

<FIG>, <FIG>, <FIG> and <FIG> are views showing lifting work for lifting up the intermediate boom member <NUM> using the suspension device <NUM>. <FIG> and <FIG> are views showing lifting work for lifting up a structure member using a suspension device <NUM> according to a reference example.

<FIG> is an enlarged perspective view showing a state in which a sling <NUM> of the suspension device <NUM> according to the reference example is attached to a protrusion <NUM> of an intermediate boom member 106A, and <FIG> is a side view showing the state. <FIG> is an enlarged side view showing a state in which the sling <NUM> of the suspension device <NUM> according to the reference example is disengaged from the protrusion <NUM> of the intermediate boom member 106A.

First, the suspension device according to the reference example and a suspending method using the same will be briefly described. As shown in <FIG> and <FIG>, the suspension device <NUM> according to the reference example is configured with a plurality of the slings <NUM>. The intermediate boom member 106A includes a plurality of the protrusions <NUM> (suspending rings) for attaching the plurality of slings <NUM>. A worker conducting slinging work hangs both rings of the sling <NUM> on the hook <NUM> of the auxiliary crane. As a result, the sling <NUM> forms a loop. Next, the worker hooks a portion near a lower end of the loop on the protrusion <NUM> of the intermediate boom member 106A. As a result, the sling <NUM> is attached to the hook <NUM> and the protrusion <NUM>. The worker conducts the above-described attaching work for each of the plurality of slings <NUM>.

As shown in <FIG>, at the time when the attaching work for the plurality of slings <NUM> is completed, each of the plurality of slings <NUM> is in a loosened state between the hook <NUM> and the protrusion <NUM>. Therefore, the operator who operates the auxiliary crane conducts operation (hook raising operation) for gradually raising the hook <NUM> of the auxiliary crane so as to have a state change from a state where the plurality of slings <NUM> are loosened (relaxed state) as shown in <FIG> to a state where the plurality of slings <NUM> are taut (tensioned state) as shown in <FIG>.

Since as shown in <FIG> and <FIG>, the sling <NUM> is in the relaxed state, the portion near the lower end of the loop hooked on the protrusion <NUM> of the intermediate boom member 106A might come off the protrusion <NUM> in the raising process of the hook <NUM> by the hook raising operation as shown in <FIG>. Accordingly, the worker who conducts the slinging work needs to conduct assisting work so that each of the plurality of slings <NUM> does not come off the protrusion <NUM> in the raising process of the hook <NUM>. Further, in cooperation with the worker, the operator who operates the auxiliary crane needs to carefully conduct the hook raising operation to cause the hook <NUM> gradually to rise such that each of the plurality of slings <NUM> does not come off the protrusion <NUM>.

Meanwhile, the suspending method according to the present embodiment is conducted by the following procedure.

As shown in <FIG>, first, the intermediate boom member <NUM> is prepared. The prepared intermediate boom member <NUM> is disposed, for example, on a plurality of bases H.

Next, by conducting operation for causing the electric motor <NUM> to operate by the worker conducting the slinging work or the operator operating the auxiliary crane, the support member <NUM> of each of the plurality of retention devices <NUM> is disposed at the entry allowed position.

Next, as shown in <FIG>, the operator of the auxiliary crane moves the suspension device <NUM> downward by conducting operation of lowering the hook <NUM> of the auxiliary crane. As a result, the plurality of retention devices <NUM> move downward, and as shown in <FIG>, between the first leg portion main body 21A and the second leg portion main body 22A of each retention device <NUM>, the corresponding retained portion <NUM> enters.

Next, the support member <NUM> of each of the plurality of retention devices <NUM> is disposed at the retention position by the operation for causing the electric motor <NUM> to operate by the worker conducting the slinging work or the operator operating the auxiliary crane. The retention device <NUM> is attached to the intermediate boom member <NUM> so that the support member <NUM> is located between the two inclined pipes P2, P2. This suppresses the retention device <NUM> from being displaced in the front-rear direction with respect to the intermediate boom member <NUM>.

Next, as shown in <FIG>, the operator moves the suspension device <NUM> upward by conducting operation of raising the hook <NUM> of the auxiliary crane. As a result, the plurality of retention devices <NUM> move upward, and the intermediate boom member <NUM> is lifted up.

As described above, in the present embodiment, each of the plurality of retention devices <NUM> moves downward relative to the retained portion <NUM> in a state where the support member <NUM> is disposed at the entry allowed position, whereby the retained portion <NUM> enters between the first leg portion main body 21A and the second leg portion main body 22A. Then, with the retained portion <NUM> disposed in the housing portion A1, the support member <NUM> of each of the plurality of retention devices <NUM> moves from the entry allowed position to the retention position. As a result, the retained portion <NUM> is retained on the support member <NUM>, whereby the retained portion <NUM> is prevented from moving downward relative to the support member <NUM>, so that the retained portion <NUM> is retained in the housing portion A1. Retaining the retained portion <NUM> in this way makes it possible to simplify or omit the assisting work by the worker in the raising process of the hook <NUM> by the hook raising operation, and also enables the operator to quickly conduct the hook raising operation.

<FIG> is a perspective view showing a retention device of a suspension device <NUM> according to a first embodiment of the invention. As shown in <FIG>, in the first modification, each of the plurality of retention devices <NUM> further includes an upper pressing member <NUM>, an upper pressing member moving mechanism <NUM>, and a restricting portion.

The upper pressing member <NUM> is interposed between the proximal end portion <NUM> and the support member <NUM>. The upper pressing member <NUM> has an opposing surface <NUM> opposed to an upper portion of the retained portion <NUM> disposed in the housing portion A1 and retained on the support member <NUM>. The opposing surface <NUM> is configured with a lower surface of the upper pressing member <NUM>. In the first modification, the opposing surface <NUM> is formed of a flat surface. Specifically, the opposing surface <NUM> is formed of a horizontal plane.

In this first modification, even in a case where a relatively large gap is formed between the retained portion <NUM> and the proximal end portion <NUM> due to a relatively large difference between a distance in the up-down direction between the proximal end portion <NUM> and the support member <NUM> and a dimension in the up-down direction of the retained portion <NUM>, the gap is reduced by the upper pressing member <NUM> interposed between the proximal end portion <NUM> and the support member <NUM>. This enables rattling of the retained portion <NUM> that is retained on the support member <NUM> to be suppressed.

The upper pressing member <NUM> is preferably formed of a material having hardness lower than that of the proximal end portion <NUM>. This suppresses the retained portion <NUM> of the intermediate boom member <NUM> from being scratched. The upper pressing member <NUM> more preferably has a cushioning property.

In the present embodiment, the upper pressing member <NUM> is supported by the proximal end portion <NUM> via the upper pressing member moving mechanism <NUM>.

The upper pressing member moving mechanism <NUM> is configured with a pair of cylinders 29A and 29B that operate so as to move the upper pressing member <NUM> relative to the proximal end portion <NUM> in the up-down direction. Each of the pair of cylinders 29A and 29B has a cylinder main body <NUM> and a cylinder rod <NUM>. The cylinder main body <NUM> is fixed to the proximal end portion <NUM>. The cylinder rod <NUM> is configured to be movable in the up-down direction relative to the cylinder main body <NUM>. The cylinder rod <NUM> is inserted into a through hole that penetrates the proximal end portion <NUM> in the up-down direction, and a lower end portion of the cylinder rod <NUM> is located below the proximal end portion <NUM> and is fixed to the upper pressing member <NUM>.

Each of the pair of cylinders 29A and 29B is operated by, for example, hydraulic oil supplied from the drive source 1B shown in <FIG> via an oil passage (not shown). A switching valve (not shown) is disposed in the oil passage. When the switching valve is set at a neutral position, the hydraulic oil from the drive source 1B is not supplied to the pair of cylinders 29A and 29B. When the switching valve is switched from the neutral position to a first position and the hydraulic oil is supplied to a head side chamber of each of the pair of cylinders 29A and 29B, a dimension of the cylinder rod <NUM> protruding downward from the cylinder main body <NUM> becomes large. As a result, the upper pressing member <NUM> is lowered. By contrast, when the switching valve is switched from the neutral position to a second position and the hydraulic oil is supplied to a rod side chamber of each of the pair of cylinders 29A and 29B, the dimension of the cylinder rod <NUM> protruding downward from the cylinder main body <NUM> becomes small. As a result, the upper pressing member <NUM> rises. The pair of cylinders 29A and 29B may be electric cylinders, and in this case, the drive source 1B is configured with a power source. Further, the upper pressing member moving mechanism <NUM> is not limited to a configuration including the pair of cylinders 29A and 29B, and may be configured by a single cylinder or may be configured by three or more cylinders.

The restricting portion is configured to be switched between a restriction state of restricting movement of the support member <NUM> from the retention position and an allowable state of allowing the support member <NUM> to move from the retention position to the entry allowed position. In the present embodiment, the restricting portion is configured with a cylinder <NUM>. The cylinder <NUM> has a cylinder main body <NUM> and a cylinder rod <NUM>.

Although in the present embodiment, the cylinder main body <NUM> is fixed to the second leg portion <NUM>, it may be fixed, for example, to the first leg portion <NUM> or fixed to the proximal end portion <NUM>. The cylinder rod <NUM> is configured to be movable in the up-down direction relative to the cylinder main body <NUM>.

The cylinder <NUM> is operated by, for example, hydraulic oil supplied from the drive source 1B shown in <FIG> via an oil passage (not shown). A switching valve (not shown) is disposed in the oil passage. When the switching valve is set at a neutral position, the hydraulic oil from the drive source 1B is not supplied to the cylinder <NUM>.

When the switching valve is switched from the neutral position to a first position and the hydraulic oil is supplied to a head side chamber of the cylinder <NUM>, a dimension of the cylinder rod <NUM> protruding downward from the cylinder main body <NUM> becomes large. As a result, as a lower end portion of the cylinder rod <NUM> is inserted into a through hole <NUM> that penetrates the end portion of the support member <NUM> in the up-down direction (the restriction state). Upon switching of the cylinder <NUM> to the restriction state, it is possible to reliably prevent the support member <NUM> from moving from the retention position to the entry allowed position against an intention of work-related personnel such as the worker or the operator when the intermediate boom member <NUM> is lifted up in the lifting work. The through hole <NUM> is formed at a position corresponding to the cylinder rod <NUM> when the support member <NUM> is disposed at the retention position, that is, directly below the cylinder rod <NUM>.

By contrast, when the switching valve is switched from the neutral position to a second position and the hydraulic oil is supplied to a rod side chamber of the cylinder <NUM>, the dimension of the cylinder rod <NUM> protruding from the cylinder main body <NUM> becomes small. As a result, the lower end portion of the cylinder rod <NUM> is retracted from the support member <NUM> (the allowable state). When the cylinder <NUM> is switched to the allowable state, the support member <NUM> is allowed to move from the retention position to the entry allowed position. The cylinder <NUM> may be an electric cylinder, and in this case, the drive source 1B is configured with a power source.

<FIG> is a perspective view showing a retention device <NUM> of a suspension device <NUM> according to a second modification of the first embodiment. <FIG> is a perspective view showing a state in which the retention device <NUM> of the suspension device <NUM> according to the second modification is attached to a retained portion <NUM> of the intermediate boom member <NUM>. <FIG> is a front view of <FIG>, the view illustrating a state before moving the position of the upper pressing member <NUM> of the retention device <NUM>. <FIG> is a front view of <FIG>, the view illustrating a state after moving the position of the upper pressing member <NUM> of the retention device <NUM>.

As shown in <FIG>, in this second modification, the shape of the opposing surface <NUM> (lower surface) of the upper pressing member <NUM> is different from that of the first modification. Further, in this second modification, the restricting portion is omitted.

In the second modification, the opposing surface <NUM> of the upper pressing member <NUM> has a shape corresponding to a shape of the upper portion of the retained portion <NUM>. Specifically, the opposing surface <NUM> has a shape along a curved shape (arc shape) of an upper surface of the main pipe P1 in the retained portion <NUM>. The upper pressing member <NUM> having such opposing surface <NUM> can further suppress occurrence of rattling of the retained portion <NUM> that is retained on the support member <NUM> in the lifting work. Although in the specific example shown in <FIG>, the opposing surface <NUM> is configured with a horizontal plane at the center and a pair of inclined planes located on both sides of the horizontal plane, the opposing surface is not limited to such a configuration. For example, the opposing surface <NUM> may have a curved shape along the curved shape (arc shape) of the upper surface of the main pipe P1.

As shown in <FIG>, the retention device <NUM> is attached to the intermediate boom member <NUM> so that the support member <NUM> is located between the upper end portions of the two inclined pipes P2, P2, and the main pipe P1 is located between the upper pressing member <NUM> and the support member <NUM>.

As shown in <FIG> and <FIG>, a relative position in the up-down direction of the upper pressing member <NUM> with respect to the proximal end portion <NUM> can be changed by the upper pressing member moving mechanism <NUM> according to the dimension in the up-down direction of the retained portion <NUM>. As a result, even in a case where the dimension in the up-down direction of the retained portion <NUM> differs for each lifting work, the relative position of the upper pressing member <NUM> can be adjusted to a position suitable for the dimension in the up-down direction of the retained portion <NUM>, thereby enabling rattling of the retained portion <NUM> to be suppressed in the housing portion A1.

<FIG> is a perspective view showing a retention device <NUM> of a suspension device <NUM> according to a third modification of the first embodiment, the view illustrating a state before moving positions of a first side pressing member <NUM> and a second side pressing member <NUM> of the retention device <NUM>. <FIG> is a perspective view showing the retention device <NUM> of the suspension device <NUM> according to the third modification, the view illustrating a state after moving the positions of the first side pressing member <NUM> and the second side pressing member <NUM> of the retention device <NUM>.

As shown in <FIG> and <FIG>, the suspension device <NUM> according to the third modification differs from the above-described embodiment and modifications in that each of the plurality of retention devices <NUM> further includes the first side pressing member <NUM>, the second side pressing member <NUM>, a first side pressing member moving mechanism <NUM>, and a second side pressing member moving mechanism <NUM>. The same reference numerals are given to the same configurations as those of the embodiment and the modifications, and description thereof will be omitted.

The first side pressing member <NUM> is interposed between the first leg portion main body 21A and the second leg portion main body 22A. The first side pressing member <NUM> is supported by the first leg portion main body 21A via the first side pressing member moving mechanism <NUM>. The first side pressing member <NUM> has a first opposing surface <NUM> opposed to a first side portion of the retained portion <NUM> that is retained on the support member <NUM>.

The second side pressing member <NUM> is interposed between the first leg portion main body 21A and the second leg portion main body 22A. The second side pressing member <NUM> is supported by the second leg portion main body 22A via the second side pressing member moving mechanism <NUM>. The second side pressing member <NUM> has a second opposing surface <NUM> opposed to a second side portion of the retained portion <NUM> that is retained on the support member <NUM>.

The first side pressing member moving mechanism <NUM> operates so as to move the first side pressing member <NUM> relative to the first leg portion main body 21A, and the second side pressing member moving mechanism <NUM> operates so as to move the second side pressing member <NUM> relative to the second leg portion main body 22A. As a result, a horizontal distance between the first opposing surface <NUM> and the second opposing surface <NUM> changes.

The first side pressing member moving mechanism <NUM> is configured with a plurality of first cylinders <NUM> (four cylinders in the drawing). Each of the plurality of first cylinders <NUM> has a cylinder main body <NUM> and a cylinder rod <NUM>. The cylinder main body <NUM> is fixed to the corresponding first leg portion main body 21A. The cylinder rod <NUM> is configured to be relatively movable laterally (for example, in the horizontal direction) with respect to the cylinder main body <NUM>. The cylinder rod <NUM> is inserted into a through hole that horizontally penetrates the first leg portion main body 21A, and a distal end portion of the cylinder rod <NUM> is fixed to the first side pressing member <NUM>.

The second side pressing member moving mechanism <NUM> is configured with a plurality of second cylinders <NUM> (four cylinders in the drawing). Each of the plurality of second cylinders <NUM> has a cylinder main body <NUM> and a cylinder rod <NUM>. The cylinder main body <NUM> is fixed to the corresponding second leg portion main body 22A. The cylinder rod <NUM> is configured to be relatively movable laterally (for example, in the horizontal direction) with respect to the cylinder main body <NUM>. The cylinder rod <NUM> is inserted into a through hole that horizontally penetrates the second leg portion main body 22A, and a distal end portion of the cylinder rod <NUM> is fixed to the second side pressing member <NUM>.

Each of the plurality of first cylinders <NUM> and the plurality of second cylinders <NUM> is operated by, for example, hydraulic oil supplied from the drive source 1B shown in <FIG> via an oil passage (not shown). A switching valve (not shown) is disposed in the oil passage. When the switching valve is set at a neutral position, the hydraulic oil from the drive source 1B is not supplied to the cylinders <NUM> and <NUM>. When the switching valve is switched from the neutral position to a first position and the hydraulic oil is supplied to a head side chamber of each of the cylinders <NUM> and <NUM>, dimensions of the cylinder rods <NUM> and <NUM> protruding laterally from the cylinder main bodies <NUM> and <NUM> become large. As a result, the first side pressing member <NUM> and the second side pressing member <NUM> move in a direction to near to each other.

By contrast, when the switching valve is switched from the neutral position to a second position and the hydraulic oil is supplied to a rod side chamber of each of the cylinders <NUM> and <NUM>, the dimensions of the cylinder rods <NUM> and <NUM> protruding from the cylinder main bodies <NUM> and <NUM> become small. As a result, the first side pressing member <NUM> and the second side pressing member <NUM> move in a direction to go away from each other. The cylinders <NUM> and <NUM> may be electric cylinders, and in this case, the drive source 1B is configured with a power source. Further, each of the first side pressing member moving mechanism <NUM> and the second side pressing member moving mechanism <NUM> is not limited to a configuration including the four cylinders, but may be configured with a single cylinder, or with a plurality of cylinders other than four.

In this third modification, even in a case where a relatively large gap is formed between the leg portion main bodies 21A, 22A and the retained portion <NUM> due to a relatively large difference between a horizontal distance between the first leg portion main body 21A and the second leg portion main body 22A and a horizontal dimension of the retained portion <NUM>, the gap is reduced by the first and second side pressing members <NUM> and <NUM> interposed between the first leg portion main body 21A and the second leg portion main body 22A. This enables rattling of the retained portion <NUM> that is retained on the support member <NUM> to be suppressed.

<FIG> illustrates conceptual views each showing a state in which the retained portion is retained by the retention device of the suspension device according to the third modification. As shown in <FIG>, in the third modification, the horizontal distance between the first opposing surface <NUM> and the second opposing surface <NUM> can be changed according to the horizontal dimension of the retained portion <NUM>. As a result, even in a case where the horizontal dimension of the retained portion <NUM> differs for each lifting work, it is possible to adjust the horizontal distance between the first opposing surface <NUM> and the second opposing surface <NUM> so as to be suitable for the horizontal dimension of the retained portion <NUM>, thereby suppressing occurrence of rattling of the retained portion <NUM> that is retained on the support member <NUM>.

Further, in the third modification, as shown in <FIG>, the retention device <NUM> preferably further includes the upper pressing member <NUM> and the upper pressing member moving mechanism <NUM> similarly to the second modification. In this mode, a relative position of the upper pressing member <NUM> with respect to the proximal end portion <NUM> can be changed according to the dimension in the up-down direction of the retained portion <NUM>. As a result, even in a case where the dimension in the up-down direction of the retained portion <NUM> differs for each lifting work, the relative position of the upper pressing member <NUM> can be adjusted to a position suitable for the dimension in the up-down direction of the retained portion <NUM> to suppress occurrence of rattling of the retained portion <NUM> that is retained on the support member <NUM>.

Although in <FIG> and <FIG> showing the specific example of the third modification, each of the first opposing surface <NUM> and the second opposing surface <NUM> is formed of a flat surface, it may be configured with a following surface. Specifically, it is preferable that the first opposing surface <NUM> has a shape corresponding to a shape of the first side portion (side portion opposed to the first opposing surface <NUM>) of the retained portion <NUM> that is retained on the support member <NUM>, and that the second opposing surface <NUM> has a shape corresponding to a shape of the second side portion (side portion opposed to the second opposing surface <NUM>) of the retained portion <NUM> that is retained on the support member <NUM>. Specifically, it is preferable that the first opposing surface <NUM> has a shape along a curved shape (arc shape) of a side surface (surface on the first side portion) of the main pipe P1 in the retained portion <NUM>, and that the second opposing surface <NUM> has a shape along a curved shape (arc shape) of a side surface (surface on the second side portion) of the main pipe P1 in the retained portion <NUM>. In this mode, the first side pressing member <NUM> having such first opposing surface <NUM> as described above and the second side pressing member <NUM> having such second opposing surface <NUM> as described above can further suppress occurrence of rattling of the retained portion <NUM> that is retained on the support member <NUM> during the lifting work.

<FIG> and <FIG> are perspective views showing a retention device <NUM> of a suspension device <NUM> according to a second embodiment. The suspension device <NUM> according to the second embodiment is different from the first embodiment in that the first leg portion main body 21A and the second leg portion main body 22A are movable in the up-down direction with respect to the proximal end portion <NUM>. In the following, description will be made of the difference, and description of the other configurations will be omitted.

In the second embodiment, the distance between the proximal end portion <NUM> and the support member <NUM> in the up-down direction can be changed by changing the relative positions in the up-down direction of the first leg portion main body 21A and the second leg portion main body 22A with respect to the proximal end portion <NUM> according to the dimension in the up-down direction of the retained portion <NUM>. As a result, even in a case where the dimension in the up-down direction of the retained portion <NUM> differs for each lifting work, the relative positions of the first leg portion main body 21A and the second leg portion main body 22A with respect to the proximal end portion <NUM> can be adjusted to positions suitable for the dimension in the up-down direction of the retained portion <NUM>, thereby suppressing occurrence of rattling of the retained portion <NUM> retained on the support member <NUM>.

In the following, the second embodiment will be specifically described.

As shown in <FIG>, each of the plurality of retention devices <NUM> includes an up-down moving mechanism <NUM> that operates to cause the first leg portion main body 21A and the second leg portion main body 22A to move in the up-down direction relative to the proximal end portion <NUM>. The up-down moving mechanism <NUM> includes a first cylinder <NUM>, a second cylinder <NUM>, a plurality of first guide members <NUM>, and a plurality of second guide members <NUM>.

The first cylinder <NUM> has a cylinder main body <NUM> and a cylinder rod <NUM>. The cylinder main body <NUM> is fixed to the proximal end portion <NUM>. The cylinder rod <NUM> is configured to be movable in the up-down direction relative to the cylinder main body <NUM>. The cylinder rod <NUM> is inserted into a through hole that penetrates the proximal end portion <NUM> in the up-down direction, and a lower end portion of the cylinder rod <NUM> is located below the proximal end portion <NUM> and is fixed to an upper portion of the first leg portion main body 21A.

Similarly, the second cylinder <NUM> has a cylinder main body <NUM> and a cylinder rod <NUM>. The cylinder main body <NUM> is fixed to the proximal end portion <NUM>. The cylinder rod <NUM> is configured to be movable in the up-down direction relative to the cylinder main body <NUM>. The cylinder rod <NUM> is inserted into a through hole that penetrates the proximal end portion <NUM> in the up-down direction, and a lower end portion of the cylinder rod <NUM> is located below the proximal end portion <NUM> and is fixed to an upper portion of the second leg portion main body 22A.

Each of the first and second cylinders <NUM> and <NUM> is operated by, for example, hydraulic oil supplied from the drive source 1B shown in <FIG> via an oil passage (not shown). A switching valve (not shown) is disposed in the oil passage. When the switching valve is set at a neutral position, the hydraulic oil from the drive source 1B is not supplied to the first and second cylinders <NUM> and <NUM>. When the switching valve is switched from the neutral position to a first position and the hydraulic oil is supplied to head side chambers of the first and second cylinders <NUM> and <NUM>, dimensions of the cylinder rods <NUM> and <NUM> protruding downward from the cylinder main bodies <NUM> and <NUM> become large. As a result, the first leg portion main body 21A and the second leg portion main body 22A are lowered. By contrast, when the switching valve is switched from the neutral position to a second position and the hydraulic oil is supplied to a rod side chamber of each of the first and second cylinders <NUM> and <NUM>, the dimensions of the cylinder rods <NUM> and <NUM> protruding downward from the cylinder main bodies <NUM> and <NUM> become small. As a result, the first leg portion main body 21A and the second leg portion main body 22A rise. The first and second cylinders <NUM> and <NUM> may be electric cylinders, and in this case, the drive source 1B is configured with a power source.

Each of the plurality of first guide members <NUM> has a rod shape. An upper end portion of each of the plurality of first guide members <NUM> is fixed to the proximal end portion <NUM>. Each of the plurality of first guide members <NUM> extends downward from the proximal end portion <NUM> and is inserted into a hole portion formed in the up-down direction in the first leg portion main body 21A. The plurality of first guide members <NUM> move in the up-down direction relative to the first leg portion main body 21A as the first leg portion main body 21A moves in the up-down direction, thereby stabilizing the movement of the first leg portion main body 21A in the up-down direction. Similarly, the plurality of second guide members <NUM> have the same configuration as the plurality of first guide members <NUM>, and stabilize movement of the second leg portion main body 22A in the up-down direction.

<FIG> is a perspective view showing a retention device <NUM> of a suspension device <NUM> according to a third embodiment. The suspension device <NUM> according to the third embodiment differs from the second embodiment in further including a configuration in which the first leg portion main body 21A and the second leg portion main body 22A are movable relative to the proximal end portion <NUM> in the horizontal direction. In the following, description will be made of the difference, and description of the other configurations will be omitted.

In this third embodiment, a horizontal distance between the first leg portion main body 21A and the second leg portion main body 22A can be changed according to a horizontal dimension of the retained portion <NUM>. As a result, even in a case where the horizontal dimension of the retained portion <NUM> differs for each lifting work, the horizontal distance between the first leg portion main body 21A and the second leg portion main body 22A can be adjusted to be suitable for the horizontal dimension of the retained portion <NUM>, thereby suppressing occurrence of rattling of the retained portion <NUM> that is retained on the support member <NUM>.

In the following, the third embodiment will be specifically described.

As shown in <FIG>, the first leg portion <NUM> includes not only the first leg portion main body 21A but also a first upper member 21B disposed above the first leg portion main body 21A. The second leg portion <NUM> includes not only the second leg portion main body 22Abut also a second upper member 22B disposed above the second leg portion main body 22A. The first upper member 21B and the second upper member 22B are disposed on both sides of the proximal end portion <NUM>. In other words, the first upper member 21B, the proximal end portion <NUM>, and the second upper member 22B are disposed in this order in the horizontal direction.

The first leg portion main body 21A is supported by the first upper member 21B by means of a first cylinder <NUM> of an up-down moving mechanism <NUM> having the same structure as that of the up-down moving mechanism <NUM> in the second embodiment, and is configured to be movable in the up-down direction relative to the first upper member 21B. The second leg portion main body 22A is supported by the second upper member 22B by means of a second cylinder <NUM> of an up-down moving mechanism <NUM> having the same structure as that of the up-down moving mechanism <NUM> in the second embodiment, and is configured to be movable in the up-down direction relative to the second upper member 22B. Since the configurations of the first and second cylinders <NUM> are the same as those of the second embodiment, the same reference numerals as those of the second embodiment are given thereto to omit detailed description thereof.

In the third embodiment shown in <FIG>, each of the plurality of retention devices <NUM> further includes a side moving mechanism <NUM>. The side moving mechanism <NUM> operates so as to change the horizontal distance between the first leg portion main body 21A and the second leg portion main body 22A by moving the first leg portion main body 21A and the second leg portion main body 22A relative to the proximal end portion <NUM>. The side moving mechanism <NUM> includes a plurality of first cylinders <NUM> (a pair of cylinders in the illustrated example), a plurality of second cylinders <NUM> (a pair of cylinders in the illustrated example), a plurality of first guide members <NUM>, and a plurality of second guide members <NUM>.

Each of the plurality of first cylinders <NUM> has a cylinder main body <NUM> and a cylinder rod <NUM>. The cylinder main body <NUM> is fixed to the first upper member 21B. The cylinder rod <NUM> is configured to be movable relative to the cylinder main body <NUM> in the horizontal direction. The cylinder rod <NUM> is inserted into a through hole that horizontally penetrates the first upper member 21B, and a distal end portion of the cylinder rod <NUM> is fixed to a side portion of the proximal end portion <NUM>.

Similarly, each of the plurality of second cylinders <NUM> has a cylinder main body <NUM> and a cylinder rod <NUM>. The cylinder main body <NUM> is fixed to the second upper member 22B. The cylinder rod <NUM> is configured to be movable relative to the cylinder main body <NUM> in the horizontal direction. The cylinder rod <NUM> is inserted into a through hole that horizontally penetrates the second upper member 22B, and a distal end portion of the cylinder rod <NUM> is fixed to the side portion of the proximal end portion <NUM>.

Each of the first and second cylinders <NUM> and <NUM> is operated by, for example, hydraulic oil supplied from the drive source 1B shown in <FIG> via an oil passage (not shown). A switching valve (not shown) is disposed in the oil passage. When the switching valve is set at a neutral position, the hydraulic oil from the drive source 1B is not supplied to the first and second cylinders <NUM> and <NUM>.

When the switching valve is switched from the neutral position to a first position, and the hydraulic oil is supplied to head side chambers of the first and second cylinders <NUM> and <NUM>, dimensions of the cylinder rods <NUM> and <NUM> protruding laterally from the cylinder main bodies <NUM> and <NUM> become large. This causes the first upper member 21B to move in a direction to go away from the proximal end portion <NUM> (horizontal direction), and the second upper member 22B to move in a direction to go away from the proximal end portion <NUM> (horizontal direction). As a result, the first leg portion <NUM> including the first leg portion main body 21A and the first upper member 21B moves in a direction (horizontal direction) to go away from the proximal end portion <NUM>, and the second leg portion <NUM> including the second leg portion main body 22A and the second upper member 22B moves in a direction (horizontal direction) to go away from the proximal end portion <NUM>.

On the other hand, when the switching valve is switched from the neutral position to a second position and the hydraulic oil is supplied to rod side chambers of the first and second cylinders <NUM> and <NUM>, the dimensions of the cylinder rods <NUM> and <NUM> protruding from the cylinder main bodies <NUM> and <NUM> become small. This causes the upper member 21B to move in a direction (horizontal direction) to near the proximal end portion <NUM>, and the second upper member 22B to move in a direction (horizontal direction) to near the proximal end portion <NUM>. As a result, the first leg portion <NUM> including the first leg portion main body 21A and the first upper member 21B moves in a direction (horizontal direction) to near the proximal end portion <NUM>, and the second leg portion <NUM> including the second leg portion main body 22A and the second upper member 22B moves in a direction (horizontal direction) to near the proximal end portion <NUM>. The first and second cylinders <NUM> and <NUM> may be electric cylinders, and in this case, the drive source 1B is configured with a power source.

Each of the plurality of first guide members <NUM> has a rod shape. Each proximal end portion of the plurality of first guide members <NUM> is fixed to the first upper member 21B. Each of the plurality of first guide members <NUM> extends horizontally from the first upper member 21B and is inserted into a horizontal hole formed in the proximal end portion <NUM>. The plurality of first guide members <NUM> move in the horizontal direction as the first upper member 21B moves in the horizontal direction, thereby stabilizing horizontal movement of the first upper member 21B. Similarly, the plurality of second guide members <NUM> have the same configuration as the plurality of first guide members <NUM>, and stabilize horizontal movement of the second upper member 22B.

In the embodiments, the inclined surfaces <NUM> and <NUM> of the first leg portion main body 21A and the second leg portion main body 22A can be omitted. Further, in the embodiments, the base member <NUM> can be omitted. In the embodiments, the support member moving mechanism <NUM> and the drive part <NUM> can be omitted.

Although in the embodiments, the suspension device <NUM> includes four retention devices <NUM>, it may include a plurality of retention devices <NUM> other than four.

Although in the embodiments, as shown in <FIG> and <FIG>, the retained portion <NUM> of the intermediate boom member <NUM> to which the retention device <NUM> is attached is a connection part at which the pair of inclined pipes P2, P2 are connected to the main pipe P1 in the intermediate boom member <NUM>, and the support member <NUM> of the retention device <NUM> is disposed between the pair of inclined pipes P2, P2, the retained portion <NUM> is not limited to the part shown in <FIG> and <FIG>, and a part where the support member <NUM> is disposed is not limited to the part shown in <FIG> and <FIG>. The following mode is among modifications of these parts.

<FIG> is a view showing a positional relationship between a support member <NUM> of the retention device <NUM> according to a modification and a retained portion <NUM> of the intermediate boom member <NUM>, and <FIG> is a view showing lifting work of lifting up the intermediate boom member <NUM> by using the suspension device <NUM> provided with the support member <NUM> according to the modification of <FIG>. Although the suspension device <NUM> according to the modification includes, for example, four retention devices <NUM> disposed in a manner as shown in <FIG>, in the side views of <FIG> and <FIG>, only the two retention devices <NUM> of the four retention devices <NUM> are illustrated. Further, in <FIG>, in order to describe a positional relationship between the support member <NUM> and a main pipe P1 and a pair of inclined pipes P2, P2 of the intermediate boom member <NUM>, only a cross section of the support member <NUM> is illustrated among the members constituting each retention device <NUM>.

In this modification, as shown in <FIG> and <FIG>, the retained portion <NUM> of the intermediate boom member <NUM> to which the retention device <NUM> is attached is located at a position deviated to one side in a longitudinal direction of the main pipe P1 with respect to a connection part C at which the pair of inclined pipes P2, P2 are connected to the main pipe P1 in the intermediate boom member <NUM>. Further, as shown in <FIG>, the support member <NUM> of each retention device <NUM> is not disposed in a region M between the pair of inclined pipes P2, P2, but is disposed at a position deviated to one side in the longitudinal direction with respect to the region M.

Each support member <NUM> has a shape corresponding to a shape of a lower portion of the retained portion <NUM> retained on the support member <NUM>. Specifically, each support member <NUM> has an upper surface <NUM> (an example of a contact surface) along a lower surface of the main pipe P1 in the retained portion <NUM> and an inclined surface <NUM> (an example of a contact surface) inclined along a side surface of one inclined pipe P2 (a side surface of the left inclined pipe P2 in <FIG>). The upper surface <NUM> is formed of a flat surface or a curved surface along the lower surface of the main pipe P1. Further, as shown in <FIG>, when the support member <NUM> is viewed in the longitudinal direction thereof, the inclined surface <NUM> is inclined in the same direction as the one inclined pipe P2 with respect to the vertical direction.

Although a cross-sectional shape of the support member <NUM> according to the modification shown in <FIG> is trapezoidal, the cross-sectional shape of the support member <NUM> is not limited thereto, and may be another shape such as a triangular shape as shown in <FIG>. The support member <NUM> having a triangular shape shown in <FIG> has the upper surface <NUM> and the inclined surface <NUM> similarly to the support member <NUM> shown in <FIG>.

When coupling the intermediate boom member <NUM> (the second intermediate boom member <NUM>) to the first intermediate boom member <NUM> shown in <FIG>, for example, as shown in <FIG>, the intermediate boom member <NUM> may be disposed to have an inclined attitude with respect to the ground. For disposing the intermediate boom member <NUM> so as to have such an inclined attitude, it is only necessary to adjust lengths of the four cylinders <NUM> such that lengths of two rear cylinders <NUM> shown in <FIG> out of the four cylinders <NUM> of the attachment part <NUM> are larger than lengths of two front cylinders <NUM>. In such an inclined attitude, the upper surface <NUM> and the inclined surface <NUM> of the support member <NUM> are in contact with the lower surface of the main pipe P1 and the side surface of the one inclined pipe P2 in the retained portion <NUM>, respectively. This enables the intermediate boom member <NUM> to be stably retained in the inclined attitude by the four retention devices <NUM>.

<FIG> is a view showing another example of a positional relationship between the support member <NUM> and the retained portion <NUM> according to the modification. In this modification, as shown in <FIG>, of the four retained portions <NUM> of the intermediate boom member <NUM> to which the retention devices <NUM> are attached, the rear retained portion <NUM> is located at a position deviated to one side (rear side in <FIG>) of the longitudinal direction of the main pipe P1 with respect to the connection part C at which the pair of inclined pipes P2, P2 are connected to the main pipe P1 in the intermediate boom member <NUM>. Of the four retained portions <NUM>, the front retained portion <NUM> is located at a position deviated to the other side (front side in <FIG>) in the longitudinal direction of the main pipe P <NUM> with respect to the connection part C of the intermediate boom member <NUM>.

Although not shown, in the modifications of <FIG>, a part of the four retained portions <NUM> may be the connection part C at which the pair of inclined pipes P2, P2 are connected to the main pipe P1 in the intermediate boom member <NUM> (e.g., such a part as shown in <FIG>), and the corresponding support member <NUM> may be disposed in the region M between the pair of inclined pipes P2, P2 (e.g., such arrangement as shown in <FIG>).

There is provided a work machine suspension device according to claim <NUM>.

In this work machine suspension device, with the support member of each of the plurality of retention devices disposed at the entry allowed position, each of the plurality of retention devices is lowered relative to the corresponding retained portion, thereby causing the corresponding retained portion to enter between the first leg portion main body and the second leg portion main body. Next, the support member of each of the plurality of retention devices is moved from the entry allowed position to the retention position. As a result, while being supported by the first leg portion main body and the second leg portion main body, the support member can retain the retained portion on the support member, so that the structure member can be lifted up by lifting up the attachment part of the work machine suspension device by the lifting equipment. Accordingly, this work machine suspension device makes it possible to simplify or omit the assisting work by the worker in the raising process of the hook by the hook raising operation, and enables the operator to quickly conduct the hook raising operation. Therefore, this work machine suspension device enables worker's labor to be reduced in the lifting work and time required for the lifting work to be shortened.

Here, the attachment part may have a simple mode, for example, may be configured with only a plurality of wire ropes that support the plurality of retention devices. In this case, an upper end portion of each of the plurality of wire ropes is attached to the hook of the lifting equipment, and a lower end portion of each of the plurality of wire ropes is attached to the corresponding retention device among the plurality of retention devices. It is noted that in a case where the attachment part includes the following base member, stability when the structure member is lifted up in the lifting work is improved as compared with the case where the attachment part is configured with only the plurality of wire ropes.

In other words, it is preferable that in the work machine suspension device, the attachment part includes a base member that supports the plurality of retention devices, and that the plurality of retention devices are fixed to the base member so as to be capable of hanging from the base member at intervals from each other in a horizontal direction.

In this mode, since the plurality of retention devices fixed to the base member are hung from the base member at intervals from each other in the horizontal direction, the relative positions of the plurality of retention devices can be easily maintained, so that stability when the structure member is lifted up in the lifting work is improved.

Here, the operation of moving of the support member between the retention position and the entry allowed position may be manually conducted by a worker such as a slinging worker. It is noted that the following mode makes it possible to further reduce the labor of the worker.

In other words, in the work machine suspension device, each of the plurality of retention devices preferably further includes: a support member moving mechanism that operates so as to move the support member between the entry allowed position and the retention position; and a drive part that drives the support member moving mechanism.

In this mode, since the support member is moved between the retention position and the entry allowed position by the support member moving mechanism driven by the drive part, it is not necessary for the worker to manually move the support member, resulting in further reducing the labor of the worker.

It is preferable that in the work machine suspension device, the support member has a contact surface in contact with the retained portion that is retained on the support member, the contact surface having a shape corresponding to a shape of the retained portion.

In this mode, the support member having the contact surface as described above can retain the retained portion more stably in the lifting work.

It is preferable that in the work machine suspension device, each of the plurality of retention devices further includes a restricting portion configured to be switched between a restriction state of restricting movement of the support member from the retention position and an allowable state of allowing the support member to move from the retention position to the entry allowed position.

In this mode, when the structure member is lifted up in the lifting work, it is possible to reliably prevent the support member from moving from the retention position to the entry allowed position against an intention of work-related personnel such as the worker or the operator.

In the work machine suspension device, each of the plurality of retention devices includes an upper pressing member that is interposed between the proximal end portion and the support member so as to be supported by at least one of the proximal end portion, the first leg portion, and the second leg portion, the upper pressing member having an opposing surface opposed to an upper portion of the retained portion that is retained on the support member.

In this mode, even in a case where a relatively large gap is formed between the retained portion and the proximal end portion due to a relatively large difference between a distance in an up-down direction between the proximal end portion and the support member and a dimension in the up-down direction of the retained portion, the gap is reduced by the upper pressing member interposed between the proximal end portion and the support member. As a result, it is possible to suppress occurrence of rattling of the retained portion that is retained on the support member.

In the work machine suspension device, each of the plurality of retention devices preferably further includes an upper pressing member moving mechanism that operates so as to move the upper pressing member in an up-down direction relative to the proximal end portion.

In this mode, a relative position of the upper pressing member with respect to the proximal end portion can be changed according to the dimension in the up-down direction of the retained portion. As a result, even in a case where the dimension in the up-down direction of the retained portion differs for each lifting work, the relative position of the upper pressing member can be adjusted to a position suitable for the dimension in the up-down direction of the retained portion, thereby enabling occurrence of rattling of the retained portion that is retained on the support member to be suppressed.

In the work machine suspension device, the opposing surface of the upper pressing member preferably has a shape corresponding to a shape of the upper portion of the retained portion.

In this mode, the upper pressing member having the opposing surface as described above can further suppress occurrence of rattling of the retained portion that is retained on the support member in the lifting work.

In the work machine suspension device, each of the plurality of retention devices may further include: a first side pressing member that is interposed between the first leg portion main body and the second leg portion main body so as to be supported by at least one of the first leg portion main body and the proximal end portion, and has a first opposing surface opposed to a first side portion of the retained portion that is retained on the support member; and a second side pressing member that is interposed between the first leg portion main body and the second leg portion main body so as to be supported by at least one of the second leg portion main body and the proximal end portion, and has a second opposing surface opposed to a second side portion of the retained portion that is retained on the support member.

In this mode, even in a case where due to a relatively large difference between a horizontal distance between the first leg portion main body and the second leg portion main body and a horizontal dimension of the retained portion, a relatively large gap is formed between the leg portion main bodies and the retained portion, the gap is reduced by the first and second side pressing members interposed between the first leg portion main body and the second leg portion main body. As a result, it is possible to suppress occurrence of rattling of the retained portion that is retained on the support member.

In the work machine suspension device, each of the plurality of retention devices preferably further includes a side pressing member moving mechanism that operates so as to change a horizontal distance between the first opposing surface and the second opposing surface by conducting at least one of relative movement of the first side pressing member with respect to the first leg portion main body and relative movement of the second side pressing member with respect to the second leg portion main body.

In this mode, the horizontal distance between the first opposing surface and the second opposing surface can be changed according to the horizontal dimension of the retained portion. As a result, even in a case where the horizontal dimension of the retained portion differs for each lifting work, it is possible to adjust the horizontal distance between the first opposing surface and the second opposing surface to be suitable for the horizontal dimension of the retained portion, thereby suppressing occurrence of rattling of the retained portion that is retained on the support member.

It is preferable that in the work machine suspension device, the first opposing surface has a shape corresponding to a shape of the first side portion of the retained portion that is retained on the support member, and that the second opposing surface has a shape corresponding to a shape of the second side portion of the retained portion that is retained on the support member.

In this mode, the first side pressing member having the first opposing surface and the second side pressing member having the second opposing surface as described above enable the occurrence of rattling of the retained portion that is retained on the support member to be further suppressed in the lifting work.

In the work machine suspension device, each of the plurality of retention devices may further include an up-down moving mechanism that operates so as to move the first leg portion main body and the second leg portion main body in the up-down direction relative to the proximal end portion.

In this mode, the distance in the up-down direction between the proximal end portion and the support member can be changed by changing relative positions in the up-down direction of the first leg portion main body and the second leg portion main body with respect to the proximal end portion according to the dimension in the up-down direction of the retained portion. As a result, even in a case where the dimension in the up-down direction of the retained portion differs for each lifting work, the relative positions of the first leg portion main body and the second leg portion main body with respect to the proximal end portion can be adjusted to positions suitable for the dimension in the up-down direction of the retained portion, thereby suppressing occurrence of rattling of the retained portion that is retained on the support member.

In the work machine suspension device, each of the plurality of retention devices may further include a side moving mechanism that operates so as to change a horizontal distance between the first leg portion main body and the second leg portion main body by moving at least one of the first leg portion main body and the second leg portion main body relative to the proximal end portion.

In this mode, the horizontal distance between the first leg portion main body and the second leg portion main body can be changed according to the horizontal dimension of the retained portion. As a result, even in a case where the horizontal dimension of the retained portion differs for each lifting work, the horizontal distance between the first leg portion main body and the second leg portion main body can be adjusted to be suitable for the horizontal dimension of the retained portion, thereby suppressing occurrence of rattling of the retained portion that is retained on the support member.

In the work machine suspension device, each of a lower end portion of the first leg portion and a lower end portion of the second leg portion preferably has such an inclined surface that makes a distance in a horizontal direction between the lower end portions increase downward.

In this mode, the retained portion can smoothly enter between the first leg portion main body and the second leg portion main body while being guided by the inclined surface.

There is provided a retention device according to claim <NUM>.

This retention device enables worker's labor to be reduced in the lifting work and time required for the lifting work to be shortened.

The retention device preferably further includes: a support member moving mechanism that operates so as to move the support member between the entry allowed position and the retention position; and a drive part that drives the support member moving mechanism.

In the retention device, the support member preferably has a contact surface in contact with the retained portion that is retained on the support member, the contact surface having a shape corresponding to a shape of the retained portion.

The retention device preferably further includes a restricting portion configured to be switched between a restriction state of restricting movement of the support member from the retention position and an allowable state of allowing the support member to move from the retention position to the entry allowed position.

The retention device includes an upper pressing member that is interposed between the proximal end portion and the support member so as to be supported by at least one of the proximal end portion, the first leg portion, and the second leg portion, the upper pressing member having an opposing surface opposed to an upper portion of the retained portion that is retained on the support member.

The retention device preferably further includes an upper pressing member moving mechanism that operates so as to move the upper pressing member in an up-down direction relative to the proximal end portion.

The retention device may further include a first side pressing member that is interposed between the first leg portion main body and the second leg portion main body so as to be supported by at least one of the first leg portion main body and the proximal end portion, and has a first opposing surface opposed to a first side portion of the retained portion that is retained on the support member; and a second side pressing member that is interposed between the first leg portion main body and the second leg portion main body so as to be supported by at least one of the second leg portion main body and the proximal end portion, and has a second opposing surface opposed to a second side portion of the retained portion that is retained on the support member.

The retention device preferably further includes a side pressing member moving mechanism that operates so as to change a horizontal distance between the first opposing surface and the second opposing surface by conducting at least one of relative movement of the first side pressing member with respect to the first leg portion main body and relative movement of the second side pressing member with respect to the second leg portion main body.

The retention device may further include an up-down moving mechanism that operates so as to move the first leg portion main body and the second leg portion main body in the up-down direction relative to the proximal end portion.

The retention device may further include a side moving mechanism that operates so as to change a horizontal distance between the first leg portion main body and the second leg portion main body by moving at least one of the first leg portion main body and the second leg portion main body relative to the proximal end portion.

There is provided a method for suspending a structure member by using the work machine suspension device according to one of claims <NUM> to <NUM>.

Claim 1:
A retention device (<NUM>) to be attached to a structure member included in a work machine (<NUM>) for conducting lifting work of lifting up the structure member by lifting equipment, the retention device (<NUM>) comprising:
a proximal end portion (<NUM>);
a first leg portion (<NUM>) that is supported by the proximal end portion (<NUM>) and includes a first leg portion main body (21A) that is disposed below the proximal end portion (<NUM>);
a second leg portion (<NUM>) that is supported by the proximal end portion (<NUM>) and includes a second leg portion main body (22A) disposed below the proximal end portion (<NUM>), the second leg portion main body (22A) being disposed at an interval in a horizontal direction from the first leg portion main body (21A); and
a support member (<NUM>) supported by the first leg portion main body (21A) so as to be movable between an entry allowed position and a retention position,
the entry allowed position being a position where the support member (<NUM>) retracts from the second leg portion main body (22A) to allow a retained portion (<NUM>) as a part of the structure member to enter between the first leg portion main body (21A) and the second leg portion main body (22A), and
the retention position being a position where the retained portion (<NUM>) is retained on the support member (<NUM>) while the support member (<NUM>) is supported by the first leg portion main body (21A) and the second leg portion main body (22A);
characterized in that
the retention device (<NUM>) further comprises
an upper pressing member (<NUM>) that is interposed between the proximal end portion (<NUM>) and the support member (<NUM>) so as to be supported by at least one of the proximal end portion (<NUM>), the first leg portion (<NUM>), and the second leg portion (<NUM>),
the upper pressing member (<NUM>) having an opposing surface opposed to an upper portion of the retained portion (<NUM>) that is retained on the support member (<NUM>).