AU2018400554B2

AU2018400554B2 - Materials Handling Machine

Info

Publication number: AU2018400554B2
Application number: AU2018400554A
Authority: AU
Inventors: Katsuaki Hirai; Kunihiko Tanaka
Original assignee: Kawasaki Heavy Industries Ltd; Kawasaki Jukogyo KK
Current assignee: Kawasaki Motors Ltd
Priority date: 2018-01-11
Filing date: 2018-12-27
Publication date: 2021-03-11
Anticipated expiration: 2038-12-27
Also published as: JP6955448B2; CN111372878B; JP2019123565A; WO2019138907A1; KR20200100191A; TW201932392A; KR102468484B1; TWI701204B; PH12020550968A1; CN111372878A; AU2018400554A1

Abstract

This load handling and transporting machine is provided with: a traveling machine body; a rotating base provided on the traveling machine body so as to be capable of rotating horizontally; a boom having a base end supported on the rotating base; a boom conveyor; a counterweight beam; a counterweight provided at the front end of the counterweight beam; and at least one raising and lowering cylinder, one end of which in the extension and contraction direction of the cylinder is connected to the rotating table so that the cylinder can pivot, the other end of which in the extension and contraction direction is connected to the counterweight so that the cylinder can pivot, and which extends and contracts in the extension and contraction direction to raise and lower the boom.

Description

MATERIALS HANDLING MACHINE

Technical Field

[0001] The present invention relates to a materials handling machine, such as a stacker or a reclaimer, equipped with a boom that is luffed (i.e., raised and lowered).

Background Art

[0002] Conventionally, unloaded bulk materials, such as ore and coal, are stored at a stockyard that has a vast area. At the stockyard, a materials handling machine is installed. The materials handling machine is, for example, a stacker serving as stacking means, a reclaimer serving as reclaiming means, or a stacker-reclaimer having the functions of both the stacker and the reclaimer.

[0003] The stacker includes a conveyor that carries a bulk material. The stacker carries the bulk material into the stockyard, and stacks the bulk material into a pile at the stockyard. The reclaimer includes: a boom that is slewable horizontally and luffable; a bucket wheel provided on the distal end of the boom; and a boom conveyor provided along the boom. The bucket wheel breaks the pile of the bulk material, and scoops the bulk material from the pile. The bulk material thus removed from the pile is relocated to a predetermined location by the boom conveyor. This type of reclaimer is disclosed by Patent Literature 1.

[0004] FIG. 6 shows a conventional reclaimer of the type disclosed by Patent Literature 1. FIG. 6 shows a conventional reclaimer 100, which includes: a traveling unit 2; a slewing frame 3 supported by the traveling unit 2, such that the slewing frame 3 is slewable horizontally; a boom 4 supported by the slewing frame 3, such that the boom 4 is luffable via a support shaft 35; a boom conveyor 8 provided along the boom 4; a bucket wheel 7 provided on the distal end of the boom 4; and a luffing cylinder 5, which drives the boom 4 to be luffed.

[0005] The conventional reclaimer 100 includes a balancing structure 9' in order to suppress a shift in the center of gravity when the boom 4 is luffed. The balancing structure 9' includes: a mast 92 coupled to the boom 4; a counter weight beam 90 coupled to the proximal end of the boom 4; a counter weight 91 provided on the distal end of the counter weight beam 90; a tension bar 93, which spans between the distal end of the mast 92 and the distal end of the boom 4; and a tension bar 94, which spans between the distal end of the mast 92 and the counter weight 91. The balancing structure 9'pulls the boom 4 with the tension bars 93 and 94 by utilizing the weight of the counter weight 91, and thereby the overall balance is achieved.

[0006] The distal end of the luffing cylinder 5 is rotatably coupled to a point of effort 50, which is set on a non-end portion of the counter weight beam 90 in the longitudinal direction thereof. The luffing cylinder 5 extends or retracts, thereby applying a load to the point of effort 50, and as a result, the boom 4 is luffed. Since a stress concentrates on the point of effort 50, the balancing structure 9' further includes a stiffening frame 95 and a stiffening frame 96. The stiffening frame 95 spans between the distal end of the mast 92 and the point of effort 50 of the counter weight beam 90. The stiffening frame 96 spans between the distal end of the mast 92 and a non-end portion of the boom 4 in the longitudinal direction thereof.

Citation List Patent Literature

[0007] PTL 1: Japanese Laid-Open Patent Application Publication No. 2016-204063

Summary of Invention Technical Problem

[0008] As described above, in the conventional reclaimer 100, the load is applied to the non-end portion of the counter weight beam 90 in the longitudinal direction thereof. For this reason, the stiffening frame 95, which is intended for preventing deflection of the counter weight beam 90, is an essential component. However, if the stiffening frame 95 can be eliminated, the number of components constituting the balancing structure 9' can be reduced, and thus the weight and cost of the balancing structure 9' can be reduced. Moreover, if the stiffening frame 95 can be eliminated, the number of components positioned above the luffing cylinder 5 can be reduced, which makes it possible to improve the maintainability of the luffing cylinder 5.

[0009] The present invention has been made in view of the above, and an object of the present invention is to reduce the number of stiffening components in a materials handling machine that includes: a boom that is luffable; a luffing cylinder that luffs the boom; and a counter weight beam and a counter weight that apply a load that causes the distal end portion of the boom to rotate upward.

Solution to Problem

[0010] A materials handling machine according to one aspect of the present invention includes: a traveling unit; a slewing frame provided on the traveling unit, such that the slewing frame is slewable horizontally; a boom whose proximal end portion is supported by the slewing frame, such that the boom is luffable about a horizontal support shaft; a boom conveyor provided along the boom; a counter weight beam that, when seen in a plan view, extends from the proximal end portion of the boom in a direction opposite the boom; a counter weight provided on a distal end portion of the counter weight beam; and at least one luffing cylinder that luffs the boom by extending and retracting in an extending-retracting direction, the luffing cylinder having one end in the extending-retracting direction rotatably coupled to the slewing frame and having another end in the extending-retracting direction rotatably coupled to the counter weight.

[0011] In the above materials handling machine, when luffing the boom, the point of application of a load from the luffing cylinder is present on the counter weight. Since the counter weight is a rigid body, the counter weight is neither deflected nor deformed when such a load is applied thereto. Therefore, the member for suppressing the deflection of the counter weight beam 90, such as one used in the reclaimer 100 according to the conventional art shown in FIG. 6 (i.e., the stiffening frame 95), can be eliminated. In other words, the number of stiffening components (e.g., the stiffening frame 95) included in the materials handling machine can be reduced.

[0012] In the above materials handling machine, the counter weight may be provided with a weight-side stay positioned below the counter weight beam, the weight-side stay protruding from a periphery of the counter weight toward the slewing frame. The luffing cylinder may be coupled to the weight-side stay.

[0013] According to this configuration, the overall length of the luffing cylinder can be reduced compared to a case where the peripheral surface of the counter weight is coupled to one end of the luffing cylinder in the extending-retracting direction. By thus reducing the overall length of the luffing cylinder, a cylinder with less stiffness can be adopted as the luffing cylinder. This makes it possible to reduce the cost of the luffing cylinder.

[0014] In the above materials handling machine, when the boom is in a horizontal orientation, a direction in which the weight-side stay protrudes from the periphery of the counter weight may be parallel to a straight line that connects between a base-side stay provided on the slewing frame and a center of gravity of the counter weight.

[0015] According to this configuration, when the boom is in the horizontal orientation, it means that the boom is substantially in the middle of its luffing movement range. Therefore, over the luffing movement range of the boom, the amount of shift between the line of action of the load applied to the counter weight and the center of gravity of the counter weight can be reduced.

[0016] In the above materials handling machine, the counter weight may be supported by the counter weight beam, and may include a counter weight shaft and at least one weight block, the counter weight shaft extending in a direction orthogonal to an extending direction of the counter weight beam, the weight block being supported by the counter weight shaft. The luffing cylinder may be coupled to the counter weight shaft.

[0017] By using the counter weight thus constituted by a plurality of members, the structure in which the counter weight and the luffing cylinder are coupled to each other can be realized more inexpensively and more easily than in the case where the counter weight is a single-mass rigid body.

[0018] In the above materials handling machine, the counter weight beam may include a pair of parallel beam members. When seen in a plan view, the luffing cylinder may be positioned between the pair of beam members.

[0019] According to this configuration, at the time of removing the luffing cylinder to perform maintenance work, the luffing cylinder can be hoisted from below the counter weight beam to above the counter weight beam in a manner to pass between the pair of beam members of the counter weight beam.

[0020] In the above materials handling machine, a first securing part that is secured by one end of a securing rope may be provided on a lower part of the boom, and a second securing part that is secured by another end of the securing rope may be provided on the slewing frame.

[0021] According to this configuration, at the time of removing the luffing cylinder to perform maintenance work, the orientation of the boom can be kept by connecting the securing rope to the first securing part and the second securing part.

Advantageous Effects of Invention

[0022] The present invention makes it possible to reduce the number of stiffening components in a materials handling machine that includes: a boom that is luffable; a luffing cylinder that luffs the boom; and a counter weight beam and a counter weight that apply a load that causes the distal end portion of the boom to rotate upward.

Brief Description of Drawings

[0023] FIG. 1 is a side view of a reclaimer according to one embodiment of the present invention. FIG. 2 shows a luffing cylinder and its mounting configuration. FIG. 3 shows a variation of the luffing cylinder and its mounting configuration. FIG. 4 is a side view of the reclaimer, showing a variation of a counter weight. FIG. 5 is a plan view showing the counter weight, the luffing cylinder, and its mounting configuration in the reclaimer of FIG. 4.

FIG. 6 is a side view of a conventional reclaimer.

Description of Embodiments

[0024] Next, an embodiment of the present invention is described with reference to the drawings. The description hereinafter describes the embodiment, in which the present invention is applied to a reclaimer that is one example of a materials handling machine. However, the present invention is also applicable to other materials handling machines, such as a stacker and a stacker-reclaimer having the functions of both the stacker and the reclaimer.

[0025] FIG. 1 is a side view of a reclaimer 1 according to one embodiment of the present invention. As shown in FIG. 1, the reclaimer 1 includes: a traveling unit 2, which travels on unshown rails; a slewing frame 3, which slews horizontally on the traveling unit 2; a boom 4 supported by the slewing frame 3, such that the boom 4 is luffable; a luffing cylinder 5 serving as a luffing actuator that luffs the boom 4; a balancing structure 9, which applies a load to the boom 4, the load causing the distal end of the boom 4 to rotate upward; and a cabin 6 supported by the slewing frame 3. There is a control room inside the cabin 6.

[0026] The proximal end portion of the boom 4 is supported by the slewing frame 3, such that the boom 4 is luffable about a horizontal support shaft 35. A boom conveyor 8, which carries a bulk material along the boom 4, is provided in a manner to extend from the distal end portion to the proximal end portion of the boom 4. The boom conveyor 8 includes: an endless conveyor belt extending along the boom 4; and a drive device (not shown) that drives the conveyor belt. A bucket wheel 7 is provided on the distal end portion of the boom 4. The bucket wheel 7 includes: a wheel; a plurality of buckets provided around the wheel; and a drive device (not shown) that drives the wheel to rotate.

[0027] The balancing structure 9 includes: a mast 92 coupled to the proximal end portion of the boom 4; a counter weight beam 90 coupled to the proximal end portion of the boom 4; a counter weight 91 provided on the distal end portion of the counter weight beam 90; a tension bar 93 coupled to the distal end portion of the mast 92 and the distal end portion of the boom 4; and a tension bar 94 coupled to the distal end portion of the mast 92 and the counter weight 91. When seen in a plan view, the counter weight beam 90 extends from the proximal end portion of the boom 4 in a direction opposite the boom 4. The mast 92 extends upward as seen from the slewing frame 3. When seen in a side view, the boom 4, the tension bar 93, and the mast 92 form a triangle. Similarly, when seen in a side view, the counter weight beam 90, the counter weight 91, the tension bar 94, and the mast 92 also form a triangle.

[0028] The balancing structure 9 configured as above pulls the distal end of the boom 4 upward with the tension bars 93 and 94 by utilizing the weight of the counter weight 91, and thereby the overall structure including the boom 4 and the balancing structure 9 is balanced.

[0029] The luffing cylinder 5 includes: a rod 51; a cylinder tube 52, in which the rod 51 is inserted such that the rod 51 is movable forward and backward; and a driving unit 53, which drives the rod 51 to move forward/backward relative to the cylinder tube 52. The luffing cylinder 5 according to the embodiment is an electric cylinder.

[0030] FIG. 2 shows the luffing cylinder 5 and its mounting configuration. As shown in FIG. 2, the driving unit 53 of the luffing cylinder 5 includes: two electric motors 61; two gear reducers 62; one motion converter 63; and two friction clutches 64. In the driving unit 53, two drive systems each having substantially the same configuration are formed. Each drive system extends from a corresponding one of the electric motors 61 to the rod 51. That is, the driving unit 53 has redundancy. Normally, one of the two drive systems of the driving unit 53 operates. If malfunctioning of one of the drive systems occurs, the other drive system operates instead of the one drive system.

[0031] The electric motors 61 are equipped with respective brake devices 65. However, as an alternative, the electric motors 61, and the brake devices 65 which apply a brake to the electric motors 61, maybe provided independently of each other. Each of the gear reducers 62 amplifies the torque of rotational power transmitted thereto, and outputs the resulting rotational power to the motion converter 63. The motion converter 63 converts the rotational output from each of the gear reducers 62 into linear reciprocating motion of the rod 51. When an excessive load is inputted to the luffing cylinder 5, the mechanical friction clutches 64, which are interposed between the electric motors 61 and the gear reducers 62, prevent the excessive load from being transmitted to the electric motors 61.

[0032] When seen in a plan view, the luffing cylinder 5 is disposed between a pair of beam members 90a and 90b of the counter weight beam 90. The distal end portion of the rod 51 of the luffing cylinder 5 is rotatably coupled to a weight-side stay 98, which protrudes from the counter weight 91 toward the slewing frame 3. The proximal end portion of the cylinder tube 52 of the luffing cylinder 5 is rotatably coupled to a base-side stay 33 provided on the slewing frame 3. The luffing cylinder 5 is tensioned between the slewing frame 3 and the counter weight 91.

[0033] The counter weight 91 is formed by filling the inside of a drum-shaped box with a heavymaterial. The weight-side stay 98 is fixed to the box of the counterweight 91, or integrally formed on the box of the counter weight 91. As shown in FIG. 1, when the boom 4 is in a horizontal orientation, the weight-side stay 98 is positioned below the counter weight beam

90. Also, as shown in FIG. 1, when the boom 4 is in the horizontal orientation, i.e., when the boom 4 is substantially in the middle of its luffing movement range, as seen in a side view, a straight line L connecting between a center of gravity 91g of the counter weight 91 and a supporting pin 34 of the base-side stay 33 is parallel to a direction in which the weight-side stay 98 protrudes from the counterweight 91. At the time, it is more desirable that the weight-side stay 98 be positioned on the straight line L. According to the weight-side stay 98 thus configured, when the boom 4 is in the horizontal orientation, as seen in a side view, the straight line L connecting between the center of gravity 91g of the counter weight 91 and the supporting pin 34 of the base-side stay 33 is parallel to the direction of the center axis of the luffing cylinder 5 (i.e., parallel to the extending direction of the rod 51).

[0034] In the reclaimer 1 configured as above, the slewing frame 3 is slewed to slew the boom 4, and also, the boom 4 is luffed by the luffing cylinder 5 serving as the luffing means, thereby bringing the bucket wheel 7 provided on the distal end portion of the boom 4 close to the piled-up bulk material. Here, when the driving unit 53 causes the rod 51 to move forward from the cylinder tube 52, i.e., when the rod 51 extends, the boom 4 rotates downward such that the distal end portion of the boom 4 is lowered. Also, when the driving unit 53 causes the rod 51 to move backward into the cylinder tube 52, i.e., when the rod 51 retracts, the boom 4 rotates upward such that the distal end portion of the boom 4 is raised.

[0035] Then, the rotating bucket wheel 7 breaks the pile of the bulk material, and collects the bulk material with the buckets. The bulk material collected with the buckets is fed to the boom conveyor 8 by the rotation of the bucket wheel 7. The bulk material placed on the boom conveyor 8 is carried from the distal end portion to the proximal end portion of the boom 4, and fed to an unshown ground conveyor through a chute 31 formed in the slewing frame 3.

[0036] At the time of performing maintenance work on the luffing cylinder 5 of the reclaimer 1 configured as above, the orientation of the boom 4 is kept by tying between a securing part 32 and a securing part 42 by a securing rope 44. The securing part 32 is provided on the slewing frame 3, and the securing part 42 is provided on the lower part of the boom 4. The securing rope 44 may be a wire, a chain, or a rod. In a state where the orientation of the boom 4 is kept in this manner, the luffing cylinder 5 is removed from the weight-side stay 98 and the base-side stay 33. Neither the boom 4 nor the boom conveyor 8 is present above the luffing cylinder 5, but only the counter weight beam 90 is present above the luffing cylinder 5. This makes it easy to perform an operation of hoisting the luffing cylinder 5 with an unshown crane at the time of carrying the luffing cylinder 5 out of the reclaimer 1.

[0037] As described above, the reclaimer 1 (which is one example of the materials handling machine) of the present embodiment includes: the traveling unit 2; the slewing frame 3 provided on the traveling unit 2, such that the slewing frame 3 is slewable horizontally; the boom 4 whose proximal end portion is supported by the slewing frame 3, such that the boom 4 is luffable about the horizontal support shaft 35; the boom conveyor 8 provided along the boom 4; the counter weight beam 90, which, when seen in a plan view, extends from the proximal end portion of the boom in a direction opposite the boom; the counter weight 91 provided on the distal end portion of the counter weight beam 90; and at least one luffing cylinder 5, which luffs the boom 4 by extending and retracting in an extending-retracting direction, the luffing cylinder 5 having one end in the extending-retracting direction rotatably coupled to the slewing frame 3 and having the other end in the extending-retracting direction rotatably coupled to the counter weight 91.

[0038] In the reclaimer 1 according to the present embodiment, when luffing the boom 4, the point of application of a load from the luffing cylinder 5 is present on the counter weight 91. Since the counter weight 91 is a rigid body, the counter weight 91 is neither deflected nor deformed when such a load is applied thereto. Therefore, the member for suppressing the deflection of the counter weight beam 90, such as one used in the reclaimer 100 according to the conventional art shown in FIG. 6 (i.e., the stiffening frame 95), can be eliminated. In other words, the number of stiffening components (e.g., a stiffening frame) included in the materials handling machine can be reduced.

[0039] Moreover, in the reclaimer 1 according to the present embodiment, the counter weight 91 is provided with the weight-side stay 98 positioned below the counter weight beam 90, the weight-side stay 98 protruding from the periphery of the counter weight 91 toward the slewing frame 3. The luffing cylinder 5 is coupled to the weight-side stay 98.

[0040] According to this configuration, the overall length of the luffing cylinder 5 can be reduced compared to a case where the peripheral surface of the counter weight 91 is coupled to one end of the luffing cylinder 5 in the extending-retracting direction. By thus reducing the overall length of the luffing cylinder 5, a cylinder with less stiffness can be adopted as the luffing cylinder 5. This makes it possible to reduce the cost of the luffing cylinder 5.

[0041] Furthermore, in the reclaimer 1 according to the present embodiment, when the boom 4 is in a horizontal orientation, the direction in which the weight-side stay 98 protrudes from the periphery of the counter weight 91 is parallel to the straight line L, which connects between the base-side stay 33 provided on the slewing frame 3 and the center of gravity 91g of the counter weight 91.

[0042] When the boom 4 is in the horizontal orientation, it means that the boom 4 is substantially in the middle of its luffing movement range. Therefore, over the luffing movement range of the boom 4, the amount of shift between the line of action of the load applied to the counter weight 91 and the center of gravity 91g of the counter weight 91 can be reduced.

[0043] Still further, in the reclaimer 1 according to the present embodiment, the counter weight beam 90 includes the pair of parallel beam members 90a and 90b, and when seen in a plan view, the luffing cylinder 5 is positioned between the pair of beam members 90a and 90b.

[0044] According to this configuration, at the time of removing the luffing cylinder 5 to perform maintenance work, the luffing cylinder 5 can be hoisted, with a crane or the like, from below the counter weight beam 90 to above the counter weight beam 90 in a manner to pass between the pair of beam members 90a and 90b of the counter weight beam 90. However, the manner of disposing the luffing cylinder 5 is not limited to the one described in the present embodiment. Alternatively, the luffing cylinder 5 may be disposed such that, when seen in a plan view, the luffing cylinder 5 overlaps the pair of beam members 90a and 90b. Even in this case, since the number of stiffening components is less than in the case of the conventional reclaimer 100, the luffing cylinder 5 can be hoisted, with a crane or the like, from below the counter weight beam 90 to above the counter weight beam 90 in a manner to pass between the pair of beam members 90a and 90b of the counter weight beam 90.

[0045] Still further, in the reclaimer 1 according to the present embodiment, the first securing part 42, which is secured by one end of the securing rope 44, is provided on the lower part of the boom 4, and the second securing part 32, which is secured by the other end of the securing rope 44, is provided on the slewing frame 3.

[0046] According to this configuration, at the time of removing the luffing cylinder 5 to perform maintenance work, the orientation of the boom 4 can be kept by connecting the securing rope 44 to the first securing part 42 and the second securing part 32.

[0047] Although the preferred embodiment of the present invention is as described above, specific structural and/or functional details of the above-described embodiment can be modified without departing from the spirit of the present invention, and such modifications fall within the scope of the present invention. The configuration of the above-described reclaimer 1 can be modified, for example, in the following manner.

[0048] For example, in the reclaimer 1 according to the above embodiment, the luffing cylinder 5 is an electric cylinder. However, instead of the electric cylinder, a hydraulic cylinder with a known configuration may be adopted as the luffing cylinder 5.

[0049] Also, for example, the reclaimer 1 according to the above embodiment includes one luffing cylinder 5. However, as an alternative, the reclaimer 1 may include a plurality of luffing cylinders 5. FIG. 3 shows a variation of the luffing cylinder and its mounting configuration.

As shown in FIG. 3, in a case where the reclaimer 1 includes a plurality of luffing cylinders 5, each of the plurality of luffing cylinders 5 has substantially the same configuration, and the plurality of luffing cylinders 5 are arranged in parallel with each other between the weight-side stay 98 and the base-side stay 33. When seen in a plan view, the plurality of luffing cylinders 5 are arranged between the pair of beam members 90a and 90b of the counter weight beam 90. The plurality of luffing cylinders 5 are arranged in close proximity to each other. Accordingly, although there are cases where a deviation occurs between the plurality of luffing cylinders 5 in terms of extension/retraction margin, since the plurality of luffing cylinders 5 are thus arranged in close proximity to each other and the counter weight 91 is a rigid body, the extending/retracting motion of one of the luffing cylinders 5 follows the extending/retracting motion of the remaining luffing cylinder 5, and thereby the deviation between the plurality of luffing cylinders 5 in terms of extension/retraction margin is reduced.

[0050] Also, for example, in the reclaimer 1 according to the above embodiment, the counter weight 91 is a single-mass rigid body. However, the counter weight 91 is not thus limited. FIG. 4 is aside view of the reclaimer 1, showing a counterweight 91', which is a variation of the counterweight 91. FIG. 5 is a plan view showing the counterweight 91', the luffing cylinder 5, and its mounting configuration in the reclaimer 1 of FIG. 4.

[0051] The counter weight 91' shown in FIG. 4 and FIG. 5 is constituted by a counter weight shaft 91a and at least one weight block 91b. The counterweight shaft 91a spans between the pair of beam members 90a and 90b of the counter weight beam 90, and extends in a direction orthogonal to the extending direction of the counter weight beam 90.

[0052] Each weight block 91b is fixed to the counter weight shaft 91a, or placed on and supported by the counterweight shaft 91a. In the counterweight 91'of this example, two weight blocks 91b are arranged on both sides of a weight-side stay 98', respectively.

[0053] The weight-side stay 98' is integrally provided on, or fixed to, the counter weight shaft 91a at substantially the center of the counter weight shaft 91a in its extending direction. The weight-side stay 98' extends from the counter weight shaft 91a toward the base-side stay 33. The luffing cylinder 5 is rotatably coupled to the weight-side stay 98' integrally provided on the counter weight shaft 91a, and thereby the luffing cylinder 5 is coupled to the counter weight shaft91a. However, as an alternative, the luffing cylinder 5 maybe directly and rotatably coupled to the periphery of the counter weight shaft 91a.

[0054] By using the counter weight 91' thus constituted by a plurality of members, the structure in which the counter weight 91' and the luffing cylinder 5 are coupled to each other can be realized more inexpensively and more easily than in the case where the counter weight 91 is a single-mass rigid body. In addition, at the time of performing maintenance work on the counter weight 91', only the counter weight shaft 91a, which tends to fatigue more than the weight block 91b does, can be replaced, which makes it possible to reduce the maintenance cost.

Reference Signs List

[0055] 1: reclaimer (one example of a materials handling machine) 2: traveling unit 3: slewing frame 4: boom 5: luffing cylinder 6: cabin 7: bucket wheel 8: boom conveyor 9: balancing structure 31: chute 32: securing part 33: base-side stay 34: supporting pin 35: support shaft 42: securing part 44: securing rope 50: point of effort 51: rod 52: cylinder tube 53: driving unit 61: electric motor 62: gear reducer 63: motion converter 64: friction clutch 65: brake device 90: counter weight beam 90a, 90b: beam member 91, 91': counter weight 91a: counter weight shaft

91b: weight block 91g: center of gravity 92: mast 93, 94: tension bar 95, 96: stiffening frame 98, 98': weight-side stay

Claims

CLAIMS 1. A materials handling machine including: a traveling unit; a slewing frame provided on the traveling unit, such that the slewing frame is slewable horizontally; a boom whose proximal end portion is supported by the slewing frame, such that the boom is luffable about a horizontal support shaft; a boom conveyor provided along the boom; a counter weight beam that, when seen in a plan view, extends from the proximal end portion of the boom in a direction opposite the boom; a counter weight provided on a distal end portion of the counter weight beam; and at least one luffing cylinder that luffs the boom by extending and retracting in an extending-retracting direction, the luffing cylinder having one end in the extending-retracting direction rotatably coupled to the slewing frame and having another end in the extending retracting direction rotatably coupled to the counter weight.
2. The materials handling machine according to claim 1, wherein the counter weight is provided with a weight-side stay positioned below the counter weight beam, the weight-side stay protruding from a periphery of the counter weight toward the slewing frame, and the luffing cylinder is coupled to the weight-side stay.
3. The materials handling machine according to claim 2, wherein when the boom is in a horizontal orientation, a direction in which the weight-side stay protrudes from the periphery of the counter weight is parallel to a straight line that connects between a base-side stay provided on the slewing frame and a center of gravity of the counter weight.
4. The materials handling machine according to claim 1, wherein the counter weight is supported by the counter weight beam, and includes a counter weight shaft and at least one weight block, the counter weight shaft extending in a direction orthogonal to an extending direction of the counter weight beam, the weight block being supported by the counter weight shaft, and the luffing cylinder is coupled to the counter weight shaft.
5. The materials handling machine according to any one of claims 1 to 4, wherein the counter weight beam includes a pair of parallel beam members, and when seen in a plan view, the luffing cylinder is positioned between the pair of beam members.
6. The materials handling machine according to any one of claims 1 to 5, wherein a first securing part that is secured by one end of a securing rope is provided on a lower part of the boom, and a second securing part that is secured by another end of the securing rope is provided on the slewing frame.