Bracket, telescopic boom and construction machine

Abstract

To provide a bracket, which holds an end part of a wire rope for extending / contracting a telescopic boom and can be prevented from being deformed by tensile force of the wire rope, a telescopic boom capable of improving the certainty of the extension and contraction operation, and a construction machine capable of performing construction work efficiently.SOLUTION: A bracket for fixing one end part of a telescopic wire rope for extending / contracting a boom of a construction machine in a longitudinal direction, includes a main plate fixed to the boom in which a locking hole for locking the one end part of the wire rope is formed and a pair of reinforcement plates fixed to the boom and the main plate to be separated from each other such that the locking hole is sandwiched with one surface side of the main plate. Respective surfaces of the pair of reinforcement plates facing each other are nonparallel to each other.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a bracket, a telescopic boom, and a construction machine. [Background technology]

[0002] A construction machine such as a crane having a boom that is extendable in a longitudinal direction is known. The extendable boom generally has a base boom, one or more intermediate booms nested within the base boom, and a tip boom nested within the intermediate boom.

[0003] The boom can be extended or retracted by using hydraulic cylinder units for both the intermediate boom and the tip boom, or, as shown in Patent Document 1, for example, the intermediate boom is extended or retracted by a hydraulic cylinder unit while the tip boom is extended or retracted by a wire rope that is linked to the extension or retraction of the intermediate boom. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-127494 Summary of the Invention [Problem to be solved by the invention]

[0005] In the boom described in the above publication, one end of the extension wire rope of the telescopic wire rope of the tip boom is fixed to the base boom. Specifically, the ends of the two extension wire ropes are crimped with one fastener, and the fastener is fixed to a wire locking member provided on the base boom. Since a relatively large tension is applied to the telescopic wire rope, the plate-shaped wire locking member that fixes the fastener may be deformed and even damaged. If the wire locking member is deformed, it becomes difficult to extend and retract the boom to an appropriate length, and there is a risk that a construction machine equipped with the boom may tip over, and the efficiency of construction work may decrease due to the difficulty in extending and retracting the boom.

[0006] In consideration of the above-mentioned circumstances, the present invention has an object to provide a bracket that holds the end of a wire rope for extending and retracting a telescopic boom, which can suppress deformation due to the tension of the wire rope, a telescopic boom that can improve the reliability of telescopic operation, and a construction machine that can perform efficient construction work. [Means for solving the problem]

[0007] One aspect of the present invention devised to solve the above-mentioned problems is a bracket for fixing one end of an extension wire rope that extends and retracts the boom of a construction machine in the longitudinal direction, comprising a main plate fixed to the boom and having an engagement hole formed therein for engaging one end of the wire rope, and a pair of reinforcing plates fixed to the boom and main plate at a distance from each other on one side of the main plate so as to sandwich the engagement hole, and the opposing surfaces of the pair of reinforcing plates are non-parallel to each other.

[0008] Another embodiment of the present invention is a telescopic boom for a construction machine that is extendable and contractable in a longitudinal direction and includes the above bracket.

[0009] Yet another embodiment of the present invention is a construction machine including the above-mentioned telescopic boom, an upper rotating body supporting the telescopic boom, and a lower traveling body supporting the upper rotating body so as to be rotatable. Effect of the Invention

[0010] The bracket of the present invention can suppress deformation due to tension of the telescopic wire rope. The telescopic boom of the present invention can improve the reliability of telescopic operation. The construction machine of the present invention can perform construction work efficiently. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic side view showing a construction machine according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic side view showing a state in which a telescopic boom provided on the construction machine of FIG. 1 is contracted. [Diagram 3] FIG. 3 is a schematic side view showing a state in which the telescopic boom in FIG. 2 is partially extended. [Figure 4] FIG. 4 is a schematic side view showing a state in which the telescopic boom of FIG. 2 is extended. [Diagram 5] FIG. 5 is a schematic partial side view showing a second boom of a telescopic four-section boom. [Figure 6] 6 is a left side view of the second boom of FIG. 5. FIG. [Figure 7] 7 is a top view of the second boom of FIG. 5. FIG. [Figure 8] 8 is a bottom view of the second boom of FIG. 5. FIG. [Figure 9] FIG. 9 is a schematic side view showing a bracket different from the bracket of the second boom in FIG. [Figure 10] FIG. 10 is a schematic side view showing a bracket which is different from the brackets of the second boom shown in FIGS. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] One aspect of the present invention devised to solve the above-mentioned problems is a bracket for fixing one end of an extension wire rope that extends and retracts the boom of a construction machine in the longitudinal direction, comprising a main plate fixed to the boom and having an engagement hole formed therein for engaging one end of the wire rope, and a pair of reinforcing plates fixed to the boom and main plate at a distance from each other on one side of the main plate so as to sandwich the engagement hole, and the opposing surfaces of the pair of reinforcing plates are non-parallel to each other.

[0013] The bracket includes a pair of reinforcing plates that reinforce the main plate, and therefore can suppress deformation of the main plate due to tension of the wire rope. In addition, the pair of reinforcing plates are arranged with their opposing surfaces non-parallel to each other, so that the stress propagating from the main plate can be dispersed, and deformation of the pair of reinforcing plates can be suppressed. Since the pair of reinforcing plates disperse the stress propagating from the main plate, deformation of the surface of the boom to which the pair of reinforcing plates are attached can also be suppressed. As described above, the bracket can suppress deformation due to tension of the wire rope.

[0014] It is preferable that the distance between the opposing surfaces of the pair of reinforcing plates increases as the reinforcing plates are spaced apart from the main plate, thereby making it possible to further suppress deformation of the pair of reinforcing plates.

[0015] Alternatively, it is preferable that the distance between the opposing surfaces of the pair of reinforcing plates decreases as the reinforcing plates are spaced apart from the main plate. This also makes it possible to further suppress deformation of the pair of reinforcing plates.

[0016] Another embodiment of the present invention is a telescopic boom for a construction machine that is equipped with the above bracket and is extendable and contractible in the longitudinal direction.

[0017] Since the telescopic boom is provided with the bracket, the reliability of the telescopic operation can be improved.

[0018] Yet another embodiment of the present invention is a construction machine including the above-mentioned telescopic boom, an upper rotating body supporting the telescopic boom, and a lower traveling body supporting the upper rotating body so as to be rotatable.

[0019] Since the construction machine is equipped with the telescopic boom, it can carry out construction work efficiently.

[0020] [Details of the embodiment of the invention] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings as appropriate. Note that the drawings are schematic diagrams for explaining the present invention, and the shape, scale, etc. of each component (each member) may differ from the actual ones.

[0021] [crane] The construction machine of the present invention is, for example, a crane 100 as shown in FIG. 1, and mainly comprises a boom 10 that is extendable and contractable in the longitudinal direction, an upper rotating body 20 that supports this telescopic boom 10, and a lower running body 30 that supports this upper rotating body 20 so that it can rotate.

[0022] The lower traveling body 30 has a pair of crawlers as a traveling device, and travels in any direction to enable the movement of the crane 100. The upper rotating body 20 is rotatably mounted on the lower traveling body 30, and has an operator's cabin 21, a cylinder unit (not shown) for tilting the telescopic boom 10, a hoisting winch (not shown) for sending out and winding up a hoisting cable etc. suspended from the tip of the telescopic boom 10, etc. Note that "tilting" means that the telescopic boom 10 swings between an upright position and a lowered position.

[0023] 〔boom〕 The base end of the telescopic boom 10 is fixed to the upper rotating body 20, and the telescopic boom 10 is raised and lowered in a direction perpendicular to the plane of rotation of the upper rotating body 20. The telescopic boom 10 of this embodiment is composed of four boom sections. Specifically, the telescopic boom 10 has a first boom 11 having a base end fixed to the upper rotating body 20, a second boom 12 a portion of which can be accommodated in the first boom 11, a third boom 13 a portion of which can be accommodated in the second boom 12, and a fourth boom 14 a portion of which can be accommodated in the third boom 13. The "base end" refers to the end of the telescopic boom 10 on the upper rotating body 20 side in the longitudinal direction, and the "tip" refers to the end on the opposite side.

[0024] As shown in Figs. 2, 3 and 4, the telescopic boom 10 incorporates a first cylinder unit 121 for extending and retracting the second boom 12 in the longitudinal direction within the second boom 12. An end of a rod 121a of the first cylinder unit 121 is fixed to the first boom 11. The telescopic boom 10 incorporates a second cylinder unit 131 for extending and retracting the third boom 13 in the longitudinal direction within the third boom 13. An end of a rod 131a of the second cylinder unit 131 is fixed to the second boom 12. The telescopic boom 10 has an extension wire rope 15 for extending the fourth boom 14 in the longitudinal direction, an extension sheave 132 around which the extension wire rope 15 is hung, a retraction wire rope 16 for retracting the fourth boom 14 in the longitudinal direction, and a retraction sheave 133 around which the retraction wire rope 16 is hung.

[0025] In this embodiment, the extension sheave 132 is provided on the tip side of the third boom 13. The retraction sheave 133 is provided on the base end side of the third boom 13. One end of the extension wire rope 15 is engaged with the bracket 122 provided on the tip side of the second boom 12, and the other end is engaged with a locking portion 141 provided on the base end side of the fourth boom 14 via the extension sheave 132. The locking portion 141 locks the other end of the extension wire rope 15 with one end of the retraction wire rope 16. The retraction wire rope 16 has one end engaged with the locking portion 141, and the other end is engaged with a bracket 123 provided on the tip side of the second boom 12 via the retraction sheave 133.

[0026] To extend the telescopic boom 10 (FIG. 2) in the contracted state, first, the rod 121a of the first cylinder unit 121 is extended to cause the second boom 12 to protrude relative to the first boom 11 (FIG. 3). Next, the rod 131a of the second cylinder unit 131 is extended to cause the third boom 13 to protrude relative to the second boom 12. As the third boom 13 protrudes relative to the second boom 12, the fourth boom protrudes from the third boom 13 by the extension wire rope 15. That is, the third boom 13 and the fourth boom 14 are extended at the same time (FIG. 4).

[0027] To retract the telescopic boom 10 in the extended state, first, the rod 131a of the second cylinder unit 131 is retracted to store the third boom 13 in the second boom 12. As the third boom 13 is retracted in the second boom 12, the fourth boom 14 is retracted in the third boom 13 by the retraction wire rope 16. That is, the third boom 13 and the fourth boom 14 are retracted simultaneously. Once the third boom 13 is retracted in the second boom 12 and the fourth boom 14 is retracted in the third boom 13, respectively, the rod 121a of the first cylinder unit 121 is retracted to store the second boom 12 in the first boom 11.

[0028] In addition, in Figures 2, 3 and 4, the extension sheave 132 is shown on the side of the boom 10, the bracket 40 for engaging the one end of the extension wire rope 15 is shown on the upper surface of the boom 10, and the bracket 50 for engaging the other end of the retraction wire rope 16 is shown on the lower surface of the boom 10, but these arrangements are not particularly limited.

[0029] (bracket) In the following, a bracket for locking an end of a wire rope is provided on the side of a second boom of a telescopic boom composed of four boom sections. As shown in Figs. 5, 6, 7 and 8, the bracket 40, 50 includes a main plate 41, 51 having a locking hole 411, 511 for locking one end of the wire rope, and a pair of reinforcing plates 42, 43, 52, 53 arranged on one side of the main plate 41, 51. The opposing surfaces 421, 431, 521 of the pair of reinforcing plates 42, 43, 52, 53 are not parallel to each other. The main plate 41, 51 and the pair of reinforcing plates 42, 43, 52, 53 are fixed to the side of the second boom 12 by a known method such as welding.

[0030] The brackets 40, 50 in this embodiment are formed on both sides of the second boom 12. The pair of brackets 40, 50 are arranged symmetrically on both sides of the second boom 12 with the second boom 12 in between. That is, the pair of brackets 40, 50 are formed in the same shape on both sides of the second boom 12. Both of the pair of brackets 40, 50 lock the ends of the extension wire rope 150. That is, in this embodiment, the telescopic boom 10 includes two extension wire ropes 150 and two extension sheaves 132. The pair of brackets 40, 50 includes main plates 41, 51 and a pair of reinforcing plates 42, 43, 52, 53 arranged to support the main plates 41, 51.

[0031] The main plates 41, 51 are plate-shaped members and are erected on the side surfaces of the tip side of the second boom 12. At least a portion of the surface of the main plates 41, 51 is disposed so as to be approximately perpendicular to the longitudinal direction of the second boom 12. Locking holes 411, 511 are formed in the portions of the main plates 41, 51 disposed so as to be perpendicular to the longitudinal direction of the second boom 12. An end of the extension wire rope 150 is locked in the locking holes 411, 511. By hanging the extension wire rope 150 on both side surfaces of the second boom 12, the fourth boom 14 can be smoothly extended.

[0032] The height of the main plates 41, 51 from the side surface of the second boom 12 is greatest at the portion where the locking holes 411, 511 are formed, and is formed so that the height decreases toward the upper and lower surfaces of the second boom 12. In this manner, the brackets 40, 50 can be made lighter and less expensive.

[0033] One end of the extension wire rope 150 is connected to a substantially cylindrical locking fitting 60. A female screw is formed on the outer circumferential surface of the locking fitting 60. The locking fitting 60 is inserted into the locking hole 411 and a nut 70 is screwed onto the base end side of the main plate 40, thereby locking one end of the extension wire rope 150 to the main plate 40 (FIG. 5). A reinforcing portion 412 is provided on the surface on the base end side of the main plate 41 to reinforce the periphery of the locking hole 411. Note that in FIGS. 6, 7, and 8, the extension wire rope 150, the locking fitting 60, and the nut 70 are omitted.

[0034] A pair of reinforcing plates 42, 43, 52, 53 are disposed on the base end side of the main plates 41, 51. The pair of reinforcing plates 42, 43, 52, 53 are plate-shaped members and are erected on the side surface of the tip end side of the second boom 12 so as to support the main plates 41, 51. Specifically, the pair of reinforcing plates 42, 43, 52, 53 are partially connected to the main plates 41, 51 and are erected on the side surface of the tip end side of the second boom 12 so as to extend toward the base end side. One reinforcing plate 42, 52 (upper reinforcing plate 42, 52) of the pair of reinforcing plates 42, 43, 52, 53 is disposed above the locking holes 411, 511, and the other reinforcing plate 43, 53 (lower reinforcing plate 43, 53) is disposed below the locking holes 411, 511. That is, the locking holes 411 and 511 are formed so as to be positioned between the upper reinforcing plates 42 and 52 and the lower reinforcing plates 43 and 53 .

[0035] The height of the reinforcing plates 42, 43, 52, 53 from the side surface of the second boom 12 is highest at the portion connected to the main plate 41, 51 and is formed so as to decrease in height as it moves away from the main plate 41, 51. In this manner, the weight and cost of the brackets 40, 50 can be reduced.

[0036] The opposing surfaces of the upper reinforcing plates 42, 52 and the lower reinforcing plates 43, 53 are non-parallel to each other. In this embodiment, the distance between the opposing surfaces of the upper reinforcing plates 42, 52 and the lower reinforcing plates 43, 53 increases as they move away from the main plates 41, 51. The tension wire rope 150 applies tension to the main plates 41, 51 toward the tip side. By arranging the pair of reinforcing plates 42, 43, 52, 53 supporting the main plates 41, 51 so that their surfaces move away from each other as they move away from the main plates 41, 51, the stress propagated from the main plates 41, 51 and applied to the pair of reinforcing plates 42, 43, 52, 53 is dispersed, and deformation, damage, etc. of the pair of reinforcing plates 42, 43, 52, 53 can be suppressed. In addition, since the main plates 41, 51 are supported by a pair of reinforcing plates 42, 43, 52, 53, deformation, damage, etc. due to the tension of the extension wire rope 150 can be suppressed.

[0037] Furthermore, by making the pair of reinforcing plates 42, 43, 52, 53 non-parallel, a space for manipulating a tool for screwing the nut 70 into the locking fitting 60 can be secured, improving operability.

[0038] The pair of reinforcing plates 42, 43, 52, 53 of this embodiment has a first spaced portion in which the opposing surfaces are gradually spaced apart as they move away from the main plate 41, 51, and a second spaced portion that is continuous with the first spaced portion and is spaced apart more as they move away from the main plate 41, 51. That is, in the first spaced portion that is provided at a predetermined distance from the base end side surface of the main plate 41, 51, the opposing surfaces of the pair of reinforcing plates 42, 43, 52, 53 are spaced apart at a relatively small rate, and in the second spaced portion that is provided beyond the predetermined distance, the surfaces are spaced apart at a relatively large rate. In this way, the stress applied to the pair of reinforcing plates 42, 43, 52, 53 can be more effectively distributed.

[0039] The upper reinforcing plates 42, 52 in this embodiment are disposed so that the end on the base end side is approximately perpendicular to the longitudinal direction of the second boom 12. The hanging ring holes 422, 522 are formed in the portion disposed so as to be approximately perpendicular. By forming the hanging ring holes 422, 522 in the upper reinforcing plates 42, 52, the telescopic boom 10 can be hung approximately parallel when removing the telescopic boom 10 from the construction machine 100 or when attaching the telescopic boom 10 to the construction machine 100. Depending on the size of the construction machine 100, the construction machine 100 may be disassembled and transported due to weight restrictions. By forming the hanging ring holes 422, 522 in the upper reinforcing plates 42, 52, the telescopic boom 10 can be easily attached to and detached from the construction machine 100.

[0040] The upper reinforcing plates 42, 52 and the lower reinforcing plates 43, 53 are not formed symmetrically about the axis of the locking holes 411, 511. In other words, the lower reinforcing plates 43, 53, which do not have a hanging ring hole, are formed to have a different shape and are relatively small compared to the upper reinforcing plates 42, 52, which have the hanging ring holes 422, 522. In this way, the brackets 40, 50 can be made lighter and less expensive.

[0041] The lengths of the upper reinforcing plates 42, 52 and the lower reinforcing plates 43, 53 (the distance from the portion connected to the main plate 41, 51 to the end portion separated from the main plate 41, 51) are not particularly limited and may be designed according to the required strength, etc. If the lengths of the upper reinforcing plates 42, 52 and the lower reinforcing plates 43, 53 are made longer than necessary, it may become difficult to reduce the weight and cost of the brackets 40, 50.

[0042] 〔advantage〕 The main plates 41, 51 are supported by a pair of reinforcing plates 42, 43, 52, 53, and therefore can be prevented from being deformed or damaged by the tension of the extension wire rope 150. The pair of reinforcing plates 42, 43, 52, 53 are arranged so that their opposing surfaces are non-parallel to distribute stress, and therefore can be prevented from being deformed or damaged. Therefore, the brackets 40, 50 can be prevented from being deformed or damaged by the tension of the extension wire rope 150.

[0043] [Other embodiments] The above-mentioned embodiment does not limit the configuration of the present invention. Therefore, the above-mentioned embodiment may omit, replace or add components of each part of the above-mentioned embodiment based on the description in this specification and common general technical knowledge, and it should be understood that all of these are within the scope of the present invention.

[0044] In the above embodiment, a bracket is described that is disposed on the second boom of a telescopic boom consisting of four boom sections, however, the bracket may also be disposed on the first boom (base end boom) of a telescopic boom consisting of three boom sections, or on the third boom from the tip side of a telescopic boom consisting of five or more boom sections.

[0045] Further, the location where the bracket is disposed is not limited to the side surface of the boom, but the bracket may be disposed on the upper or lower surface of the boom. Further, the bracket may be disposed on one side surface of the boom.

[0046] In the above embodiment, a nut is used to fasten the end of the extension wire rope to the bracket, but the method of fastening the end of the wire rope is not limited to this and other known methods may be used.

[0047] In the above embodiment, the hanging ring hole is formed in the upper reinforcing plate, but the hanging ring hole is not an essential component. The upper reinforcing plate and the lower reinforcing plate may be formed to have similar shapes.

[0048] In the above-described embodiment, the pair of reinforcing plates is described as having a first spacing portion where the opposing surfaces are spaced apart at a relatively small rate and a second spacing portion where the surfaces are spaced apart at a relatively large rate. However, as shown in FIG. 9, the pair of reinforcing plates 401, 402 may be arranged so that the surfaces are spaced apart at a constant rate.

[0049] Alternatively, as shown in FIG. 10, a pair of reinforcing plates 500 may be disposed such that the opposing surfaces of the reinforcing plates 500 approach each other as they move away from the main plate 41 .

[0050] The lower traveling body may have wheels instead of crawlers as the traveling device. [Industrial Applicability]

[0051] The bracket according to the present invention can be suppressed from deformation, breakage, etc., and is therefore suitable for use in booms of construction machines that extend and retract using wire ropes. [Explanation of symbols]

[0052] 10 Telescopic boom 11 First Boom 12,120 Second Boom 121 First cylinder unit 121a Rod 122,123 Bracket 13 Third Boom 131 Second cylinder unit 131a Rod 132 Extension sheave 133 Reduction sheave 14 Fourth Boom 141 Locking part 15,150 Extension wire rope 16 Wire rope for reduction 20 Upper rotating body 21 Pilot's Cabin 30 Undercarriage 40,50 bracket 41,51 Main plate 411,511 Locking hole 412 Reinforcement 42,43,52,53,401,402,403,404 Reinforcement plate 421, 431, 521 Surfaces (opposing surfaces of a pair of reinforcing plates 42, 43, 52, 53) 422,522 Hanging ring hole 60 Locking hardware 70 Nut 100 Crane

Claims

1. A bracket for fixing one end of an extension wire rope for extending and retracting a boom of a construction machine in the longitudinal direction, A main plate fixed to the boom and having a locking hole for locking one end of the extension wire rope; a pair of reinforcing plates fixed to the boom and the main plate on one surface side of the main plate, the reinforcing plates being spaced apart from each other so as to sandwich the locking hole; Equipped with A bracket in which the opposing surfaces of the pair of reinforcing plates are non-parallel to each other.

2. 2. The bracket of claim 1, wherein the distance between opposing surfaces of said pair of reinforcing plates increases with distance from said main plate.

3. 2. The bracket of claim 1, wherein the distance between opposing surfaces of said pair of reinforcing plates decreases with increasing distance from said main plate.

4. A telescopic boom for a construction machine, which is extendable and contractable in a longitudinal direction, and which is provided with the bracket according to claim 1, 2 or 3.

5. The telescopic boom according to claim 4, An upper rotating body supporting the telescopic boom; a lower traveling body that supports the upper rotating body so as to be able to rotate; Construction machinery equipped with

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