KR20230072251A - Deflection Resistant Type Multi-Stage Boom For Boom Crane - Google Patents

Abstract

The present invention relates to a multi-stage boom for boom cranes with low deflection. According to the present invention, the multi-stage boom for boom cranes comprises: a boom (3) rotatably installed on a vehicle (10) and expandable and contractable in multiple stages by a plurality of unit boom bodies (31, 32, 33); and a deflection resistance beam (5) coupled to an upper surface of the boom (3) in multiple stages so as to be expandable and contractible together. Therefore, since the deflection of the boom that is used for high-altitude work while extended can be minimized by the deflection resistance beam, it is possible to improve the safety and efficiency of work at heights as well as prevent safety accidents.

Description

Multi-stage boom for boom crane with low deflection {Deflection Resistant Type Multi-Stage Boom For Boom Crane}

The present invention relates to a multi-stage boom for a boom crane with low deflection, and more particularly, to prevent a multi-stage boom crane that extends upward during operation from sagging downward due to its own weight or a load at its tip, deflection by a deflection resistance pipe It relates to a multi-stage boom for a boom crane with low deflection with increased resistance of the boom to the boom.

In general, a boom crane is designed to transport goods, equipment, or workers to a work position at a height by expanding and contracting a multi-stage multi-stage boom in the axial direction, and the stability of the multi-stage boom that determines the transport height determines the performance.

One example of such a multi-stage boom for a boom crane may be the crane shown in FIG. 1 (light truck crane, Registration No. 10-0278973). This multi-stage boom is rotatably installed in the vehicle 101 as shown, and the height of the front end of the multi-stage boom is adjusted by extending and contracting the boom stand 103.

However, in the conventional multi-stage boom as described above, since the boom unit 103 is inevitably supported in the form of a cantilever on the upper body 105 of the vehicle 101, Due to the vertical downward deflection, there is a problem in that the stability of the front end of the boom stand 103, which is a working position, is greatly reduced.

Accordingly, when the dimension of the boom 103 is increased to reduce deflection, a problem occurs that the weight of the boom 103 itself increases, and when the boom 103 is made of non-ferrous metal such as aluminum to reduce the weight, the unit boom body 105 ) is increased, and the sagging is still increased, so there is a problem that work stability is lowered.

Accordingly, when the boom 103 is made of a material with high rigidity, such as cast iron, that is, low deformation, the deflection of the boom 103 can be reduced, but there is a possibility that the boom 103 is brittle and fractured, improving work stability There are also problems that cannot be guaranteed.

KR 10-0278973

The present invention has been proposed to solve the above problems of the conventional boom crane, while suppressing the vertical downward deflection of the boom pole used in the form of a cantilever while extending long during work, the boom pole itself is made of a light weight material with good ductility The purpose is to improve the work convenience or stability of the boom stand by enabling it to be manufactured.

That is, by structurally suppressing the deflection of the boom, the material of the boom is lightened, and accordingly, the convenience of using the boom, such as transporting or driving the crane, as well as the convenience of manufacturing the boom is aimed at improving. .

In addition, by making it possible to structurally suppress the deflection of the boom, it is possible to adopt a highly ductile material such as aluminum as the material of the boom, preventing brittle fracture of the boom, thereby improving the stability of work at height through the boom Its purpose is to secure

In order to achieve this object, the present invention is a boom that is rotatably installed in a vehicle and is telescopically installed in multiple stages by a plurality of unit boom bodies; It provides a multi-stage boom for a boom crane with less deflection including; and a deflection resistance beam coupled to the upper surface of the boom bar in multiple stages so as to be stretchable together.

In addition, the deflection resistance beam includes a plurality of deflection resistance tubes collapsibly coupled in the axial direction so as to correspond one-to-one with the plurality of unit boom bodies 31, 32, and 33 while the size of the cross section gradually decreases; and a plurality of brackets coupled to the upper surfaces of the front ends of each of the plurality of unit boom bodies 31, 32, and 33 so as to protrude upward and supporting the corresponding front ends of the deflection resistance tubes.

In addition, each of the deflection resistance tubes is arranged side by side so as to extend in a rail form at both ends of the upper surface of each corresponding unit boom body, so that the deflection resistance beams formed on the upper surface of the boom base have a rail form. do.

In addition, it is preferable that each of the deflection resistance tubes is arranged to extend in a monorail shape at the center of the upper surface of each corresponding unit boom body, so that the deflection resistance beam formed on the upper surface of the boom base has a monorail shape.

In addition, each of the deflection resistance tubes is preferably disposed and extended one by one on both side surfaces of each corresponding unit boom body, so that the deflection resistance beams are formed in pairs on the side surface of the boom bar.

In addition, it is preferable that the first deflection resistance tube among the plurality of deflection resistance tubes is directly attached to the upper surface of the corresponding first unit boom body by removing a corresponding bracket.

In addition, each of the plurality of resistance deflection tubes preferably has a circular cross-sectional shape or a polygonal cross-sectional shape including a quadrangle.

In addition, each of the deflection resistance tubes is preferably made of any one material selected from a metal including aluminum or carbon fiber.

In addition, a bending boom that is hinged to be tiltable to the front end of the boom, and is capable of being stretched in multiple stages by a plurality of unit bending boom bodies; It is preferable to include a bending boom 20 comprising a; and a bending deflection resistance beam coupled to the upper surface of the bending boom bar in multiple stages so as to be stretchable together.

According to the multi-stage boom for a boom crane with low deflection of the present invention, even if the boom is extended for height work, the deflection resistance beam is extended together to support the boom, thereby minimizing the deflection occurring at the tip of the boom. It is possible to reduce the vertical fluctuation of the tip of the boom bar, and accordingly, it is possible to further improve the stability of work at high places using a multi-stage boom.

In addition, since the deflection of the boom can be suppressed by the deflection resistance beam as above, it is possible to use non-ferrous metal such as aluminum, which is relatively lightweight and has good ductility, as a material for the boom, thereby greatly reducing the overall weight of the multi-stage boom From the manufacturing stage of the multi-stage boom to the use and management stage, the handling convenience can be greatly improved.

In addition, since non-ferrous metal such as lightweight and ductile aluminum is used as the material of the boom as above, the brittleness of the boom as a whole can be lowered, and therefore, safety accidents at the site due to brittle fracture of the boom can be prevented in advance.

Therefore, in the case of a European boom crane using a boom with low rigidity, that is, with high ductility, the sagging of the boom, that is, the vertical fluctuation of the tip of the boom, can be greatly reduced through the deflection resistance beam. In the case of a domestic boom crane using a boom bar with high brittleness, the boom bar can be made of a material with high ductility, that is, low brittleness such as aluminum, without worrying about sagging of the boom bar. The risk of breakage can be avoided.

1 is a front view of a crane to which a conventional multi-stage boom is applied.
2 is a perspective view of a vehicle to which a multi-stage boom for a boom crane having less deflection according to an embodiment of the present invention is applied in a transport state.
Figure 3 is a perspective view showing the multi-stage boom of Figure 2 in an extended state;
Figure 4 is a perspective view showing the multi-stage boom shown in Figure 2;
5 is an enlarged view of part A of FIG. 3;
6 is an enlarged view of part B of FIG. 5;
7 is a cross-sectional view taken along line CC of FIG. 6;
8 is an enlarged view of part D of FIG. 2;
Figure 9 is a bottom view of the boom shown in Figure 3;
10 is a perspective view showing another embodiment of the deflection resistance tube shown in FIG. 6;
Figure 11 is a perspective view showing another embodiment of the deflection resistance tube and bracket shown in Figure 6;
12 is a perspective view showing another embodiment of the deflection resistance tube shown in FIG. 11;
Figure 13 is a perspective view showing another embodiment of the deflection resistance tube and bracket shown in Figure 6;

Hereinafter, a multi-stage boom for a boom crane having less deflection according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The multi-stage boom of the present invention is a lifting device widely used in small and medium-sized cranes such as mobile cranes, and as shown by reference numeral 1 in FIGS. , It is reduced as shown in FIG. 2 during transportation, and extends upward from the bottom connected to the vehicle 10 to the top as shown in FIG. It is hinged and installed.

In particular, the multi-stage boom 1 of the present invention is designed to suppress vertical downward deflection through the deflection resistance beam 5, as shown in FIGS. 2 to 4, the boom 3 and the deflection resistance beam ( 5) is included.

Here, the boom bar 3 is a body of the multi-stage boom 1, and as shown in FIGS. 2 to 4, the lower end is rotatably installed in the vehicle 10, and at the same time, it is folded or retractable in multiple stages It consists of a plurality of unit boom bodies (31, 32, 33) so as to extend.

Each unit boom body 31, 32, 33 takes the form of a square cylinder as a whole, as shown in FIGS. 2 to 4, 8, and 9, and the first unit boom body 31 at the lowest level The lower end of the second unit boom body 32 is inserted into the upper end of the second unit boom body 32 so that the lower end of the third unit boom body 33 slides and can be folded.

To this end, each of the unit boom bodies 31, 32, and 33 can be manufactured in various ways, such as simply manufacturing by bending a metal plate to have a rectangular cross section, but in this embodiment, as shown in FIGS. 8 and 9 Similarly, the left and right frame bodies 41 having a U-shaped cross section are placed facing each other, the lower ends of the left and right frame bodies 41 are connected with a plurality of transverse bars 43, and the upper ends are connected through a plurality of holes It can be manufactured by connecting with the plate 45 and having the shape of a square frame as a whole. At this time, the left and right frame body 41 is made of a square frame at the bottom so that it can stably support the unit boom bodies 32 and 33 of the lower order that are folded by sliding inside.

On the other hand, as shown in FIGS. 2 and 3, the first unit boom body 31, that is, the outer boom body, located at the lowest among the plurality of unit boom bodies 31, 32, and 33 as above, has a lower end of the vehicle 10. It is hingedly connected to the swivel table 11, and the elevating cylinder 13 extending from the swivel table 11 is connected to the middle portion, so that the boom bar 3 is connected to the vehicle 10 through the first unit boom body 31. In addition to being flexible, it should be installed so that it can be rotated and tilted.

The deflection resistance beam 5 is a means for suppressing the vertical downward sagging of the multi-stage boom 1, and as shown in FIGS. 2 to 9, it is coupled to the upper surface of the boom 3 in multiple stages, the boom ( 3), a plurality of deflection resistance tubes (51, 52, 53) corresponding to each of the unit boom bodies (31, 32, 33) one-to-one, and these deflection resistance tubes (51, 52, 53) as units It includes a plurality of brackets 61 attached to the boom bodies 31, 32, and 33.

Here, each of the deflection resistance tubes 51, 52, and 53 is mutually collapsible with the adjacent deflection resistance tubes so as to enable the expansion and contraction of the deflection resistance beam 5. To this end, each of the deflection resistance pipes 51, 52, and 53 is preferably manufactured as a cylindrical body having a rectangular cross section as shown in FIGS. It may be manufactured to have. In addition, as for the material of the deflection resistance tubes 51, 52, and 53, it is preferable to adopt aluminum or alumina materials having high strength and lightness, but metal materials having similar properties such as iron as well as light and high strength carbon fiber, etc. A non-metallic material may be employed. In particular, the deflection resistance tubes 51, 52, and 53 may be made of different materials. For example, in consideration of coupling with the first unit boom body 31 made of metal such as aluminum, It is made of metal such as aluminum, and the remaining second and third deflection resistance tubes 52 and 53 may be made of non-metallic material such as carbon fiber.

Each of the deflection resistance tubes 51 , 52 , and 53 manufactured in a cylindrical shape in this way gradually decreases in cross section as the arrangement position increases from bottom to top so that it can be folded in the axial direction. That is, the cross sectional area of the first deflection resistance tube 51 at the lowermost end is the largest, and the cross sectional area of the third deflection resistance tube 53 at the uppermost end, for example, is the smallest. In addition, each of the deflection resistance pipes 51, 52, and 53 are fixed to the unit boom bodies 31, 32, and 33 corresponding one-to-one through brackets 61 coupled to the upper ends, and as a result, the upper ends of the brackets 61 ) is fixed to the upper surface of the corresponding unit boom body (31, 32, 33), and the lower end slides inside the lower deflection resistance tube (51, 52, 53), that is, the senior deflection resistance tube (51, 52, 53). It is movably inserted and supported.

On the other hand, each of the deflection resistance tubes 51, 52, and 53 is a preferred embodiment, as shown in FIGS. 2 to 9, in the form of a rail on the upper surface of each corresponding unit boom body 31, 32, and 33. They can be arranged in pairs. In this case, each of the deflection resistance pipes 51, 52, and 53 has a vertically long rectangular cross section, and is disposed extending side by side at both ends of the upper surface of the unit boom bodies 31, 32, and 33 in the longitudinal direction. Therefore, the deflection resistance pipes 51, 52, and 53 can avoid interference with other auxiliary equipment such as a lead-out cable installed in the longitudinal direction at the center of the upper surface of the unit boom body 31, 32, 33.

However, since the lowermost first deflection resistance tube 51 of the plurality of deflection resistance tubes 51, 52, and 53 does not need to be spaced apart from the corresponding first unit boom body 31, it is shown in FIG. 10 as another embodiment. As described above, the bottom plate, which does not significantly affect the overall deflection resistance performance of the deflection resistance beam 5, may be removed to have a U-shaped cross section open downward. In this case, the bracket 61 to be described later also has a U-shape in which a hole for inserting the first deflection resistance tube 51 is opened downward. Accordingly, the deflection resistance performance of the first deflection resistance tube 51 is not greatly deteriorated, but the weight of the first deflection resistance tube 51 can be reduced by the weight of the bottom plate.

As described above, the bracket 61 is a means for fixing and supporting the front end of each of the deflection resistance tubes 51, 52, and 53 to the upper surface of the front end of the corresponding unit boom body 31, 32, and 33, and is a means for supporting each deflection resistance tube. (51, 52, 53) is integrated with each unit boom body (31, 32, 33) corresponding through the bracket (61), and is moved along with the unit boom body (31, 32, 33).

To this end, as shown in FIGS. 4 to 9 , the bracket 61 is coupled to the upper surface of each front end of the unit boom bodies 31 , 32 , and 33 so as to protrude upward. At this time, the bracket 61 can fold and move the corresponding deflection resistance tubes 51, 52, and 53 on the upper surface of the corresponding unit boom bodies 31, 32, and 33 together with the corresponding unit boom bodies 31, 32, and 33. It is free to manufacture in any shape as long as it can be supported. Therefore, although the bracket 61 is not shown as it is in FIGS. 5 to 7, the rim portion 63 protruding upward to surround the entire outer circumference of the deflection resistance tubes 51, 52, and 53 like a horn, and the rim portion ( 63) can be simply made of a base 64 attached to the upper surface of the unit boom body 31, 32, 33 while integrally connecting it. However, the bracket 61 preferably expands and changes the base 64 into a square band shape, and as shown in FIGS. can be made with

Conversely, in the case of the first deflection resistance tube 51, the corresponding bracket 61 may be removed and only the first deflection resistance tube 51 may be directly attached to the upper surface of the first unit boom body 31. .

On the other hand, as the deflection resistance beam 5 is another embodiment, as shown in FIG. 11, each of the deflection resistance tubes 51, 52, and 53 may be manufactured in the form of a monorail. In this case, each of the deflection resistance tubes 51, 52, and 53 is arranged to extend long like a monorail on the upper surface of the boom bar 3, and each of the deflection resistance tubes 51, 52, and 53 is a single sideways rectangular shape. It is disposed in the center of the upper surface of each unit boom body (31, 32, 33) corresponding to the tubular body, and at the same time, the corresponding unit boom body (31, 32, 33) The lower end is slidably inserted into the lower deflection resistance tubes 51, 52, and 53, that is, the senior deflection resistance tubes 51, 52, and 53 so that they can be folded in the longitudinal direction, and the upper end is supported by a bracket ( 61) is fixed to the upper surface of the corresponding unit boom body (31, 32, 33).

At this time, each of the deflection resistance tubes 51, 52, and 53 is spaced apart from the upper surface of the corresponding unit boom body 31, 32, and 33 to avoid interference with the lead-out cable C, as shown in FIG. Create space (S). To this end, the bracket 61 forms a support 65 in the form of a broken middle of the base 64. Therefore, the plurality of outgoing cables (C) pass between the unit boom bodies (31, 32, 33) and the deflection resistance pipes (51, 52, 53) along the interstitial space (S).

In addition, since the lowermost first deflection resistance tube 51, as another embodiment, does not need to be spaced apart from the corresponding first unit boom body 31, as shown in FIG. 12, the overall deflection of the deflection resistance beam 5 It can be manufactured to have a U-shaped cross section open downward by removing the bottom plate that does not significantly affect resistance performance. In this case, the bracket 61 to be described later also has a U-shape in which a hole for inserting the first deflection resistance tube 51 is opened downward. Accordingly, although the deflection resistance performance is not significantly reduced, the weight of the first deflection resistance tube 51 can be reduced by the weight of the bottom plate.

However, in this case, similarly, in FIG. 12, a gap space (S) for passing a plurality of lead cables (C) is secured between the bottom surface of the second deflection resistance pipe (52) and the upper surface of the first unit boom body (31). As shown, one or more spaced protrusions 55 protrude from the upper surface of the first unit boom body 31 . Therefore, even if the second deflection resistance tube 52 is folded and entered into the first deflection resistance tube 51 opened downward, the lead-out cable C along the interstitial space S 2 It operates without causing interference with the deflection resistance tube 52.

In addition, the bracket 61 fixes the front end of each of the deflection resistance tubes 51, 52, and 53 to the upper surface of the front end of the corresponding unit boom body 31, 32, and 33, as shown in FIG. 11, each While integrally connecting the deflection resistance tubes 51, 52, and 53 to the corresponding unit boom bodies 31, 32, and 33, the unit boom bodies 31, 32, and 33 are stretched and moved together.

To this end, as shown in FIG. 11, the bracket 61 is coupled to the upper surface of the front end of each of the unit boom bodies 31, 32, and 33 so as to protrude upward. At this time, the bracket 61 can also fold and move the corresponding deflection resistance tubes 51, 52, and 53 on the upper surface of the corresponding unit boom bodies 31, 32, and 33 together with the corresponding unit boom bodies 31, 32, and 33. Anything that can be supported can be manufactured in any shape, and although it is not shown as it is in FIG.

Even in this case, the bracket 61 is preferably manufactured in a form that encloses the circumferences of the unit boom bodies 31, 32, and 33 at the same time by enlarging and changing the lower surface of the partition into a square strip shape, as shown in FIG. can Similarly, the first deflection resistance tube 51 may be directly attached to the upper surface of the first unit boom body 31 by removing the corresponding bracket 61 and the first deflection resistance tube 51 itself.

On the other hand, the deflection resistance beam 5 is another embodiment, and as shown in FIG. 13, each of the deflection resistance tubes 51, 52, and 53 may be disposed on both sides of the boom bar 3. At this time, each of the deflection resistance tubes 51, 52, and 53 is a vertically long rectangular cylinder, and is installed to extend one by one on both side surfaces of the corresponding unit boom bodies 31, 32, and 33, respectively. Accordingly, each of the deflection resistance tubes 51, 52, and 53 is linked with the deflection resistance tubes in the first and second order to form a pair of deflection resistance beams 5 that can be folded in the longitudinal direction on the side of the boom stand 3 .

That is, each of the deflection resistance tubes 51, 52, and 53, as in the above embodiment, has a lower end so that it can be folded in the longitudinal direction along the corresponding unit boom body 31, 32, 33, the lower deflection resistance tube 51, 52,53) That is, it is slidably inserted into and supported inside the senior deflection resistance tubes 51,52,53, and the upper end is supported through the bracket 61 on both sides of the corresponding unit boom body 31,32,33 are fixed to each

In addition, the bracket 61 fixes the front end of each of the deflection resistance tubes 51, 52, and 53 to the side of the corresponding unit boom body 31, 32, and 33, as shown in FIG. 13, each deflection While integrally connecting the resistance tubes 51, 52, and 53 to the corresponding unit boom bodies 31, 32, and 33, the unit boom bodies 31, 32, and 33 are stretched and moved together.

To this end, as shown in FIG. 13, the bracket 61 is coupled to both side surfaces of the front ends of each of the unit boom bodies 31, 32, and 33 so as to protrude laterally. At this time, the bracket 61 can fold and move the corresponding deflection resistance tubes 51, 52, and 53 together with the corresponding unit boom bodies 31, 32, and 33 on the side surfaces of the corresponding unit boom bodies 31, 32, and 33. Anything that can be supported can be manufactured in any shape, and unlike that shown in FIG. 13, it is sufficient if it is in the form of a partition surrounding the deflection resistance tubes 51, 52, and 53

However, as shown in FIG. 13, the bracket 61 preferably extends the upper and lower ends of the inner surface of the partition laterally and connects the left and right sides into one, forming a square frame as a whole and forming the circumference of the unit boom body 31, 32, 33. It can be made in the form of enclosing.

Meanwhile, in this embodiment, in the case of the first deflection resistance tube 51, the corresponding bracket 61 can be removed, and the first deflection resistance tube 51 itself can be directly attached to the upper surface of the first unit boom body 31. there is.

In addition, as mentioned above, the boom unit 3 may include a bending boom 20 at its tip. As shown in FIGS. 2 to 4, the bending boom 20 includes a bending boom 23 and a bending deflection resistance beam 25, the bending boom 23 is larger than the boom 3 Although small, it is configured to be stretchable in multiple stages, for example, in two stages, by a plurality of unit bending boom bodies, similarly to the boom unit 3. In addition, the bending deflection resistance beam 25 is also made in multiple stages by a plurality of unit deflection resistance beams, similar to the deflection resistance beam 5, and each bending deflection resistance beam is integrally connected to the upper surface of the corresponding unit bending boom body. It is designed to be stretchable together with the unit bending boom body.

Now, the action of the multi-stage boom 1 for a boom crane with less deflection according to a preferred embodiment of the present invention will be described.

The multi-stage boom 1 of the present invention is stored in a folded state as shown in FIGS. 2 and 4 when not in use, but when in use, the bending boom 20 at the tip of the multi-stage boom 1, as shown in FIG. However, the working bucket is extended to reach the target point. When extended in this way, the multi-stage boom 1 not only resists deflection by itself, but also resists through the deflection resistance beam 5, so deflection can be greatly reduced. That is, since the deflection resistance tubes 51, 52, and 53 can greatly increase the moment of inertia in comparison to their small cross-sectional area, resistance to deflection can be greatly improved.

On the other hand, as shown in FIGS. 2 to 4, the bending boom 20 tiltably installed at the tip of the boom 3 is also bent like the boom 3 when the bending boom 23 is extended for work. Deflection of the bending boom 23 can be suppressed by the deflection resistance tube 25 .

Therefore, since the multi-stage boom 1 suppresses deflection by the deflection resistance beam 5, the material of the boom stand 3 can be selected from aluminum or alumina, which has a higher elongation than conventional steel, that is, is ductile. In this case, the sagging of the boom (3), that is, work instability due to downward bending, can be greatly reduced compared to when the boom (3) is made of a material with a high elongation rate such as aluminum without the deflection resistance beam (5), as is popular in Europe. do. On the contrary, in order to reduce the deflection of the boom bar (3) without the sagging resistance beam (5) as is popular in Korea, the risk of brittle fracture that can occur when the boom bar (3) is made of a material such as cast iron with high rigidity is greatly reduced. be able to

Moreover, the deflection resistance beam 5 shown in FIGS. 4 to 10 includes the deflection resistance tubes 51, 52, and 53 constituting the body and the deflection resistance tubes 51, 52, and 53 respectively of the unit boom body 31, 32 and 33), as mentioned above, the deflection resistance tubes 51, 52, and 53 are in the form of rails, and the brackets 61 are in the form of cones, paired side by side on both ends of the upper surface of the boom bar 3 Since it extends in the longitudinal direction while forming, it is possible to avoid interference with auxiliary equipment such as a lead-out cable installed in the longitudinal direction at the center of the upper surface of the boom bar (3).

On the other hand, in the deflection resistance beam 5 shown in FIGS. 11 and 12, as the deflection resistance tubes 51, 52, and 53 and the bracket 61 are mentioned above, the deflection resistance tubes 51, 52, and 53 are mono In the form of a rail, the bracket 61 extends in the longitudinal direction at the center of the upper surface of the boom bar 3 in the form of a partition, and the cross-sectional shape of the deflection resistance tubes 51, 52, and 53 is a left and right long rectangle or a downward open U-shaped Since it takes the shape, it is possible to increase the resistance against sagging as well as the resistance and strength against external force in the lateral direction.

In addition, in the deflection resistance beam 5 shown in FIG. 13, since the deflection resistance tubes 51, 52, and 53 are disposed on both sides of the boom unit 3, the resistance to deflection of the boom unit 3 is increased, and the boom unit ( 3), it is possible to increase the resistance or strength against the lateral external force.

1: multi-stage boom 3: boom stand
5: deflection resistance beam 10: vehicle
11: rotary table 13: lifting cylinder
20: bending boom 31, 32, 33: first, second, third unit boom body
51, 52, 53: first, second, third deflection resistance pipe
61: bracket

Claims (9)

A boom unit 3 that is rotatably installed in the vehicle 10 and is telescopically installed in multiple stages by a plurality of unit boom bodies 31, 32, and 33; and
A multi-stage boom for a boom crane with low deflection, characterized in that it includes a; The method of claim 1,
The deflection resistance beam 5,
A plurality of deflection resistance pipes (51, 52, 53) collapsibly coupled in the axial direction so as to correspond one-to-one with the plurality of unit boom bodies (31, 32, 33) while the size of their cross section gradually decreases; and
A plurality of brackets 61 coupled to the upper surfaces of the front ends of each of the plurality of unit boom bodies 31, 32, and 33 so as to protrude upward to support the front ends of the corresponding deflection resistance tubes 51, 52, and 53; A multi-stage boom for a boom crane with low deflection, characterized in that comprising a. The method of claim 2,
Each of the deflection resistance tubes 51, 52, and 53 are arranged side by side so as to extend in pairs in the form of rails on both ends of the upper surface of the respective unit boom bodies 31, 32, and 33, respectively, so that the boom unit 3 A multi-stage boom for a boom crane with low deflection, characterized in that the deflection resistance beam (5) formed on the upper surface has a rail shape. The method of claim 2,
Each of the deflection resistance tubes 51, 52, and 53 is arranged to extend in the form of a monorail at the center of the upper surface of each of the corresponding unit boom bodies 31, 32, and 33, forming the upper surface of the boom bar 3. A multi-stage boom for a boom crane with low deflection, characterized in that the deflection resistance beam (5) has a monorail shape. The method of claim 2,
Each of the deflection resistance tubes 51, 52, and 53 is disposed and extended one by one on both side surfaces of the respective unit boom bodies 31, 32, and 33, thereby forming a pair on the side surface of the boom stand 3. A multi-stage boom for a boom crane with low deflection, characterized in that the deflection resistance beam (5) is formed. The method according to any one of claims 1 to 4,
Among the plurality of deflection resistance pipes (51, 52, 53), the first deflection resistance pipe (51) is directly attached to the upper surface of the corresponding first unit boom body (31) by removing the corresponding bracket (61). Multi-stage boom for boom cranes with low deflection. The method according to any one of claims 1 to 5,
A multi-stage boom for a boom crane with low deflection, characterized in that each of the plurality of deflection resistance pipes (51, 52, 53) has a circular cross-sectional shape or a polygonal cross-sectional shape including a quadrangle. The method according to any one of claims 1 to 5,
Each of the deflection resistance tubes (51, 52, 53) is a multi-stage boom for a boom crane with low deflection, characterized in that made of any one material selected from metal containing aluminum or carbon fiber. The method according to any one of claims 1 to 5,
a bending boom (23) hinged to the front end of the boom (3) so as to be tiltable, and capable of being stretched in multiple stages by a plurality of unit bending boom bodies; and
A multi-stage boom for a boom crane with low deflection, characterized in that it includes a bending boom 20 comprising a bending deflection resistance beam 25 coupled to the upper surface of the bending boom stand 23 in multiple stages so as to be stretchable together.

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