JP2012017601A - Swing structure of construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a swing structure of a construction machine that reduces weight of a bracket, enhances rigidity of the bracket and further protects a hydraulic hose.SOLUTION: A swing structure includes a bracket 31 which is arranged on a turntable to be rotatable in a right and left direction via a pin 19 and a hydraulic hose 30 which is arranged to pass through the inside of the bracket 31. The bracket 31 includes an upper side pin fixing section 32, a lower side pin fixing section 33, a side fixing section 34, a first side surface section 35 and a second side surface section, and a front surface section 38 which is located in front of the side fixing section 34 to be fixed to the first side surface section 35 and the second side surface section. The front surface section 38, the side fixing section 34, the first side surface section 35 and the second side surface section include an upper side opening 43 and a lower side opening 44 to form an internal space 45 through which the hydraulic hose 30 can be passed in a vertical direction. The swing structure including the internal space 45 is constituted by closed sections from the upper side opening 43 up to the lower side opening 44.

Description

  The present invention relates to a swing structure of a construction machine such as a hydraulic excavator.

  In general, a construction machine such as a hydraulic excavator is provided with a turntable 2 that can turn above a crawler main body 1 as shown in FIG. 7, and an operation unit 3a and a driver's seat 3b are mounted on the top of the turntable 2, and further the turntable. A working device 4 is arranged in front of 2.

  The working device 4 includes a bracket 6 that can be rotated in the left-right direction by a swing cylinder 5 (see FIGS. 8 and 10) with respect to the turntable 2, and a boom that can be rotated in the up-down direction by a cylinder 7 with respect to the bracket 6. 8, an arm 10 that can be turned up and down by a cylinder 9 with respect to the boom 8, and a bucket 12 that can be turned up and down by a cylinder 11 with respect to the tip of the arm 10.

  As shown in FIG. 8, the turntable 2 includes a plate-like base portion 13, and a first frame vertical plate 14 and a second frame vertical plate 15 that are located on both sides of the axis of the base portion 13 and extend. . An upper frame plate 16 and a lower frame plate 17 (see FIG. 12) are provided on the front side of the first frame vertical plate 14 and the second frame vertical plate 15, and further, the first frame vertical plate 14 and the second frame vertical plate 15 A cylindrical support portion 18 (see FIG. 12) is provided at the tip to support the pin 19, and the bracket 6 is fixed to the pin 19. Here, the pin 19 is supported at an intermediate position by the support portion 18 and the axis of the pin 19 is directed in the vertical direction.

  The bracket 6 is arranged on the upper side of the support portion 18 (see FIG. 12) and fixed on the upper side of the pin 19 and the lower side of the support portion 18 as shown in FIGS. A lower pin fixing portion 21 that fixes the lower portion of the pin 19, a side fixing portion 22 that is positioned on the front outer side of the support portion 18 and fixes the upper pin fixing portion 20 and the lower pin fixing portion 21, and upper pin fixing The first side surface portion 23 and the second side surface portion 24 fixed to both sides of the portion 20 and the lower pin fixing portion 21 and the side fixing portion 22, and the lower side pin fixing portion 21 are formed on the first side surface portion 23. And a lever portion 25 located at the lower part of the outer surface. Here, the first side surface portion 23 and the second side surface portion 24 include a boom foot fixing portion 26 extending upward so as to sandwich the lower end of the boom 8 as shown in FIG. The boom foot fixing part 26 is provided with an upper fixing pin mounting hole 27 and an upper fixing pin (not shown) is arranged, and the boom 8 is connected by the upper fixing pin. Further, an intermediate side fixing pin mounting hole 28 is provided at an intermediate position between the first side surface part 23 and the second side surface part 24 and an intermediate fixing pin (not shown) is arranged, and the cylinder 7 (FIG. 7, FIG. (See FIG. 8). Further, the lever portion 25 is provided with a lower fixing pin mounting hole 29 and a lower fixing pin (not shown) is arranged, and the swing cylinder 5 (see FIGS. 8 and 9) is connected by the lower fixing pin. In FIG. 10, reference numeral 5 a indicates a swing cylinder fixing portion that connects the rear end of the swing cylinder 5.

  Further, between the first side surface portion 23 and the second side surface portion 24 of the bracket 6, a hydraulic hose 30 (see FIG. 12) connected to the cylinders 7, 9, and 11 as shown in FIGS. The hydraulic hose 30 is connected to a control valve device (not shown) and the like, and the boom 8, the arm 10, and the bucket 12 are connected via the cylinders 7, 9, 11 and the like. The rotation is controlled.

  Further, in such a swing structure, as shown in FIG. 9, a strong torsional moment like a torsion bar is generated between the upper pin fixing portion 20 and the lower pin fixing portion 21 in various operations, and the upper pin fixing portion 20. Since the distance between the lower pin fixing portion 21 and the lower pin fixing portion 21 is set to be long, the first side surface portion 23, the second side surface portion 24, the side fixing portion 22 and the like are thickened to increase the rigidity.

  Here, the case where a strong torsional moment such as a torsion bar is generated between the upper pin fixing portion 20 and the lower pin fixing portion 21 will be described in detail. When excavation work is performed as shown in FIG. Depending on the state and conditions, the lateral load F1 acts on the tip of the bucket 12 in the horizontal and lateral direction, and the bracket is further in accordance with the distance from the tip of the bucket 12 to the swing axis S1 (the axis of the pin 19) and the magnitude of the lateral load F1. The torsional moment M1 acts around the swing axis on the boom foot fixing part 26 (the upper part of the bracket 6). Further, as shown in FIG. 9, the torsional moment M1 transmits loads F2 and F3 to the first side surface portion 23 and the second side surface portion 24 to generate a torsional moment M2 in the upper pin fixing portion 20, and the bracket 6 is twisted in the twisting direction. Try to rotate to. At this time, since the stroke of the swing cylinder 5 is normally fixed, the lower part of the bracket 6 receives a reaction force from the swing cylinder 5 so that the swing cylinder 5 pushes the lever portion 25 (indicated by a load F4) ( A strong torsional moment is generated between the upper pin fixing part 20 and the lower pin fixing part 21 like a torsion bar.

  The reason why the distance between the upper pin fixing portion 20 and the lower pin fixing portion 21 is increased will be described in detail. The position of the boom foot fixing portion 26 is an operation above the bucket 12 or a scooping work of earth and sand. Since the lever portion 25 is set at a low position corresponding to the swing cylinder 5, the torsional moment M2 is set so that a sufficient working range can be secured. , M3, the distance between the upper pin fixing portion 20 and the lower pin fixing portion 21 is long. Further, when the support portion 18 (see FIG. 12) of the turntable 2 is sandwiched between the upper pin fixing portion 20 and the lower pin fixing portion 21 and fastened with a single pin 19, the rigidity of the support portion 18 is increased. In order to increase the height of the support portion 18, the distance between the upper pin fixing portion 20 and the lower pin fixing portion 21 that receive the torsional moments M2 and M3 is further increased.

  In addition, as prior art document information of the swing structure of a construction machine highly relevant to the present invention, for example, there are the following Patent Documents 1 to 3.

Japanese Patent Application No. 3-125899 Japanese Patent Application No. 8-272461 Japanese Patent Application No. 2002-195103

  However, when the thickness of the first side surface portion 23, the second side surface portion 24, the side fixing portion 22 and the like is increased so as to correspond to the strong torsion moments M2, M3, etc., the weight of the bracket 6 is increased. Since there is a problem of becoming heavy, it has been required to further increase the rigidity while reducing the weight of the bracket 6. Further, the bracket 6 through which the hydraulic hose 30 is passed is opened during the operation because the front surface in the circumferential direction is opened as in Patent Document 1, or the hydraulic hose 30 is arranged with a hole in a part as in Patent Documents 2 and 3. There is a problem in that the hydraulic hose 30 is not sufficiently protected against flying stones generated in the case.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a swing structure for a construction machine that reduces the weight of the bracket, increases the rigidity, and further protects the hydraulic hose.

The present invention relates to a bracket disposed on a turntable so as to be pivotable in the left-right direction via a pin, a boom disposed so as to be pivotable in the vertical direction with respect to the bracket, and a hydraulic pressure disposed through the bracket. A swing structure for construction equipment comprising a hose,
The bracket includes an upper pin fixing portion for fixing the upper portion of the pin, a lower pin fixing portion for fixing the lower portion of the pin, and an upper pin fixing portion and a lower side formed along the side portion of the pin. A side fixing part for fixing the pin fixing part, a first side part and a second side part fixed to both sides of the upper pin fixing part and the lower pin fixing part and the side part so as to sandwich the lower end of the boom; And a front surface portion positioned in front of the side fixing portion and fixed to the first side surface portion and the second side surface portion,
The front surface portion, the side fixing portion, the first side surface portion, and the second side surface portion are provided with an upper opening and a lower opening to form an internal space through which a hydraulic hose can be passed in the up and down direction. The present invention relates to a swing structure for a construction machine, characterized in that it has a closed cross section from an upper opening to a lower opening.

  In the swing structure of the construction machine according to the present invention, it is preferable that at least one of the lower end of the front surface portion, the lower end of the first side surface portion, and the lower end of the second side surface portion is disposed at a position below the lower end of the lower pin fixing portion. .

  In the swing structure for a construction machine according to the present invention, it is preferable that a bottom portion extending from the lower end of the front surface portion to below the pin is provided.

  According to the swing structure of the construction machine of the present invention, the internal space formed by the front surface portion, the side fixing portion, the first side surface portion, and the second side surface portion is configured with a closed cross section from the upper side opening to the lower side opening. Therefore, the thickness of the side fixing portion, the first side surface portion, and the second side surface portion can be reduced to reduce the weight of the bracket, and the rigidity can be increased with a closed cross section. In addition, a hydraulic hose is passed vertically through the internal space formed by the front surface portion, the side fixing portion, the first side surface portion, and the second side surface portion to the upper opening and the lower opening, and further from the upper opening to the lower opening. Since it has a closed cross section, the hydraulic hose is not exposed around the internal space through which the hydraulic hose passes, and the hydraulic hose can be protected against flying stones generated during work. Can be played.

It is a conceptual diagram which shows the bracket of the 1st example of embodiment which implements this invention. It is a conceptual sectional view showing the first example of the form for carrying out the present invention. It is a comparison figure which shows the case where the case of an open section and the case of a closed section are modeled and compared. It is a conceptual sectional view showing the second example of the form for carrying out the present invention. It is a conceptual sectional view showing the 3rd example of the form which carries out the present invention. It is a conceptual sectional view showing the 4th example of an embodiment which carries out the present invention. It is a side view which shows a construction machine. It is a conceptual diagram which shows typically the structure of a turntable, a bracket, a boom, an arm, and a bucket. It is a conceptual diagram which shows the state which the torsion moment is acting on a bracket. It is a conceptual diagram which shows the position of a swing cylinder. It is a conceptual diagram which shows the structure of the conventional bracket. It is a conceptual sectional view showing the structure of a conventional bracket.

  Hereinafter, a first example of an embodiment of the present invention will be described with reference to FIGS. In addition, in the figure, the part which attached | subjected the code | symbol same as FIGS. 7-12 represents the same thing.

  The swing structure of the construction machine of the first example of the embodiment is obtained by changing the shape of the bracket, and the other members have the same shape and configuration.

  The bracket 31 is formed along the upper pin fixing portion 32 disposed on the upper portion of the support portion 18, the lower pin fixing portion 33 disposed on the lower portion of the support portion 18, and the side portion of the pin 19, and fixed on the upper pin. Side fixing portion 34 for fixing portion 32 and lower pin fixing portion 33, first side surface portion 35 fixed to both sides of upper pin fixing portion 32, lower pin fixing portion 33, and side fixing portion 34, and Two side portions 36, a lever portion 37 formed in the lower pin fixing portion 33 and positioned at the lower outer surface of the first side surface portion 35, and the first side surface portion 35 and the first side portion 35 positioned in front of the side fixing portion 34. And a front surface portion 38 fixed to the two side surface portions 36.

  The upper pin fixing portion 32 has a cylindrical shape coaxially with the cylindrical support portion 18 to fix the upper portion of the pin 19, and the lower pin fixing portion 33 is connected to the cylindrical support portion 18. A cylindrical shape is provided on the same axis, and the lower portion of the pin 19 is fixed.

  The side fixing portion 34 is a plate material disposed outside the support portion 18 so as to be located on the side (front side) away from the turntable 2, and adversely affects the left-right rotation of the turntable 2 and the bracket 31. It is configured not to give.

  The first side surface portion 35 and the second side surface portion 36 are plate members extending in the vertical direction so as to sandwich the lower end of the boom 8, and the upper ends of the first side surface portion 35 and the second side surface portion 36 are the rotations of the boom 8. The lower end of the first side surface portion 35 and the second side surface portion 36 are at the same height as the lower end of the lower pin fixing portion 33 and are not in contact with other movements during the operation of the construction machine. It is in a position that does not interfere. Further, the first side surface portion 35 and the second side surface portion 36 are provided with a boom foot fixing portion 39 at the upper portion, and the boom foot fixing portion 39 is provided with an upper fixing pin mounting hole 40 and an upper fixing pin (not shown) is arranged. The boom 8 is connected by the upper fixing pin. Further, an intermediate fixing pin mounting hole 41 is provided at an intermediate position between the first side surface portion 35 and the second side surface portion 36, and an intermediate fixing pin (not shown) is arranged, and the cylinder 7 (see FIG. 7) is provided by the intermediate fixing pin. ) Is connected.

  The lever portion 37 includes a lower fixing pin mounting hole 42 and a lower fixing pin (not shown). The swing cylinder 5 is connected by the lower fixing pin.

  The front surface portion 38 is a plate member disposed between the side fixing portion 34 and the intermediate side fixing pin mounting hole 41, and the upper end of the front surface portion 38 is located at the same height as the upper end of the upper pin fixing portion 32. The lower end of the front portion 38 is located at the same height as the lower end of the lower pin fixing portion 33 and interferes with other structures during the operation of the construction machine. It is in a position that does not. Here, the front surface portion 38 is not limited to the shape along the vertical direction, and the upper side may be inclined forward, and the upper side and / or the lower side may be curved.

  The front surface portion 38, the first side surface portion 35, the second side surface portion 36, the side fixing portion 34, the upper pin fixing portion 32, and the lower pin fixing portion 33 form an internal space 45 having an upper opening 43 and a lower opening 44. The hydraulic hose 30 formed and connected to the cylinders 7, 9, 11 (see FIG. 7) or the like is passed through in the vertical direction. Here, a clip for fixing the hydraulic hose 30 to at least one of the front surface portion 38, the first side surface portion 35, the second side surface portion 36, the side fixing portion 34, the upper pin fixing portion 32, and the lower pin fixing portion 33. (Not shown) may be provided.

  In addition, the structure having the internal space 45 has a front surface portion 38 and a first side surface portion so that a wide upper and lower range from the upper pin fixing portion 32 to the lower pin fixing portion 33 has a closed cross section without holes or notches. 35, the 2nd side part 36, and the side fixing | fixed part 34 are comprised, and the rigidity from the upper side pin fixing | fixed part 32 to the lower side pin fixing | fixed part 33 is high. Further, the hydraulic hose 30 located in the internal space 45 is not exposed to the outside.

Here, when a torsional stress is generated in the cross section of the internal space 45 of the bracket 31, the case where the structure having the internal space 45 is an open cross section and the case where the structure having the internal space 45 is a closed cross section are modeled. Compared. Here, in FIG. 3, (A) shows the case of the open cross section, and (B) shows the case of the closed cross section. In the case of the open cross section, the torsional stress of the portion of thickness t ₂ on the back side is calculated Yes.
The torsional stress τ in the case of an open section is calculated by the following equation of material mechanics in FIG.
[Formula 1]
τ = 3t ₂ · T / (s ₁ · t ₁ ³ + s ₂ · t ₂ ³ + s ₃ · t ₃ ³ )
τ: torsional stress (N / mm ² )
T: Torque (Nm)
s ₁ : Length (mm)
s ₂ : Length (mm)
s ₃ : Length (mm)
t ₁ : thickness (mm)
t ₂ : thickness (mm)
t ₃ : thickness (mm)
The torsional stress τ in the case of a closed cross section is calculated by the following equation of material mechanics in FIG.
[Formula 2]
τ = T / {2t · (at) (bt)}
τ: torsional stress (N / mm ² )
T: Torque (Nm)
a: Length (mm)
b: Length (mm)
t: Thickness (mm)

  The cross-sectional area A and the torsional stress τ were calculated from the data in [Table 1] for the open section and the closed section in which the structure having the internal space 45 was modeled, and the results are shown in the lower part of [Table 1]. . The cross-sectional area A is calculated from a basic area formula.

From the results in the lower part of [Table 1], in the cross-sectional area A, the open cross section is 10000 mm ² , the closed cross section is 4944 mm ² , and the closed cross section has a weight that is approximately that of the open cross section. It is less than 1/2. Also with respect to 120 N / mm ² in the case of open cross-section in twisting stress tau, in the case of closed cross section was 28N / mm ^2, in the case of closed section, torsional stress as compared with the opening cross section is less than about 1/4 It has become. Therefore, it is clear that the bracket 31 having the internal space 45 with the closed cross section is lighter and more rigid than the bracket 31 having the internal space 45 with the open cross section. Further, as in the embodiment, when the front side 38, the first side 35, the second side 36, and the side fixing part 34 have no holes or notches, the strength is increased, while the front 38, When holes or notches are formed on the side surfaces of the first side surface portion 35, the second side surface portion 36, and the side fixing portion 34, it is clear that stress is concentrated on the holes and the notch portions, and the strength is reduced. .

  Thus, according to the first example of the embodiment, the front surface portion 38, the side fixing portion 34, the first side surface portion 35, the second side surface portion 36, the upper pin fixing portion 32, and the lower pin fixing portion 33 Since the formed internal space 45 has a closed cross section from the upper opening 43 to the lower opening 44, the thickness of the side fixing portion 34, the first side surface portion 35, and the second side surface portion 36 is reduced to reduce the bracket 31. The weight can be reduced and the rigidity can be increased.

  Further, an upper opening 43 and a lower side are formed in an internal space 45 formed by the front surface portion 38, the side fixing portion 34, the first side surface portion 35, the second side surface portion 36, the upper pin fixing portion 32, and the lower pin fixing portion 33. Since the hydraulic hose 30 is passed in the vertical direction up to the opening 44 and the upper opening 43 to the lower opening 44 are configured in a closed cross section, the hydraulic hose 30 is exposed around the internal space 45 through which the hydraulic hose 30 passes. The hydraulic hose 30 can be protected against flying stones generated during the operation.

  Furthermore, since only the upper opening 43 and the lower opening 44 are provided in the internal space 45, the hydraulic hose 30 can be appropriately guided when the hydraulic hose 30 is assembled, and the hydraulic hose 30 can be easily installed.

  Hereinafter, a second example of the embodiment of the present invention will be described with reference to FIG. In the figure, the same reference numerals as those in FIGS. 1 to 3 denote the same components.

  The swing structure of the construction machine of the second example of the embodiment is a modification of the configuration of the first side surface part 35 and the second side surface part 36 of the bracket 31 of the first example, and other parts are the same as the first example. It has the same configuration.

  In the bracket 51 of the second example, the first side surface portion 52 and the second side surface portion (not shown) are plate members extending in the vertical direction so as to sandwich the lower end of the boom 8 (see FIG. 1). The upper ends of the portion 52 and the second side surface portion are positions that do not interfere with the rotation of the boom 8, and the lower ends of the first side surface portion 52 and the second side surface portion are below the lower end of the lower pin fixing portion 33. It is positioned so that it does not interfere with other structures during the work of the construction machine. Here, the lower ends of the first side surface portion 52 and the second side surface portion have a predetermined vertical width so as to protect the hydraulic hose 30 passing through the lower position of the pin 19, and turn from the lower end of the lower pin fixing portion 33. It is located between the lower surface height of the lower surface frame plate 17 of the table 2.

  Further, the first side surface portion 52 and the second side surface portion are provided with a boom foot fixing portion 39 (see FIG. 1) at the upper portion, and the boom foot fixing portion 39 is provided with an upper fixing pin mounting hole 40 (see FIG. 1). A fixing pin (not shown) is arranged, and the boom 8 (see FIG. 1) is connected by the upper fixing pin. Further, an intermediate fixing pin mounting hole 53 is provided at an intermediate position between the first side surface portion 52 and the second side surface portion, and an intermediate fixing pin (not shown) is arranged, and the cylinder 7 (see FIG. 7) is provided by the intermediate fixing pin. Is connected.

  Thus, according to the second example of the embodiment, the same effect as the first example can be obtained.

  In the second example of the embodiment, when the lower end of the first side surface portion 52 and the lower end of the second side surface portion are arranged below the lower end of the lower pin fixing portion 33, the hydraulic pressure that passes through the lower position of the pin 19. Since the hose 30 can be protected, the hydraulic hose 30 can be sufficiently protected against flying stones generated during the work.

  Hereinafter, a third example of the embodiment of the present invention will be described with reference to FIG. In the figure, the same reference numerals as those in FIGS. 1 to 4 denote the same components.

  The swing structure of the construction machine of the third example of the embodiment is a modification of the configuration of the front surface portion 38 of the second example, and the other parts have the same configuration as the second example.

  In the bracket 61 of the third example, the front surface portion 62 is a plate material disposed between the side fixing portion 34 and the intermediate side fixing pin mounting hole 53, and the upper end of the front surface portion 62 is the upper end of the upper pin fixing portion 32. It is located at the same height so as not to interfere with the rotation of the boom 8, and the lower end of the front surface portion 62 is positioned below the lower end of the lower pin fixing portion 33 so that it can be used during the operation of the construction machine. So as not to interfere with the structure.

  Here, the lower end of the front surface portion 62 has a predetermined vertical width so as to protect the hydraulic hose 30 passing below the pin 19, and the lower frame plate 17 of the turntable 2 from the lower end of the lower pin fixing portion 33. It is located between the lower surface height of the. In FIG. 5, the lower end of the front surface portion 62 has the same height as the lower end of the first side surface portion and the lower end of the second side surface portion in the second example.

  Thus, according to the third example of the embodiment, the same effects as the first and second examples can be obtained.

  In the third example of the embodiment, when the front surface portion 62 is arranged below the lower end of the lower pin fixing portion 33, the hydraulic hose 30 passing through the lower position of the pin 19 can be protected. The hydraulic hose 30 can be sufficiently protected against the generated flying stones.

  A fourth example of the embodiment of the present invention will be described below with reference to FIG. In the figure, the same reference numerals as those in FIGS. 1 to 5 denote the same components.

  The swing structure of the construction machine of the fourth example of the embodiment is a modification of the configuration of the bottom part of the bracket 61 of the third example, and the other parts have the same configuration as the third example.

  In the bracket 71 of the fourth example, the front side portion 52, the second side portion (not shown), and the lower end of the front side portion 62 extend from the lower end of the front side portion 62 to below the pin 19. A plate-like bottom portion 72 formed from the lower end of 62 to the rear end of the first side surface portion 52 and the rear end of the second side surface portion is provided. Further, a second internal space 73 in which the hydraulic hose 30 can be disposed is provided between the lower end of the pin 19 and the bottom portion 72, and the second internal space 73 includes a front surface portion 62, a first side surface portion 52, and a second second space 73. It communicates with the internal space 45 formed by the side surface portions and the side fixing portions 34. Here, the bottom portion 72 may be fixed to the first side surface portion 52, the second side surface portion, and the front surface portion 62, or may be configured to be detachable. The configuration of the side surface portion and the side fixing portion 34 may be curved from the internal space 45 to the second internal space 73. Furthermore, the lower opening may be the rear end of the second internal space 73.

  Thus, according to the fourth example of the embodiment, the same effects as the first to third examples can be obtained.

  Further, in the fourth example of the embodiment, when the bottom portion 72 extending from the lower end of the front surface portion 62 to the lower side of the pin 19 is provided, the hydraulic hose 30 passing through the lower position of the pin 19 is further protected, and the hydraulic hose 30 is further protected. Is prevented from drooping downward, so that the hydraulic hose 30 can be sufficiently protected.

  It should be noted that the swing structure of the construction machine of the present invention is not limited to the above illustrated example, and the construction equipment may be other construction equipment as long as it has a bracket that can be rotated via a pin. The cross section of the internal space is not limited to a square, and may be a circle, an ellipse, or other polygons as long as the effects of the present invention are produced, and various other modifications may be made without departing from the spirit of the present invention. Of course, changes can be made.

2 Turntable 8 Boom 9 Cylinder 19 Pin 30 Hydraulic hose 31 Bracket 34 Side fixing part 35 First side part 36 Second side part 38 Front part 43 Upper opening 44 Lower opening 45 Internal space 51 Bracket 52 First side part 53 Intermediate side fixing pin mounting hole 61 Bracket 62 Front part 71 Bracket 72 Bottom part

Claims (3)

A bracket disposed on the turntable via a pin so as to be pivotable in the left-right direction, a boom disposed so as to be pivotable in the vertical direction with respect to the bracket, and a hydraulic hose disposed within the bracket. A swing structure for construction equipment,
The bracket includes an upper pin fixing portion for fixing the upper portion of the pin, a lower pin fixing portion for fixing the lower portion of the pin, and an upper pin fixing portion and a lower side formed along the side portion of the pin. A side fixing portion for fixing the pin fixing portion, a first side surface portion and a second side surface fixed to both sides of the upper pin fixing portion, the lower pin fixing portion, and the side fixing portion so as to sandwich the lower end of the boom. And a front surface portion positioned in front of the side fixing portion and fixed to the first side surface portion and the second side surface portion,
The front surface portion, the side fixing portion, the first side surface portion, and the second side surface portion have an upper opening and a lower opening to form an internal space through which a hydraulic hose can be passed in the vertical direction, and the structure having the internal space is A swing structure for a construction machine, characterized in that it has a closed cross section from an upper opening to a lower opening.   The construction machine according to claim 1, wherein at least one of a lower end of the front surface portion, a lower end of the first side surface portion, and a lower end of the second side surface portion is arranged at a position below the lower end of the lower pin fixing portion. Swing structure.   The swing structure for a construction machine according to claim 1 or 2, further comprising a bottom portion extending from a lower end of the front surface portion to a position below the pin.

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