JP2008291541A - Construction machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a construction machine capable of preventing a cab (a cab structure) from being pressed against a boom and being deformed when a vehicle turns over. <P>SOLUTION: This construction machine constituted by arranging the boom 16 turnably on a side of the cab structure 11 is provided with a retaining member 18 arranged on the boom 16 in close proximity to the cab structure 11 and retaining the cab structure 11 attempting to move onto a boom 16 side to prevent the cab structure 11 from being pressed against the boom 16 and being deformed when the vehicle turns over. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a construction machine such as a hydraulic excavator in which a boom is rotatably disposed on a side of a cab (cab structure).

  A construction machine such as a hydraulic excavator may be used on a slope such as a mountain. In that case, the construction machine (vehicle) may be out of balance and fall (upside down). If the vehicle falls down, it is necessary to suppress deformation of the cab in order to ensure the safety of passengers in the cab of the vehicle. In order to ensure such safety, a configuration is known that suppresses deformation of the cab by attaching a reinforcing member to the pillar of the cab and increasing the rigidity of the cab itself (see, for example, Patent Document 1).

JP 2001-279721 A

  By the way, when the vehicle falls to the cab side, the cab collides with the ground, a lateral load due to the ground collision acts on the upper part of the cab, and then the vehicle is turned upside down and a vertical load due to the vehicle's own weight acts on the upper part of the cab. Will be.

  When simulating the deformation of the cab when the vehicle falls in the state where the boom pivots downward (the bottom dead center of the boom), the vertical middle of the front pillar of the cab is pressed against the corner of the boom with the first lateral load. As a result, it was found that the closed cross section of the front pillar was crushed, and stress was concentrated on the crushed portion of the cab's front pillar due to the subsequent vertical load, leading to large deformation (buckling deformation) of the cab.

  Accordingly, an object of the present invention is to provide a construction machine that can prevent a cab from being pressed against a boom and deformed when the vehicle falls.

  In order to achieve the above object, the present invention provides a construction machine in which a boom is rotatably disposed on a side of a cab structure, and the cab structure is placed on the boom in the vicinity of the cab structure when the vehicle falls. In order to prevent an object from being pressed against the boom and deformed, a receiving member is provided for receiving the cab structure to be moved to the boom side.

  Here, the receiving member may be located from the middle part in the up-down direction to the upper end part of the cab structure in a state where the boom is pivoted downward most.

  The receiving member may be disposed on an extension line of the front header of the cab structure.

  The receiving member may be detachably provided on the boom.

  According to the present invention, an excellent effect is exhibited that the cab can be prevented from being deformed by being pressed against the boom when the vehicle falls.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a side view of a construction machine according to an embodiment of the present invention. FIG. 2 is a front view of the construction machine shown in FIG.

  As shown in FIGS. 1 and 2, the construction machine 1 according to this embodiment is a hydraulic excavator, and mainly includes a lower mechanism 2, an upper mechanism 3, and a work mechanism 4.

  The lower mechanism 2 has a lower frame 5. The lower mechanism 2 according to the present embodiment is of a crawler type, and a crawler 6 is attached to the lower frame 5. The lower mechanism 2 may be of a wheel type (tire type). In that case, a wheel (tire) is attached to the lower frame 5.

  The upper mechanism 3 is attached to the lower frame 5 via a turning device (not shown) and has an upper frame 7 that can turn with respect to the lower frame 5. The upper frame 7 is provided with an engine room 8 for accommodating an engine and the like, and the rear portion of the upper frame 7 is provided with a counterweight 9 for balancing the weight of the work mechanism 4.

  A cab structure (hereinafter referred to as a cab) 11 having a cab frame 10 composed of a plurality of pillars (pillars) or the like is attached to the front portion of the upper frame 7 via a vibration-proof mount device (not shown). Yes. Specifically, the cab frame 10 mainly includes a front pillar 12, a rear pillar 13, a roof rail 14, a front header 15, and the like.

  A pair of left and right front pillars 12 extending in the vertical direction of the cab frame 10 is provided at the front portion of the cab 11, and the rear portion of the cab 11 is substantially parallel to the front pillar 12 (that is, in the vertical direction). A pair of left and right rear pillars 13 are installed. The front pillars 12 and the rear pillars 13 are connected by roof rails 14 extending in the vehicle front-rear direction at their upper ends, and the pair of left and right front pillars 12 extend in the vehicle width direction at their upper ends. Connected by a front header 15. The front pillar 12, the rear pillar 13, the roof rail 14, the front header 15, and the like are made of pipes (steel pipes) or a combination of plate materials.

  The working mechanism 4 is a front portion of the upper frame 7 and is arranged at a predetermined interval on the side of the cab 11 (cab frame 10), and is connected to the upper frame 7 so as to be freely rotatable. It has an arm (not shown) rotatably connected to the tip, and an attachment (not shown) such as a bucket rotatably connected to the arm tip.

  A hydraulic cylinder (boom cylinder) 17 is interposed between the upper frame 7 and the boom 16, and the boom 16 is rotated with respect to the upper frame 7 by expanding and contracting the boom cylinder 17. A hydraulic cylinder (arm cylinder) (not shown) is interposed between the boom 16 and the arm, and the arm is rotated with respect to the boom 16 by expanding and contracting the arm cylinder. A hydraulic cylinder (bucket cylinder) (not shown) is interposed between the arm and the bucket, and the bucket is rotated with respect to the arm by expanding and contracting the bucket cylinder.

  On the boom 16, the cab 11 is placed close to the cab 11 to catch the cab 11 that is about to move toward the boom 16 in order to prevent the cab 11 from being deformed by being pushed against the corners of the boom 16 when the vehicle falls. A receiving member 18 is provided.

  As shown in FIG. 3, the receiving member 18 according to the present embodiment has a frame 19 formed in a box shape of a truncated pyramid shape (a shape obtained by cutting off the top of the pyramid), and the transverse section is a closed section. It has become. In the present embodiment, the rib 20 is mounted in the frame 19.

  The receiving member 18 is made of a material having higher rigidity (or strength) than the cab 11 and is not easily broken by an external force. Further, if the receiving member 18 is made of a material having high specific rigidity (or specific strength), it is advantageous because the increase in weight of the boom 16 can be minimized. Further, when the receiving member 18 is made of a highly transparent material or includes a portion made of a highly transparent material, the receiving member 18 does not interfere with the occupant's field of view when the upper mechanism 3 and the working mechanism 4 are turned. This is advantageous.

  In this embodiment, the receiving member 18 is detachably attached to the boom 16 with a bolt or the like. Therefore, the receiving member 18 is mounted on the boom 16 only when the construction machine 1 is used on a slope such as a mountain, and when the construction machine 1 is used on a flat ground where the possibility of falling is low or when the construction machine 1 is transported. The receiving member 18 can be removed from the boom 16.

  The receiving member 18 has an upper end portion from an intermediate portion in the vertical direction of the cab 11 (front pillar 12) in a state where the boom 16 is pivoted downward (boom bottom dead center) as shown by a one-dot chain line in FIGS. It is located over.

  Further, the receiving member 18 is disposed on an extension line in the longitudinal direction of the front header 15 of the cab 11. That is, the receiving member 18 is disposed close to the longitudinal end of the front header 15 of the cab 11 (or the upper end of the front pillar 12).

  Next, the operation of this embodiment will be described with reference to FIG.

  FIG. 4 shows a state in which the boom 16 is rotated most downward (boom bottom dead center). When the external force F (lateral load) is not acting on the cab 11 as shown in FIG. The cab 11, the boom 16, and the receiving member 18 are separated from each other, and the front pillar 12 and the like constituting the cab 11 are not naturally deformed. When the vehicle falls to the cab 11 side (the right side in FIG. 4), the uppermost cab 11 in the vehicle first collides with the ground and an external force F acts on the upper portion of the cab 11, and as a result, The cab 11 attached to the upper frame 7 starts to move toward the boom 16 via the anti-vibration mount device (begins to tilt with respect to the upper frame 7). When the movement of the cab 11 toward the boom 16 (inclination of the cab 11 with respect to the upper frame 7) proceeds to some extent, as shown in FIG. The upper end portion of the cab 11 (the upper end portion of the front pillar 12 or the longitudinal end portion of the front header 15) is the upper end of the receiving member 18 before the front intermediate portion 12 of the front pillar 12 is pressed against the corner 16 a of the boom 16. It is received by contacting the part. Accordingly, since the front pillar 12 of the cab 11 is not pressed against the corner 16a of the boom 16, the deformation of the front pillar 12 of the cab 11 that triggers a large deformation (buckling deformation) of the cab 11 when the vehicle falls. It becomes possible to suppress.

  In addition, since the receiving member 18 is positioned from the middle part in the vertical direction of the cab 11 to the upper end part in the state where the boom 18 is pivoted downward, the vehicle falls while the boom 16 is pivoted downwards. Since the construction machine 1 is supported by the receiving member 18 and the counterweight 9, the passenger in the cab 11 can be protected.

  Further, since the receiving member 18 is disposed on the extension line of the front header 15 of the cab 11, the external force F applied to the cab 11 when the vehicle falls can be transmitted to the boom 16 via the front header 15 and the front header 15 is strengthened. It becomes possible to suppress the deformation | transformation of the cab 11 over a passenger | crew's area.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and various other embodiments can be adopted.

  For example, as shown in FIG. 5, the receiving member 18 may be mounted on the boom 16 so as to be rotatable rearward of the vehicle with a hinge or the like. When the construction machine 1 is transported, the maximum height position of the receiving member 18 is changed by rotating the receiving member 18 toward the rear of the vehicle as shown by a one-dot chain line in FIG. At this time, the receiving member 18 does not become an obstacle.

FIG. 1 is a side view of a construction machine according to an embodiment of the present invention. FIG. 2 is a front view of the construction machine shown in FIG. FIG. 3 is a perspective view of the receiving member. FIG. 4A is an explanatory view showing a state in which a lateral load is not applied to the cab, and FIG. 4B is an explanatory view showing a state in which a lateral load is applied to the cab. FIG. 5 is a side view of the construction machine showing a modification of the receiving member.

Explanation of symbols

1 Construction machinery 11 Cab (cab structure)
15 Front header 16 Boom 18 Receiving member

Claims (4)

  In a construction machine in which a boom is pivotably arranged on the side of a cab structure, the cab structure is pressed on the boom and deformed when the vehicle falls over the boom, in proximity to the cab structure. A construction machine comprising a receiving member for receiving the cab structure to be moved to the boom side in order to prevent the movement.   2. The construction machine according to claim 1, wherein the receiving member is located from an intermediate portion in an up-down direction of the cab structure to an upper end portion in a state where the boom is rotated downward most.   The construction machine according to claim 1 or 2, wherein the receiving member is disposed on an extension line of a front header of the cab structure.   The construction machine according to claim 1, wherein the receiving member is detachably provided on the boom.

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