Patent Publication Number: US-7722308-B2

Title: Construction machine

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a construction machine provided with a construction for inserting and removing a boom foot pin such as a hydraulic excavator. 
   2. Description of the Related Art 
   The related art will be described with an example of a hydraulic excavator which is a preferred example of the present invention. 
   An upper rotating body of the hydraulic excavator is provided with an upper frame. A cabin is installed on one of left and right sides (generally on the left side) of the upper frame. A pair of left and right boom attachment frames are provided on the inner side of the upper frame to the cabin (on the middle part in the lateral direction). A base end of the boom (boom foot) is attached to the boom attachment frames by a boom foot pin. 
   On the opposite side (on the right side) of the upper frame to the cabin, a side cover is provided on a side surface part, and a front cover is provided on a part covering a front surface part and an upper surface part, respectively. In a device chamber covered by both the covers on the front-right side, are installed various devices including a working oil tank. 
   The boom is attached to and detached from the upper rotating body at the time of transportation of the machine, maintenance and the like. In this case, since the cabin is located on the left side of the boom foot pin as mentioned above, the boom foot pin is inserted and removed only from the right side. 
   However, on an extended line of an axis of the boom foot pin (hereinafter, referred to as pin insertion and removal line), is located the working oil tank disturbing the insertion and removal of the pin. 
   Therefore, there are proposed means that a through hole sufficient for inserting and removing the boom foot pin is provided in the working oil tank (Known Technique 1), or, as disclosed in Japanese Patent Laid-Open Nos. Hei10-18347 and 2000-291056, means that the devices such as a tank is installed at a position apart from the pin insertion and removal line in the device chamber so that a pin insertion and removal space is ensured on the pin insertion and removal line (Known Technique 2). 
   However, in Known Technique 1, with a complicated shape of the working oil tank, troublesome processing and high cost, there is a fear that the tank is damaged when the pin is inserted or removed. Since there are a lot of harmful effects as mentioned, Known Technique 1 is not the best idea. 
   Meanwhile, according to Known Technique 2, since the devices are not changed, the problem in Known Technique 1 can be solved. However, since the boom foot pin is not supported in the pin insertion and removal space, there occurred new problems that when the pin is inserted and removed (particularly when removed), the boom foot pin is inclined from the pin insertion and removal line and brought into contact with surrounding structures such as hydraulic piping, or the pin is dropped off as soon as removed from the boom attachment frames so that the pin itself and the structures are damaged. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a construction machine capable of preventing contact of a boom foot pin with surrounding structures and drop-off of the pin when the pin is inserted and removed, based on a construction for ensuring a pin insertion and removal space. 
   Firstly, the construction machine according to the present invention has the following basic construction. 
   That is, the construction machine of the present invention comprises an upper rotating body mounted on the lower traveling body rotatably around a vertical axis, a cabin installed on one of left and right sides of an upper frame constructing the upper rotating body, a boom whose base end is attached to the upper frame by a boom foot pin on the inner side of the upper frame to the cabin, and various devices installed on the upper frame, and the devices are installed on the laterally opposite side of the upper frame to the cabin in a state that a pin insertion and removal space sufficient for inserting and removing the boom foot pin in the axial direction is ensured. Further, the construction machine of the present invention comprises pin guide for guiding the boom foot pin in the insertion and removal direction, the pin guide being provided in the pin insertion and removal space. 
   According to the present invention, since the pin insertion and removal space is ensured on the opposite side (on the right side in the above example) of the cabin on the upper frame, and then the pin guide for guiding the boom foot pin in the insertion and removal direction is provided in the pin insertion and removal space, there is no fear that when the pin is inserted and removed, the boom foot pin is brought into contact with the surrounding structures such as hydraulic piping and the pin is dropped off, and hence it is possible to surely preventing damage of the pin itself and the structures. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a plan view of an upper rotating body of a hydraulic excavator according to an embodiment of the present invention; 
       FIG. 2  is a partially notched side view of the upper rotating body of the hydraulic excavator according to the embodiment of the present invention; 
       FIG. 3  is a perspective view of the upper rotating body of the hydraulic excavator according to the embodiment of the present invention; 
       FIG. 4  is a perspective view of a bracket provided with a pin guide; 
       FIG. 5  is a partially enlarged view of  FIG. 2 ; 
       FIG. 6  is a sectional view by line VI-VI of  FIG. 5 ; and 
       FIG. 7  is an overall side view of a hydraulic excavator to which the present invention is applied. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Embodiments of the present invention will be described with reference to  FIGS. 1 to 6 . 
   The embodiments are exemplified in a case where the present invention is applied to a hydraulic excavator. An upper rotating body  21  of the hydraulic excavator is shown in  FIGS. 1 to 3 . 
   A basic construction of the upper rotating body  21  is shown in  FIG. 7 . On a crawler type lower traveling body  1 , is installed the upper rotating body  21  rotatably around a vertical axis. To a front part of the upper rotating body  21 , is attached a working attachment  9  provided with a boom  25 , an arm  4 , a bucket  5  and hydraulic cylinders (boom cylinder, arm cylinder, bucket cylinder)  6 ,  7  and  8  for operating the boom, the arm and the bucket. 
   That is, the upper rotating body  21  is provided with an upper frame  22 , and on the left side of the upper frame  22 , is installed a cabin  23 . On the inner side of the upper frame to the cabin  23  (on the middle part in the lateral direction), are provided a pair of left and right boom attachment frames  24 . To the boom attachment frames  24 , is attached a base end (boom foot)  25   a  of the boom  25  by a boom foot pin  26 . It should be noted that the attachment frames  24  are omitted in  FIG. 2  for simplification of the figure. 
   On a right side surface part of the upper frame  22 , is provided a side cover  27 , and on a part covering a front surface part and an upper surface part, is provided a front cover  28  respectively. In a device chamber  29  covered by both the covers  27  and  28 , are installed various devices, while on the rear side of the device chamber  29 , are laterally aligned a fuel tank  30  and a working oil tank  31 . 
   The devices in the device chamber  29  are installed in a state that a pin insertion and removal space (no specific reference numeral) sufficient for inserting and removing the pin  26  is ensured around an insertion and removal line L of the boom foot pin  26 . In the pin insertion and removal space, to the upper frame  22 , is attached a bracket  32  serving as a support body for attaching both the covers  27  and  28 . 
   In the bracket  32 , as shown in  FIG. 4  and the like, are provided a side cover attachment portion  33  provided with hinge attachment pins  33   a  (refer to  FIG. 4 ) to which a hinge (not shown) serving as support point for opening and closing the side cover  27  is attached, and a front cover attachment portion  34  to which the front cover  28  is attached. 
   The front cover  28  is constructed as a cover also serving as steps, as provided with several up and down steps  28   a  for performing maintenance of parts from the upper surface side of the machine. An upper part of the front cover  28  is attached to and supported by the front cover attachment portion  34 . 
   In a middle part of the bracket  32  in the height direction, is provided a pin guide  35  on the pin insertion and removal line L. 
   The pin guide  35  is formed in a horizontal and square tube shape having a section size enabling insertion of the boom foot pin  26  in the axial direction. When the pin is inserted and removed, the boom foot pin  26  is guided to the insertion and removal direction by the pin guide  35 . 
   That is, the boom foot pin  26  is pulled out to the right side and inserted from the right side in a state that the side cover  27  is opened. 
   In this case, while pulled out from the attachment frames  24 , the pin  26  is fitted into the pin guide  35  (refer to  FIG. 6 ), and supported and guided by the pin guide  35 . When the pin is inserted, while supported and guided by the pin guide  35 , the pin  26  is inserted into the attachment frames  24 . 
   By the supporting and guiding effect of the pin guide  35 , the boom foot pin  26  is inserted and removed on the pin insertion and removal line L and there is no fear that the pin is inclined from the pin insertion and removal line L. Therefore, since there is no fear that, when the pin is inserted and removed, the pin  26  is brought into contact with surrounding structures such as hydraulic piping and dropped off, it is possible to surely preventing damage of the pin itself and the structures. 
   In the device chamber  29  covered by both the side cover  27  and the front cover  28 , is formed the pin insertion and removal space, and in the bracket  32  provided in the pin insertion and removal space, are provided the pin guide  35  and the attachment portions  33  and  34  of both the side cover  27  and the front cover  28 . In other words, the pin guide  35  is provided in the bracket  32  which is originally required as a structure for attaching the cover. Therefore, in comparison to a case where the pin guide  35  is independently provided, it is possible to simplify a construction within the device chamber  29  and to lower the cost. 
   In addition, it is possible to strengthen the bracket  32  by the pin guide  35  and enhance the strength as the structure for attaching the cover. 
   Further, in the present embodiment, focusing on a point that when the side cover  27  is opened, the inside of the device chamber  29  including the bracket  32  is opened to the outside, on the lower side of the pin guide  35  in the bracket  32 , is disposed a tool box  36  so that various tools are taken in and out from the outside. 
   By this, the bracket  32  can be multi-functionalized and intensified, and the construction within the device chamber  29  can further be simplified. 
   Other Embodiments 
   (1) The above embodiment is exemplified in a case where the front cover  28  also serving as steps is attached to the part covering the front surface and the upper surface of the device chamber  29 . However, a front cover only for covering without steps may be attached. 
   Further, a fuel supply unit provided with a fuel supply hose and a fuel supply pump for fueling the fuel tank  30  may be attached to the front cover attachment portion  34  in the above embodiment. In this case, the front cover  28  may be attached by overlapping an upper surface of the fuel supply unit, or attached to the front cover attachment portion separately provided in the bracket  32 . 
   (2) In the above embodiment, the bracket  32  is provided with three parts including the pin guide  35 , both the side cover and front cover attachment portions  33  and  34 , and the tool box  36 . However, only two of the three parts or one of the three parts may be provided. An attachment portion for attaching other equipment in addition to the three parts may be added.
 
(3) Essentially, the shape of the pin guide  35  is anything which is capable of supporting and guiding the boom foot pin  26 . Therefore, it is possible to select not only a square tube shape but also a cylindrical shape or the like accordingly.
 
   Although the invention has been described with reference to the preferred embodiments in the attached figures, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims.