Abstract:
A construction machine equipped with an air cleaner is disclosed which does not affect the efficiency of an engine and that of a radiator and which makes an effective utilization of space. A rotatable superstructure is partitioned into a front portion and a rear portion by means of a shielding plate, one end of an attachment capable of rise and fall is secured to near the center of the said front portion, an engine space and a radiator space for accommodating an engine and a radiator respectively therein are formed in said rear portion, and an air cleaner for filtering the air to be fed to the engine is disposed between the mounted portion of the attachment and the shielding plate.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a hydraulic excavator equipped with an air cleaner. 
     2. Description of the Related Art 
     Generally, a hydraulic excavator is driven by an internal combustion engine installed in the interior of a rotatable superstructure. A fan is attached to the engine and a radiator is disposed in front of the fan. The radiator, into which cooling water is introduced for cooling the engine, is cooled with air. The air for cooling the radiator is introduced into the interior of the rotatable superstructure from the exterior by means of the above fan. The air thus introduced cools the radiator and thereafter passes the engine space where the engine is disposed. The engine space and the space where the radiator is disposed are usually partitioned from each other by both the radiator and a shielding means to prevent hot air from reverse flowing from the engine space into the radiator space. 
     The air to be used for combustion in the engine carried on the hydraulic excavator is sucked in from an intake port, then is filtered through an air cleaner and is thereafter fed to the engine. The air thus fed is used for the combustion of fuel in the engine and is subsequently discharged to the exterior through a muffler attached to the engine. 
     The aforesaid air cleaner used in the hydraulic excavator, in view of its purpose of use, has heretofore been disposed in the engine space or in the radiator space in many cases. 
     However, in the hydraulic excavator called a small-sized swing type, the rotatable superstructure itself is small in comparison with that in other conventional hydraulic excavators and there is no margin in the interior space. Therefore, when the air cleaner is to be disposed in the engine space as in the prior art, it is unavoidable for the air cleaner to be disposed near the muffler or the engine which become high in temperature. As a result, the air cleaner itself is heated and the temperature of intake air to the engine becomes high, thus giving rise to the problem that the engine efficiency is deteriorated. 
     On the other hand, if the air cleaner is disposed in the radiator space, it is possible to solve the above-mentioned problem of deteriorated engine efficiency which is caused in the case of disposing the air cleaner in the engine space. However, since the air cleaner blocks the passage of air, the air will not pervade the whole of the radiator, thus resulting in deterioration of the radiator cooling efficiency. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a hydraulic excavator provided with an air cleaner which does not affect the efficiency of an engine and that of a radiator and which can attain an effective utilization of space. 
     The hydraulic excavator according to the present invention comprises a rotatable superstructure, a shielding plate which partitions the rotatable superstructure into a front portion and a rear portion, with an engine and a radiator being disposed in the rear portion, an attachment mounting portion disposed near the center of the front portion and to which one end of an attachment is mounted, and an air cleaner disposed between the attachment mounting portion and the shielding plate to filter the air to be fed to the engine. 
     According to this construction, since the air cleaner and the engine are partitioned for each other by the shielding plate, there is no fear that hot air present in the engine may be transferred to the air cleaner, nor is there any fear of the air cleaner itself being heated which would cause deterioration of the engine efficiency. Further, the space between the attachment mounting portion and the shielding plate is a very narrow space which has not been effectively utilized heretofore, but in the above construction according to the present invention, since the air cleaner is disposed in the said space, the space in question of the rotatable superstructure can be utilized effectively. 
     In the present invention, the rear portion of the rotatable superstructure may be partitioned into an engine space for accommodating the engine therein and a radiator space for accommodating the radiator therein, and a suction port of the air cleaner may be disposed in the radiator space. 
     According to this construction, since the suction port is smaller in size than the air cleaner, the disposition of the suction port is easier than disposing the air cleaner itself in the radiator space and it is not likely at all that the air passage will be blocked and hence there is no fear of deterioration in the radiator cooling efficiency. 
     In the present invention, the air cleaner may be disposed inside a guard of the rotatable superstructure. 
     According to this construction, there is no fear of any extra projection being formed on top of the rotatable superstructure, thus leading to an improvement in beauty of appearance, nor is there any fear that the rear view from the cabin may be obstructed, thus leading to an improvement of safety. 
     In the present invention, the air cleaner may be disposed above a rotating motor for rotating the rotatable superstructure. 
     According to this construction, since the space above the rotating motor is very narrow and has not been effectively utilized heretofore, the disposition of the air cleaner in such a space permits an effective utilization of space in the rotatable superstructure. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of a hydraulic excavator as an example to which the present invention is applied; 
     FIG. 2 is a plan view thereof; 
     FIG. 3 is a top view showing an internal structure of a rotatable superstructure of a hydraulic excavator embodying the present invention; and 
     FIG. 4 is a left side view thereof 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention will be described in detail hereinunder with reference to the accompanying drawings, in which FIG. 1 is a side view of a hydraulic excavator as an example to which the present invention is applied and FIG. 2 is a plan view thereof. 
     In FIGS. 1 and 2, the reference numeral  10  denotes a hydraulic excavator. The hydraulic excavator  10  is provided with a lower carriage  11  capable of traveling, a rotatable superstructure  12  carried rotatably on the lower carriage  11 , and an attachment  13  which is secured at one end thereof to a central position of the front portion of the rotatable superstructure  12  so as to be capable of rising and fall pivotally. 
     The lower carriage  11  is provided with a pair of right and left crawlers  11   a  disposed in an endless rotatable manner at both ends of a center frame. 
     On the left-hand side of the front portion of the rotatable superstructure  12  is mounted a cabin  18  which is provided with an operator&#39;s seat. The rear portion of the rotatable superstructure  12 , in which a counter weight  19  is provided, is covered with a guard  17 . Inside the guard  17  are accommodated an engine and various other devices. A cover  22  capable of being opened and closed is attached o the upper surface of the guard  17  so as to be opened for maintenance of the engine, etc. Also on the left-hand side of the rear portion of the guard  17  is mounted a cover  20  so that it can be opened and closed. Air is introduced through a vent opening formed in the cover  20  to cool a radiator, etc. 
     The attachment  13  has a boom  14  one end of which is secured to the rotatable superstructure  12 , an arm  15  one end of which is secured to the opposite end side of the boom  14 , and a bucket  16  secured to a front end portion of the arm  15 . The boom  14  can be made to rise and fall by a pair of boom cylinders  14   a  both ends of which are connected to the front portion of the rotatable superstructure and the boom  14 , respectively. The arm  15  is made pivotable by an arm cylinder  15   a  disposed between the back side of the boom  14  and an end portion of the arm  15 . Further, the bucket  16  is made pivotable by a bucket cylinder  16   a  disposed between the bucket  16  and the back side of the arm  15 . 
     FIG. 3 is a top view showing an internal structure of a rotatable superstructure of a hydraulic excavator embodying the present invention and FIG. 4 is a left side view thereof. In both figures, as to the portions identified by the same reference numerals as in FIGS. 1 and 2, explanations thereof will be omitted. 
     In FIGS. 3 and 4, the numeral  31  denotes an engine, and a fan  33  is secured to the front portion of the engine  31  rotatably. In front of the fan  33  is mounted a radiator  32 . The fan  33  introduces air from the exterior of a rotatable superstructure  12  like arrow A. The air cools the radiator  32  and then passes the engine  31 . 
     The space where the radiator  32  and the engine  31  are disposed is partitioned into a radiator space  35  and an engine space  34  by the radiator  32 , whereby hot air present in the engine space  34  is prevented from reverse flowing into the radiator space  35 . 
     In a left central portion of the rotatable superstructure  12  is mounted a tank  38  and a cabin  18  is provided in front of the tank  38 . In a front central portion of the rotatable superstructure  12  are erected a pair of brackets  39  in a sandwiching relation to a plate  40 . Holes  42  for the boom, as attachment mounting portions, are formed respectively in the tops of the brackets  39 . The holes  42  and a boom  41  are engaged with each other pivotably through a boom foot pin (not shown). Further, in a right front portion of the rotatable superstructure  12  are disposed hydraulic devices (not shown), and centrally disposed is a rotating motor  43  for rotating the rotatable superstructure  12 . 
     The rear portion of the rotatable superstructure  12  having the radiator space  35  and the engine space  34  and the front portion thereof having the cabin  18  and hydraulic devices are partitioned from each other by a shielding plate  37 , whereby hot air and noise generated in the rear portion of the rotatable superstructure  12  are prevented from being transmitted to the front portion of the rotatable superstructure. As to the portion where the shielding plate  37  and the rotating motor  43  interfere with each other, the shielding plate  37  is cut out and thereafter the gap between the shielding plate and the rotating motor is filled up with a soundproofing material or the like. Part of the shielding plate  37  may be substituted by, say, one side of the cabin  18 . It is not always necessary for the shielding plate  37  to be provided throughout the entire portion concerned, but the shielding plate may be provided at only a required portion. 
     An air cleaner  44  is accommodated in the central portion of the rotatable superstructure  12 , that is, between the attachment mounting portion and the shielding plate  37  and inside a guard  17  which is disposed above the rotating motor  43 . A suction port  45  of the air cleaner  44  is provided on the shielding plate  37  side of an upper portion of the radiator space  35  so that air can be introduced into the air cleaner through a suction pipe  46 . The air thus introduced is filtered with a filter provided within the air cleaner and is then fed to the engine  31  trough an air feed pipe  47  for use in combustion in the engine. The portions of the shielding plate  37  where the suction pipe  46  and the air feed pipe  47  interfere with the shielding plate are cut out and both pipes are inserted through the cutout portions, thereafter the resulting gaps are filled up using a soundproofing material or the like. 
     Since the air cleaner is thus installed inside the guard  17 , there is attained an improvement in the beauty of appearance as compared with the conventional air cleaner projecting from the upper surface of the rotatable superstructure. Besides, the safety is improved because there is no fear of the rear view from the cabin being obstructed. Further, since the air cleaner  44  can be received in a very narrow space which is formed between the attachment mounting portion and the shielding plate  37  and inside the guard  17  above the rotating motor  43  and which has not been utilized effectively heretofore, there can be attained a great contribution to an effective utilization of space. Additionally, since the shielding plate  37  is present, it is not likely at all that the air cleaner will be affected by hot air of the engine and hence there is no fear of deterioration in efficiency of the engine  31 . 
     Further, since the suction port  45  is disposed on the shielding plate  37  side of the upper portion of the radiator space  35 , the proportion occupied by the air cleaner can be diminished and the passage of air is not obstructed in comparison with the case where the air cleaner is disposed directly in the radiator space. Thus, the efficiency of the radiator  32  is not deteriorated. Moreover, through the suction port  45 , the air (arrow A) which has been introduced into the rotatable superstructure  12  from the exterior can be fed directly to the air cleaner  44 . 
     Although in the above construction the suction port  45  is disposed in the radiator space  35 , this constitutes no limitation. For example, the suction port  45  may be disposed on the upper surface of the guard  17 . That is, the position of the suction port  45  is not specially limited insofar as it does not lead to the deterioration in efficiency of the engine or the radiator.