Motor vehicles – Bodies
Reexamination Certificate
1998-05-29
2001-01-09
Mai, Lanna (Department: 3619)
Motor vehicles
Bodies
C180S089120, C180S089130, C180S327000, C280S760000
Reexamination Certificate
active
06170588
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a revolving construction machine such as a hydraulic excavator, for example, and more particularly to a revolving construction machine being able to swing with a small swing radius.
2. Description of the Related Art
Generally, hydraulic excavators and so on are known as revolving construction machines. A hydraulic excavator is made up of a lower track structure, an upper revolving structure rotatably mounted on the lower track structure, and a working device attached to a front portion of the upper revolving structure.
The upper revolving structure is mainly constructed of a revolving frame having a skeleton structure, a counterweight disposed on a rear portion of the revolving frame to balance with the working device, an engine cover positioned in front of the counterweight to cover an engine mounted on the revolving frame, a floor panel positioned in front of the engine cover to cover an upper surface of the revolving frame, and an operator's seat positioned in front of the engine cover and mounted on the floor panel. The working device is mounted to a front portion of the revolving frame.
Hydraulic excavators include revolving hydraulic excavators called the tail end small swing radius type and the minimal swing radius type (hereinafter referred to simply as small swing radius type hydraulic excavators). The small swing radius type hydraulic excavator is constructed such that when viewed from above, at least a portion of the upper revolving structure where the counterweight is positioned is substantially circular with respect to the center of rotation of the upper revolving structure, and when the upper revolving structure swings, at least the side of the counterweight is kept substantially within the track structure width. With that construction, the counterweight portion for which the operator has poor visibility from the operator's seat is able to swing substantially within the track structure width, and safety in work is ensured. According to descriptions, hydraulic excavators wherein a rear portion of an upper revolving structure projects beyond the track structure width until about 20% thereof, can be regarded as falling in the category of the tail end small swing radius type and the minimal swing radius type. Also, as for the term “within the track structure width”, even if an upper revolving structure of a practical hydraulic excavator projects beyond the track structure width to some extent, such an upper revolving structure is also regarded as being substantially within the track structure width.
SUMMARY OF THE INVENTION
Meanwhile, the conventional small swing radius type hydraulic excavator stated above is frequently employed to carry out work in a narrow work site and an obstacle such as a wall is often closely present on the left side of the hydraulic excavator. In such a work site, the upper revolving structure and the wall are so close to each other that it is difficult for the operator to board on or alight from the operator's seat. Also, when walls are present on both sides of the hydraulic excavator, there arises a problem that a person cannot pass through the work site in the longitudinal direction of the hydraulic excavator.
In a hydraulic excavator of the cabin type that the operator's seat is covered by a cabin cover, the operator has to go in or out of the cabin cover by opening a door provided in the cabin cover. If the cabin cover is positioned close to the wall, the door cannot be fully opened. This raises a problem that each time the operator boards on or alights from the operator's seat, he has to take such an additional care of moving the hydraulic excavator to a place having a wide space; hence working efficiency deteriorates.
Another problem is that when the operator goes in or out of the cabin cover, the door is more likely to hit against the wall and is susceptible to damage in spite of the door being opened a little or not fully.
It would be conceivable that the door provided in the cabin cover could be fully opened by designing the radius of swing of the upper revolving structure to be much smaller than the width of the lower track structure. That design however accompanies a problem that the upper revolving structure is greatly reduced in size, apparatus and devices must be arranged in a cramped space, and working capability is deteriorated.
In view of the above-mentioned problems in the related art, an object of the present invention is to provide a revolving construction machine which allows the operator to easily board on or alight from an operator's seat even in a narrow work site, and improves working efficiency.
Note that the terms “front and rear” and “right and left” used in the specification mean the direction or side with respect to the operator sitting on an operator's seat, respectively.
A revolving construction machine according to the present invention comprises a lower track structure, an upper revolving structure rotatably mounted on the lower track structure, and a working device attached to a front portion of the upper revolving structure.
To achieve the above object, in accordance with the present invention, the upper revolving structure comprises a revolving frame having a skeleton structure, a counterweight disposed on a rear portion of the revolving frame to balance with the working device, an engine cover positioned in front of the counterweight to cover an engine mounted on the revolving frame, a side cover portion provided as part of the engine cover to extend in a front and rear direction on one of right and left sides of the upper revolving structure, a floor panel covering an upper surface of the revolving frame from the front side of the engine cover to a side of the side cover portion, an operator's seat positioned in front of the engine cover and mounted on the floor panel, and a walk-through passageway defined by the side cover portion of the engine cover and a floor panel side portion of the floor panel positioned laterally of the side cover portion for allowing a person to walk through the construction machine in the front and rear direction by passing a space laterally of the operator's seat and the engine cover.
By so constructing the upper revolving structure, even in the case of, e.g., carrying out work along a wall or parking a construction machine along a wall, since the walk-through passageway is left laterally of the operator's seat and the side cover portion of the engine cover relative to the wall, the operator can board on or alight from the operator's seat and walk through the construction machine in the front and rear direction by passing the walk-through passageway. In a construction machine of the cabin type that the operator's seat is covered by a cabin cover, particularly, a door can be opened within the walk-through passageway to such an extent allowing the operator to get on or off the cabin cover even in a narrow work site.
Preferably, a front end of a portion of the upper revolving structure at the floor panel side portion defining the walk-through passageway, where the revolving frame is positioned, is formed to have a corner portion radially projecting beyond a swing radius defined on the basis of an outer periphery of the counterweight.
With that feature, when going to swing the upper revolving structure, the operator can perform the operation while surely avoiding the counterweight portion, for which the operator has poor visibility, from contacting any surrounding obstacle such as a wall just by viewing from the operator's seat the corner portion of the front end of the upper revolving structure where the revolving frame is positioned and confirming that the corner portion does not contact the obstacle, even if the counterweight portion is sized to project beyond the track structure width to some extent.
Preferably, a handrail is provided on the floor panel side portion defining the walk-through passageway. With that feature, the
Endo Shinichiro
Irino Teruo
Nishimura Takaharu
Hitachi Construction Machinery Co. Ltd.
Mai Lanna
Mattingly, Stanger & Malur
To Toan
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