Construction Machine

Abstract

Disclosed is a construction machine that enables an operator to operate a vehicle width changing control lever while visually confirming positions of crawlers. The construction machine includes a lower track structure 1 whose left and right crawler track devices 11 A and 11 B are adapted to change in spatial interval, and an upper swing structure 2 swingably mounted above the lower track structure. The construction machine further includes a hydraulically actuated cylinder for changing vehicle width, disposed between the left and right crawler track devices, the vehicle width changing cylinder changing the interval between the left and right crawler track devices upon supply and discharge of a hydraulic fluid being controlled by a vehicle width changing control valve, and a vehicle width changing control lever 34 disposed on a left section of a swing body support structure 50 relative to an operator's seat 23 , the vehicle width changing control lever operating the vehicle width changing control valve.

What is claimed is: 
     
         1 . A construction machine comprising:
 a lower track structure whose left and right crawler track devices are adapted to change in spatial interval;   an upper swing structure swingably mounted above the lower track structure, the upper swing structure including
 a swing frame that forms a support structure, 
 a counterweight disposed at a rear section of the swing frame, 
 a seat base supported by the swing frame, disposed at a front side of the counterweight, and forming a swing body support structure in combination with the swing frame, 
 an operator's seat placed on the seat base, and 
 a floor panel positioned at a front side of the seat base and the operator's seat and forming an operator's accessway; 
   a hydraulically actuated cylinder for changing vehicle width, disposed between the left and right crawler track devices, the vehicle width changing cylinder changing the interval between the left and right crawler track devices upon supply and discharge of a hydraulic fluid being controlled by a vehicle width changing control valve; and   a vehicle width changing control lever disposed on a left section of the swing body support structure relative to the operator's seat, the vehicle width changing control lever operating the vehicle width changing control valve.   
     
     
         2 . The construction machine according to  claim 1 , further comprising:
 a control lever device disposed on a front left section of the seat base relative to the operator's seat,   wherein the vehicle width changing control lever is disposed at a rear section of the control lever device on the seat base and adapted to tilt back and forth.   
     
     
         3 . The construction machine according to  claim 1 ,
 wherein the vehicle width changing control lever includes a lever section mounted on the swing body support structure and adapted to tilt back and forth, and a grip section mounted at a distal end of the lever section,   the lever section is bent backward at the distal end where the grip section is mounted.   
     
     
         4 . The construction machine according to  claim 1 , further comprising:
 a lever locking device that locks the vehicle width changing control lever at its neutral position,   wherein the vehicle width changing control lever includes a lever section tiltably mounted on the swing body support structure, and a grip section mounted at an upper end of the lever section,   the swing body support structure includes an upper panel at where the vehicle width changing control lever is disposed, the upper panel being formed with an elongated lever hole into which the lever section is inserted and encompassing a region in which the vehicle width changing control lever is adapted to move,   the lever locking device includes a movable plate mounted on the upper panel via a hinge and adapted to turn between a horizontally tilted position and a raised position, the movable plate being formed with a notched recess at an edge opposite to the hinge, and   the movable plate, when in the horizontally tilted position, locks the lever section by covering the lever hole and engaging the lever section in the notched recess, and when in the raised position, unlocks the lever section by uncovering the lever hole and releasing the lever section from the notched recess.   
     
     
         5 . The construction machine according to  claim 4 ,
 wherein the lever locking device further includes, at the edge of the movable plate where the notched recess is formed, a holding section disposed so as to rise from the movable plate.   
     
     
         6 . The construction machine according to  claim 4 ,
 wherein the lever locking device further includes a flexible, plate-shaped sealing member on a face of the movable plate, the face adapted to face the lever hole.   
     
     
         7 . The construction machine according to  claim 2 ,
 wherein the vehicle width changing control lever includes a lever section mounted on the swing body support structure and adapted to tilt back and forth, and a grip section mounted at a distal end of the lever section,   the lever section is bent backward at the distal end where the grip section is mounted.   
     
     
         8 . The construction machine according to  claim 5 ,
 wherein the lever locking device further includes a flexible, plate-shaped sealing member on a face of the movable plate, the face adapted to face the lever hole.