Abstract: A bulldozer includes a vehicle frame, a bulldozer blade, an engine, an engine cover and an operator cab. The vehicle frame has a front end and a rear end. The bulldozer blade is disposed in front of the front end of the vehicle frame. The engine is disposed at a front portion of the frame. The engine cover covers the engine. The operator cab is secured to the frame behind the engine. The operator cab includes a front window disposed on a front face of the operator cab. When the bulldozer blade is placed on the ground, a top surface of the engine cover is disposed below a line extending between an upper edge of the bulldozer blade and a lower edge of the front window as viewed from a side of the bulldozer.

Abstract: A control device controls a hydrostatic transmission vehicle having a hydrostatic transmission including a variable displacement pump and a variable displacement hydraulic motor. The control device is configured to set a set vehicle speed based on a forward/rearward travel command and a gear stage command instructed by an operator, to set a torque limit usable for the hydrostatic transmission based on an engine speed, to set a vehicle speed limit based on a pressure in the hydraulic circuit and the torque limit, to select a lower one of the set vehicle speed and the vehicle speed limit, and to control respective displacements of the variable displacement pump and the variable displacement hydraulic motor based on the selected vehicle speed.

Abstract: A control device controls a hydrostatic transmission vehicle having a hydrostatic transmission including a variable displacement pump and a variable displacement hydraulic motor. The control device is configured to set a set vehicle speed based on a forward/rearward travel command and a gear stage command instructed by an operator, to set a torque limit usable for the hydrostatic transmission based on an engine speed, to set a vehicle speed limit based on a pressure in the hydraulic circuit and the torque limit, to select a lower one of the set vehicle speed and the vehicle speed limit, and to control respective displacements of the variable displacement pump and the variable displacement hydraulic motor based on the selected vehicle speed.

Abstract: A bulldozer includes a vehicle frame, a bulldozer blade, an engine, an engine cover and an operator cab. The vehicle frame has a front end and a rear end. The bulldozer blade is disposed in front of the front end of the vehicle frame. The engine is disposed at a front portion of the frame. The engine cover covers the engine. The operator cab is secured to the frame behind the engine. The operator cab includes a front window disposed on a front face of the operator cab. When the bulldozer blade is placed on the ground, a top surface of the engine cover is disposed below a line extending between an upper edge of the bulldozer blade and a lower edge of the front window as viewed from a side of the bulldozer.

Abstract: A control device controls a hydrostatic transmission vehicle having a hydrostatic transmission including a variable displacement pump and a variable displacement hydraulic motor. The control device is configured to set a set vehicle speed based on a forward/rearward travel command and a gear stage command instructed by an operator, to set a torque limit usable for the hydrostatic transmission based on an engine speed, to set a vehicle speed limit based on a pressure in the hydraulic circuit and the torque limit, to select a lower one of the set vehicle speed and the vehicle speed limit, and to control respective displacements of the variable displacement pump and the variable displacement hydraulic motor based on the selected vehicle speed.

Abstract: A bulldozer provides improved visibility in front and/or rear of the bulldozer. The bulldozer includes an engine arranged in the front of the bulldozer and a cooling module for cooling the engine arranged elsewhere in the bulldozer, such as behind driver's seat. In the bulldozer, the arrangement of the engine, the vehicle, and the cooling module provides improved visibility in front of the bulldozer so that the operator of the bulldozer can view the upper middle portion of the bulldozer blade.

Abstract: A control device controls a hydrostatic transmission vehicle having a hydrostatic transmission with a variable displacement pump and a variable displacement hydraulic motor. The control device is configured to set a set vehicle speed based on a forward/rearward travel command and a gear stage command instructed by an operator, to set an upper limit of the engine speed with respect to the set vehicle speed for limiting the upper limit of the engine speed to a predetermined partial engine speed set to be lower than a high idle engine speed when the set vehicle speed is in a preliminarily set low and intermediate speed range, and to control respective displacements of the variable displacement pump and the variable displacement hydraulic motor based on the set vehicle speed for allowing a vehicle speed to reach the set vehicle speed even when the engine is rotated at the partial engine speed.

Abstract: A control device controls a hydrostatic transmission vehicle having a hydrostatic transmission with a variable displacement pump and a variable displacement hydraulic motor. The control device is configured to set a set vehicle speed based on a forward/rearward travel command and a gear stage command instructed by an operator, to set an upper limit of the engine speed with respect to the set vehicle speed for limiting the upper limit of the engine speed to a predetermined partial engine speed set to be lower than a high idle engine speed when the set vehicle speed is in a preliminarily set low and intermediate speed range, and to control respective displacements of the variable displacement pump and the variable displacement hydraulic motor based on the set vehicle speed for allowing a vehicle speed to reach the set vehicle speed even when the engine is rotated at the partial engine speed.

Abstract: A control device controls a hydrostatic transmission vehicle having a hydrostatic transmission including a variable displacement pump and a variable displacement hydraulic motor. The control device is configured to set a set vehicle speed based on a forward/rearward travel command and a gear stage command instructed by an operator, to set a torque limit usable for the hydrostatic transmission based on an engine speed, to set a vehicle speed limit based on a pressure in the hydraulic circuit and the torque limit, to select a lower one of the set vehicle speed and the vehicle speed limit, and to control respective displacements of the variable displacement pump and the variable displacement hydraulic motor based on the selected vehicle speed.

Abstract: A bulldozer is provided with a boat shaped main frame and a substantially U-shaped gate frame as a frame structure that mounts a cap having a rollover protection structure (ROPS) and forms the skeleton of the bulldozer. The gate frame is installed on the upper portion of the main frame, has a pair of left and right columns that are disposed along a substantially vertical direction, and has a beam that connects the upper ends thereof. Mount units for mounting the cab and stopper units for firmly grasping the cab are arranged on the upper surface of the beam.

Abstract: A structure of a main frame of a construction machine and a method for manufacturing the same are invented. Portions of the main frame to which an external force is applied by traveling units and working machines are formed into unitary casting modules, and the other portions of the main frame are formed into modules of sheeted structures. Then, these modules are combined to form the main frame. In the manufacturing process, required machining operations for the modules are completed before the combining of the same modules together.

Abstract: A bulldozer is provided with a boat shaped main frame and a substantially U-shaped gate frame as a frame structure that mounts a cap having a rollover protection structure (ROPS) and forms the skeleton of the bulldozer. The gate frame is installed on the upper portion of the main frame, has a pair of left and right columns that are disposed along a substantially vertical direction, and has a beam that connects the upper ends thereof. Mount units for mounting the cab and stopper units for firmly grasping the cab are arranged on the upper surface of the beam.

Abstract: An idler guide unit for crawler type traveling apparatuses which attains the facilitation of clearance regulating operations and the reduction, which is owing to the facilitation of the mentioned operations, of traveling noise. This idler guide unit is formed so that the clearance regulating operations are carried out by using tapering blocks 26, position regulators 41, 50 for the tapering blocks 26 being also provided.

Abstract: A main frame 2 used for a construction machine having a working machine, in which a traveling unit 3 is attached to a side extending along a posterior-anterior direction of the construction machine, and the working machine is attached to a front portion and/or rear portion of the construction machine includes a plurality of frame modules 21, 22, 23, 24 arranged in the posterior-anterior direction of the construction machine with respective end surfaces jointed to each other, in which the frame modules 22, 24 disposed at a position where a loading is applied among the plurality of frame modules 21, 22, 23, 24 are formed by integral casting.

Abstract: A blade pitch control structure for a bulldozer is provided in which angling control of a blade can be performed in a plane parallel to the ground irrespective of the state of pitch control of the blade, thereby realizing good operating accuracy and high operating performance in ground-leveling work. A pin which engages the front end of a pitch support link with a bracket provided on the back side of the blade is constructed as an eccentric pin, and in the eccentric pin, a first shaft part which turnably engages with the front end of the pitch support link and a second shaft part which is fitted into the bracket are mutually eccentric, and the eccentric pin is turned to perform the pitch control.

Abstract: A structure of a main frame of a construction machine and a method for manufacturing the same are invented. Portions of the main frame to which an external force is applied by traveling units and working machines are formed into unitary casting modules, and the other portions of the main frame are formed into modules of sheeted structures. Then, these modules are combined to form the main frame. In the manufacturing process, required machining operations for the modules are completed before the combining of the same modules together.

Abstract: In a blade support structure of a bulldozer, a rotational axis of an angle control can be formed as a rotational axis which is always directed to one vertical direction, without reference to a pitch control of a blade. A pitching joint is arranged in a front end portion of a pitch support link having a fixed length, an eccentric disc is engaged with a pitching shaft, and the eccentric disc is fitted to a fitting hole formed in a bracket arranged in a back surface of the blade. A rotational axis at a time of an angle control which is constituted by a rotational center of a universal joint rotatably supporting the blade back surface and by a rotational center of the pitching joint is formed on a vertical line with respect to the ground surface.

Abstract: A taper-like block (26) slides on a slide plate (27) arranged on a track frame (11) by screwing an adjusting bolt (41). A bearing (21) moves to an upper side of the track frame (11) via rails (23, 24) fitted to a first inclined surface (26a) of the taper-like block (26). Accordingly, it is possible to adjust a gap (S2) between a slide plate (31) on a hook portion (21c) of the bearing (21) and a slide plate (33) firmly fixed to a lower surface of the track frame (11).