Construction machine

Abstract

A rear half part of a surface of a main body of a working oil tank installed in line with a control valve opposing to the valve is dented in an inclining surface shape in the direction moving away from the valve so that between both the tank and the valve, is formed a working space for attaching and detaching a pressure compensating spool, while return tubes are separately connected to the upper and the lower side of a filter case side wall within the body. Within the body, is provided a cylindrical filter case having a bottom in which a return filter for return oil is housed, and the return tubes are connected to the case side wall in a state of communicating with the inside of the filter case. In this configuration, a filter receiving plate is provided in a lower part within the filter case with leaving a gap between the plate and the filter case bottom wall in a state that the plate is supported by a return pipe, the return filter is disposed on the plate, and the return tubes are connected to the filter case side wall on the lower side than the plate.

1 . A construction machine, comprising:
 a control valve for controlling an action of a hydraulic actuator;   a working oil tank installed in line with said control valve;   a filter case in which a return filter for filtering return oil is housed, the filter case being provided within a tank main body of said working oil tank; and   a plurality of return tubes connected to a side wall of said filter case, wherein   a surface of the tank main body of said working oil tank opposing to said control valve is inwardly dented so that between both said working oil tank and said control valve, is formed a working space which is necessary for attaching and detaching a part of said control valve, while said return tubes are separately connected to the upper side and the lower side of the side wall of said filter case.   
   
   
       2 . The construction machine according to  claim 1 , wherein
 said control valve is provided with a main spool for controlling the working direction and speed of the hydraulic actuator and a pressure compensating spool for compensating a working pressure of the hydraulic actuator, the pressure compensating spool being provided at right angles with the main spool, and the surface of the tank main body opposing to said control valve is inwardly dented so that between said control valve and said working oil tank, is formed a working space which is necessary for attaching and detaching the pressure compensating spool.   
   
   
       3 . The construction machine according to  claim 1 , wherein
 the surface of the tank main body opposing to said control valve is dented in an inclining surface shape in the direction moving away from said control valve so that a working space gradually spreading in one direction is formed.   
   
   
       4 . The construction machine according to  claim 1 , wherein
 a filter receiving plate is provided in a lower part within said filter case of said working oil tank with leaving a gap between the filter receiving plate and a filter case bottom wall, the return filter is provided on the filter receiving plate, a plurality of said return tubes are separated into the upper side and the lower side and on the lower part, connected to the side wall of said filter case on the lower side than the filter receiving plate.