Hydraulic control valve for construction machinery
It is addressed to provide a hydraulic control valve for preventing high-speed rotation of a valve body of a check valve incorporated in the hydraulic control valve of a type that pressure oil is supplied from a tandem, path and a parallel path via the check valve. A check valve unit is constituted by a main unit and a valve body of a first check valve. A throttle is provided on a right side of an O-ring groove. On a main unit side, there is formed a cylindrical housing portion in which a threaded portion is formed on an outer peripheral portion for fixation to a casing of the hydraulic control valve. On an inner peripheral surface of the housing portion, a groove is formed in an axial direction. Meanwhile, the valve body of the first check valve has a rib. At a time of assembly, the rib, is inserted into the groove of the main unit as indicated by an arrow. After the valve body is assembled to the main unit and fixed to the casing, even with imbalance such as phase shift of the pressure-oil path, the rib having fit into the groove, namely the valve body, is prevented to rotate while it is slidable in the axial direction. Thus, the casing of a seating part of the valve body is not abraded.
1. A hydraulic control valve for construction machinery for taking in pressure oil from one of a tandem path and a parallel path which are connected to a variable delivery pump, wherein
a check valve unit is fixedly incorporated in a casing, the check valve unit having an opening portion on an inner peripheral side of a housing portion, and slidably and unrotatably housing a valve body of a first check valve which operates so as to block communication with the tandem path in a state in which the pressure oil from the parallel path is supplied, and
a pressure-oil path from the parallel path is formed between an inner peripheral surface of the housing portion of the check valve unit and an outer peripheral surface of the valve body;
wherein the valve body of the first check valve comprises:
a seating part that is larger in width than the opening portion of the check valve unit, which comes into contact with the housing portion of the check valve unit when the check valve unit closes;
a first section connected to the seating part that is smaller in width than the opening portion of the check valve unit;
a second section connected to the first section that is smaller in width than the first section; and
a rib formed in a sliding direction on an outer surface of the second section, the rib having a predetermined length; and
wherein a groove for receiving the rib is formed on the inner peripheral surface of the housing portion of the check valve unit.
2. The hydraulic control valve for construction machinery according to claim 1 , wherein the check valve unit comprises a second check valve for blocking flux of the pressure oil from the parallel path into the pressure-oil path.
3. The hydraulic control valve for construction machinery according to claim 2 , wherein a valve body of the second check valve is slidably housed in the valve body of the first check valve.
4. A hydraulic control valve for construction machinery for taking in pressure oil from one of a tandem path and a parallel path which are connected to a variable delivery pump, wherein
a check valve unit is fixedly incorporated in a casing, the check valve unit having an opening portion on an inner peripheral side of the of a housing portion, and slidably and unrotatably housing a valve body of a first check valve which operates so as to block communication with the tandem path in a state in which the pressure oil from the parallel path is supplied, and
a pressure-oil path from the parallel path is formed between an inner peripheral surface of a housing portion of the check valve unit and an outer peripheral surface of the valve body,
wherein, the housing portion of the check valve unit comprises:
a rib formed on the inner peripheral surface of the housing portion of the check valve unit, the rib having a predetermined length; and
wherein the valve body of the check valve unit comprises:
a seating part that is larger in width than the opening portion of the check valve unit, which comes into contact with the housing portion of the check valve unit when the check valve unit closes;
a first section connected to the seating part that is smaller in width than the opening portion of the check valve unit;
a second section connected to the first section that is smaller in width than the first section; and
a groove for receiving the rib is formed on an outer surface of the first and second sections of the valve body of the first check valve.
5. The hydraulic control valve for construction machinery according to claim 4 , wherein the check valve unit comprises a second check valve for blocking flux of the pressure oil from the parallel path into the pressure-oil path.
6. The hydraulic control valve for construction machinery according to claim 5 , wherein a valve body of the second check valve is slidably housed in the valve body of the first check valve.