JP2018169004A5

JP2018169004A5 -

Info

Publication number: JP2018169004A5
Application number: JP2017068216A
Authority: JP
Filing date: 2017-03-30
Publication date: 2019-01-31
Anticipated expiration: 2037-03-30

Description

そして、本発明が採用する構成の特徴は、前記パイロット圧制御装置は、前記パイロットポンプの吐出側に接続されるパイロット圧供給管路と、前記タンクに接続されるタンク管路と、前記パイロット圧供給管路に接続される第１ポンプポート、前記タンク管路に接続される第１タンクポートおよび前記制御弁の油圧パイロット部に接続される第１出力ポートを有し、前記電気信号に従って前記第１出力ポートを前記第１ポンプポートまたは第１タンクポートに選択的に接続し前記制御弁の切換制御を行う第１電磁弁と、前記パイロット圧供給管路に接続される第２ポンプポート、前記タンク管路に接続される第２タンクポートおよび第２出力ポートを有し、前記電気信号に従って前記第２出力ポートを前記第２ポンプポートまたは第２タンクポートに選択的に接続する第２電磁弁と、を含んで構成され、前記第２電磁弁は、前記パイロット圧制御装置内を流通する作動油の油温を上昇させるため前記第２ポンプポートから前記第２出力ポートに流れる圧油が前記タンク管路に還流される構成とし、前記第２電磁弁の前記第２出力ポートと前記タンク管路との間には、前記タンク管路に還流される戻り油の流量を制限する固定絞りが設けられていることにある。
A feature of the configuration adopted by the present invention is that the pilot pressure control device includes a pilot pressure supply line connected to a discharge side of the pilot pump, a tank line connected to the tank, and the pilot pressure. A first pump port connected to a supply line, a first tank port connected to the tank line, and a first output port connected to a hydraulic pilot part of the control valve; A first solenoid valve that selectively connects one output port to the first pump port or the first tank port and performs switching control of the control valve; a second pump port connected to the pilot pressure supply line; A second tank port connected to the tank line and a second output port, and the second output port is connected to the second pump port or the second tank according to the electric signal; A second solenoid valve selectively connected to the port, wherein the second solenoid valve is connected to the second pump port in order to raise the temperature of the hydraulic fluid flowing through the pilot pressure control device. The pressure oil flowing through the second output port is returned to the tank pipeline, and is returned to the tank pipeline between the second output port of the second solenoid valve and the tank pipeline. The fixed throttle restricting the flow rate of the return oil is provided .

Claims

A main hydraulic pump and a pilot pump that are driven by the prime mover of the work machine and suck in hydraulic oil from the tank and discharge the pressure oil;
A hydraulic actuator provided in the work machine and driven by pressure oil supplied from the hydraulic pump;
A control valve which is provided between the hydraulic pump and the hydraulic actuator, and controls supply of pressure oil to the hydraulic actuator by supplying pilot pressure from the pilot pump to a hydraulic pilot unit;
An electric operation device that outputs an electric signal in accordance with an external operation to control the operation of the hydraulic actuator by switching the control valve;
A pilot pressure control device that variably controls the pilot pressure supplied to the hydraulic pilot portion of the control valve in accordance with the electrical signal from the electric operation device;
In the hydraulic control device for work machines provided with
The pilot pressure control device
A pilot pressure supply line connected to the discharge side of the pilot pump;
A tank line connected to the tank;
A first pump port connected to the pilot pressure supply line; a first tank port connected to the tank line; and a first output port connected to a hydraulic pilot part of the control valve; A first solenoid valve that selectively connects the first output port to the first pump port or the first tank port to perform switching control of the control valve,
A second pump port connected to the pilot pressure supply line; a second tank port connected to the tank line; and a second output port. The second output port is connected to the second pump according to the electrical signal. A second solenoid valve selectively connected to the port or the second tank port;
Comprising
The second solenoid valve has a configuration in which pressure oil flowing from the second pump port to the second output port is recirculated to the tank pipe line in order to increase the temperature of hydraulic oil flowing through the pilot pressure control device. and,
An operation is provided between the second output port of the second solenoid valve and the tank pipe, and a fixed throttle for limiting a flow rate of return oil returned to the tank pipe is provided. Hydraulic control device for machinery.

A temperature sensor that detects the temperature of the return oil that is returned from the tank line to the tank;
A pressure sensor provided between a first output port of the first solenoid valve and a hydraulic pilot part of the control valve for detecting the pilot pressure;
A controller for controlling the first and second electromagnetic valves in accordance with drive information of the prime mover, an electrical signal from the electric operation device, and detection signals from the temperature sensor and pressure sensor. The hydraulic control device for a work machine according to claim 1.

The said pilot pressure control apparatus has a common valve housing in which the heat by the oil temperature rise of the said hydraulic fluid is transmitted between the said 1st, 2nd solenoid valves. Hydraulic control device for work machines.

The pilot pressure control device includes a common valve housing to which heat due to a rise in oil temperature of the hydraulic oil is transmitted between the first and second electromagnetic valves and the fixed throttle. Item 2. A hydraulic control device for a work machine according to Item 1 .