JP2012141037A5

JP2012141037A5 -

Info

Publication number: JP2012141037A5
Application number: JP2011000584A
Authority: JP
Filing date: 2011-01-05
Publication date: 2013-04-18

Description

また、第２の発明は、第１の発明において、前記建設機械の駆動を指令する操作レバー装置と、前記操作レバー装置の操作量に応じて前記各コントロールバルブのスプールを駆動させる２系統の制御油回路とを備え、前記検出油路は、前記各制御油回路の圧力を取り出す２系統の油路であり、前記２系統の油路に入力側が接続され、これらの油路の圧力を比較していずれか高圧側の油路を出力側に連通させる最高圧選択手段と、前記最高圧選択手段により連通された油路の圧力を満たすように、前記油圧ポンプの吐出流量を制御するポジコン制御型の前記レギュレータとを備えたことを特徴とする。 Further, according to a second aspect, in the first aspect, an operation lever device for instructing driving of the construction machine and two-system control for driving a spool of each control valve according to an operation amount of the operation lever device. An oil circuit, and the detection oil passages are two oil passages for extracting the pressure of each control oil circuit, and the input side is connected to the oil passages of the two systems, and the pressures of these oil passages are compared. and the highest pressure selecting means for communicating the output side oil passage of either the high pressure side Te, said to meet the pressure of the oil passage communicating with the highest pressure selecting means, the positive control control type for controlling the discharge flow rate of the hydraulic pump The regulator is provided.

更に、第３の発明は、第１の発明において、前記検出油路は、前記各コントロールバルブからセンタバイパスを介してタンクへ還流する圧油の還流量に応じた圧力を取り出す２系統の油路であり、前記２系統の油路に入力側が接続され、これらの油路の圧力を比較していずれか低圧側の油路を出力側に連通させる最小圧選択手段と、前記最小圧選択手段により連通された油路の圧力を満たすように、前記油圧ポンプの吐出流量を制御するネガコン制御型の前記レギュレータとを備えたことを特徴とする。 Further, according to a third aspect of the present invention, in the first aspect, the detection oil passage is a two-system oil passage that takes out a pressure corresponding to a recirculation amount of the pressure oil that recirculates from the control valves to the tank via the center bypass. The input side is connected to the oil passages of the two systems, the pressures of these oil passages are compared, and the minimum pressure selection means for communicating one of the low pressure side oil passages to the output side, and the minimum pressure selection means The negative control type regulator that controls the discharge flow rate of the hydraulic pump so as to satisfy the pressure of the oil passage communicated with the regulator is provided.

また、第４の発明は、第３の発明において、前記最小圧選択手段は、前記各コントロールバルブから前記各センタバイパスを介して前記タンクへ還流する２系統の油路における圧力を弁駆動圧として、前記２系統の油路のうち低圧側の油路を選択する切替弁であることを特徴とする。 In a fourth aspect based on the third aspect, the minimum pressure selecting means uses the pressure in the two oil passages returning from the control valves to the tank via the center bypass as a valve driving pressure. The switching valve selects a low-pressure side oil passage among the two oil passages.

第１及び第２流量制御スプール５−１，５−２，６−１，６−２はいずれもセンタバイパス型の切換弁である。第１流量制御スプール５−１と５−２のセンタバイパス油路は、直列に接続されていて、第１流量制御スプール５−２のセンタバイパス油路の排出側には、一端をタンク１１に開口した第１排出油路５ａの他端が接続されている。第１排出油路５ａには、分岐部が設けられていて、この分岐部には、第１還流油路５ｂの一端側が接続され、第１還流油路５ｂの他端側は、最小圧選択弁１２の一方の入力ポート１２ｅに接続されている。この分岐部とタンク１１側の開口部との間に還流する油路の圧力を取り出すための第１オリフィス９が設けられている。 The first and second flow rate control spools 5-1, 5-2, 6-1, 6-2 are both center bypass type switching valves. The center bypass oil passages of the first flow control spools 5-1 and 5-2 are connected in series, and one end is connected to the tank 11 on the discharge side of the center bypass oil passage of the first flow control spool 5-2. The other end of the opened first drain oil passage 5a is connected. The first discharge oil passage 5a is provided with a branch portion, and one end side of the first return oil passage 5b is connected to the branch portion, and the other end side of the first return oil passage 5b is selected as a minimum pressure. It is connected to one input port 12e of the valve 12. A first orifice 9 is provided between the branch portion and the opening on the tank 11 side to take out the pressure of the oil passage that circulates.

Claims

A first hydraulic actuator group and a second hydraulic actuator group comprising at least one actuator for driving a work machine of a construction machine;
A variable capacity hydraulic pump for supplying pressure oil to the hydraulic actuator group;
A regulator that changes a pump tilt angle of the hydraulic pump;
A diversion valve that inputs the pressure oil discharged from the hydraulic pump, diverts it to a constant flow rate ratio, and outputs it;
A hydraulic actuator drive circuit for a construction machine, comprising two control valves for controlling the direction and flow rate of pressure oil in each of two oil passages diverted from the diversion valve and supplying the hydraulic oil to each hydraulic actuator group. And
Two detection oil passages that respectively take in the required flow rates of the control valves;
Selection means for selecting the maximum value of each required flow rate taken in each detection oil passage;
A hydraulic actuator drive circuit for a construction machine, comprising: the regulator that controls a discharge flow rate of the hydraulic pump so as to satisfy a maximum required flow rate selected by the selection unit.

The hydraulic actuator drive circuit for a construction machine according to claim 1,
An operation lever device for instructing driving of the construction machine;
A control oil circuit of two systems for driving the spool of each control valve according to the operation amount of the operation lever device;
The detection oil passage is a two-system oil passage that takes out the pressure of each control oil circuit,
A maximum pressure selection means for connecting an input side to the oil passages of the two systems, comparing pressures of these oil passages, and communicating one of the high pressure side oil passages to the output side;
A positive actuator control type regulator for controlling the discharge flow rate of the hydraulic pump so as to satisfy the pressure of the oil passage communicated by the maximum pressure selection means .

The hydraulic actuator drive circuit for a construction machine according to claim 1,
The detection oil passages are two oil passages for taking out pressures corresponding to the recirculation amount of the pressure oil recirculating from the control valves to the tank via the center bypass,
A minimum pressure selecting means for connecting an input side to the two oil passages, comparing pressures of these oil passages, and communicating one of the low pressure side oil passages to the output side;
A hydraulic actuator drive circuit for a construction machine, comprising: a negative control type regulator that controls a discharge flow rate of the hydraulic pump so as to satisfy a pressure of an oil passage communicated by the minimum pressure selection means .

In the hydraulic actuator drive circuit of the construction machine according to claim 3,
The minimum pressure selecting means uses the pressure in the two oil passages returning from the control valves to the tank via the center bypass as a valve drive pressure, and the oil passage on the low pressure side of the two oil passages. A hydraulic actuator drive circuit for a construction machine, characterized in that it is a switching valve for selecting.