JP4668445B2 - Hydraulic control equipment, construction machinery and hydraulic excavators - Google Patents

Hydraulic control equipment, construction machinery and hydraulic excavators Download PDF

Info

Publication number
JP4668445B2
JP4668445B2 JP2001094572A JP2001094572A JP4668445B2 JP 4668445 B2 JP4668445 B2 JP 4668445B2 JP 2001094572 A JP2001094572 A JP 2001094572A JP 2001094572 A JP2001094572 A JP 2001094572A JP 4668445 B2 JP4668445 B2 JP 4668445B2
Authority
JP
Japan
Prior art keywords
switching valve
pressure
valve group
flow rate
adjusting means
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP2001094572A
Other languages
Japanese (ja)
Other versions
JP2002295405A (en
Inventor
哲 松本
隆 新家
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shibaura Machine Co Ltd
Original Assignee
Toshiba Machine Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Machine Co Ltd filed Critical Toshiba Machine Co Ltd
Priority to JP2001094572A priority Critical patent/JP4668445B2/en
Priority to DE2002114089 priority patent/DE10214089A1/en
Publication of JP2002295405A publication Critical patent/JP2002295405A/en
Application granted granted Critical
Publication of JP4668445B2 publication Critical patent/JP4668445B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/161—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load
    • F15B11/162—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load for giving priority to particular servomotors or users
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F15B11/161—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load
    • F15B11/167—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors with sensing of servomotor demand or load using pilot pressure to sense the demand
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/2053—Type of pump
    • F15B2211/20546—Type of pump variable capacity
    • F15B2211/20553—Type of pump variable capacity with pilot circuit, e.g. for controlling a swash plate
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30505—Non-return valves, i.e. check valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/305—Directional control characterised by the type of valves
    • F15B2211/30525—Directional control valves, e.g. 4/3-directional control valve
    • F15B2211/3053—In combination with a pressure compensating valve
    • F15B2211/30555—Inlet and outlet of the pressure compensating valve being connected to the directional control valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3105—Neutral or centre positions
    • F15B2211/3111—Neutral or centre positions the pump port being closed in the centre position, e.g. so-called closed centre
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/31—Directional control characterised by the positions of the valve element
    • F15B2211/3105—Neutral or centre positions
    • F15B2211/3116—Neutral or centre positions the pump port being open in the centre position, e.g. so-called open centre
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/32—Directional control characterised by the type of actuation
    • F15B2211/329—Directional control characterised by the type of actuation actuated by fluid pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/30—Directional control
    • F15B2211/35—Directional control combined with flow control
    • F15B2211/351—Flow control by regulating means in feed line, i.e. meter-in control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/405—Flow control characterised by the type of flow control means or valve
    • F15B2211/40515—Flow control characterised by the type of flow control means or valve with variable throttles or orifices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/42—Flow control characterised by the type of actuation
    • F15B2211/428—Flow control characterised by the type of actuation actuated by fluid pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/45—Control of bleed-off flow, e.g. control of bypass flow to the return line
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/46—Control of flow in the return line, i.e. meter-out control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/505—Pressure control characterised by the type of pressure control means
    • F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
    • F15B2211/50518—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using pressure relief valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/505—Pressure control characterised by the type of pressure control means
    • F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
    • F15B2211/50536—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using unloading valves controlling the supply pressure by diverting fluid to the return line
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/515—Pressure control characterised by the connections of the pressure control means in the circuit
    • F15B2211/5151—Pressure control characterised by the connections of the pressure control means in the circuit being connected to a pressure source and a directional control valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/50—Pressure control
    • F15B2211/55—Pressure control for limiting a pressure up to a maximum pressure, e.g. by using a pressure relief valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/605—Load sensing circuits
    • F15B2211/6051—Load sensing circuits having valve means between output member and the load sensing circuit
    • F15B2211/6052—Load sensing circuits having valve means between output member and the load sensing circuit using check valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/605—Load sensing circuits
    • F15B2211/6051—Load sensing circuits having valve means between output member and the load sensing circuit
    • F15B2211/6054—Load sensing circuits having valve means between output member and the load sensing circuit using shuttle valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/60—Circuit components or control therefor
    • F15B2211/605—Load sensing circuits
    • F15B2211/6051—Load sensing circuits having valve means between output member and the load sensing circuit
    • F15B2211/6057—Load sensing circuits having valve means between output member and the load sensing circuit using directional control valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/71—Multiple output members, e.g. multiple hydraulic motors or cylinders
    • F15B2211/7142—Multiple output members, e.g. multiple hydraulic motors or cylinders the output members being arranged in multiple groups
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/78—Control of multiple output members

Description

【０００１】
【発明の属する技術分野】
本発明は、油圧ショベル等の建設機械のように複数のアクチュエータを有する機械に最適な油圧制御装置に関し、特に複数のアクチュエータを同時操作する場合の操作性向上に関するものである。
【０００２】
【従来の技術】
従来技術には特開平１０−１０３３０５号にあるようなロードセンシング機能を持つ制御弁を使用するもの、ロードセンシング機能を持たない制御弁を使用するもの、その組み合わせのもの等種々のものがある。
【０００３】
特開平１０−１０３３０５号を図６に基づいて説明する。図６において可変容量ポンプＰに対して制御弁２〜５がパラレルに接続されている。これらの制御弁はすべて等しくロードセンシング機能を備えている。本装置が油圧ショベルに使用され、例えば大きな慣性を有する旋回を操作した場合、旋回への圧油の供給は、ポンプ圧を最高負荷圧よりも所定の圧力だけ常に高く保つというロードセンシング機能により、常に圧力補償されているので起動時に飛び出し感があり、この為運転者は起動時にショックを感じ、スムースな操作が非常に難しいことが経験的にも知られている。
【０００４】
この為、小型の油圧ショベルでは旋回用の別ポンプを追加し、ロードセンシング機能を持たない通常のオープンセンタ型の旋回操作用切換弁を別に設けている場合が多い。しかし、この場合には旋回専用のポンプが追加となりコスト上も問題がある。更には小型の油圧ショベル等の機械では制御機器を搭載するスペースが小さく、したがって旋回専用のポンプを付加すると、各機器全体のレイアウトが非常に難しいとの問題も発生する。
【０００５】
一方、各制御弁のロードセンシング機能を除去し、圧力補償機能を有しない制御弁も従来から油圧ショベルの操作等に使用されているが、この場合には、負荷圧力によって制御弁の操作量が異なるため、アクチュエータによっては操作がしにくいことも従来から知られている。
【０００６】
【発明が解決しようとする課題】
本発明は、ロードセンシング機能を有する切換弁から構成される第一切換弁群に接続されたアクチュエータと、ロードセンシング機能を有しない切換弁から構成される第二切換弁群に接続されたアクチュエータとを、共通の可変容量ポンプで駆動し、第一切換弁群内の切換弁と第二切換弁群内の切換弁とを同時操作した場合にも確実なアクチュエータの同時操作が出来るとともに、第二切換弁群の切換弁はその必要に応じてオープンセンタ型又はクローズドセンタ型の切換弁を使用することにより非常に操作性に優れ、運転者の感覚に一致した油圧制御装置を提供することにある。
【０００７】
【課題を解決するための手段】
前述の課題を解決するため、本発明の油圧制御装置は、吐出量が可変である可変容量ポンプと、前記可変容量ポンプの吐出ラインを分岐した第一の吐出ラインに接続されロードセンシング機能を有する切換弁を少なくとも一つ含む第一の切換弁群と、前記可変容量ポンプの吐出ラインを分岐した第二の吐出ラインに接続された圧力補償流量調整手段と、前記第二の吐出ラインに前記圧力補償流量調整手段を介して接続される少なくとも一つの切換弁を含む第二の切換弁群と、を具備し、前記圧力補償流量調整手段は、前記第一の切換弁群に含まれる切換弁と第二の切換弁群に含まれる切換弁とが同時に操作されたとき、第一の切換弁群に含まれる切換弁の操作により流量低減方向に調整されるとともに、第二の切換弁群に含まれる切換弁の操作により流量増加方向に調整されることを特徴とする。
【０００９】
さらにまた、吐出量が可変である可変容量ポンプと、
前記可変容量ポンプの吐出ラインを分岐した第一の吐出ラインに接続されロードセンシング機能を有する切換弁を少なくとも一つ含む第一の切換弁群と、
前記可変容量ポンプの吐出ラインを分岐した第二の吐出ラインに接続された圧力補償流量調整手段と、
前記第二の吐出ラインに前記圧力補償流量調整手段を介して接続される少なくとも一つの切換弁を含む第二の切換弁群と、
を具備し、
前記圧力補償流量調整手段は、前記第一の切換弁群に含まれる切換弁と第二の切換弁群に含まれる切換弁とが同時に操作されたとき、第二の切換弁群に含まれる切換弁の操作に応じて生成される信号から第一の切換弁群に含まれる切換弁の操作に応じて生成される信号を減じた信号により流量増加方向に調整されるよう構成することができる。
【００１０】
さらに、前記圧力補償流量調整手段は、
開閉スプールと、
この開閉スプールの下流に設けられた調整スプールと、
を具備し、
前記開閉スプールは第二の切換弁群に含まれる切換弁の操作に応じて開度が調整され、前記調整スプールは前記開閉スプールの上流側の圧力により絞り方向に調整されるとともに前記開閉スプールの下流側圧力とバネ力とにより開き方向に調整されるよう構成することができる。
【００１１】
さらに、前記圧力補償流量調整手段の前記開閉スプールと前記調整スプールとの間の圧力を、前記第一の切換弁群のロードセンシングラインに接続するよう構成することができる。
【００１２】
さらに、前記第一の切換弁群と前記圧力補償流量調整手段と前記第二の切換弁群とを一体的に構成し、前記第一の切換弁群を構成するブロックと前記第二の切換弁群を構成するブロックとの間に前記圧力補償流量調整手段を構成するブロックを設けることよう構成することができる。
【００１３】
また、前記可変ポンプの吐出ラインから分岐されたバイパスラインと、
このバイパスライン上に設けた圧力調整手段と、
前記バイパスライン上の前記圧力調整手段の下流に設けた圧力発生手段と、
前記第一の切換弁群に含まれる各切換弁のロードセンシング圧力と前記圧力補償流量調整手段の前記開閉スプールと前記調整スプールとの間の圧力のうちの最高圧力を検出する手段と、
を具備し、
前記圧力調整手段の開き方向には前記可変ポンプの吐出ラインの圧力を作用させるとともに、閉じ方向には前記最高圧力検出手段によって検出された最高圧力とバネ力とを作用させ、前記圧力発生手段の上流側圧力に対応して可変容量ポンプの吐出流量を調整するよう構成することができる。
【００１４】
また、前記可変ポンプの吐出ラインから分岐されたバイパスラインと、
このバイパスライン上に設けた圧力調整手段と、
前記バイパスライン上の前記圧力調整手段の下流に設けた流量検出手段と、
前記第一の切換弁群に含まれる各切換弁のロードセンシング圧力と前記圧力補償流量調整手段の前記開閉スプールと前記調整スプールとの間の圧力のうちの最高圧力を検出する手段と、
を具備し、
前記圧力調整手段の開き方向には前記可変ポンプの吐出ラインの圧力を作用させるとともに、閉じ方向には前記最高圧力検出手段によって検出された最高圧力とバネ力とを作用させ、前記流量検出手段で検出された流量に対応して可変容量ポンプの吐出流量を調整するよう構成することができる。
【００１５】
さらに、前記第二の切換弁群は少なくとも１つのオープンセンター型切換弁を含む切換弁群とすることができる。
【００１６】
また、前記第二の切換弁群は少なくとも１つのクローズドセンター型切換弁を含む切換弁群とすることもできる。
【００１７】
さらに、前記第一の切換弁群は、この第一の切換弁群に含まれる各々の切換弁とタンクラインとの間に分流補償弁を有するよう構成することができる。
【００１８】
さらにまた、前記第一の切換弁群は、この第一の切換弁群に含まれる各々の切換弁と、その切換弁に接続されたアクチュエータとの間に分流補償弁を有するよう構成することができる。
【００１９】
さらに、本発明は油圧ショベル等の建設機械に適用することができる。
【００２０】
この場合、第一の切換弁群に含まれる切換弁の１つはブーム操作用切換弁であり、第二の切換弁群に含まれる切換弁の１つは旋回操作用切換弁であるよう構成することができる。
【００２１】
さらに、前記第一の切換弁群と前記圧力補償流量調整手段と前記第二の切換弁群とを一体的に構成し、前記第一の切換弁群を構成するブロックと前記第二の切換弁群を構成するブロックとの間に前記圧力補償流量調整手段を構成するブロックを設けるとともに、前記第一の切換弁群に含まれる切換弁のうちブーム用切換弁を、また前記第二の切換弁群に含まれる切換弁のうちの旋回操作用切換弁を、それぞれ前記圧力補償流量調整手段を構成するブロックに最も近い位置に配置するよう構成することができる。
【００２２】
【発明の実施の形態】
以下に、この発明の実施形態例を、図面を用いて説明する。
【００２３】
図１は本発明の第一実施例を示す油圧回路図である。図中１は可変容量ポンプであり、この吐出ライン１７は供給ライン１８、１９に分岐され、第一の切換弁群（以下切換弁群Ａと称する）は吐出ライン１８を介して可変容量ポンプ１に接続されている。第二の切換弁群（以下切換弁群Ｂと称する）は吐出ライン１９および圧力補償流量調整手段（以下ブロックＣと称する）を介して可変容量ポンプ１に接続されている。切換弁群Ａには切換弁Ａ−１とＡ−２が供給ライン１８を介して吐出ライン１７にパラレルに接続されているとともに各切換弁の戻りライン２８、２９とタンクライン３０、３１との間に分流補償弁２６、２７がそれぞれ設けられておりタンクライン３０、３１からの排出油はタンク３８へ排出される。
【００２４】
切換弁群Ａに含まれる切換弁及び分流補償弁の機能は、本願と同一出願人による特願平１０−１１９７４５に記載されている通りであるが、例えば図１において、切換弁Ａ−２を図中左方へ単独操作した場合、供給ライン１８の油は切換弁内の絞り５０を経て逆止弁５２、通路５３、５４、５５を経て油圧ショベルのアームシリンダ５６へ供給され、同時にアームシリンダ５６からの戻り油は通路５７、５８、戻りライン２９を経て分流補償弁２７に至り、更にタンクライン３１を経てタンク３８に至る。この際、絞り５０を通過後の圧油は逆止弁５２の上流側で分岐しており、この分岐通路はさらに通路３９と通路４０とに分岐している。そして、通路３９は逆止弁４５を経てロードセンシングライン２５に接続されている。通路４０の圧力は、ばね４４とともに分流補償弁２７の開き方向に作用し、ロードセンシングライン２５の圧力は通路５９を経て分流補償弁２７の絞り方向に作用する。ただし、今の場合、切換弁Ａ−２の単独操作であるので、分流補償弁２７の開き方向に作用する通路４０の圧力と、その閉じ方向に作用する通路５９の圧力とは等しく、かつ、分流補償弁２７の開き方向には、ばね４４の力も作用しているので、分流補償弁２７は全開の位置に保持されている。
【００２５】
一方供給ライン１８からはバイパスライン３７が分岐され、このバイパスライン３７上に圧力調整手段３および圧力発生手段４が設けられている。この圧力調整手段３には、その閉じ方向にバネ４８による力と、ロードセンシングライン４７を介してロードセンシングライン２５の圧力とが作用し、また、供給ライン１８の圧力が通路４９を経て圧力調整手段３の開き方向に作用している。さらにバイパスライン３７の圧力調整手段３の下流側であって圧力発生手段４の上流側の部分から通路５が分岐しており、この通路５の圧力は可変容量ポンプ１の吐出流量調整機構２に作用し、可変容量ポンプ１の吐出流量をネガティーブ方式で制御している。
【００２６】
従って、この様な構成における圧力調整手段３の開度は以下のようになる。圧力調整手段３の開き方向には、切換弁Ａ−２内の絞り５０の上流側の圧力が、通路４９を経て作用する。一方、圧力調整手段３の閉じ方向にはバネ４８の力と、ロードセンシングライン４７を介して切換弁Ａ−２内の絞り５０の下流側の圧力とが作用する。つまり圧力調整手段３は、切換弁Ａ−２内の絞り５０の前後の差圧に依る力とバネ４８の力とがバランスする開度に調整され、その開度に対応した流量の油が圧力発生手段４へ流れる。従って、圧力発生手段４の上流側には上記流量に対応した圧力が発生し、この圧力が通路５を介して吐出流量調整機構２に作用し、可変容量ポンプ１の吐出量が調整される。ここで、切換弁Ａ−２内の絞り５０の前後の差圧は、絞り５０の開度が一定であればアームシリンダ５６の負荷圧には無関係に一定となるので、圧力調整手段３の開度も一定となる。つまり圧力調整手段３の開度は、切換弁Ａ−２の絞り５０の開度にのみ依存することになる。切換弁Ａ−２の絞り５０の開度は切換弁Ａ−２の操作量によって変化するので、吐出流量調整機構２に作用する圧力、ひいては可変容量ポンプ１からアームシリンダ５６へ供給される油量は、アームシリンダ５６の負荷圧に関係なく切換弁Ａ−２の操作量に依って調整されることになる。
【００２７】
次に切換弁Ａ−２に加えて切換弁Ａ−１を操作し、かつ切換弁Ａ―１に接続されたブームシリンダ７０の負荷がアームシリンダ５６の負荷よりも大きいとする。この場合、切換弁Ａ―１に接続されたブームシリンダ７０の負荷圧力は通路４１、逆止弁４６を経てロードセンシングライン２５に作用する。ここで、切換弁ブームシリンダ７０の負荷の方がアームシリンダ５６の負荷よりも大きいので、その圧力は通路５９を経て、軽負荷側（つまりアームシリンダ５６）の分流補償弁２７に対して閉じる方向に作用するのでアームシリンダ５６の見かけの圧力が上昇し、結果的に両切換弁において絞り５０、５１での差圧が等しくなり、これら切換弁Ａ−２、Ａ―１に接続されたアクチュエータはそれらの負荷が異なる場合でも同時に動かすことが出来ることになる。
【００２８】
次に、ブロックＣ（圧力補償流量調整手段）、及びこの下流に接続された切換弁群Ｂ（第二の切換弁群）について説明する。
【００２９】
ブロックＣには可変吐出ポンプ１の吐出ライン１７から分岐した供給ライン１９が設けられており、この下流に開閉弁８が設けられている。開閉弁８の下流には補償弁２２が設けてあり、更には、上記開閉弁８の下流であって、補償弁２２の上流側の圧力は通路２３及び逆止弁２４を経て切換弁群Ａのロードセンシングライン２５に接続されている。開閉弁８は、その開き方向には通路２０を経て開閉弁８の上流側の圧力が作用し、一方その閉じ方向には通路２３、通路６６を経て、開閉弁８の下流側の圧力がバネ９の力とともに作用している。尚、開閉弁８はバネ２１の力により中立位置にあるときは供給ライン１９から補償弁２２への通路を遮断している。ブロックＣの下流には切換弁群Ｂが設けられ、補償弁２２を経た油は切換弁群Ｂの供給ライン６０に供給される。図１の場合、切換弁群Ｂを構成する切換弁Ｂ−１、Ｂ−２は通常のオープンセンター型の切換弁であり、供給ライン６０に供給された油は各切換弁が中立位置にあるときはセンターバイパス通路６１、３２を経てタンク３８へ放出される。さらに、切換弁Ｂ−１は図示してないパイロットバルブに信号ライン１３、１４を介して接続されており、信号ライン１３、１４は、シャトル弁１５を介して、信号ライン１１を経て開閉弁８の絞り側に接続されている。
【００３０】
次にブロックＣ及び切換弁群Ｂについて、切換弁群Ｂに含まれる切換弁のみが操作された場合の動作を図１、図４および図５に基づいて説明する。切換弁群Ｂの切換弁Ｂ−１に、図示してないパイロットバルブを操作して信号ライン１３を介して信号圧力を与えると、切換弁Ｂ−１は図１において左方に移動する。これと同時に信号ライン１３の信号圧力はシャトル弁１５、信号ライン１１を経て、開閉弁８に作用しその通路を全閉位置から絞り位置に移動させる。つまり、開閉弁８は切換弁Ｂ−１の操作量に連動してその開度が調整される。尚、開閉弁内の絞り６４の開度は、図４に示すように、通常、信号ライン１１の圧力の上昇に応じて次第に大きくなるように設定してある。信号ライン１３に信号圧力を与え、切換弁Ｂ−１、及び開閉弁８を操作し、切換弁Ｂ−１が図５のイの位置まで移動すると供給ライン６０は逆止弁６２を介して旋回モータ３４へ接続されるとともに、この旋回モータ３４からの戻り油は図５のイの位置において対応する通路を経由し、戻りライン６５を経てタンク３８へ排出される。この場合供給ライン１９からブロックＣを経て供給ライン６０へ供給される油量は、切換弁８の絞り６４の開度と、補償弁２２の開度により決定される。
【００３１】
ここで補償弁２２の開度について考察する。補償弁２２には、切換弁８の絞り６４の上流側の圧力がその閉じ方向に作用し、一方、切換弁８の絞り６４の下流側の圧力とバネ９の力とがその開き方向作用している。つまり補償弁２２は、切換弁８の絞り６４の上流側と下流側との圧力差（つまり絞り６４前後の差圧）により閉じられようとし、バネ９の力により開かれようとすることになる。従って、補償弁２２の開度は、絞り６４前後の差圧とバネ９の力がバランスする開度に自動調整される。つまり補償弁２２の開度は、アクチュエータの作動圧力に関係無く、開閉弁８の開度、従って、切換弁Ｂ−１の操作量にのみ依存する。一方開閉弁８の下流側の圧力は通路２３、逆止弁２４、ロードセンシングライン２５、４７を経て圧力調整手段３の開き側へ導かれており、開閉弁８の絞り６４の上流側の圧力は、供給ライン１８、１９、通路４９を経て圧力調整手段３の閉じ側へ導かれている。従って、可変容量ポンプ１の吐出流量は開閉弁８の絞り６４に依る圧力降下（つまり絞り６４前後の差圧）がバネ４８の力とバランスするよう調整される。
【００３２】
信号ライン１３の圧力が上昇すると、開閉弁８の絞り６４の開度が増大するので、ブロックＣから切換弁群Ｂへ供給される油量は増大する。さらに、切換弁Ｂ−１はオープンセンター型の切換弁であるので、その操作量に応じて図５に示すようにセンターバイパス通路が次第に閉じられつつ旋回モータ３４への通路の開度が次第に大きくなる、つまり切換弁Ｂ−１の操作量の増加に応じて旋回モータ３４への圧油の供給量は増加するので、その操作性はスムースである。従って、たとえば旋回モータ３４が油圧ショベルの旋回モータ等の非常に慣性の大きなアクチュエータを駆動する場合でも、ロードセンシング機能によって常に圧力補償されているために発生する起動時の飛び出し感がなく、スムースな起動特性を得ることが出来る。
【００３３】
以上のように、本発明のような構成とすることにより、切換弁群Ａに接続されたアクチュエータに対してはロードセンシング機能を持たせると同時に、切換弁群Ｂに接続されたアクチュエータに対しては別ポンプを用意することなくオープンセンター型の機能を持たせることが出来る。つまり、ロードセンシング機能を持った切換弁との接続に適するアクチュエータと、オープンセンター型の機能を持った切換弁との接続に適するアクチュエータとを、共通の可変容量ポンプで駆動することができる。従って、油圧ショベルのようにそれぞれのアクチュエータによって慣性、負荷圧が非常に異なる複数のアクチュエータを同時に操作する場合でも、それぞれのアクチュエータの特性に最適な操作を行うことが出来るとともに、たとえば旋回用に別ポンプを設けることによるコスト上昇の問題、制御機器類のレイアウトが困難であるといった問題を解消することが出来る。
【００３４】
さらに、切換弁群Ｂに含まれる切換弁は、クローズドセンター型切換弁を使用することもできる。また、切換弁群Ｂに含まれる切換弁は、それがオープンセンター型切換弁であっても、クローズドセンター型切換弁であっても、通常の市販品を使用できるので、切換弁群Ｂを構成するのは容易、簡便である。さらに、現状ロードセンシング機能を持った切換弁のみで構成されている油圧制御回路に対しても、切換弁群Ｂを付加するのも容易である。
【００３５】
なお、図１において分流補償弁２６、２７は、それぞれ切換弁Ａ−１、Ａ−２とタンクラインとの間に配設されているが、この分流補償弁２６、２７は切換弁Ａ−１、Ａ−２と、その各々の切換弁に接続されたアクチュエータとの間に配設しても上記と同様の作用を有することは明らかである。
【００３６】
図２は本発明の第二実施例を示す油圧回路図である。切換弁Ａ−１のブーム上げ信号は信号ライン６を介して、図示しないブーム操作用パイロットバルブから切換弁Ａ−１に作用する。さらにこのブーム上げ信号は、信号ライン６から分岐した信号ライン１０を経て開閉弁８の閉じ方向に作用している。一方供給ライン１８から分岐したバイパスライン３７上の圧力調整手段３の下流には、圧力調整手段３を通過する圧油の流量を検出するための流量検出手段８０が設けられている。さらに流量検出手段８０が検出した流量は、信号ライン８１を介して電磁弁８２に作用し、ポンプ８３から吐出され電磁弁８２を通過する油の流量を制御している。電磁弁８２を通過した油は通路８４を介して可変容量ポンプ１の吐出流量調整機構２に作用し、可変容量ポンプ１の吐出量をネガティーブ方式により調整している。上述した以外の構成は図１に示す第一実施例と同一であるので、説明を省略する。
【００３７】
このように構成すると、開閉弁８には、信号ライン１３または１４を介して切換弁Ｂ−１に作用する旋回の操作信号と、それに対抗して信号ライン１０を介して切換弁Ａ−１に作用するブーム上げ信号とが与えられるので、開閉弁８の開度は旋回単独操作の場合と比較して減少し、旋回用切換弁Ｂ−１への供給流量が減少する。従って、ブーム用切換弁Ａ−１への供給油量が増加する。油圧ショベルでは旋回操作とブーム上げ操作を同時に行う頻度が多く、この２つのアクチュエータの流量配分が重要となるが、本実施例では、上述した構成にすることで、ブーム上げ操作を旋回操作に優先させることが可能となる。
【００３８】
ここで、ブロックＣ、切換弁群Ａ、Ｂは一体的に接合することが、設置スペースや配管処理を考慮した場合に有効である。さらにその場合、ブロックＣの両接合面に最も近い切換弁としてブーム用、旋回用各切換弁を配置することにより、ブーム用、旋回用各切換弁からブロックＣ内の開閉弁８への信号通路を各切換弁群Ａ、Ｂ及びブロックＣの内部を通して接続できるので、付加的な信号ライン、つまり外付の配管が不要となり、スペース効率および組立性がより向上する。
【００３９】
図３は本発明の第三実施例を示す油圧回路図である。上記第二実施例においては、ブロックＣの開閉弁８の開度を切換弁群Ａに含まれる切換弁の操作により低減する方法として、旋回操作信号に対抗して行う方法を示したが、第三実施例ではさらに別の方法の例を示す。図３に示すように、旋回操作用切換弁Ｂ−１の操作信号１３または１４を開閉弁８の開き側へ作用させる信号ライン１１上に弁１２を設ける。ここで信号ライン１１上に新たに設けた弁１２とシャトル弁１５との間の通路は信号ライン１６と呼ぶことにする。弁１２は外部信号Ｓにより２次圧力が低減する可変減圧弁である。上述した以外の構成は図１に示す第一実施例と同一であるので、説明を省略する。
【００４０】
このように構成し、弁１２に与える外部信号Ｓとして切換弁群Ａ中の切換弁の操作信号、例えば切換弁Ａ−１のブーム上げ信号を作用させれば、ブームの駆動圧力の上昇に応じて信号ライン１６から信号ライン１１へ流れる圧油の圧力が低減するので、開閉弁８の開き側への移動、つまり開度は外部信号Ｓが作用していないときよりも減少する。従って、本実施例では、上述した構成にすることで第二実施例と同様に、ブーム上げ操作を旋回操作に優先させることが可能となり、操作性、生産性の向上が図れる。
【００４１】
【発明の効果】
ロードセンシング機能を有する切換弁群とロードセンシング機能を有しない切換弁群とを共通の可変容量ポンプに接続し、これら各々の切換弁群の切換弁に接続されたアクチュエータが慣性、負荷圧力が異なる場合でもかつ同時に駆動しても、極めて簡単な方法で、それぞれのアクチュエータの特性に応じて非常にスムースな起動特性、操作性を得ることが出来る。
【図面の簡単な説明】
【図１】本発明の実施形態の一例を示す油圧回路図である。
【図２】本発明の実施形態の、別の一例を示す油圧回路図である。
【図３】本発明の実施形態の、さらに別の一例を示す油圧回路図である。
【図４】切換弁８の中間切換位置を示す図である。
【図５】切換弁Ｂ−１の中間切換位置を示す図である。
【図６】従来の油圧制御装置を説明する油圧回路図である。
【符号の説明】
１ 可変容量ポンプ
２ 吐出流量調整機構
３ 圧力調整手段
４ 圧力発生手段
５、２０、２３、３９、４０、４１、４９、５３、５４、５５、５７、５８、５９、６６、８４ 通路
６、１０、１１、１３、１４、１６、８１ 信号ライン
８ 開閉弁
９、２１、４４、４８ バネ
１２ 弁
１５ シャトル弁
１７ 吐出ライン
１８、１９、６０ 供給ライン
２２ 補償弁
２４、４５、４６、５２、６２ 逆止弁
２５、４７ ロードセンシングライン
２６、２７ 分流補償弁
２８、２９、６５ 戻りライン
３０、３１ タンクライン
３２、６１ センターバイパス通路
３４ 旋回モータ
３７ バイパスライン
３８ タンク
５０、５１、６４ 絞り
５６ アームシリンダ
７０ ブームシリンダ
８０ 流量検出手段
８２ 電磁弁
８３ ポンプ
Ａ，Ｂ 切換弁群
Ａ−１、Ａ−２、Ｂ−１、Ｂ−２ 切換弁
Ｃ 圧力補償流量調整手段
Ｓ 外部信号[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hydraulic control apparatus that is most suitable for a machine having a plurality of actuators such as a construction machine such as a hydraulic excavator, and more particularly to improvement in operability when a plurality of actuators are operated simultaneously.
[0002]
[Prior art]
There are various conventional techniques such as those using a control valve having a load sensing function as disclosed in JP-A-10-103305, those using a control valve having no load sensing function, and combinations thereof.
[0003]
Japanese Patent Laid-Open No. 10-103305 will be described with reference to FIG. In FIG. 6, control valves 2 to 5 are connected to the variable displacement pump P in parallel. All these control valves are equally equipped with load sensing function. When this device is used in a hydraulic excavator, for example, when turning with a large inertia is operated, the supply of pressure oil to the turning is performed by a load sensing function that keeps the pump pressure always higher than the maximum load pressure by a predetermined pressure, It has been empirically known that since the pressure is always compensated, there is a feeling of popping out at the start, and the driver feels a shock at the start, and the smooth operation is very difficult.
[0004]
For this reason, small hydraulic excavators are often provided with a separate turning pump and a separate open center type turning operation switching valve having no load sensing function. However, in this case, a pump dedicated to swiveling is added and there is a problem in cost. Furthermore, in a machine such as a small hydraulic excavator, a space for mounting a control device is small. Therefore, when a pump dedicated to swiveling is added, there is a problem that the layout of each device is very difficult.
[0005]
On the other hand, control valves that have removed the load sensing function of each control valve and have no pressure compensation function have been conventionally used for hydraulic excavator operations, etc., but in this case, the amount of operation of the control valve depends on the load pressure. It is also conventionally known that operation is difficult depending on actuators because of differences.
[0006]
[Problems to be solved by the invention]
The present invention relates to an actuator connected to a first switching valve group composed of a switching valve having a load sensing function, and an actuator connected to a second switching valve group composed of a switching valve not having a load sensing function. Are driven by a common variable displacement pump, and even when the switching valve in the first switching valve group and the switching valve in the second switching valve group are operated simultaneously, reliable simultaneous operation of the actuator can be performed. The switching valve of the switching valve group is to provide a hydraulic control device that is extremely excellent in operability and matches the driver's feeling by using an open center type or closed center type switching valve as required. .
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, a hydraulic control device according to the present invention has a variable displacement pump having a variable discharge amount and a load sensing function connected to a first discharge line branched from the discharge line of the variable displacement pump. A first switching valve group including at least one switching valve, a pressure compensation flow rate adjusting means connected to a second discharge line branched from the discharge line of the variable displacement pump, and the pressure in the second discharge line. A second switching valve group including at least one switching valve connected via a compensation flow rate adjusting means, and the pressure compensation flow rate adjusting means includes a switching valve included in the first switching valve group, When the switching valve included in the second switching valve group is operated at the same time, it is adjusted in the flow rate reduction direction by the operation of the switching valve included in the first switching valve group, and is included in the second switching valve group. Operation of the switching valve Characterized in that it is adjusted to a flow rate increase direction by.
[0009]
Furthermore, a variable displacement pump whose discharge amount is variable,
A first switching valve group including at least one switching valve connected to a first discharge line branched from the discharge line of the variable displacement pump and having a load sensing function;
Pressure compensated flow rate adjusting means connected to a second discharge line branched from the discharge line of the variable displacement pump;
A second switching valve group including at least one switching valve connected to the second discharge line via the pressure compensation flow rate adjusting means;
Comprising
The pressure-compensated flow rate adjusting means is configured to switch the switching valve included in the second switching valve group when the switching valve included in the first switching valve group and the switching valve included in the second switching valve group are operated simultaneously. It can be configured such that the flow rate is adjusted in the increasing direction by a signal obtained by subtracting the signal generated according to the operation of the switching valve included in the first switching valve group from the signal generated according to the operation of the valve.
[0010]
Further, the pressure compensation flow rate adjusting means includes:
Open and close spool,
An adjustment spool provided downstream of the open / close spool;
Comprising
The opening / closing spool is adjusted in opening according to the operation of a switching valve included in the second switching valve group, the adjusting spool is adjusted in the throttle direction by the pressure upstream of the opening / closing spool, and the opening / closing spool It can be configured to be adjusted in the opening direction by the downstream pressure and the spring force.
[0011]
Furthermore, the pressure between the open / close spool of the pressure compensation flow rate adjusting means and the adjustment spool can be connected to the load sensing line of the first switching valve group.
[0012]
Further, the first switching valve group, the pressure compensation flow rate adjusting means, and the second switching valve group are integrally configured, and the block configuring the first switching valve group and the second switching valve are configured. A block constituting the pressure compensation flow rate adjusting means may be provided between the blocks constituting the group.
[0013]
A bypass line branched from the discharge line of the variable pump;
Pressure adjusting means provided on the bypass line;
Pressure generating means provided downstream of the pressure adjusting means on the bypass line;
Means for detecting the highest pressure among the load sensing pressure of each switching valve included in the first switching valve group and the pressure between the open / close spool and the adjustment spool of the pressure compensation flow rate adjusting means;
Comprising
A pressure of the discharge line of the variable pump is applied in the opening direction of the pressure adjusting means, and a maximum pressure and a spring force detected by the maximum pressure detecting means are applied in the closing direction, and the pressure generating means The discharge flow rate of the variable displacement pump can be adjusted corresponding to the upstream pressure.
[0014]
A bypass line branched from the discharge line of the variable pump;
Pressure adjusting means provided on the bypass line;
A flow rate detecting means provided downstream of the pressure adjusting means on the bypass line;
Means for detecting the highest pressure among the load sensing pressure of each switching valve included in the first switching valve group and the pressure between the open / close spool and the adjustment spool of the pressure compensation flow rate adjusting means;
Comprising
The pressure of the discharge line of the variable pump is applied in the opening direction of the pressure adjusting means, and the maximum pressure and the spring force detected by the maximum pressure detecting means are applied in the closing direction, and the flow rate detecting means The discharge flow rate of the variable displacement pump can be adjusted in accordance with the detected flow rate.
[0015]
Further, the second switching valve group may be a switching valve group including at least one open center type switching valve.
[0016]
The second switching valve group may be a switching valve group including at least one closed center type switching valve.
[0017]
Furthermore, the first switching valve group can be configured to have a shunt compensation valve between each switching valve included in the first switching valve group and the tank line.
[0018]
Furthermore, the first switching valve group may be configured to have a shunt compensation valve between each switching valve included in the first switching valve group and an actuator connected to the switching valve. it can.
[0019]
Furthermore, the present invention can be applied to construction machines such as hydraulic excavators.
[0020]
In this case, one of the switching valves included in the first switching valve group is a boom operation switching valve, and one of the switching valves included in the second switching valve group is a turning operation switching valve. can do.
[0021]
Further, the first switching valve group, the pressure compensation flow rate adjusting means, and the second switching valve group are integrally configured, and the block configuring the first switching valve group and the second switching valve are configured. A block constituting the pressure compensation flow rate adjusting means is provided between the blocks constituting the group, the boom switching valve among the switching valves included in the first switching valve group, and the second switching valve. Of the switching valves included in the group, the switching valve for turning operation can be arranged at a position closest to the block constituting the pressure compensation flow rate adjusting means.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0023]
FIG. 1 is a hydraulic circuit diagram showing a first embodiment of the present invention. In the figure, reference numeral 1 denotes a variable displacement pump. This discharge line 17 is branched into supply lines 18 and 19, and a first switching valve group (hereinafter referred to as switching valve group A) is connected to the variable displacement pump 1 via the discharge line 18. It is connected to the. The second switching valve group (hereinafter referred to as switching valve group B) is connected to the variable displacement pump 1 via the discharge line 19 and the pressure compensation flow rate adjusting means (hereinafter referred to as block C). In the switching valve group A, switching valves A-1 and A-2 are connected in parallel to the discharge line 17 via the supply line 18, and the return lines 28 and 29 of each switching valve and the tank lines 30 and 31 are connected to each other. The shunt compensation valves 26 and 27 are provided between them, and the oil discharged from the tank lines 30 and 31 is discharged to the tank 38.
[0024]
The functions of the switching valve and the shunt compensation valve included in the switching valve group A are as described in Japanese Patent Application No. 10-119745 by the same applicant as the present application. For example, in FIG. When operated alone to the left in the figure, the oil in the supply line 18 is supplied to the arm cylinder 56 of the hydraulic excavator through the restrictor 50 in the switching valve, the check valve 52, and the passages 53, 54, and 55. The return oil from 56 reaches the shunt compensation valve 27 through the passages 57 and 58 and the return line 29, and further reaches the tank 38 through the tank line 31. At this time, the pressure oil after passing through the throttle 50 is branched on the upstream side of the check valve 52, and this branch passage is further branched into a passage 39 and a passage 40. The passage 39 is connected to the load sensing line 25 via a check valve 45. The pressure in the passage 40 acts in the opening direction of the shunt compensation valve 27 together with the spring 44, and the pressure in the load sensing line 25 acts in the throttle direction of the shunt compensation valve 27 through the passage 59. However, in this case, since the switching valve A-2 is operated alone, the pressure of the passage 40 acting in the opening direction of the shunt compensation valve 27 is equal to the pressure of the passage 59 acting in the closing direction, and Since the force of the spring 44 is also acting in the opening direction of the shunt compensation valve 27, the shunt compensation valve 27 is held in the fully open position.
[0025]
On the other hand, a bypass line 37 is branched from the supply line 18, and the pressure adjusting means 3 and the pressure generating means 4 are provided on the bypass line 37. The pressure adjusting means 3 is subjected to the force of the spring 48 in the closing direction and the pressure of the load sensing line 25 via the load sensing line 47, and the pressure of the supply line 18 is adjusted via the passage 49. Acting in the opening direction of the means 3. Further, a passage 5 is branched from a portion of the bypass line 37 downstream of the pressure adjusting means 3 and upstream of the pressure generating means 4, and the pressure of this passage 5 is supplied to the discharge flow rate adjusting mechanism 2 of the variable displacement pump 1. In effect, the discharge flow rate of the variable displacement pump 1 is controlled in a negative manner.
[0026]
Therefore, the opening degree of the pressure adjusting means 3 in such a configuration is as follows. In the opening direction of the pressure adjusting means 3, the pressure on the upstream side of the throttle 50 in the switching valve A- 2 acts through the passage 49. On the other hand, the force of the spring 48 and the pressure on the downstream side of the throttle 50 in the switching valve A-2 act through the load sensing line 47 in the closing direction of the pressure adjusting means 3. That is, the pressure adjusting means 3 is adjusted to an opening that balances the force due to the differential pressure before and after the throttle 50 in the switching valve A-2 and the force of the spring 48, and the oil at a flow rate corresponding to the opening is pressure. It flows to the generating means 4. Accordingly, a pressure corresponding to the flow rate is generated on the upstream side of the pressure generating means 4, and this pressure acts on the discharge flow rate adjusting mechanism 2 through the passage 5, and the discharge amount of the variable displacement pump 1 is adjusted. Here, the differential pressure before and after the throttle 50 in the switching valve A-2 is constant regardless of the load pressure of the arm cylinder 56 if the opening of the throttle 50 is constant. The degree is also constant. That is, the opening degree of the pressure adjusting means 3 depends only on the opening degree of the throttle 50 of the switching valve A-2. Since the opening degree of the throttle 50 of the switching valve A-2 changes depending on the operation amount of the switching valve A-2, the pressure acting on the discharge flow rate adjusting mechanism 2 and the amount of oil supplied from the variable displacement pump 1 to the arm cylinder 56 Is adjusted according to the operation amount of the switching valve A-2 regardless of the load pressure of the arm cylinder 56.
[0027]
Next, it is assumed that the switching valve A-1 is operated in addition to the switching valve A-2, and the load of the boom cylinder 70 connected to the switching valve A-1 is larger than the load of the arm cylinder 56. In this case, the load pressure of the boom cylinder 70 connected to the switching valve A-1 acts on the load sensing line 25 via the passage 41 and the check valve 46. Here, since the load of the switching valve boom cylinder 70 is larger than the load of the arm cylinder 56, the pressure passes through the passage 59 and closes with respect to the shunt compensation valve 27 on the light load side (that is, the arm cylinder 56). As a result, the apparent pressure of the arm cylinder 56 rises, and as a result, the differential pressures at the throttles 50 and 51 become equal in both switching valves, and the actuators connected to these switching valves A-2 and A-1 are Even if those loads are different, they can be moved simultaneously.
[0028]
Next, the block C (pressure compensation flow rate adjusting means) and the switching valve group B (second switching valve group) connected downstream thereof will be described.
[0029]
In the block C, a supply line 19 branched from the discharge line 17 of the variable discharge pump 1 is provided, and an on-off valve 8 is provided downstream thereof. A compensation valve 22 is provided downstream of the on-off valve 8, and further, the pressure on the downstream side of the on-off valve 8 and upstream of the compensation valve 22 passes through the passage 23 and the check valve 24 and switches the switching valve group A. Are connected to the load sensing line 25. The on-off valve 8 operates in the opening direction via the passage 20 and the pressure upstream of the on-off valve 8, while in the closing direction via the passage 23 and the passage 66, the pressure on the downstream side of the on-off valve 8 springs. It works with 9 forces. The on-off valve 8 blocks the passage from the supply line 19 to the compensation valve 22 when in the neutral position by the force of the spring 21. A switching valve group B is provided downstream of the block C, and the oil that has passed through the compensation valve 22 is supplied to the supply line 60 of the switching valve group B. In the case of FIG. 1, the switching valves B-1 and B-2 constituting the switching valve group B are normal open center type switching valves, and the oil supplied to the supply line 60 is in the neutral position. At this time, the fuel is discharged to the tank 38 through the center bypass passages 61 and 32. Further, the switching valve B-1 is connected to a pilot valve (not shown) via signal lines 13 and 14, and the signal lines 13 and 14 are connected to the on-off valve 8 via the shuttle valve 15 and the signal line 11. Connected to the aperture side.
[0030]
Next, with respect to the block C and the switching valve group B, the operation when only the switching valve included in the switching valve group B is operated will be described based on FIG. 1, FIG. 4, and FIG. When a signal pressure is applied to the switching valve B-1 of the switching valve group B via the signal line 13 by operating a pilot valve (not shown), the switching valve B-1 moves to the left in FIG. At the same time, the signal pressure in the signal line 13 acts on the on-off valve 8 via the shuttle valve 15 and the signal line 11 to move the passage from the fully closed position to the throttle position. That is, the opening degree of the on-off valve 8 is adjusted in conjunction with the operation amount of the switching valve B-1. As shown in FIG. 4, the opening degree of the throttle 64 in the on-off valve is normally set to gradually increase as the pressure of the signal line 11 increases. When a signal pressure is applied to the signal line 13 and the switching valve B-1 and the on-off valve 8 are operated so that the switching valve B-1 moves to the position A in FIG. 5, the supply line 60 turns through the check valve 62. While being connected to the motor 34, the return oil from the turning motor 34 is discharged to the tank 38 through the corresponding path at the position of FIG. In this case, the amount of oil supplied from the supply line 19 via the block C to the supply line 60 is determined by the opening degree of the throttle 64 of the switching valve 8 and the opening degree of the compensation valve 22.
[0031]
Here, the opening degree of the compensation valve 22 will be considered. On the compensation valve 22, the pressure upstream of the throttle 64 of the switching valve 8 acts in the closing direction, while the pressure downstream of the throttle 64 of the switching valve 8 and the force of the spring 9 act in the opening direction. ing. That is, the compensation valve 22 tends to be closed by the pressure difference between the upstream side and the downstream side of the throttle 64 of the switching valve 8 (that is, the differential pressure before and after the throttle 64), and is opened by the force of the spring 9. . Therefore, the opening degree of the compensation valve 22 is automatically adjusted to an opening degree that balances the differential pressure before and after the throttle 64 and the force of the spring 9. That is, the opening degree of the compensation valve 22 depends only on the opening degree of the on-off valve 8 and, therefore, the operation amount of the switching valve B-1, regardless of the operating pressure of the actuator. On the other hand, the pressure on the downstream side of the on-off valve 8 is guided to the opening side of the pressure adjusting means 3 through the passage 23, the check valve 24, and the load sensing lines 25, 47, and the pressure on the upstream side of the throttle 64 of the on-off valve 8. Is led to the closing side of the pressure adjusting means 3 through the supply lines 18 and 19 and the passage 49. Therefore, the discharge flow rate of the variable displacement pump 1 is adjusted so that the pressure drop due to the throttle 64 of the on-off valve 8 (that is, the differential pressure before and after the throttle 64) balances with the force of the spring 48.
[0032]
When the pressure in the signal line 13 increases, the opening degree of the throttle 64 of the on-off valve 8 increases, so that the amount of oil supplied from the block C to the switching valve group B increases. Further, since the switching valve B-1 is an open center type switching valve, the opening degree of the passage to the turning motor 34 is gradually increased while the center bypass passage is gradually closed as shown in FIG. That is, as the amount of operation of the switching valve B-1 increases, the amount of pressure oil supplied to the swing motor 34 increases, so the operability is smooth. Therefore, for example, even when the swing motor 34 drives an actuator having a very large inertia such as a swing motor of a hydraulic excavator, the pressure sensing is always compensated for by the load sensing function, so that there is no feeling of popping out at the start-up and smooth. Startup characteristics can be obtained.
[0033]
As described above, by adopting the configuration of the present invention, the actuator connected to the switching valve group A is provided with a load sensing function, and at the same time, the actuator connected to the switching valve group B is used. Can have an open center type function without preparing a separate pump. That is, an actuator suitable for connection with a switching valve having a load sensing function and an actuator suitable for connection with a switching valve having an open center type function can be driven by a common variable displacement pump. Therefore, even when a plurality of actuators having very different inertia and load pressure are simultaneously operated by each actuator, such as a hydraulic excavator, the optimum operation can be performed for the characteristics of each actuator. It is possible to solve the problem of the cost increase due to the provision of the pump and the problem that the layout of the control devices is difficult.
[0034]
Further, the switching valve included in the switching valve group B may be a closed center type switching valve. In addition, since the switching valves included in the switching valve group B can be ordinary commercial products regardless of whether they are open center type switching valves or closed center type switching valves, the switching valve group B is constituted. It is easy and convenient to do. Furthermore, it is easy to add the switching valve group B to the hydraulic control circuit that is configured only by the switching valve having the current load sensing function.
[0035]
In FIG. 1, the shunt compensation valves 26 and 27 are disposed between the switching valves A-1 and A-2 and the tank line, respectively. However, the shunt compensation valves 26 and 27 are the switching valve A-1. , A-2 and the actuator connected to each switching valve have the same effect as described above.
[0036]
FIG. 2 is a hydraulic circuit diagram showing a second embodiment of the present invention. The boom raising signal of the switching valve A-1 acts on the switching valve A-1 from a boom operation pilot valve (not shown) via the signal line 6. Further, the boom raising signal acts in the closing direction of the on-off valve 8 through the signal line 10 branched from the signal line 6. On the other hand, a flow rate detection means 80 for detecting the flow rate of the pressure oil passing through the pressure adjustment means 3 is provided downstream of the pressure adjustment means 3 on the bypass line 37 branched from the supply line 18. Further, the flow rate detected by the flow rate detection means 80 acts on the electromagnetic valve 82 via the signal line 81, and controls the flow rate of oil discharged from the pump 83 and passing through the electromagnetic valve 82. The oil that has passed through the electromagnetic valve 82 acts on the discharge flow rate adjusting mechanism 2 of the variable displacement pump 1 via the passage 84, and the discharge amount of the variable displacement pump 1 is adjusted by a negative method. The configuration other than that described above is the same as that of the first embodiment shown in FIG.
[0037]
With this configuration, the on-off valve 8 has a turning operation signal that acts on the switching valve B-1 via the signal line 13 or 14 and a signal line 10 that counters the operation signal. Since the boom raising signal is applied, the opening degree of the on-off valve 8 is reduced as compared with the case of the single turning operation, and the supply flow rate to the turning switching valve B-1 is reduced. Accordingly, the amount of oil supplied to the boom switching valve A-1 is increased. In a hydraulic excavator, the turning operation and the boom raising operation are frequently performed at the same time, and the flow distribution of these two actuators is important. In this embodiment, the boom raising operation has priority over the turning operation by using the above-described configuration. It becomes possible to make it.
[0038]
Here, it is effective that the block C and the switching valve groups A and B are integrally joined in consideration of installation space and piping processing. Further, in that case, by arranging the switching valves for boom and turning as switching valves closest to both joint surfaces of the block C, the signal path from the switching valves for boom and turning to the on-off valve 8 in the block C. Can be connected through the switching valve groups A and B and the inside of the block C, so that an additional signal line, that is, an external pipe is not required, and the space efficiency and the assemblability are further improved.
[0039]
FIG. 3 is a hydraulic circuit diagram showing a third embodiment of the present invention. In the second embodiment, as a method of reducing the opening degree of the on-off valve 8 of the block C by operating the switching valve included in the switching valve group A, a method is shown that is performed against the turning operation signal. In the third embodiment, another example of the method is shown. As shown in FIG. 3, a valve 12 is provided on a signal line 11 that causes the operation signal 13 or 14 of the turning operation switching valve B- 1 to act on the opening side of the on-off valve 8. Here, a passage between the valve 12 newly provided on the signal line 11 and the shuttle valve 15 is referred to as a signal line 16. The valve 12 is a variable pressure reducing valve whose secondary pressure is reduced by an external signal S. The configuration other than that described above is the same as that of the first embodiment shown in FIG.
[0040]
If the operation signal of the switching valve in the switching valve group A, for example, the boom raising signal of the switching valve A-1, is applied as the external signal S applied to the valve 12 in this way, the boom driving pressure increases. Since the pressure of the pressure oil flowing from the signal line 16 to the signal line 11 is reduced, the movement of the on-off valve 8 toward the opening side, that is, the opening degree is smaller than when the external signal S is not acting. Therefore, in the present embodiment, by using the above-described configuration, the boom raising operation can be prioritized over the turning operation similarly to the second embodiment, and operability and productivity can be improved.
[0041]
【The invention's effect】
A switching valve group having a load sensing function and a switching valve group not having a load sensing function are connected to a common variable displacement pump, and the actuators connected to the switching valves of these switching valve groups have different inertia and load pressure. Even if it is driven at the same time, it is possible to obtain very smooth start-up characteristics and operability in accordance with the characteristics of each actuator in a very simple manner.
[Brief description of the drawings]
FIG. 1 is a hydraulic circuit diagram showing an example of an embodiment of the present invention.
FIG. 2 is a hydraulic circuit diagram showing another example of the embodiment of the present invention.
FIG. 3 is a hydraulic circuit diagram showing still another example of the embodiment of the present invention.
4 is a view showing an intermediate switching position of the switching valve 8. FIG.
FIG. 5 is a view showing an intermediate switching position of the switching valve B-1.
FIG. 6 is a hydraulic circuit diagram illustrating a conventional hydraulic control device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Variable displacement pump 2 Discharge flow rate adjusting mechanism 3 Pressure adjusting means 4 Pressure generating means 5, 20, 23, 39, 40, 41, 49, 53, 54, 55, 57, 58, 59, 66, 84 Passages 6, 10 , 11, 13, 14, 16, 81 Signal line 8 On-off valve 9, 21, 44, 48 Spring 12 Valve 15 Shuttle valve 17 Discharge line 18, 19, 60 Supply line 22 Compensation valve 24, 45, 46, 52, 62 Check valve 25, 47 Load sensing line 26, 27 Shunt compensation valve 28, 29, 65 Return line 30, 31 Tank line 32, 61 Center bypass passage 34 Turning motor 37 Bypass line 38 Tank 50, 51, 64 Restriction 56 Arm cylinder 70 Boom cylinder 80 Flow rate detecting means 82 Solenoid valve 83 Pump A, B Switching valve group A-1, A-2, B-1, B-2 OFF Valve C pressure compensating flow controller S external signal

Claims (15)

吐出量が可変である可変容量ポンプと、
前記可変容量ポンプの吐出ラインを分岐した第一の吐出ラインに接続されロードセンシング機能を有する切換弁を少なくとも一つ含む第一の切換弁群と、前記可変容量ポンプの吐出ラインを分岐した第二の吐出ラインに接続された圧力補償流量調整手段と、
前記第二の吐出ラインに前記圧力補償流量調整手段を介して接続される少なくとも一つの切換弁を含む第二の切換弁群と、
を具備し、
前記圧力補償流量調整手段は、前記第一の切換弁群に含まれる切換弁と第二の切換弁群に含まれる切換弁とが同時に操作されたとき、第一の切換弁群に含まれる切換弁の操作により流量低減方向に調整されるとともに、第二の切換弁群に含まれる切換弁の操作により流量増加方向に調整されることを特徴とする油圧制御装置。A variable displacement pump with variable discharge volume;
A first switching valve group including at least one switching valve having a load sensing function connected to a first discharge line branched from the discharge line of the variable displacement pump, and a second branched from the discharge line of the variable displacement pump Pressure-compensated flow rate adjusting means connected to the discharge line of
A second switching valve group including at least one switching valve connected to the second discharge line via the pressure compensation flow rate adjusting means;
Comprising
The pressure-compensated flow rate adjusting means includes a switch included in the first switch valve group when the switch valve included in the first switch valve group and the switch valve included in the second switch valve group are operated simultaneously. A hydraulic control device characterized by being adjusted in a flow rate decreasing direction by an operation of a valve and adjusted in a flow increasing direction by an operation of a switching valve included in a second switching valve group. 吐出量が可変である可変容量ポンプと、
前記可変容量ポンプの吐出ラインを分岐した第一の吐出ラインに接続されロードセンシング機能を有する切換弁を少なくとも一つ含む第一の切換弁群と、
前記可変容量ポンプの吐出ラインを分岐した第二の吐出ラインに接続された圧力補償流量調整手段と、
前記第二の吐出ラインに前記圧力補償流量調整手段を介して接続される少なくとも一つの切換弁を含む第二の切換弁群と、
を具備し、
前記圧力補償流量調整手段は、前記第一の切換弁群に含まれる切換弁と第二の切換弁群に含まれる切換弁とが同時に操作されたとき、第二の切換弁群に含まれる切換弁の操作に応じて生成される信号から第一の切換弁群に含まれる切換弁の操作に応じて生成される信号を減じた信号により流量増加方向に調整されることを特徴とする油圧制御装置。A variable displacement pump with variable discharge volume;
A first switching valve group including at least one switching valve connected to a first discharge line branched from the discharge line of the variable displacement pump and having a load sensing function;
Pressure compensated flow rate adjusting means connected to a second discharge line branched from the discharge line of the variable displacement pump;
A second switching valve group including at least one switching valve connected to the second discharge line via the pressure compensation flow rate adjusting means;
Comprising
The pressure-compensated flow rate adjusting means is configured to switch the switching valve included in the second switching valve group when the switching valve included in the first switching valve group and the switching valve included in the second switching valve group are operated simultaneously. Hydraulic control characterized by being adjusted in the flow rate increasing direction by a signal obtained by subtracting a signal generated according to operation of a switching valve included in the first switching valve group from a signal generated according to operation of the valve apparatus. 前記圧力補償流量調整手段は、
開閉スプールと、
この開閉スプールの下流に設けられた調整スプールと、
を具備し、
前記開閉スプールは第二の切換弁群に含まれる切換弁の操作に応じて開度が調整され、前記調整スプールは前記開閉スプールの上流側の圧力により絞り方向に調整されるとともに、前記開閉スプールの下流側圧力とバネ力とにより開き方向に調整されることを特徴とする請求項１又は２に記載の油圧制御装置。The pressure compensation flow rate adjusting means is
Open and close spool,
An adjustment spool provided downstream of the open / close spool;
Comprising
The opening / closing spool is adjusted in opening according to the operation of a switching valve included in the second switching valve group, and the adjusting spool is adjusted in the throttle direction by the pressure upstream of the opening / closing spool, and the opening / closing spool The hydraulic control device according to claim 1 , wherein the hydraulic control device is adjusted in an opening direction by a downstream pressure and a spring force. 前記圧力補償流量調整手段の前記開閉スプールと前記調整スプールとの間の圧力を、前記第一の切換弁群のロードセンシングラインに接続したことを特徴とする請求項３に記載の油圧制御装置。4. The hydraulic control device according to claim 3 , wherein a pressure between the open / close spool and the adjustment spool of the pressure compensation flow rate adjusting means is connected to a load sensing line of the first switching valve group. 前記第一の切換弁群と前記圧力補償流量調整手段と前記第二の切換弁群とを一体的に構成し、前記第一の切換弁群を構成するブロックと前記第二の切換弁群を構成するブロックとの間に前記圧力補償流量調整手段を構成するブロックを設けることを特徴とする請求項１乃至４のいずれかに記載の油圧制御装置。The first switching valve group, the pressure-compensated flow rate adjusting means, and the second switching valve group are integrally configured, and a block that configures the first switching valve group and the second switching valve group are provided. The hydraulic control device according to any one of claims 1 to 4 , wherein a block constituting the pressure compensation flow rate adjusting means is provided between the constituting block. 前記可変ポンプの吐出ラインから分岐されたバイパスラインと、
このバイパスライン上に設けた圧力調整手段と、
前記バイパスライン上の前記圧力調整手段の下流に設けた圧力発生手段と、前記第一の切換弁群に含まれる各切換弁のロードセンシング圧力と前記圧力補償流量調整手段の前記開閉スプールと前記調整スプールとの間の圧力のうちの最高圧力を検出する手段と、
を具備し、
前記圧力調整手段の開き方向には前記可変ポンプの吐出ラインの圧力を作用させるとともに、閉じ方向には前記最高圧力検出手段によって検出された最高圧力とバネ力とを作用させ、前記圧力発生手段の上流側圧力に対応して可変容量ポンプの吐出流量を調整することを特徴とする請求項１乃至５のいずれかに記載の油圧制御装置。A bypass line branched from the discharge line of the variable pump;
Pressure adjusting means provided on the bypass line;
Pressure generating means provided downstream of the pressure adjusting means on the bypass line, load sensing pressure of each switching valve included in the first switching valve group, the open / close spool of the pressure compensation flow adjusting means, and the adjustment Means for detecting the highest pressure among the pressures with the spool;
Comprising
A pressure of the discharge line of the variable pump is applied in the opening direction of the pressure adjusting means, and a maximum pressure and a spring force detected by the maximum pressure detecting means are applied in the closing direction, and the pressure generating means hydraulic control device according to any one of claims 1 to 5, characterized in that to adjust the discharge flow rate of the variable displacement pump in response to upstream pressure. 前記可変ポンプの吐出ラインから分岐されたバイパスラインと、
このバイパスライン上に設けた圧力調整手段と、
前記バイパスライン上の前記圧力調整手段の下流に設けた流量検出手段と、
前記第一の切換弁群に含まれる各切換弁のロードセンシング圧力と前記圧力補償流量調整手段の前記開閉スプールと前記調整スプールとの間の圧力のうちの最高圧力を検出する手段と、
を具備し、
前記圧力調整手段の開き方向には前記可変ポンプの吐出ラインの圧力を作用させるとともに、閉じ方向には前記最高圧力検出手段によって検出された最高圧力とバネ力とを作用させ、前記流量検出手段で検出された流量に対応して可変容量ポンプの吐出流量を調整することを特徴とする請求項１乃至５のいずれかに記載の油圧制御装置。A bypass line branched from the discharge line of the variable pump;
Pressure adjusting means provided on the bypass line;
A flow rate detecting means provided downstream of the pressure adjusting means on the bypass line;
Means for detecting the highest pressure among the load sensing pressure of each switching valve included in the first switching valve group and the pressure between the open / close spool and the adjustment spool of the pressure compensation flow rate adjusting means;
Comprising
The pressure of the discharge line of the variable pump is applied in the opening direction of the pressure adjusting means, and the maximum pressure and the spring force detected by the maximum pressure detecting means are applied in the closing direction, and the flow rate detecting means hydraulic control device according to any one of claims 1 to 5, characterized in that to adjust the discharge flow rate of the variable displacement pump in response to the detected flow rate. 前記第二の切換弁群は少なくとも１つのオープンセンター型切換弁を含む切換弁群であることを特徴とする請求項１乃至７のいずれかに記載の油圧制御装置。Hydraulic control device according to any one of claims 1 to 7 wherein the second switching valve group is characterized by a change-over valve group including at least one open-center type directional control valve. 前記第二の切換弁群は少なくとも１つのクローズドセンター型切換弁を含む切換弁群であることを特徴とする請求項１乃至７のいずれかに記載の油圧制御装置。Hydraulic control device according to any one of claims 1 to 7, wherein the second switching valve group is switching valve group including at least one closed center type selector valve. 前記第一の切換弁群は、この第一の切換弁群に含まれる各々の切換弁とタンクラインとの間に分流補償弁を有することを特徴とする請求項１乃至９のいずれかに記載の油圧制御装置。Said first switching valve group according to any one of claims 1 to 9, characterized in that it has a shunt compensation valve between the first of each included in the switching valve group switching valve and a tank line Hydraulic control device. 前記第一の切換弁群は、この第一の切換弁群に含まれる各々の切換弁と、その切換弁に接続されたアクチュエータとの間に分流補償弁を有することを特徴とする請求項１乃至９のいずれかに記載の油圧制御装置。2. The first switching valve group includes a shunt compensation valve between each switching valve included in the first switching valve group and an actuator connected to the switching valve. The hydraulic control apparatus in any one of thru | or 9 . 請求項１乃至１１のいずれかに記載の油圧制御装置を具備することを特徴とする建設機械。Construction machine characterized by comprising a hydraulic control apparatus according to any one of claims 1 to 11. 請求項１乃至１１のいずれかに記載の油圧制御装置を具備することを特徴とする油圧ショベル。Hydraulic excavator, characterized in that it comprises a hydraulic control apparatus according to any one of claims 1 to 11. 第一の切換弁群に含まれる切換弁の１つはブーム操作用切換弁であり、第二の切換弁群に含まれる切換弁の１つは旋回操作用切換弁であることを特徴とする請求項１３記載の油圧ショベル。One of the switching valves included in the first switching valve group is a boom operation switching valve, and one of the switching valves included in the second switching valve group is a turning operation switching valve. The hydraulic excavator according to claim 13 . 前記第一の切換弁群と前記圧力補償流量調整手段と前記第二の切換弁群とを一体的に構成し、前記第一の切換弁群を構成するブロックと前記第二の切換弁群を構成するブロックとの間に前記圧力補償流量調整手段を構成するブロックを設けるとともに、前記第一の切換弁群に含まれる切換弁のうちブーム用切換弁を、また前記第二の切換弁群に含まれる切換弁のうちの旋回操作用切換弁を、それぞれ前記圧力補償流量調整手段を構成するブロックに最も近い位置に配置することを特徴とする請求項１４記載の油圧ショベル。The first switching valve group, the pressure-compensated flow rate adjusting means, and the second switching valve group are integrally configured, and a block that configures the first switching valve group and the second switching valve group are provided. A block constituting the pressure compensation flow rate adjusting means is provided between the constituting block and the boom switching valve among the switching valves included in the first switching valve group, and the second switching valve group. The excavator according to claim 14 , wherein the switching valve for turning operation among the switching valves included is arranged at a position closest to a block constituting the pressure compensation flow rate adjusting means.
JP2001094572A 2001-03-29 2001-03-29 Hydraulic control equipment, construction machinery and hydraulic excavators Expired - Fee Related JP4668445B2 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2001094572A JP4668445B2 (en) 2001-03-29 2001-03-29 Hydraulic control equipment, construction machinery and hydraulic excavators
DE2002114089 DE10214089A1 (en) 2001-03-29 2002-03-28 Hydraulic control system for a construction machine, in particular a hydraulic excavator

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2001094572A JP4668445B2 (en) 2001-03-29 2001-03-29 Hydraulic control equipment, construction machinery and hydraulic excavators

Publications (2)

Publication Number Publication Date
JP2002295405A JP2002295405A (en) 2002-10-09
JP4668445B2 true JP4668445B2 (en) 2011-04-13

Family

ID=18948744

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2001094572A Expired - Fee Related JP4668445B2 (en) 2001-03-29 2001-03-29 Hydraulic control equipment, construction machinery and hydraulic excavators

Country Status (2)

Country Link
JP (1) JP4668445B2 (en)
DE (1) DE10214089A1 (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102004005606B3 (en) * 2004-02-05 2005-10-06 Hydac Fluidtechnik Gmbh circuitry
CN100410549C (en) * 2004-12-28 2008-08-13 东芝机械株式会社 Hydraulic control apparatus
JP4081487B2 (en) * 2004-12-28 2008-04-23 東芝機械株式会社 Hydraulic control valve
JP5042471B2 (en) * 2005-06-30 2012-10-03 コベルコ建機株式会社 Hydraulic control equipment for construction machinery
JP4846456B2 (en) * 2006-06-01 2011-12-28 東芝機械株式会社 Hydraulic control valve
EP2569547B1 (en) * 2010-05-11 2019-03-27 Parker-Hannificn Corporation Pressure compensated hydraulic system having differential pressure control
JP6982474B2 (en) * 2017-11-22 2021-12-17 川崎重工業株式会社 Hydraulic drive system

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0526204A (en) * 1991-07-17 1993-02-02 Toshiba Mach Co Ltd Hydraulic driving device
JPH0552204A (en) * 1991-08-22 1993-03-02 Toshiba Mach Co Ltd Hydraulic drive unit
WO1993005301A1 (en) * 1991-09-02 1993-03-18 Hitachi Construction Machinery Co., Ltd. Valve device
JP2000035006A (en) * 1998-07-16 2000-02-02 Kayaba Ind Co Ltd Hydraulic control circuit

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0526204A (en) * 1991-07-17 1993-02-02 Toshiba Mach Co Ltd Hydraulic driving device
JPH0552204A (en) * 1991-08-22 1993-03-02 Toshiba Mach Co Ltd Hydraulic drive unit
WO1993005301A1 (en) * 1991-09-02 1993-03-18 Hitachi Construction Machinery Co., Ltd. Valve device
JP2000035006A (en) * 1998-07-16 2000-02-02 Kayaba Ind Co Ltd Hydraulic control circuit

Also Published As

Publication number Publication date
DE10214089A1 (en) 2002-11-14
JP2002295405A (en) 2002-10-09

Similar Documents

Publication Publication Date Title
JP3689211B2 (en) Flow confluence device for heavy equipment
EP1760326B1 (en) Hydraulic controller for working machine
EP1790859B1 (en) Hydraulic controller for working machine
KR100752115B1 (en) Hydraulic pump control system for an excavator
KR100749316B1 (en) Hydraulic circuit
EP3492661B1 (en) Excavator, and control valve for excavator
JP4668445B2 (en) Hydraulic control equipment, construction machinery and hydraulic excavators
JP2002206508A (en) Hydraulic driving device
JPH08105078A (en) Variable priority device
JP6577431B2 (en) Hydraulic drive unit for construction machinery
JP4229872B2 (en) Hydraulic control device
JP4926627B2 (en) Electric oil system
JP3772982B2 (en) Construction machine remote control valve hydraulic circuit
KR101281232B1 (en) Apparatus for controlling displacement of variable displacement type of hydraulic pump
JP3760055B2 (en) Hydraulic drive control device for construction machinery
JPH04285303A (en) Hydraulic circuit for improving operability in load sensing system
JPH04312630A (en) Hydraulic circuit for construction equipment
JP3705916B2 (en) Hydraulic control device
JP2002089511A (en) Hydraulic circuit for construction equipment
JP3689554B2 (en) Hydraulic control circuit
JPH06264901A (en) Oil pressure control device
JP5110846B2 (en) Load sensing hydraulic controller
JP3798187B2 (en) Hydraulic drive
JP3481675B2 (en) Hydraulic circuit of construction machinery
JP2002021809A (en) Hydraulic circuit for construction machine

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20080311

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20100831

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20100928

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20101126

RD02 Notification of acceptance of power of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7422

Effective date: 20101126

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20110105

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20110113

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20140121

Year of fee payment: 3

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

S111 Request for change of ownership or part of ownership

Free format text: JAPANESE INTERMEDIATE CODE: R313113

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

LAPS Cancellation because of no payment of annual fees