JPH0448966B2 - - Google Patents

Info

Publication number
JPH0448966B2
JPH0448966B2 JP59101358A JP10135884A JPH0448966B2 JP H0448966 B2 JPH0448966 B2 JP H0448966B2 JP 59101358 A JP59101358 A JP 59101358A JP 10135884 A JP10135884 A JP 10135884A JP H0448966 B2 JPH0448966 B2 JP H0448966B2
Authority
JP
Japan
Prior art keywords
valve
pilot
pump
flow rate
chamber
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 - Lifetime
Application number
JP59101358A
Other languages
Japanese (ja)
Other versions
JPS60245806A (en
Inventor
Masaaki Myahara
Nobuyuki Nakamura
Masaaki Suhara
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.)
Daikin Industries Ltd
Original Assignee
Daikin Kogyo 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 Daikin Kogyo Co Ltd filed Critical Daikin Kogyo Co Ltd
Priority to JP59101358A priority Critical patent/JPS60245806A/en
Publication of JPS60245806A publication Critical patent/JPS60245806A/en
Publication of JPH0448966B2 publication Critical patent/JPH0448966B2/ja
Granted legal-status Critical Current

Links

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
    • F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
    • F15B11/04—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed
    • F15B11/05—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed specially adapted to maintain constant speed, e.g. pressure-compensated, load-responsive
    • F15B11/055—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed specially adapted to maintain constant speed, e.g. pressure-compensated, load-responsive by adjusting the pump output or bypass
    • 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
    • F15B2211/20—Fluid pressure source, e.g. accumulator or variable axial piston pump
    • F15B2211/205—Systems with pumps
    • F15B2211/20576—Systems with pumps with multiple pumps
    • 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
    • F15B2211/25—Pressure control functions
    • 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
    • F15B2211/265—Control of multiple pressure sources
    • F15B2211/2656—Control of multiple pressure sources by control of the pumps
    • 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
    • F15B2211/315—Directional control characterised by the connections of the valve or valves in the circuit
    • F15B2211/31523—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source and an output member
    • F15B2211/31529—Directional control characterised by the connections of the valve or valves in the circuit being connected to a pressure source and an output member having a single pressure source and a single output member
    • 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
    • F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
    • F15B2211/41572—Flow control characterised by the connections of the flow control means in the circuit being connected to a pressure source and an output member
    • 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
    • F15B2211/635—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements
    • F15B2211/6355—Circuits providing pilot pressure to pilot pressure-controlled fluid circuit elements having valve means
    • 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
    • F15B2211/80—Other types of control related to particular problems or conditions
    • F15B2211/86—Control during or prevention of abnormal conditions
    • F15B2211/8616—Control during or prevention of abnormal conditions the abnormal condition being noise or vibration

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Control Of Positive-Displacement Pumps (AREA)
  • Injection Moulding Of Plastics Or The Like (AREA)

Description

【発明の詳細な説明】 ＜産業上の利用分野＞ この発明は、たとえば射出成形機等に用いれば
好適な合流回路に関する。DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a merging circuit suitable for use in, for example, an injection molding machine.

＜従来技術＞ 従来、たとえば射出成形機に用いる流体回路と
しては、可変ポンプ（可変容量形ポンプ）に接続
したポンプラインに絞り弁を設けると共に、上記
可変ポンプの吐出量制御部に作用させる流体を制
御する制御装置のパイロツト室とバネ室に、上記
絞り弁の前後の圧力を夫々伝達して、上記絞り弁
の前後の差圧に応じて、上記制御装置を作動させ
て、可変ポンプの吐出量制御部をポンプラインま
たはタンクに切換接続して、絞り弁の前後の差圧
が一定になるように、吐出流量を制御することに
より、吐出流量および吐出圧力を要求に応じて制
御し、省エネルギーを図るようにしたものが提案
されている（たとえば、特開昭56−143803号）。<Prior art> Conventionally, for example, a fluid circuit used in an injection molding machine has been equipped with a throttle valve in a pump line connected to a variable pump (variable displacement pump), and a fluid circuit that acts on the discharge amount control section of the variable pump. The pressures before and after the throttle valve are transmitted to the pilot chamber and spring chamber of the control device to be controlled, respectively, and the control device is operated according to the differential pressure before and after the throttle valve to adjust the discharge amount of the variable pump. By connecting the control unit to the pump line or tank and controlling the discharge flow rate so that the differential pressure before and after the throttle valve remains constant, the discharge flow rate and discharge pressure can be controlled as required, saving energy. A method designed to achieve this has been proposed (for example, Japanese Patent Application Laid-open No. 143803/1983).

＜発明が解決しようとする課題＞ ところで、この種の流体回路は可変ポンプが大
容量である場合、その騒音は小容量の可変ポンプ
の騒音に対して容量に比例して増大するのではな
く、急激に増大し、さらに、可変ポンプの吐出量
に対する立ち上がり応答性が、小さな可変ポンプ
のそれに比して急激に悪くなり、さらに、可変ポ
ンプおよびそれを駆動する電動機のコストも容量
に比例する関係ではなく、急激に高くなるという
欠点がある。また、可変ポンプの市販品のサイズ
は段階的になつているため、必要容量に過不足な
く合致したサイズの可変ポンプを選定することが
困難であり、どうしても無駄があつた。<Problems to be Solved by the Invention> By the way, in this type of fluid circuit, when the variable pump has a large capacity, its noise does not increase in proportion to the capacity compared to the noise of a small capacity variable pump. Furthermore, the startup response to the discharge volume of variable pumps suddenly becomes worse than that of small variable pumps, and the cost of variable pumps and the electric motors that drive them are proportional to capacity. However, it has the disadvantage that it increases rapidly. Furthermore, since the sizes of commercially available variable pumps are graded, it is difficult to select a variable pump with a size that exactly matches the required capacity, resulting in waste.

そこで、この発明の目的は騒音を小さくし、立
ち上がり応答性を良くし、コストを低くし、しか
も容量の選定が自由にできるようにすることにあ
る。 Therefore, an object of the present invention is to reduce noise, improve start-up response, reduce cost, and allow for free selection of capacity.

＜課題を解決するための手段＞ 上記目的を達成するため、第１の発明の構成
は、第１図に例示するように、第１可変ポンプ１
に接続したポンプライン２に、上流側より順次第
１チエツク弁４と絞り弁５を設け、 上記第１チエツク弁４よりも上流側のポンプラ
イン２に、パイロツト室７３を接続すると共に、
バネ室７４を絞り１５を有するパイロツトライン
１６を介して接続した第１の圧力制御用パイロツ
ト弁６ｂを設け、 上記第１チエツク弁４よりも上流側のポンプラ
イン２にパイロツト室７１を接続すると共に、上
記絞り弁５の下流側のポンプライン２にバネ室７
２を接続した第１の流量制御用パイロツト弁６ａ
を設け、 上記第１の圧力制御用パイロツト弁６ｂのパイ
ロツト室７３とバネ室７４との流体圧力差に応動
する上記第１の圧力制御用パイロツト弁６ｂの切
換作動によつて、上記第１可変ポンプ１の吐出量
制御部７をポンプライン２または上記第１の流量
制御用パイロツト弁６ａのポートｎに切換接続す
るようになし、 上記第１の流量制御用パイロツト弁６ａのパイ
ロツト室７１とバネ室７２との流体圧力差に応動
する上記第１の流量制御用パイロツト弁６ａの切
換作動によつて、上記第１の流量制御用パイロツ
ト弁６ａの上記ポートｎを上記ポンプライン２と
タンク１３に切換接続するようになし、 上記第１の圧力制御用パイロツト弁６ｂの上記
バネ室７４をパイロツトリリーフ弁２１に接続
し、 上記第１チエツク弁４と上記絞り弁５との間の
ポンプライン２に、中間に第２チエツク弁３２を
有するポンプライン３３を介して第２可変ポンプ
３１を接続し、 上記第２チエツク弁３２よりも上流側のポンプ
ライン３３に、パイロツト室７３′を接続すると
共に、バネ室７４′を絞り１５′を有するパイロツ
トライン１６′を介して接続した第２の圧力制御
用パイロツト弁６b′を設け、 上記第２チエツク弁４よりも上流側のポンプラ
イン３３にパイロツト室７１′を接続すると共に、
上記絞り弁５の下流側のポンプライン２にバネ室
７２′を接続した第２の流量制御用パイロツト弁
６a′を設け、 上記第２の圧力制御用パイロツト弁６b′のパイ
ロツト室７３′とバネ室７４′との流体圧力差に応
動する上記第２の圧力制御用パイロツト弁６b′の
切換作動によつて、上記第２可変ポンプ３１の吐
出量制御部３４をポンプライン３３または上記第
２の流量制御用パイロツト弁６a′のポートｎに切
換接続するようになし、 上記第２の流量制御用パイロツト弁６a′のパイ
ロツト室７１′とバネ室７２′との流体圧力差に応
動する上記第２の流量制御用パイロツト弁６a′の
切換作動によつて、上記第２の流量制御用パイロ
ツト弁６a′の上記ポートｎを上記ポンプライン３
３とタンク１３′に切換接続するようになし、 上記第２の圧力制御用パイロツト弁６b′の上記
バネ室７４′を切換弁６１によつて上記パイロツ
トリリーフ弁２１の上流側またはタンクに切換接
続可能になしたことを特徴とする。<Means for Solving the Problem> In order to achieve the above object, the configuration of the first invention includes a first variable pump 1 as illustrated in FIG.
A first check valve 4 and a throttle valve 5 are sequentially provided from the upstream side on the pump line 2 connected to the pump line 2, and a pilot chamber 73 is connected to the pump line 2 on the upstream side of the first check valve 4,
A first pressure control pilot valve 6b is provided which connects the spring chamber 74 via a pilot line 16 having a throttle 15, and the pilot chamber 71 is connected to the pump line 2 upstream of the first check valve 4. , a spring chamber 7 is provided in the pump line 2 on the downstream side of the throttle valve 5.
2 is connected to the first flow rate control pilot valve 6a.
The first variable pressure control valve 6b is operated in response to the fluid pressure difference between the pilot chamber 73 and the spring chamber 74 of the first pressure control pilot valve 6b. The discharge amount control section 7 of the pump 1 is switchably connected to the pump line 2 or the port n of the first flow rate control pilot valve 6a, and the pilot chamber 71 of the first flow rate control pilot valve 6a is connected to the spring. By switching the first flow rate control pilot valve 6a in response to the fluid pressure difference with the chamber 72, the port n of the first flow rate control pilot valve 6a is connected to the pump line 2 and the tank 13. The spring chamber 74 of the first pressure control pilot valve 6b is connected to the pilot relief valve 21 so as to be connected to the pump line 2 between the first check valve 4 and the throttle valve 5. , a second variable pump 31 is connected via a pump line 33 having a second check valve 32 in the middle, and a pilot chamber 73' is connected to the pump line 33 on the upstream side of the second check valve 32. A second pressure control pilot valve 6b' is provided which is connected to the spring chamber 74' via a pilot line 16' having a throttle 15'. ′ and connect
A second flow control pilot valve 6a' with a spring chamber 72' connected to the pump line 2 on the downstream side of the throttle valve 5 is provided, and a spring chamber 73' of the second pressure control pilot valve 6b' is connected to the spring chamber 72'. By switching the second pressure control pilot valve 6b' which responds to the fluid pressure difference with the chamber 74', the discharge amount control section 34 of the second variable pump 31 is connected to the pump line 33 or the second pressure control valve 6b'. The second valve is connected to port n of the flow rate control pilot valve 6a' and responds to the fluid pressure difference between the pilot chamber 71' and the spring chamber 72' of the second flow rate control pilot valve 6a'. By switching the flow rate control pilot valve 6a', the port n of the second flow rate control pilot valve 6a' is connected to the pump line 3.
3 and a tank 13', and the spring chamber 74' of the second pressure control pilot valve 6b' is switchably connected to the upstream side of the pilot relief valve 21 or to the tank by a switching valve 61. It is characterized by what has been made possible.

また、第２の発明の構成は、第２図に例示する
ように、第１可変ポンプ１に接続したポンプライ
ン２に、上流側より順次第１チエツク弁４と絞り
弁５を設け、 上記第１チエツク弁４よりも上流側のポンプラ
イン２にパイロツト室７１を接続すると共に、上
記絞り弁５の下流側のポンプライン２にバネ室７
２を接続した第１の流量制御用パイロツト弁６ａ
を設け、 上記第１の流量制御用パイロツト弁６ａのパイ
ロツト室７１とバネ室７２との流体圧力差に応動
する上記第１の流量制御用パイロツト弁６ａの切
換作動によつて、上記第１可変ポンプ１の吐出量
制御部７を上記ポンプライン２とタンク１３に切
換接続するようになし、 上記第１の流量制御用パイロツト弁６ａの上記
バネ室７４をパイロツトリリーフ弁２１に接続
し、 上記第１チエツク弁４と上記絞り弁５との間の
ポンプライン２に、中間に第２チエツク弁３２を
有するポンプライン３３を介して第２可変ポンプ
３１を接続し、 上記第２チエツク弁３２よりも上流側のポンプ
ライン３３にパイロツト室７１′を接続すると共
に、バネ室７２′を切換弁６１によつて上記パイ
ロツトリリーフ弁２１の上流側またはタンクに切
換接続可能になした第２の流量制御用パイロツト
弁６a′を設けて、 上記第２の流量制御用パイロツト弁６a′のパイ
ロツト室７１′とバネ室７２′との流体圧力差に応
動する上記第２の流量制御用パイロツト弁６ａの
切換作動によつて、上記第２の可変ポンプ１の吐
出量制御部３４を上記ポンプライン３３とタンク
１３′に切換接続するようになしたことを特徴と
する。 Further, the configuration of the second invention is such that, as illustrated in FIG. A pilot chamber 71 is connected to the pump line 2 upstream of the check valve 4, and a spring chamber 7 is connected to the pump line 2 downstream of the throttle valve 5.
2 is connected to the first flow rate control pilot valve 6a.
is provided, and by the switching operation of the first flow rate control pilot valve 6a responsive to the fluid pressure difference between the pilot chamber 71 and the spring chamber 72 of the first flow rate control pilot valve 6a, the first variable The discharge amount control section 7 of the pump 1 is switchably connected to the pump line 2 and the tank 13, the spring chamber 74 of the first flow rate control pilot valve 6a is connected to the pilot relief valve 21, and the A second variable pump 31 is connected to the pump line 2 between the first check valve 4 and the throttle valve 5 via a pump line 33 having a second check valve 32 in the middle. A second flow rate control system in which a pilot chamber 71' is connected to the pump line 33 on the upstream side, and a spring chamber 72' can be connected to the upstream side of the pilot relief valve 21 or to a tank by means of a switching valve 61. A pilot valve 6a' is provided, and a switching operation of the second flow rate control pilot valve 6a is performed in response to a fluid pressure difference between a pilot chamber 71' and a spring chamber 72' of the second flow rate control pilot valve 6a'. Accordingly, the discharge amount control section 34 of the second variable pump 1 is selectively connected to the pump line 33 and the tank 13'.

＜作用＞ 第１の発明によれば、流量制御時、第１、第２
可変ポンプ１，３１の各吐出流体が、夫々第１、
第２チエツク弁４，３２を通つて合流させられ、
逆流が防止され、絞り弁５に供給され、上記第
１、第２可変ポンプ１，３１の吐出流量は夫々第
１、第２の流量制御用パイロツト弁６ａ，６a′で
制御されて、絞り弁５の前後の差圧が一定に制御
されて、省エネルギーが達成され、上記第１、第
２可変ポンプ１，３１の組合せで、騒音が低減さ
れ、立ち上がり応答性が迅速にされ、容量の選択
が自在にされる。<Operation> According to the first invention, when controlling the flow rate, the first and second
Each discharge fluid of the variable pumps 1 and 31 is
are merged through the second check valves 4 and 32,
Backflow is prevented and the flow is supplied to the throttle valve 5, and the discharge flow rates of the first and second variable pumps 1 and 31 are controlled by the first and second flow control pilot valves 6a and 6a', respectively. The differential pressure before and after pump 5 is controlled to be constant, thereby achieving energy saving, and the combination of the first and second variable pumps 1 and 31 reduces noise, quickens start-up response, and allows selection of capacity. be freed.

また、圧力制御時、切換弁６１によつて第２の
圧力制御用パイロツト弁６b′のバネ室７４′をタ
ンクに接続して第２可変ポンプ３１をアンロード
し、パイロツトリリーフ弁２１と第１の圧力制御
用パイロツト弁６ｂを介して第１可変ポンプ１の
吐出流体のみによつて圧力制御され、不要の圧力
が発生せず、リーク、騒音、動力損失が少なくな
り、また個別の電動機で可変ポンプを駆動する場
合は、アンロードする可変ポンプ１，３１を駆動
する電動機をオフとすることも可能である。 Also, during pressure control, the spring chamber 74' of the second pressure control pilot valve 6b' is connected to the tank by the switching valve 61, the second variable pump 31 is unloaded, and the pilot relief valve 21 and the first The pressure is controlled only by the fluid discharged from the first variable pump 1 through the pressure control pilot valve 6b, so unnecessary pressure is not generated, and leaks, noise, and power loss are reduced. When driving the pump, it is also possible to turn off the electric motor that drives the variable pumps 1 and 31 to be unloaded.

また、第２の発明によれば、流量制御時、第
１、第２可変ポンプ１，３１の各吐出流体が、
夫々第１、第２チエツク弁４，３２を通つて合流
させられ、逆流が防止され、絞り弁５に供給さ
れ、上記第１、第２可変ポンプ１，３１の吐出流
量は夫々第１、第２の流量制御用パイロツト弁６
ａ，６a′で制御されて、絞り弁５の前後の差圧が
一定に制御されて、省エネルギーが達成され、上
記第１、第２可変ポンプ１，３１の組合せで、騒
音が低減され、立ち上がり応答性が迅速にされ、
容量の選択が自在にされる。 Further, according to the second invention, during flow rate control, each discharge fluid of the first and second variable pumps 1 and 31 is
The discharge flow rates of the first and second variable pumps 1 and 31 are combined through the first and second check valves 4 and 32, respectively, to prevent backflow and are supplied to the throttle valve 5. 2 pilot valve 6 for flow control
a and 6a', the differential pressure before and after the throttle valve 5 is controlled to be constant, achieving energy saving, and the combination of the first and second variable pumps 1 and 31 reduces noise and increases the startup speed. Responsiveness is quick and
Capacity can be freely selected.

また、圧力制御時、切換弁６１によつて第２の
流量制御用パイロツト弁６ａのバネ室７２′をタ
ンクに接続し、第２可変ポンプ３１をアンロード
し、パイロツトリリーフ弁２１と第１の流量制御
用パイロツト弁６ａを介して第１可変ポンプ１の
吐出流体のみによつて圧力制御され、不要の圧力
が発生せず、リーク、騒音、動力損失が少なくな
り、また個別の電動機で可変ポンプを駆動する場
合は、アンロードする可変ポンプ１，３１を駆動
する電動機をオフとすることも可能である。 Also, during pressure control, the spring chamber 72' of the second flow control pilot valve 6a is connected to the tank by the switching valve 61, the second variable pump 31 is unloaded, and the pilot relief valve 21 and the first The pressure is controlled only by the fluid discharged from the first variable pump 1 via the flow rate control pilot valve 6a, eliminating unnecessary pressure and reducing leakage, noise, and power loss. When driving the variable pumps 1 and 31, it is also possible to turn off the electric motors that drive the variable pumps 1 and 31 to be unloaded.

＜実施例＞ 以下、この発明を図示の実施例により詳細に説
明する。<Examples> The present invention will be described in detail below with reference to illustrated examples.

第１図において、１は第１可変ポンプ、２は第
１可変ポンプ１と油圧シリンダ３とを接続するポ
ンプライン、４と５はポンプライン２に上流側よ
り順次介設した第１チエツク弁と絞り弁、６は第
１可変ポンプ１の斜板制御シリンダからなる吐出
量制御部７をポンプライン２またはタンク１３に
切換接続して、第１可変ポンプ１の吐出流量を制
御する第１制御装置である。 In FIG. 1, 1 is a first variable pump, 2 is a pump line that connects the first variable pump 1 and a hydraulic cylinder 3, and 4 and 5 are first check valves that are sequentially interposed in the pump line 2 from the upstream side. A throttle valve 6 is a first control device that controls the discharge flow rate of the first variable pump 1 by switchingly connecting the discharge rate control unit 7 consisting of a swash plate control cylinder of the first variable pump 1 to the pump line 2 or the tank 13. It is.

上記第１制御装置６は、３ポート形絞り切換弁
よりなる流量制御用パイロツト弁６ａと圧力制御
用パイロツト弁６ｂとの組み合わせにより構成し
ている。 The first control device 6 is constituted by a combination of a flow rate control pilot valve 6a and a pressure control pilot valve 6b, each of which is a three-port throttle switching valve.

上記流量制御用パイロツト弁６ａの両端のパイ
ロツト室７１とバネ室７２とには、夫々絞り弁５
の前後の圧力をパイロツトライン８と９を介して
伝えている。また上記流量制御用パイロツト弁６
ａのパイロツト室７１およびポートｌならびに上
記圧力制御用パイロツト弁６ｂのパイロツト室７
３およびポートｌには上記パイロツトライン８を
介して第１チエツク弁４の前位の圧力を伝えてい
る。上記圧力制御用パイロツト弁６ｂのバネ室７
４には、中間に絞り１５を設置したライン１６を
介して上記パイロツトライン８を接続している。
また上記圧力制御用パイロツト弁６ｂのポートｎ
はパイロツトライン１７を介して第１可変ポンプ
１の吐出量制御部７に接続すると共に、圧力制御
用パイロツト弁６ｂのポートｍは流量制御用パイ
ロツト弁６ａのポートｎに接続し、さらに流量制
御用パイロツト弁６ａのポートｍとタンク１３と
をパイロツトライン１２を介して接続している。 A throttle valve 5 is provided in a pilot chamber 71 and a spring chamber 72 at both ends of the flow control pilot valve 6a, respectively.
The pressure before and after is transmitted through pilot lines 8 and 9. In addition, the pilot valve 6 for controlling the flow rate is
The pilot chamber 71 and port l of a and the pilot chamber 7 of the pressure control pilot valve 6b.
3 and port 1, the pressure in front of the first check valve 4 is transmitted through the pilot line 8. Spring chamber 7 of the pressure control pilot valve 6b
4 is connected to the pilot line 8 through a line 16 having a throttle 15 installed in the middle.
Also, port n of the pressure control pilot valve 6b
is connected to the discharge amount control section 7 of the first variable pump 1 via the pilot line 17, and the port m of the pilot valve 6b for pressure control is connected to the port n of the pilot valve 6a for flow rate control. Port m of pilot valve 6a and tank 13 are connected via pilot line 12.

また、上記流量制御用パイロツト弁６ａのバネ
室７２には、パイロツトリリーフ弁２１をパイロ
ツトライン２２を介して接続している。 Further, a pilot relief valve 21 is connected to the spring chamber 72 of the flow rate control pilot valve 6a via a pilot line 22.

したがつて、油圧シリンダ３に対する速度制御
時すなわち流量制御時においては、上記パイロツ
トリリーフ弁２１は設定圧力となつていないの
で、圧力制御用パイロツト弁６ｂは、パイロツト
室７３とバネ室７４の両圧力が同一となつてシン
ボル位置V2に位置している。そして、流量制御
用パイロツト弁６ａはそのパイロツト室７１とバ
ネ室７２との差圧、すなわち絞り弁５の前後の差
圧に応じてシンボル位置V1に位置したり、シン
ボル位置V2に位置したりして、可変ポンプ１の
吐出量制御部７に対する流体を制御して、可変ポ
ンプ１の吐出量を制御し、絞り弁５の前後の差圧
を一定に保持し、無駄な流体を吐出することがな
く、省エネルギーを達成する。また、油圧シリン
ダ３がストロークエンド等で停止している圧力制
御時には、絞り弁５には流体が流れず、絞り弁５
の前後の圧力が同じとなるので、流量制御用パイ
ロツト弁６ａはそのバネ室のバネ力によりシンボ
ル位置V2に位置している。そして、パイロツト
ライン２２の圧力はパイロツトリリーフ弁２１の
設定圧力となつており、圧力制御用パイロツト弁
６ｂはシンボル位置V1やV2に位置して、余剰流
体を発生させることなく第１可変ポンプ１の吐出
量を制御して、ポンプライン２の圧力を一定の圧
力に保持し、省エネルギーを達成する。 Therefore, when controlling the speed of the hydraulic cylinder 3, that is, controlling the flow rate, the pilot relief valve 21 is not at the set pressure, so the pressure control pilot valve 6b maintains both the pressure in the pilot chamber 73 and the spring chamber 74. are identical and located at symbol position V2 . The flow control pilot valve 6a is positioned at the symbol position V1 or at the symbol position V2 depending on the differential pressure between the pilot chamber 71 and the spring chamber 72, that is, the differential pressure before and after the throttle valve 5. The fluid to the discharge amount control unit 7 of the variable pump 1 is controlled to control the discharge amount of the variable pump 1, the differential pressure before and after the throttle valve 5 is kept constant, and wasteful fluid is discharged. Achieve energy savings without any problems. Furthermore, during pressure control when the hydraulic cylinder 3 is stopped at the stroke end or the like, fluid does not flow to the throttle valve 5 and the throttle valve 5
Since the pressures before and after are the same, the flow control pilot valve 6a is located at the symbol position V2 by the spring force of its spring chamber. The pressure of the pilot line 22 is the set pressure of the pilot relief valve 21, and the pressure control pilot valve 6b is located at the symbol position V1 or V2 , and the first variable pump is operated without generating surplus fluid. By controlling the discharge amount of pump line 1, the pressure of pump line 2 is maintained at a constant pressure, thereby achieving energy saving.

このように、第１制御装置６を流量制御用パイ
ロツト弁６ａと圧力制御用パイロツト弁６ｂとで
構成し、流量制御と圧力制御を流量制御用パイロ
ツト弁６ａと圧力制御用パイロツト弁６ｂとによ
り別々に行なうと、その両制御が正確になり、負
荷側から見ての圧力オーバライド特性が良好にな
る。 In this way, the first control device 6 is composed of the pilot valve 6a for flow rate control and the pilot valve 6b for pressure control, and the flow control and pressure control are performed separately by the pilot valve 6a for flow rate control and the pilot valve 6b for pressure control. If this is done, both controls will be accurate and the pressure override characteristics seen from the load side will be good.

一方、上記第１チエツク弁４と絞り弁５との間
のポンプライン２には、中間に第２チエツク弁３
２を有するポンプライン３３を介して第２可変ポ
ンプ３１を接続している。上記第２可変ポンプ３
１の吐出量制御部３４は、第１制御装置６と全く
同じ構造をした第２制御装置６′によつてポンプ
ライン３３とタンク１３′とに切換接続して、第
２可変ポンプ３１の吐出量を制御して、流量制御
時に絞り弁５の前後の差圧を一定に制御するよう
にしている。上記第２制御装置６′の圧力制御用
パイロツト弁６b′のバネ室７４′には、中間に２
位置形の切換弁６１を有するパイロツトライン３
６を介してパイロツトリリーフ弁２１の上流側に
接続している。上記切換弁６１はシンボル位置S1
でパイロツトライン３６を開く一方、シンボル位
置S2で圧力制御用パイロツト弁６b′のバネ室をタ
ンク６２に連通させると共に、上記圧力制御用パ
イロツト弁６ｂと６b′の両バネ室の間の連通を断
つようにしている。そして、切換弁６１がシンボ
ル位置S1に存して、圧力制御用パイロツト弁６ｂ
と６b′の両バネ室が連通している際には、圧力制
御用パイロツト弁６ｂと６b′は全く同じように動
作する。 On the other hand, in the pump line 2 between the first check valve 4 and the throttle valve 5, there is a second check valve 3 in the middle.
A second variable pump 31 is connected via a pump line 33 having two pump lines. The second variable pump 3
The discharge amount control section 34 of the first variable pump 31 is connected to the pump line 33 and the tank 13' by a second control device 6' having the same structure as the first control device 6, and controls the discharge amount of the second variable pump 31. By controlling the amount, the differential pressure across the throttle valve 5 is controlled to be constant during flow rate control. The spring chamber 74' of the pressure control pilot valve 6b' of the second control device 6' has two valves located in the middle.
Pilot line 3 with position type switching valve 61
6 to the upstream side of the pilot relief valve 21. The above switching valve 61 is at symbol position S 1
While opening the pilot line 36 at symbol position S2 , the spring chamber of the pressure control pilot valve 6b' is communicated with the tank 62 at the symbol position S2, and communication between the spring chambers of the pressure control pilot valves 6b and 6b' is established. I try to cut it off. Then, the switching valve 61 is in the symbol position S1 , and the pressure control pilot valve 6b is
When the spring chambers 6b and 6b' are in communication, the pressure control pilot valves 6b and 6b' operate in exactly the same way.

また、第１チエツク弁４と絞り弁５との間のポ
ンプライン２から、タンク４１に向けて分流ライ
ン４３を分流させ、この分流ライン４３にサージ
圧吸収弁４５を介設して、ポンプライン２のサー
ジ圧を吸収するようにしている。このサージ圧吸
収弁４５のバネ室にはパイロツトライン４６を介
して、パイロツトリリーフ弁２１の上流側のパイ
ロツトライン２２を接続している。このサージ圧
吸収弁４５の設定圧はパイロツトリリーフ弁２１
の設定圧よりも高くしている。 In addition, a branch line 43 is branched from the pump line 2 between the first check valve 4 and the throttle valve 5 toward the tank 41, and a surge pressure absorption valve 45 is interposed in this branch line 43. It is designed to absorb the surge pressure of 2. The spring chamber of this surge pressure absorption valve 45 is connected to the pilot line 22 on the upstream side of the pilot relief valve 21 via a pilot line 46. The set pressure of this surge pressure absorption valve 45 is the same as that of the pilot relief valve 21.
The pressure is higher than the set pressure.

上記サージ圧吸収弁４５はサージ圧吸収の機能
を果すほか、ポンプライン２の圧抜き時にも使用
される。 The surge pressure absorption valve 45 has the function of absorbing surge pressure, and is also used when the pump line 2 is depressurized.

上記構成の合流回路は次のように動作する。 The confluence circuit having the above configuration operates as follows.

いま、切換弁６１をシンボル位置S1に位置させ
て、パイロツトライン３６を開き、そして油圧シ
リンダ３がストローク途中で走行している流量制
御状態にあるとすると、第１、第２可変ポンプ
１，３１からの吐出流体は夫々第１、第２チエツ
ク弁４，３２を通つて合流し、絞り弁５に供給さ
れ、そして油圧シリンダ３に供給される。 Now, assuming that the switching valve 61 is located at the symbol position S1 , the pilot line 36 is opened, and the hydraulic cylinder 3 is in a flow rate control state in which it is running in the middle of its stroke, the first and second variable pumps 1, The fluid discharged from the pump 31 passes through the first and second check valves 4 and 32, joins together, is supplied to the throttle valve 5, and is then supplied to the hydraulic cylinder 3.

このとき、第１制御装置６の流量制御用パイロ
ツト弁６ａは吐出量制御部７をポンプライン２ま
たはタンク１３に切換接続して、第１可変ポンプ
１の吐出流量を絞り弁５の前後の差圧を一定にす
るように制御し、また、第２制御装置６′の流量
制御用パイロツト弁６a′も吐出量制御部３４をポ
ンプライン３３またはタンク１３′に切換接続し
て、第２可変ポンプ３１の吐出流量を絞り弁５の
前後の差圧を一定にするように制御し、第１、第
２可変ポンプ１，３１とも余分な流体を吐出する
ことがないので省エネルギー効果を達成する。そ
して、第１、第２可変ポンプ１，３１は、小容量
であるため、それら全体の発生する騒音は、それ
らの全体容量を有する一個の大容量の可変ポンプ
の発する騒音に比して、遥かに小さくなつてい
る。また、第１、第２可変ポンプ１，３１は小容
量であるため、始動時の立ち上がり応答性は大容
量の一個の可変ポンプよりも迅速である。また、
この始動時等の過渡時において、第１、第２可変
ポンプ１，３１の作動状態に相異があつて、両者
の吐出口の圧力に相異があつても、第１、第２チ
エツク弁４，３２が第１、第２可変ポンプ１，３
１のポンプライン２，３３に存するため、流体が
第１または第２可変ポンプ１，３１に向けて逆流
することがなく、系が安定である。 At this time, the flow rate control pilot valve 6a of the first control device 6 switches and connects the discharge amount control section 7 to the pump line 2 or the tank 13, so that the discharge flow rate of the first variable pump 1 is controlled by the difference between before and after the throttle valve 5. The pressure is controlled to be constant, and the flow rate control pilot valve 6a' of the second control device 6' is also connected to the discharge rate control section 34 to the pump line 33 or the tank 13', so that the second variable pump The discharge flow rate of the pump 31 is controlled so as to keep the differential pressure before and after the throttle valve 5 constant, and since neither the first nor the second variable pump 1, 31 discharges excess fluid, an energy saving effect is achieved. Since the first and second variable pumps 1 and 31 have a small capacity, the noise generated by them as a whole is far greater than the noise generated by a single large-capacity variable pump having the overall capacity. It is getting smaller. Furthermore, since the first and second variable pumps 1 and 31 have small capacities, the start-up response at startup is faster than that of a single large-capacity variable pump. Also,
During this transient period such as startup, even if the operating states of the first and second variable pumps 1 and 31 are different and the pressures at their discharge ports are different, the first and second check valves 4 and 32 are the first and second variable pumps 1 and 3
1, the fluid does not flow back toward the first or second variable pump 1 or 31, and the system is stable.

また、このように小容量の第１、第２可変ポン
プ１，３１を組み合わせているため、可変ポンプ
自体およびそれを駆動する電動機の各コストが、
一個の大容量の可変ポンプを用いる場合に比して
安くなり、また、実際の要求に合致した最適な容
量サイズを選定でき、容量の選定に対する柔軟性
を得ることができる。 In addition, since the first and second variable pumps 1 and 31 of small capacity are combined in this way, the costs of the variable pump itself and the electric motor that drives it are reduced.
It is cheaper than using a single large-capacity variable pump, and the optimum capacity size that meets actual requirements can be selected, providing flexibility in capacity selection.

次に、この合流回路の前述の状態で油圧シリン
ダ３が停止し、力のみを出しているたとえば射出
成形機の樹脂の加工保持行程等のような圧力制御
状態にあるとする。 Next, let us assume that the hydraulic cylinder 3 is stopped in the above-described state of this merging circuit and is in a pressure control state in which only force is being output, such as during the processing and holding stroke of resin in an injection molding machine.

この圧力制御状態に移行した直後に、切換弁６
１をシンボル位置S2に切換えて、第２制御装置
６′の圧力制御用パイロツト弁６b′のバネ室７
４′をタンク６２に連通させ、かつ、圧力制御用
パイロツト弁６ｂと６b′の両バネ室間の連通を断
つ。 Immediately after transitioning to this pressure control state, the switching valve 6
1 to the symbol position S2 , and the spring chamber 7 of the pressure control pilot valve 6b' of the second control device 6' is switched to the symbol position S2.
4' is communicated with the tank 62, and the communication between the spring chambers of the pressure control pilot valves 6b and 6b' is cut off.

このとき、油圧シリンダ３が停止し、絞り弁５
に流体が流れず、絞り弁５の前後の圧力が同一と
なるので、第１制御装置６の流量制御用パイロツ
ト弁６ａはそのバネ室のバネ力によりシンボル位
置V2に位置している。そして、パイロツトライ
ン２２の圧力はパイロツトリリーフ弁２１の設定
圧力となつており、圧力制御用パイロツト弁６ｂ
はシンボル位置V1やV2に位置して、第１可変ポ
ンプ１の吐出量を制御して、ポンプライン２の圧
力を一定に保持し、省エネルギーを達成する。 At this time, the hydraulic cylinder 3 stops and the throttle valve 5
Since no fluid flows and the pressures before and after the throttle valve 5 are the same, the flow control pilot valve 6a of the first control device 6 is located at the symbol position V2 by the spring force of its spring chamber. The pressure of the pilot line 22 is the set pressure of the pilot relief valve 21, and the pressure of the pilot valve 6b for pressure control is set to the pressure of the pilot relief valve 21.
is located at the symbol position V 1 or V 2 to control the discharge amount of the first variable pump 1 to maintain the pressure of the pump line 2 constant and achieve energy saving.

一方、第２制御装置６′の圧力制御用パイロツ
ト弁６b′のバネ室７４′は、切換弁６１によつて
タンク６２に連通している。したがつて、上記圧
力制御用パイロツト弁６b′は、そのバネ室７４′
の流体圧、つまりタンク圧よりも、パイロツト室
７３′つまりポンプライン３３の圧力がバネ室７
４′のバネのバネ圧だけ高くなるように、つまり
ポンプライン３３の圧力が極く低圧になるように
シンボル位置V1やV2に位置して吐出量制御部３
４をポンプライン３３またはタンク１３′に切換
接続する。すなわち、第２可変ポンプ３１はアン
ロード運転を行なう。このように、第２可変ポン
プ３１が圧力制御時、アンロードして不要の圧力
を発生させないため、リーク、騒音が少なくな
り、また、エネルギー損失も少なくなる。 On the other hand, the spring chamber 74' of the pressure control pilot valve 6b' of the second control device 6' communicates with the tank 62 through the switching valve 61. Therefore, the pressure control pilot valve 6b' has its spring chamber 74'
The pressure in the pilot chamber 73', that is, the pump line 33, is higher than the fluid pressure in the spring chamber 73', that is, the tank pressure.
The discharge amount control unit 3 is located at the symbol position V 1 or V 2 so that the spring pressure of the spring 4' becomes high, that is, the pressure of the pump line 33 becomes extremely low.
4 to the pump line 33 or tank 13'. That is, the second variable pump 31 performs an unload operation. In this way, since the second variable pump 31 does not unload and generate unnecessary pressure during pressure control, leakage and noise are reduced, and energy loss is also reduced.

なお、このとき、第２チエツク弁３２は、圧力
差により閉鎖し、第１制御装置６による圧力制御
に悪影響を与えることがなく、また第２制御装置
６′の流量制御用パイロツト弁６a′はそのパイロ
ツト室７１′とバネ室７２′に作用する流圧の圧力
差により、シンボル位置V2に位置している。 At this time, the second check valve 32 is closed due to the pressure difference, so that the pressure control by the first control device 6 is not adversely affected, and the flow rate control pilot valve 6a' of the second control device 6' is closed. Due to the pressure difference between the fluid pressures acting on the pilot chamber 71' and the spring chamber 72', it is located at the symbol position V2 .

このように、切換弁６１、チエツク弁３２によ
り、第１可変ポンプ１側と第２可変ポンプ３１側
との連絡を断つことができるので、第１、第２可
変ポンプ１，３１を図示しないが、個別の電動機
で駆動する場合は、圧力制御時に第２可変ポンプ
３１側の電動機をオフにして、さらにエネルギー
効率を向上できる。 In this way, the switching valve 61 and the check valve 32 can cut off the communication between the first variable pump 1 side and the second variable pump 31 side, so although the first and second variable pumps 1 and 31 are not shown in the figure, In the case of driving with separate electric motors, energy efficiency can be further improved by turning off the electric motor on the second variable pump 31 side during pressure control.

上記実施例では、第１、第２制御装置６，６′
として流量制御用パイロツト弁６ａ，６a′と圧力
制御用パイロツト弁６ｂ，６b′の２つのものより
構成したが、第２図に示すように、上記流量制御
用パイロツト弁６ａ，６a′と同一構造をなす一個
の流量制御用パイロツト弁６ａ，６a′のみにより
構成してもよい。すなわち、ポートｌ，ｍは夫々
上記実施例と同様に接続する一方、ポートｎはパ
イロツトライン１７，１７′を介して可変ポンプ
１，３１の吐出量制御部７，３４に接続し、パイ
ロツト室はパイロツトライン８，８′を介して第
１チエツク弁４、第２チエツク弁３２の前位のポ
ンプライン２，３に接続する一方、流量制御用パ
イロツト弁６ａのバネ室７２はパイロツトリリー
フ弁２１を設けたパイロツトライン２２を介して
タンク２３に接続する。他の構成は第１図に示す
実施例と同様である。なお第２図において圧力制
御時のパイロツトリリーフ弁２１への制御流量の
供給は通路９，９′を介して行なわれるため絞り
１５，１５′と通路１６，１６′を省略してもよ
く、また両方を備えてもよい。そして、この流量
制御用パイロツト弁６ａは、パイロツトライン２
２の圧力がパイロツトリリーフ弁２１の設定圧に
なつていない流量制御時には、シンボル位置V1
やV2に位置して、第１可変ポンプ１の吐出量を
制御し、絞り弁５の前後の差圧を一定に制御し、
また、油圧シリンダ３がストロークエンドに行つ
て、パイロツトリリーフ弁２１が動作している圧
力制御時には、可変ポンプ１の吐出量を極く小量
に制御して、可変ポンプ１の吐出圧力を略一定値
に制御する。また、第２可変ポンプ３１は、切換
弁６１がシンボル位置S2に位置されると、アンロ
ード運転する。 In the above embodiment, the first and second control devices 6, 6'
As shown in FIG. 2, it is constructed from two pilot valves 6a, 6a' for flow rate control and pilot valves 6b, 6b' for pressure control, but as shown in FIG. It may also be configured with only one pilot valve 6a, 6a' for controlling the flow rate. That is, ports l and m are connected in the same manner as in the above embodiment, while port n is connected to the discharge amount control units 7 and 34 of variable pumps 1 and 31 via pilot lines 17 and 17', and the pilot chamber is The first check valve 4 and the second check valve 32 are connected to the pump lines 2 and 3 in front of them via the pilot lines 8 and 8', while the spring chamber 72 of the pilot valve 6a for flow rate control is connected to the pilot relief valve 21. It is connected to a tank 23 via a pilot line 22 provided. The other configurations are similar to the embodiment shown in FIG. In FIG. 2, since the control flow rate is supplied to the pilot relief valve 21 during pressure control through the passages 9 and 9', the throttles 15 and 15' and the passages 16 and 16' may be omitted; You may have both. The flow rate control pilot valve 6a is connected to the pilot line 2.
During flow control when the pressure of 2 has not reached the set pressure of the pilot relief valve 21, the symbol position V 1
and V2 to control the discharge amount of the first variable pump 1 and to keep the differential pressure across the throttle valve 5 constant.
Also, during pressure control when the hydraulic cylinder 3 reaches the stroke end and the pilot relief valve 21 is operating, the discharge amount of the variable pump 1 is controlled to an extremely small amount to keep the discharge pressure of the variable pump 1 approximately constant. Control to value. Further, the second variable pump 31 performs an unload operation when the switching valve 61 is located at the symbol position S2 .

上記実施例は、第１、第２可変ポンプ１，３
１、第１、第２チエツク弁４，３２および第１、
第２制御装置６，６′を有する２系統のものであ
るが、可変ポンプ、チエツク弁、制御装置を各々
３個以上設けて、３系統以上にしてもよいのは勿
論である。 In the above embodiment, the first and second variable pumps 1 and 3
1, first and second check valves 4, 32 and first,
Although this is a two-system system including the second control devices 6 and 6', it is of course possible to provide three or more variable pumps, check valves, and control devices to provide three or more systems.

＜発明の効果＞ 以上の説明で明らかなように、第１、第２の発
明によれば、第１、第２可変ポンプの各吐出流体
を、夫々第１、第２チエツク弁を介して合流させ
て、絞り弁に供給すると共に、上記第１、第２可
変ポンプの吐出流量を第１、第２の流量制御用パ
イロツト弁で制御して、絞り弁の前後の差圧を一
定にするようにしているので、省エネルギー効果
を達成できる上に、騒音を低減でき、安定性を保
持した上で立ち上がり応答性を迅速にでき、コス
トを低減でき、容量の選択を自在にできる。<Effects of the Invention> As is clear from the above description, according to the first and second inventions, the fluids discharged from the first and second variable pumps are combined via the first and second check valves, respectively. At the same time, the discharge flow rates of the first and second variable pumps are controlled by the first and second flow control pilot valves to maintain a constant pressure difference across the throttle valve. This makes it possible to achieve energy saving effects, reduce noise, maintain stability and quick start-up response, reduce costs, and make it possible to freely select the capacity.

また、第１、第２の発明によれば、圧力制御時
に切換弁によつて第２可変ポンプをアンロードし
て、第１可変ポンプのみによつて圧力制御できる
ので、不要の圧力を発生させることがなく、リー
ク、騒音、動力損失をさらに少なくでき、また個
別の電動機で可変ポンプを駆動する場合は、アン
ロードする可変ポンプを駆動する電動機をオフと
することもでき、エネルギー効率を極めて向上で
きる。 Further, according to the first and second inventions, the second variable pump is unloaded by the switching valve during pressure control, and the pressure can be controlled only by the first variable pump, so unnecessary pressure is not generated. This reduces leakage, noise, and power loss even further, and if a separate electric motor is used to drive the variable pump, the electric motor driving the unloading variable pump can be turned off, greatly improving energy efficiency. can.

【図面の簡単な説明】[Brief explanation of drawings]

第１図はこの発明の一実施例の回路図、第２図
は変形例の回路図である。 １……第１可変ポンプ、２，３３……ポンプラ
イン、４……第１チエツク弁、５……絞り弁、６
……第１制御装置、６′……第２制御装置、３１
……第２可変ポンプ、３２……第２チエツク弁、
６１……切換弁。 FIG. 1 is a circuit diagram of one embodiment of the invention, and FIG. 2 is a circuit diagram of a modified example. 1... First variable pump, 2, 33... Pump line, 4... First check valve, 5... Throttle valve, 6
...First control device, 6'...Second control device, 31
...Second variable pump, 32...Second check valve,
61...Switching valve.

Claims (1)

【特許請求の範囲】 １ 第１可変ポンプ１に接続したポンプライン２
に、上流側より順次第１チエツク弁４と絞り弁５
を設け、 上記第１チエツク弁４よりも上流側のポンプラ
イン２に、パイロツト室７３を接続すると共に、
バネ室７４を絞り１５を有するパイロツトライン
１６を介して接続した第１の圧力制御用パイロツ
ト弁６ｂを設け、 上記第１チエツク弁４よりも上流側のポンプラ
イン２にパイロツト室７１を接続すると共に、上
記絞り弁５の下流側のポンプライン２にバネ室７
２を接続した第１の流量制御用パイロツト弁６ａ
を設け、 上記第１の圧力制御用パイロツト弁６ｂのパイ
ロツト室７３とバネ室７４との流体圧力差に応動
する上記第１の圧力制御用パイロツト弁６ｂの切
換作動によつて、上記第１可変ポンプ１の吐出量
制御部７をポンプライン２または上記第１の流量
制御用パイロツト弁６ａのポートｎに切換接続す
るようになし、 上記第１の流量制御用パイロツト弁６ａのパイ
ロツト室７１とバネ室７２との流体圧力差に応動
する上記第１の流量制御用パイロツト弁６ａの切
換作動によつて、上記第１の流量制御用パイロツ
ト弁６ａの上記ポートｎを上記ポンプライン２と
タンク１３に切換接続するようになし、 上記第１の圧力制御用パイロツト弁６ｂの上記
バネ室７４をパイロツトリリーフ弁２１に接続
し、 上記第１チエツク弁４と上記絞り弁５との間の
ポンプライン２に、中間に第２チエツク弁３２を
有するポンプライン３３を介して第２可変ポンプ
３１を接続し、 上記第２チエツク弁３２よりも上流側のポンプ
ライン３３に、パイロツト室７３′を接続すると
共に、バネ室７４′を絞り１５′を有するパイロツ
トライン１６′を介して接続した第２の圧力制御
用パイロツト弁６b′を設け、 上記第２チエツク弁４よりも上流側のポンプラ
イン３３にパイロツト室７１′を接続すると共に、
上記絞り弁５の下流側のポンプライン２にバネ室
７２′を接続した第２の流量制御用パイロツト弁
６a′を設け、 上記第２の圧力制御用パイロツト弁６b′のパイ
ロツト室７３′とバネ室７４′との流体圧力差に応
動する上記第２の圧力制御用パイロツト弁６b′の
切換作動によつて、上記第２可変ポンプ３１の吐
出量制御部３４をポンプライン３３または上記第
２の流量制御用パイロツト弁６a′のポートｎに切
換接続するようになし、 上記第２の流量制御用パイロツト弁６a′のパイ
ロツト室７１′とバネ室７２′との流体圧力差に応
動する上記第２の流量制御用パイロツト弁６a′の
切換作動によつて、上記第２の流量制御用パイロ
ツト弁６a′の上記ポートｎを上記ポンプライン３
３とタンク１３′に切換接続するようになし、 上記第２の圧力制御用パイロツト弁６b′の上記
バネ室７４′を切換弁６１によつて上記パイロツ
トリリーフ弁２１の上流側またはタンクに切換接
続可能になした合流回路。 ２ 第１可変ポンプ１に接続したポンプライン２
に、上流側より順次第１チエツク弁４と絞り弁５
を設け、 上記第１チエツク弁４よりも上流側のポンプラ
イン２にパイロツト室７１を接続すると共に、上
記絞り弁５の下流側のポンプライン２にバネ室７
２を接続した第１の流量制御用パイロツト弁６ａ
を設け、 上記第１の流量制御用パイロツト弁６ａのパイ
ロツト室７１とバネ室７２との流体圧力差に応動
する上記第１の流量制御用パイロツト弁６ａの切
換作動によつて、上記第１可変ポンプ１の吐出量
制御部７を上記ポンプライン２とタンク１３に切
換接続するようになし、 上記第１の流量制御用パイロツト弁６ａの上記
バネ室７４をパイロツトリリーフ弁２１に接続
し、 上記第１チエツク弁４と上記絞り弁５との間の
ポンプライン２に、中間に第２チエツク弁３２を
有するポンプライン３３を介して第２可変ポンプ
３１を接続し、 上記第２チエツク弁３２よりも上流側のポンプ
ライン３３にパイロツト室７１′を接続すると共
に、バネ室７２′を切換弁６１によつて上記パイ
ロツトリリーフ弁２１の上流側またはタンクに切
換接続可能になした第２の流量制御用パイロツト
弁６a′を設けて、 上記第２の流量制御用パイロツト弁６a′のパイ
ロツト室７１′とバネ室７２′との流体圧力差に応
動する上記第２の流量制御用パイロツト弁６a′の
切換作動によつて、上記第２の可変ポンプ１の吐
出量制御部３４を上記ポンプライン３３とタンク
１３′に切換接続するようになした合流回路。[Claims] 1. Pump line 2 connected to first variable pump 1
1 check valve 4 and throttle valve 5 in order from the upstream side.
A pilot chamber 73 is connected to the pump line 2 on the upstream side of the first check valve 4, and
A first pressure control pilot valve 6b is provided which connects the spring chamber 74 via a pilot line 16 having a throttle 15, and the pilot chamber 71 is connected to the pump line 2 upstream of the first check valve 4. , a spring chamber 7 is provided in the pump line 2 on the downstream side of the throttle valve 5.
2 is connected to the first flow rate control pilot valve 6a.
The first variable pressure control valve 6b is operated in response to the fluid pressure difference between the pilot chamber 73 and the spring chamber 74 of the first pressure control pilot valve 6b. The discharge amount control section 7 of the pump 1 is switchably connected to the pump line 2 or the port n of the first flow rate control pilot valve 6a, and the pilot chamber 71 of the first flow rate control pilot valve 6a is connected to the spring. By switching the first flow rate control pilot valve 6a in response to the fluid pressure difference with the chamber 72, the port n of the first flow rate control pilot valve 6a is connected to the pump line 2 and the tank 13. The spring chamber 74 of the first pressure control pilot valve 6b is connected to the pilot relief valve 21 so as to be connected to the pump line 2 between the first check valve 4 and the throttle valve 5. , a second variable pump 31 is connected via a pump line 33 having a second check valve 32 in the middle, and a pilot chamber 73' is connected to the pump line 33 on the upstream side of the second check valve 32. A second pressure control pilot valve 6b' is provided which is connected to the spring chamber 74' via a pilot line 16' having a throttle 15'. ′ and connect
A second flow control pilot valve 6a' with a spring chamber 72' connected to the pump line 2 on the downstream side of the throttle valve 5 is provided, and a spring chamber 73' of the second pressure control pilot valve 6b' is connected to the spring chamber 72'. By switching the second pressure control pilot valve 6b' which responds to the fluid pressure difference with the chamber 74', the discharge amount control section 34 of the second variable pump 31 is connected to the pump line 33 or the second pressure control valve 6b'. The second valve is connected to port n of the flow rate control pilot valve 6a' and responds to the fluid pressure difference between the pilot chamber 71' and the spring chamber 72' of the second flow rate control pilot valve 6a'. By switching the flow rate control pilot valve 6a', the port n of the second flow rate control pilot valve 6a' is connected to the pump line 3.
3 and a tank 13', and the spring chamber 74' of the second pressure control pilot valve 6b' is switchably connected to the upstream side of the pilot relief valve 21 or to the tank by a switching valve 61. A merging circuit made possible. 2 Pump line 2 connected to the first variable pump 1
1 check valve 4 and throttle valve 5 in order from the upstream side.
A pilot chamber 71 is connected to the pump line 2 upstream of the first check valve 4, and a spring chamber 7 is connected to the pump line 2 downstream of the throttle valve 5.
2 is connected to the first flow rate control pilot valve 6a.
is provided, and by the switching operation of the first flow rate control pilot valve 6a responsive to the fluid pressure difference between the pilot chamber 71 and the spring chamber 72 of the first flow rate control pilot valve 6a, the first variable The discharge amount control section 7 of the pump 1 is switchably connected to the pump line 2 and the tank 13, the spring chamber 74 of the first flow control pilot valve 6a is connected to the pilot relief valve 21, and the A second variable pump 31 is connected to the pump line 2 between the first check valve 4 and the throttle valve 5 via a pump line 33 having a second check valve 32 in the middle. A second flow rate control system in which a pilot chamber 71' is connected to the pump line 33 on the upstream side, and a spring chamber 72' can be connected to the upstream side of the pilot relief valve 21 or to a tank by means of a switching valve 61. A pilot valve 6a' is provided, and the second flow rate control pilot valve 6a' is switched in response to a fluid pressure difference between a pilot chamber 71' and a spring chamber 72' of the second flow rate control pilot valve 6a'. A confluence circuit configured to selectively connect the discharge amount control section 34 of the second variable pump 1 to the pump line 33 and the tank 13' upon operation.
JP59101358A 1984-05-18 1984-05-18 Converging circuit Granted JPS60245806A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP59101358A JPS60245806A (en) 1984-05-18 1984-05-18 Converging circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59101358A JPS60245806A (en) 1984-05-18 1984-05-18 Converging circuit

Publications (2)

Publication Number Publication Date
JPS60245806A JPS60245806A (en) 1985-12-05
JPH0448966B2 true JPH0448966B2 (en) 1992-08-10

Family

ID=14298608

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59101358A Granted JPS60245806A (en) 1984-05-18 1984-05-18 Converging circuit

Country Status (1)

Country Link
JP (1) JPS60245806A (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0689747B2 (en) * 1986-10-30 1994-11-14 日精樹脂工業株式会社 Control device of injection molding machine
JPH0792061B2 (en) * 1986-10-30 1995-10-09 日精樹脂工業株式会社 Control device of injection molding machine
JP4548488B2 (en) * 2008-01-22 2010-09-22 ダイキン工業株式会社 Merge control system

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5659005A (en) * 1979-10-22 1981-05-22 Kobe Steel Ltd Controller for hydraulic circuit including plural variable-capacity pumps in parallel
JPS58187601A (en) * 1982-04-26 1983-11-01 Daikin Ind Ltd Combined hydraulic circuit
JPS5934003A (en) * 1982-08-14 1984-02-24 Daikin Ind Ltd Hydraulic conflux circuit
JPS5949002B2 (en) * 1982-12-28 1984-11-30 タラカベルモント株式会社 Shampoo ball device

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5949002U (en) * 1982-09-25 1984-03-31 内田油圧機器工業株式会社 Unloading circuit device for variable displacement hydraulic pump equipped with constant pressure regulator

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5659005A (en) * 1979-10-22 1981-05-22 Kobe Steel Ltd Controller for hydraulic circuit including plural variable-capacity pumps in parallel
JPS58187601A (en) * 1982-04-26 1983-11-01 Daikin Ind Ltd Combined hydraulic circuit
JPS5934003A (en) * 1982-08-14 1984-02-24 Daikin Ind Ltd Hydraulic conflux circuit
JPS5949002B2 (en) * 1982-12-28 1984-11-30 タラカベルモント株式会社 Shampoo ball device

Also Published As

Publication number Publication date
JPS60245806A (en) 1985-12-05

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