JPH044304A - Hydraulic control circuit - Google Patents
Hydraulic control circuitInfo
- Publication number
- JPH044304A JPH044304A JP10573790A JP10573790A JPH044304A JP H044304 A JPH044304 A JP H044304A JP 10573790 A JP10573790 A JP 10573790A JP 10573790 A JP10573790 A JP 10573790A JP H044304 A JPH044304 A JP H044304A
- Authority
- JP
- Japan
- Prior art keywords
- pilot
- hydraulic
- pressure
- control valve
- valve
- 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.)
- Pending
Links
- 230000007423 decrease Effects 0.000 claims description 12
- 230000007935 neutral effect Effects 0.000 description 9
- 238000010586 diagram Methods 0.000 description 8
- 230000000694 effects Effects 0.000 description 4
- 230000002159 abnormal effect Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- WQGWDDDVZFFDIG-UHFFFAOYSA-N pyrogallol Chemical compound OC1=CC=CC(O)=C1O WQGWDDDVZFFDIG-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
- F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
- F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
- F15B13/042—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure
- F15B13/0422—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure with manually-operated pilot valves, e.g. joysticks
-
- 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
- F15B11/044—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed by means in the return line, i.e. "meter out"
- F15B11/0445—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed by means in the return line, i.e. "meter out" with counterbalance valves, e.g. to prevent overrunning or for braking
-
- 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
- F15B2211/3056—Assemblies of multiple valves
- F15B2211/30565—Assemblies of multiple valves having multiple valves for a single output member, e.g. for creating higher valve function by use of multiple valves like two 2/2-valves replacing a 5/3-valve
- F15B2211/3057—Assemblies of multiple valves having multiple valves for a single output member, e.g. for creating higher valve function by use of multiple valves like two 2/2-valves replacing a 5/3-valve having two valves, one for each port of a double-acting 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
- F15B2211/30—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
- F15B2211/355—Pilot pressure 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
- F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
- F15B2211/41527—Flow control characterised by the connections of the flow control means in the circuit being connected to an output member 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
- F15B2211/40—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
- F15B2211/455—Control of flow in the 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
- F15B2211/50—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
- F15B2211/50518—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
- F15B2211/50527—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 using cross-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
- F15B2211/50545—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using braking valves to maintain a back 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
- F15B2211/50—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
- F15B2211/50—Pressure control
- F15B2211/555—Pressure control for assuring a minimum pressure, e.g. by using a back pressure 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
- F15B2211/635—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
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
- F15B2211/7058—Rotary output members
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Operation Control Of Excavators (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、油圧ショベル等の油圧駆動車両に用いる油圧
モータの油圧制御回路に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hydraulic control circuit for a hydraulic motor used in a hydraulically driven vehicle such as a hydraulic excavator.
〔従来の技術］
従来、この種の油圧制御回路としては、第６図に示され
るものが知られていた。すなわち、図示されない原動機
により駆動される油圧ポンプ１から吐出される圧油は、
油圧パイロット式制御弁２でその方向及び流量が制御さ
れ、カウンタバランス弁３０を介して、油圧モータ３に
供給される。[Prior Art] Conventionally, as this type of hydraulic control circuit, the one shown in FIG. 6 has been known. That is, the pressure oil discharged from the hydraulic pump 1 driven by a prime mover (not shown) is
Its direction and flow rate are controlled by a hydraulic pilot type control valve 2 and supplied to a hydraulic motor 3 via a counterbalance valve 30.
そして、油圧パイロット式制御弁２は、パイロット弁４
からのパイロット圧力によってそのストロク量が制御さ
れる。このパイロット弁４はパイロットポンプ５の吐出
油をレバー４ａの操作量に応じたパイロット圧力として
出力する弁４ｂ、４Ｃを備え、このパイロット圧力がパ
イロット油路４ｄ、４ｅを介して油圧パイロット弐制御
弁２の油圧パイロット室２ｄ、２ｅに供給される。The hydraulic pilot type control valve 2 includes a pilot valve 4.
The stroke amount is controlled by the pilot pressure from. This pilot valve 4 includes valves 4b and 4C that output oil discharged from the pilot pump 5 as pilot pressure according to the operating amount of the lever 4a, and this pilot pressure is applied to the hydraulic pilot control valve 2 via pilot oil passages 4d and 4e. 2 hydraulic pilot chambers 2d and 2e.
第６回の油圧制御回路は、パイロット弁４のレバー４ａ
が操作されていない中立位置にあり、油圧パイロット式
制御弁２及びカウンタバランス弁３０はそれぞれ中立位
置２ｂ、３０ｂにあって、油圧モータ３は停止している
。レバー４ａをＬ方向に操作すると、その操作量に応じ
たパイロット圧力が弁４ｂから出力され、パイロット油
路４ｄを介して油圧パイロット弐制御弁２の油圧パイロ
ット室２ｄに供給され、油圧パイロット弐制御弁２は切
換位置２ａに切り換わり、パイロット圧力に応じた開口
面積までストロークする。同時に、油圧ポンプ１からの
圧油が油路１ａからパイロット油路３０ｄを通りカウン
タバランス弁３０のパイロット弁３０ｆに作用し、カウ
ンタバランス弁３０は切換位置３０ａに切り換えられる
。このため、油圧ポンプ１の圧油は、油路１ａ、３ａを
介して、油圧モータ３に流入する。また、油圧モータ３
からの排出油は、油路３ｂ、カウンタバランス弁３０、
油路１ｂ、油圧パイロット式制御弁２を介して、タンク
６へ流出する。従って油圧モータ３は、Ｒ方向に回転す
る。なお、レバー４ａをＲ方向に操作すると、油圧パイ
ロット式制御弁２が切換位置２Ｃに切り換ると共にカウ
ンタバランス弁３０が切換位置３０ｃに切り換り、油圧
モータ３には油圧ポンプ１からの圧油が前述とは逆に給
排されるので、その回転方向は逆の矢印り方向となる。The sixth hydraulic control circuit is the lever 4a of the pilot valve 4.
is in a neutral position where it is not operated, the hydraulic pilot type control valve 2 and the counterbalance valve 30 are in neutral positions 2b and 30b, respectively, and the hydraulic motor 3 is stopped. When the lever 4a is operated in the L direction, pilot pressure corresponding to the amount of operation is output from the valve 4b, and is supplied to the hydraulic pilot chamber 2d of the hydraulic pilot 2 control valve 2 via the pilot oil passage 4d, thereby controlling the hydraulic pilot 2 control valve 2. The valve 2 switches to the switching position 2a and strokes to the opening area corresponding to the pilot pressure. At the same time, pressure oil from the hydraulic pump 1 passes from the oil path 1a through the pilot oil path 30d and acts on the pilot valve 30f of the counterbalance valve 30, and the counterbalance valve 30 is switched to the switching position 30a. Therefore, the pressure oil of the hydraulic pump 1 flows into the hydraulic motor 3 via the oil passages 1a and 3a. In addition, the hydraulic motor 3
The oil discharged from the oil passage 3b, the counterbalance valve 30,
It flows out into the tank 6 via the oil passage 1b and the hydraulic pilot type control valve 2. Therefore, the hydraulic motor 3 rotates in the R direction. Note that when the lever 4a is operated in the R direction, the hydraulic pilot type control valve 2 is switched to the switching position 2C, and the counterbalance valve 30 is switched to the switching position 30c, so that the hydraulic motor 3 receives the pressure from the hydraulic pump 1. Since oil is supplied and discharged in the opposite direction to that described above, the rotation direction is the opposite direction indicated by the arrow.
上述の油圧制御回路は、油圧駆動車両が坂道を下陳する
時、その自走を防止し、油圧モータ３の走行速度を一定
の値に制御するものである。この制御は、カウンタバラ
ンス弁３０が切換位置３０ａから中立位置３０ｂに切り
換わる途中において、油圧モータ３の排出側の油路３ｂ
とｌｂ（あるいは３ａとｌａ）の間を絞ることで行う。The above-mentioned hydraulic control circuit prevents the hydraulically driven vehicle from running on its own when it descends a slope, and controls the traveling speed of the hydraulic motor 3 to a constant value. This control is performed while the counterbalance valve 30 is being switched from the switching position 30a to the neutral position 30b.
This is done by narrowing down the gap between and lb (or 3a and la).
つまり、カウンタバランス弁３０は、油路１ａ又はｌｂ
から分岐するパイロット油路３０ｄ又は３０ｅに作用す
る油圧と、ハネ３０ｈ又は３０ｉとの押力がバランスす
る所で停止する構成であり、前記した油路３ｂとｌｂ（
あるいは３ａとｌａ）との間の絞りはこの押力をバラン
スさせるような値に決められる。具体的に説明すると、
油圧モータ３がＲ方向に駆動中に同方向に下る坂道にさ
しかかると、油圧モータ３は、自走し始める。すると、
油路３ａ、１ａの油圧が減少するので、パイロット油路
３０ｄの油圧も減少する。カウンタバランス弁３０は、
ハネ３０ｉに押圧され、切換位置３０ａから中立位置３
０ ｂへ復帰し始め、油圧モータ３の排出側の油路３ｂ
と１ｂとの間を絞る。油圧モータ３の排出側が絞られる
と、油路１ａ側の油圧が上昇するので、カウンタバラン
ス弁３０を切換位置３０ａ側に移動させる。In other words, the counterbalance valve 30 is connected to the oil passage 1a or lb
It is configured to stop when the hydraulic pressure acting on the pilot oil passage 30d or 30e branching from the pilot oil passage 30d or 30e and the pushing force of the spring 30h or 30i are balanced.
Alternatively, the aperture between 3a and 1a) is determined to a value that balances this pressing force. To explain specifically,
While the hydraulic motor 3 is driving in the R direction, when it comes to a slope going down in the same direction, the hydraulic motor 3 starts to run on its own. Then,
Since the oil pressure in the oil passages 3a and 1a decreases, the oil pressure in the pilot oil passage 30d also decreases. The counterbalance valve 30 is
Pressed by the spring 30i, from the switching position 30a to the neutral position 3
It begins to return to 0b, and the oil passage 3b on the discharge side of the hydraulic motor 3
Narrow down the gap between and 1b. When the discharge side of the hydraulic motor 3 is throttled, the oil pressure on the oil path 1a side increases, so the counterbalance valve 30 is moved to the switching position 30a side.
油圧駆動車両の走行中にレバー４ａを中立位置に戻すと
、パイロット弁４はパイロットポンプ５からの油圧を遮
断すると共に、油圧パイロット式制御弁２の油圧パイロ
ット室２ｄ又は２ｅとタンク６が連通するので、油圧パ
イロット式制御弁２とカウンタバランス弁３０はそれぞ
れの戻しバネ２（，２ｇ、３０ｈ、３０ｉにより中立位
置２ｂ３０ｂに復帰し、油圧モータ３の排出側が閉しら
れブレーキが働く。油路３ａ、３ｂの間に設けられた逃
がし弁７ａ、７ｂは、油圧モータ３にブレーキが働いた
とき、油圧モータ３を滑らかに停止させるためのもので
ある。つまり、カウンタバランス弁３０が何れかの切換
位置から中立位置に復帰し、油圧モータ３にその駆動方
向の慣性負荷が作用するとき、油圧モータ３がポンプ作
用するが、その吐出側の（Ｒ方向への慣性負荷が作用す
ると、油路３ｂの油圧を制御し、ブレーキ力を発生する
）油圧を制御し油圧モータにブレーキを作用させ、油圧
モータ３を滑らかに停止させ、異常圧の発生を防ぐこと
によって油圧モータ３の破損を防止する。When the lever 4a is returned to the neutral position while the hydraulically driven vehicle is running, the pilot valve 4 cuts off the hydraulic pressure from the pilot pump 5, and the hydraulic pilot chamber 2d or 2e of the hydraulic pilot control valve 2 communicates with the tank 6. Therefore, the hydraulic pilot type control valve 2 and the counterbalance valve 30 are returned to the neutral position 2b30b by the respective return springs 2 (, 2g, 30h, 30i), the discharge side of the hydraulic motor 3 is closed, and the brake is activated. , 3b are provided to smoothly stop the hydraulic motor 3 when the brake is applied to the hydraulic motor 3. In other words, the counterbalance valve 30 is used to switch between the two When the hydraulic motor 3 returns from the position to the neutral position and an inertial load in the driving direction acts on the hydraulic motor 3, the hydraulic motor 3 acts as a pump. The hydraulic motor 3 is prevented from being damaged by controlling the hydraulic pressure (to generate a braking force) and applying a brake to the hydraulic motor to smoothly stop the hydraulic motor 3 and prevent abnormal pressure from occurring.
従来技術で説明した油圧制御回路は、油圧回路に油圧パ
イロット式制御弁２と上記カウンタバランス弁３０を直
列接続する構成となっている。ところで、カウンタバラ
ンス弁３０は、上述したように坂道における油圧モータ
３の自走を防止するためのものであり、通常の走行中に
は必要のないものである。しかしながら、油圧モータ３
の制御回路に介在されたままであるので、回路圧損が大
きく、油圧回路の効率が悪いという問題点を有する。The hydraulic control circuit described in the prior art has a configuration in which the hydraulic pilot type control valve 2 and the counterbalance valve 30 are connected in series to the hydraulic circuit. By the way, the counterbalance valve 30 is for preventing the hydraulic motor 3 from running on a slope as described above, and is not necessary during normal running. However, the hydraulic motor 3
Since it remains interposed in the control circuit of the hydraulic circuit, there are problems in that the circuit pressure loss is large and the efficiency of the hydraulic circuit is poor.
本発明は、上記問題点を解決するためになされたもので
あり、回路圧損を発生させることなく、油圧モータの排
出側を自走の程度に応じて絞り、油圧モータの自走を防
止する油圧制御回路を提供せんとするものである。The present invention has been made in order to solve the above-mentioned problems.The present invention has been made to solve the above-mentioned problems. The purpose is to provide a control circuit.
上記課題を解決するために、本発明の油圧制御回路は、
原動機により駆動される油圧ポンプと、この油圧ポンプ
から吐出される油圧により駆動される油圧モータと、非
作動時には、油圧モータへの流出入油路を閉鎖し、作動
時には、油圧モータを回転させる圧油の流量及び方向を
制御する油圧パイロット式制御弁と、油圧モータの停止
時の高圧発生を防止する逃がし弁と、レバー操作量に応
したパイロット圧力を前記油圧パイロット弐制御弁の油
圧パイロット室に供給するパイロット弁と、を有する油
圧駆動車両の油圧制御回路において、前記油圧パイロッ
ト式制御弁の油圧パイロット室とパイロット弁を継ぐ油
路に、パイロット圧とモータ駆動側圧力とが対抗して作
用するパイロット圧力制御弁を設けこのパイロット圧力
制御弁が、油圧モータの駆動側の油圧による押力と戻し
バネ力との合計の力が、パイロット圧による押力との差
に応じて作動し、前記合計の力がパイロット圧による押
力より小さい時は、パイロット弁とパイロット室間の絞
りを小さくし、パイロット室とタンクの間の絞りを大き
くし、前記合計の力がパイロット圧による押力より大き
い時は、パイロット弁とパイロット室間の絞りを大きく
し、パイロット室とタンクの間の絞りを小さくする切換
位置を有する様にしたものである。In order to solve the above problems, the hydraulic control circuit of the present invention includes:
A hydraulic pump is driven by a prime mover, a hydraulic motor is driven by the hydraulic pressure discharged from this hydraulic pump, and when it is not in operation, the oil flow path to and from the hydraulic motor is closed, and when it is in operation, it is the pressure that rotates the hydraulic motor. A hydraulic pilot type control valve that controls the flow rate and direction of oil, a relief valve that prevents generation of high pressure when the hydraulic motor is stopped, and a pilot pressure corresponding to the amount of lever operation is applied to the hydraulic pilot chamber of the hydraulic pilot second control valve. In a hydraulic control circuit for a hydraulically driven vehicle having a pilot valve, pilot pressure and motor drive side pressure act against each other on an oil passage connecting the hydraulic pilot chamber of the hydraulic pilot type control valve and the pilot valve. A pilot pressure control valve is provided, and the pilot pressure control valve operates according to the difference between the total force of the hydraulic pressure on the driving side of the hydraulic motor and the return spring force, and the pressing force due to the pilot pressure, and the total force is increased. When the force is smaller than the pushing force caused by the pilot pressure, reduce the throttle between the pilot valve and the pilot chamber, and increase the throttle between the pilot chamber and the tank, and when the total force is larger than the pushing force caused by the pilot pressure. The valve has a switching position that increases the restriction between the pilot valve and the pilot chamber and decreases the restriction between the pilot chamber and the tank.
上記の技術的手段を有する本発明は、油圧駆動車両が坂
道を下降する時、パイロット圧力制御弁における油圧モ
ータ駆動側圧力が作用する押力と戻しハネ力との合計の
力が、パイロット圧力が作用する押力よりも小さくなり
、この押力差に応じて、油圧パイロット弐制御弁の油圧
パイロット室への油路を絞ると共に、この油圧パイロッ
ト室の油を絞りを介してタンクへ逃すので、油圧パイロ
ット式制御弁のストロークが変化し、油圧モータの排出
側油路を絞り油圧モータを制御することにより、油圧パ
イロット弐制御弁に従来のカウンタバランス弁の機能を
持たゼたので、油圧モータの油路に介在する弁の数が凍
り、回路圧損が低減する。The present invention having the above-mentioned technical means is such that when a hydraulically driven vehicle descends a slope, the total force of the pushing force exerted by the hydraulic motor drive side pressure in the pilot pressure control valve and the return spring force is reduced by the pilot pressure. It becomes smaller than the pushing force that is applied, and in accordance with this pushing force difference, the oil passage to the hydraulic pilot chamber of the hydraulic pilot two control valve is throttled, and the oil in this hydraulic pilot chamber is released to the tank via the throttle. By changing the stroke of the hydraulic pilot type control valve and controlling the hydraulic motor by throttling the oil passage on the discharge side of the hydraulic motor, the hydraulic pilot control valve 2 has the function of a conventional counterbalance valve. The number of valves in the oil path is frozen, reducing circuit pressure loss.
以下、本発明の油圧制御回路の実施例を、第１図に基づ
いて説明する。第１図において、第６図と異なる点は、
パイロット油路４ｄ、４ｅのそれぞれにパイロット圧力
制御弁８，９が設けられ、油路１ａ、ｌｂとタンク６の
間のタンク通路５ａ。Hereinafter, an embodiment of the hydraulic control circuit of the present invention will be described based on FIG. 1. The difference between Figure 1 and Figure 6 is as follows:
Pilot pressure control valves 8 and 9 are provided in the pilot oil passages 4d and 4e, respectively, and the tank passage 5a is between the oil passages 1a and lb and the tank 6.
６ｂに油圧モータ３へ油を供給する吸い込み弁１０．１
１が設けられた点である。パイロット圧力制御弁８は切
換位置８ａ、８ｂ、８ｃを有し、パイロット室８ｅに作
用するパイロット圧と対抗しつつ、パイロット室８ｄに
作用する油圧モータ駆動圧力及び戻しバネ８ｆの合計の
力によって切り換えられる。なお、パイロット圧力制御
弁９も同し構成となっている。また、油圧モータ３の駆
動を制御する油圧パイロット式制御弁２、レバー４ａの
操作量に応じたパイロット圧を発生するパイロット弁４
及び、油路３ａ、３ｂ間の逃がし弁７ａ、７ｂの構成と
作動は第６図で説明したものと同様であり、第６図と同
じ符号を付してその説明を省略する。Suction valve 10.1 that supplies oil to the hydraulic motor 3 at 6b
1 is provided. The pilot pressure control valve 8 has switching positions 8a, 8b, and 8c, and is switched by the total force of the hydraulic motor drive pressure acting on the pilot chamber 8d and the return spring 8f while opposing the pilot pressure acting on the pilot chamber 8e. It will be done. Note that the pilot pressure control valve 9 also has the same configuration. Additionally, a hydraulic pilot type control valve 2 controls the drive of the hydraulic motor 3, and a pilot valve 4 generates pilot pressure according to the amount of operation of the lever 4a.
The structure and operation of the relief valves 7a and 7b between the oil passages 3a and 3b are the same as those explained in FIG. 6, and the same reference numerals as in FIG. 6 are used to omit the explanation.
つぎに、上述した実施例の作用を以下に説明すレバー４
ａをＬ方向に操作するとその操作量に応したパイロット
圧力がパイロットポンプ５から弁４ｂ、パイロット油路
４ｄ、パイロット圧力制御弁８を通って、油圧パイロッ
ト弐制御弁２の油圧パイロット室２ｄに導かれ、油圧パ
イロット式圧力制御弁２を切換位置２ａに切り換える。Next, the action of the above-mentioned embodiment will be explained below.
When a is operated in the L direction, pilot pressure corresponding to the amount of operation is guided from the pilot pump 5 to the hydraulic pilot chamber 2d of the hydraulic pilot 2 control valve 2 through the valve 4b, the pilot oil passage 4d, and the pilot pressure control valve 8. Then, the hydraulic pilot type pressure control valve 2 is switched to the switching position 2a.
油圧ポンプ１から吐出された油は油路３ａから油圧モー
タ３へ供給され、油圧モータ３をＲの方向に駆動する。Oil discharged from the hydraulic pump 1 is supplied to the hydraulic motor 3 from the oil path 3a, and drives the hydraulic motor 3 in the R direction.
この時パイロット圧力制御弁８はパイロット室８ｅに圧
力が立つことにより、−瞬切換位置８ａから切換位置８
ｂ、８ｃに移ろうとするが、すぐに油路１ａからの油圧
モータ駆動圧が働くため、駆動圧が一定圧以上である場
合には、切換位置８ａを保つ。油圧モータ３から流出し
た油は油路３ｂ、油圧パイロット弐制御弁２、タンク通
路６ｄを通りタンク６に戻る。At this time, the pilot pressure control valve 8 changes from the -instantaneous switching position 8a to the switching position 8 due to the pressure built up in the pilot chamber 8e.
b and 8c, but since the hydraulic motor drive pressure from the oil passage 1a comes into play immediately, if the drive pressure is equal to or higher than a certain pressure, the switching position 8a is maintained. The oil flowing out from the hydraulic motor 3 returns to the tank 6 through the oil passage 3b, the hydraulic pilot control valve 2, and the tank passage 6d.
通常の走行中は油圧モータ３の駆動圧力が一定値以上で
あるため、パイロット圧力制御弁２は切換位置２ａの位
置にあるが、急な坂道などを降りる場合には車両の自重
により車速か上昇し、油圧モータ３の回転が上がり、油
路３ａからの供給油量が不足するようになる。すなわち
、油圧モータ３は外力によりポンプとして働くようにな
り、駆動側の油路３ａの圧力が低下し始め、自走ぎみに
なる。この駆動側の油路３ａの圧力は油路１ａを通って
パイロット圧力制御弁８のパイロット室８ｄに作用して
おり、この押力とハネ８ｆの合計の力がパイロット室８
ｅにおけるパイロット圧力による押圧力よりも小ざくな
ると、パイロット圧力制御弁８は切換位置８ｂに切換わ
る。この切換位置８ｂでは、パイロット油路４ｄから油
圧パイロット室２ｄへの供給が絞り８ｇで絞られると共
に油圧パイロンＩ・室２ｄの油がパイロット圧力制御弁
８の絞り８ｈを通してタンク６へと戻され、油圧パイロ
ット室２ｄの圧力は両絞り８ｇ、８ｈの開度により決め
られる中間圧となり、レバー４ａの操作量により決めら
れたパイロット圧力よりも低下する。パイロット圧力が
低下すると、油圧パイロット沃制御弁２は戻しハネ２ｇ
により、ストロークを減じられ、油圧モータ３からの流
出側油路３ｂを絞り、油圧モータ３に背圧を生しさせる
ことにより、ブレーキ力を発生させ、油圧モータ３の回
転上昇を抑える。油圧モータ３の回転が正常値となり、
油路１ａ′の駆動側圧力の押力と戻しハネ８ｆの合計の
力がパイロット室８ｅのパイロット圧力の押力よりも大
きくなると、パイロ・７１・圧力制御弁８は切換位置８
ａに復帰するので、パイロット室２ｄは、レバー４ａの
操作量により決められたパイロットになり油圧パイロッ
ト式制御弁２は切換位置２ａ位置に復帰する。油路１ａ
′の駆動側の圧力が急に低下した場合、（例えば急な坂
道にかかり、エンジンのスロットルを戻して油圧ポンプ
１の吐出量が低下したような時）などは、パイロット圧
力制御弁８は切換位置８Ｃまで切り換わり、パイロット
油路４ｄのパイロ・７ト圧力の供給を止めると共に油圧
パイロ・ノド室２ｄの圧油をタンク６へ逃がし、すばや
く油圧パイロ７Ｉ・式制御弁２のスプールストロークを
減じて、油圧モータ３の回転上昇を抑える。第２図はこ
のようなパイロット圧力制御弁８，９のストロークと絞
り開度の関係例を示す。During normal driving, the driving pressure of the hydraulic motor 3 is above a certain value, so the pilot pressure control valve 2 is at the switching position 2a, but when going down a steep slope, the vehicle speed may increase due to the vehicle's own weight. However, the rotation of the hydraulic motor 3 increases, and the amount of oil supplied from the oil passage 3a becomes insufficient. That is, the hydraulic motor 3 comes to work as a pump due to external force, and the pressure in the oil passage 3a on the driving side begins to decrease, and the hydraulic motor 3 starts to run on its own. The pressure in the oil passage 3a on the driving side passes through the oil passage 1a and acts on the pilot chamber 8d of the pilot pressure control valve 8, and the total force of this pushing force and the spring 8f is applied to the pilot chamber 8d.
When the pressure becomes smaller than the pressing force due to the pilot pressure at e, the pilot pressure control valve 8 is switched to the switching position 8b. In this switching position 8b, the supply from the pilot oil passage 4d to the hydraulic pilot chamber 2d is throttled by the throttle 8g, and the oil in the hydraulic pylon I/chamber 2d is returned to the tank 6 through the throttle 8h of the pilot pressure control valve 8. The pressure in the hydraulic pilot chamber 2d is an intermediate pressure determined by the opening degrees of both throttles 8g and 8h, and is lower than the pilot pressure determined by the operating amount of the lever 4a. When the pilot pressure decreases, the hydraulic pilot pressure control valve 2 returns 2g of pressure.
This reduces the stroke, throttles the oil passage 3b on the outflow side from the hydraulic motor 3, and generates back pressure in the hydraulic motor 3, thereby generating a braking force and suppressing the increase in rotation of the hydraulic motor 3. The rotation of the hydraulic motor 3 becomes the normal value,
When the total force of the driving side pressure of the oil passage 1a' and the return spring 8f becomes larger than the pushing force of the pilot pressure in the pilot chamber 8e, the pyro 71/pressure control valve 8 moves to the switching position 8.
a, the pilot chamber 2d becomes the pilot determined by the amount of operation of the lever 4a, and the hydraulic pilot type control valve 2 returns to the switching position 2a. Oil passage 1a
When the pressure on the drive side of It switches to position 8C, stops the supply of pyro-7 pressure in the pilot oil passage 4d, releases the pressure oil in the hydraulic pyro-nod chamber 2d to the tank 6, and quickly reduces the spool stroke of the hydraulic pyro-7I control valve 2. This suppresses the increase in rotation of the hydraulic motor 3. FIG. 2 shows an example of the relationship between the stroke and throttle opening of such pilot pressure control valves 8 and 9.
つぎに、これらの自走防止機能が働く場合の油圧パイロ
ット弐制御弁２の作動を、油圧パイロンＩ・式制御弁２
のストロークに対する開口面積の関係を示す第３図及び
第４図により説明する。第３図は、−船釣にメークイン
制御と呼ばれる開口面積線図で油圧モータ３を駆動側の
開口度合により制御する方式である。この場合、油圧モ
ータ３が自走し始め、駆動側油路３ａの圧力が低下し始
めると全速したとおり、パイロット圧力制御弁８が切換
位置８ｂに切換ねり、油圧パイロット室２ｄの圧力を減
し、油圧パイロット式制御弁２のストロークを減少させ
て、油圧モータ３の流出側油路３ｂを絞り、油圧モータ
３に背圧を立たせ、ブレーキをかけようとするが油圧モ
ータ３の駆動側油路３ａに通じる開口面積も減少する。Next, we will explain the operation of the hydraulic pilot 2 control valve 2 when these self-propulsion prevention functions are activated by the hydraulic pylon I type control valve 2.
This will be explained with reference to FIGS. 3 and 4, which show the relationship between the opening area and the stroke. FIG. 3 shows a diagram of the opening area, which is called make-in control for boat fishing, and shows a method in which the hydraulic motor 3 is controlled by the opening degree on the driving side. In this case, when the hydraulic motor 3 begins to run on its own and the pressure in the drive-side oil passage 3a begins to decrease, the pilot pressure control valve 8 switches to the switching position 8b to reduce the pressure in the hydraulic pilot chamber 2d. , the stroke of the hydraulic pilot type control valve 2 is reduced, the outflow side oil passage 3b of the hydraulic motor 3 is throttled, back pressure is built up in the hydraulic motor 3, and an attempt is made to apply the brake, but the drive side oil passage of the hydraulic motor 3 is The opening area leading to 3a also decreases.
その結果油圧モータ３への供給油量が不足し、さらに駆
動側圧力が低下するが駆動側圧力がタンク通路６ａの圧
力よりも低くなると、吸い込み弁１０を通して油が供給
されキャビテーション状態になるのを防止する。駆動側
圧力が急澹に低下すると、パイロット圧力制御弁８は切
換位置８Ｃまで切り換わり、油圧パイロット式制御井２
０ストロークは更に減少し、速やかに流出側油ｆｌ１３
ｂを絞り、ブレーキ作用させることとなる。第４図は一
般的にメータアウト制御と呼ばれる開口面積線図で油圧
モータ３を流出側の開口度合により制御する方式である
。As a result, the amount of oil supplied to the hydraulic motor 3 becomes insufficient and the drive side pressure further decreases, but when the drive side pressure becomes lower than the pressure in the tank passage 6a, oil is supplied through the suction valve 10 and a cavitation state occurs. To prevent. When the drive side pressure drops rapidly, the pilot pressure control valve 8 switches to the switching position 8C, and the hydraulic pilot control well 2
The 0 stroke further decreases, and the oil on the outflow side fl13 immediately
b will be throttled down and the brake will be applied. FIG. 4 shows an opening area diagram generally referred to as meter-out control, which is a system in which the hydraulic motor 3 is controlled by the degree of opening on the outflow side.
この場合、油圧モータ３が自走し始め、駆動側油路３ａ
の圧力が低下し始めると、前述したように、パイ日ノ１
−圧力制御弁８が切換位置８ｂに切り換わり油圧パイロ
ット室２ｄの圧力を滅し、油圧パイロット式制御弁２の
スＩ−ロークを減少させて、油圧モータ３の流出側油路
３ｂを絞り、油圧モータ３に背圧を立たせ、ブレーキを
かけようとする。In this case, the hydraulic motor 3 starts to run by itself, and the drive side oil path 3a
As mentioned above, when the pressure of
- The pressure control valve 8 switches to the switching position 8b, eliminates the pressure in the hydraulic pilot chamber 2d, reduces the stroke of the hydraulic pilot type control valve 2, throttles the outflow side oil passage 3b of the hydraulic motor 3, and Create back pressure on motor 3 and try to apply the brakes.
この場合も油圧モータ３の駆動側油路３ａに通しる開口
面積も減少するが、もともと油圧モータ３の回転速度は
流出側の開口面積で制御されており、駆動側の開口面積
は大きく取っであるので供給油間の不足が生しにくく、
キャビテーション状態にはなりにくい。仮に、供給油量
不足が生じた場合でもメータアウト制御方式で説明した
通り、吸い込の弁１０からの供給がなされキャビテーシ
ョンの発生を防止する。In this case, the opening area of the hydraulic motor 3 passing through the drive side oil passage 3a also decreases, but the rotational speed of the hydraulic motor 3 is originally controlled by the opening area on the outflow side, so the opening area on the drive side cannot be set large. Because of this, shortages between oil supplies are less likely to occur.
Cavitation is unlikely to occur. Even if a shortage of oil supply occurs, oil is supplied from the suction valve 10 to prevent cavitation from occurring, as explained in the meter-out control system.
レバー４ａを中立に戻すと、弁４ｂの供給側は閉塞され
、パイロットポンプ５からの圧油を遮断すると共に、パ
イ日ノ１−油路４ｄをタンク６に通しる。従って、油圧
パイロット室２ｄの油はパイロット圧力制御弁８、パイ
ロット油路４ｄを通り１、タンク６に通じるので、油圧
パイロット式制御弁２のスプールは戻しハネ２ｇにより
中立位置２ｂに復帰し、油圧モータ３の流出側油路３ｂ
を閉塞し、ブレーキ力を発生させ、油圧駆動車両を停止
さセる。この時ブレーキに必要な圧力以上の高圧が油路
３ｂに発生した場合、逃し弁７ａが作用し、油を油路３
ａ側に逃がす。When the lever 4a is returned to the neutral position, the supply side of the valve 4b is closed, cutting off the pressure oil from the pilot pump 5, and passing the pihino 1-oil line 4d to the tank 6. Therefore, the oil in the hydraulic pilot chamber 2d passes through the pilot pressure control valve 8 and the pilot oil passage 4d to the tank 6, so the spool of the hydraulic pilot type control valve 2 returns to the neutral position 2b by the return spring 2g, and the oil pressure Outflow side oil passage 3b of motor 3
occlusion, generates braking force, and stops the hydraulically driven vehicle. At this time, if high pressure higher than the pressure required for the brake is generated in the oil passage 3b, the relief valve 7a is activated and the oil is removed from the oil passage 3b.
Release to side a.
第５図はロジック弁１２〜１６で構成された油圧パイロ
ット弐制御弁１７を用いた第２の実施例である。ロジッ
ク弁１２〜１６はそのハネ室１２ａ−１６ａからタンク
６に通しる排出路１２ｂ〜１６ｂにロジック制御弁２２
〜２６を設け、排出路１２ｂ〜１６ｂを絞ることによっ
てロジック弁１２〜１６が閉し、排出路１２ｂ〜１６ｂ
がタンク６に通じるとロジック弁１２〜１６が開くよう
になっている。そして、ロジック制御弁２２〜２６はパ
イロット弁４′からパイロット圧力制御弁８．９を介し
たパイロット圧力に応して内部通路の絞り開度を変える
構造となっている。FIG. 5 shows a second embodiment using a hydraulic pilot control valve 17 composed of logic valves 12-16. The logic valves 12 to 16 have logic control valves 22 in the discharge passages 12b to 16b leading from the splash chambers 12a to 16a to the tank 6.
- 26 are provided, and the logic valves 12-16 are closed by narrowing the discharge passages 12b-16b, and the discharge passages 12b-16b are closed.
Logic valves 12 to 16 are opened when the flow of water leads to tank 6. The logic control valves 22 to 26 are structured to change the throttle opening degree of the internal passage in response to the pilot pressure from the pilot valve 4' via the pilot pressure control valve 8.9.
この第２の実施例における作動は以下の通りである。パ
イロット弁４′はレバー４ｆの操作量を電圧又は電流の
電気信号に変換し、弁４ｇ、４ｈを電磁操作するもので
あり、レバー４ｆが操作されていない状態では、弁４ｇ
、４ｈはパイロットポンプ５からの油を閉塞し、パイロ
ット油路４ｄ４ｅはタンク６と通している。従って、ロ
ジック弁１２〜１６を制御するロジック制御弁２２〜２
６のパイロット室２２ａ〜２６ａはタンク６と通した図
示の位置となり、ロジック弁１２は全開であり、ロジッ
ク弁１３〜１６は閉じられた状態となっている。油圧ポ
ンプ１からの吐出油はロジック弁１２を通ってタンク６
に戻る。レバー４ｆをＬ方向に操作し、パイロット弁４
ｇを作動させるトレハー操作量に応したパイロット圧が
パイロット油路４ｄに導かれる。パイロット圧はパイロ
ット圧力制御弁８を通って、ロジック制御弁２３２６及
びシャツトル弁２７を通ってロジック制御弁２２のそれ
ぞれのパイロット室２３ａ、２６ａ２２ａに導かれそれ
ぞれのロジック制御弁を作動させる。ロジック制御弁２
２は内部通路を閉じる方向に働き、バネ室１２ａからタ
ンク６に逃げていた油が絞られることにより、バネ室１
２ａに絞りに応した中間圧が発生するためロジック弁１
２の開度が変わり、タンク６に逃げる量が変わり油圧ポ
ンプ１から吐出された油の圧力が上昇する。The operation of this second embodiment is as follows. The pilot valve 4' converts the operating amount of the lever 4f into an electric signal of voltage or current, and electromagnetically operates the valves 4g and 4h. When the lever 4f is not operated, the valve 4g
, 4h block oil from the pilot pump 5, and the pilot oil passage 4d4e passes through the tank 6. Therefore, the logic control valves 22-2 that control the logic valves 12-16
The pilot chambers 22a to 26a of No. 6 are in the illustrated position passing through the tank 6, the logic valve 12 is fully open, and the logic valves 13 to 16 are in a closed state. The oil discharged from the hydraulic pump 1 passes through the logic valve 12 and enters the tank 6.
Return to Operate the lever 4f in the L direction to close the pilot valve 4.
A pilot pressure corresponding to the Trehar operation amount for operating g is guided to the pilot oil passage 4d. The pilot pressure passes through the pilot pressure control valve 8, passes through the logic control valve 2326 and the shuttle valve 27, and is led to each pilot chamber 23a, 26a22a of the logic control valve 22 to operate each logic control valve. logic control valve 2
2 acts in the direction of closing the internal passage, and the oil that had escaped from the spring chamber 12a to the tank 6 is squeezed, thereby causing the spring chamber 1 to close.
Logic valve 1 because an intermediate pressure corresponding to the restriction is generated in 2a.
2 changes, the amount of oil that escapes to the tank 6 changes, and the pressure of the oil discharged from the hydraulic pump 1 increases.
同時に、ロジック弁１３のハネ室１３ａの油がロジック
制御弁２３を通して逃げるので、ロジック弁１３が開き
油圧ポンプ１の圧力油を油路３ａを通して油圧モータ３
に供給し、油圧モータ３はＲ方向に駆動される。一方、
ロジック弁１６はハネ室１６ａがロジック制御弁２６を
通してタンク６に通じるため、油圧モータ３から流出し
た油はロジック弁１６を押しひらき、タンク通路６Ｃを
通ってタンク６に戻る。この状態で自走により油路３ａ
の駆動圧力が低下し始め、パイロット圧力制御弁８にお
ける駆動側油路１ａ’のパイロット室８ｄへの押力と戻
しハネ８ｆの合計の力が、・パイロット油路４ｄのパイ
ロット圧力によるパイロット室８ｅへの押力より小さく
なると、パイロット圧力制御弁８が切換位置８ｂ、８ｃ
へと切り換わり、ロジック制御弁２２．２３．２６のパ
イロット室２２ａ、２３ａ、２６ａの圧力を下げ、ロジ
ック弁１２は開く方向、ロジック弁１３と１６は閉しる
方向に作動する。この動きは第１図の実施例で示した油
圧パイロット式制御弁２と同様であり、同しように油圧
モータ３の回転上昇を抑える。At the same time, the oil in the splash chamber 13a of the logic valve 13 escapes through the logic control valve 23, so the logic valve 13 opens and the pressure oil of the hydraulic pump 1 is passed through the oil path 3a to the hydraulic motor 3.
The hydraulic motor 3 is driven in the R direction. on the other hand,
Since the splash chamber 16a of the logic valve 16 communicates with the tank 6 through the logic control valve 26, the oil flowing out from the hydraulic motor 3 pushes open the logic valve 16 and returns to the tank 6 through the tank passage 6C. In this state, the oil passage 3a is
The driving pressure of the pilot pressure control valve 8 begins to decrease, and the total force of the pushing force of the drive-side oil passage 1a' to the pilot chamber 8d and the return spring 8f in the pilot pressure control valve 8 is... When the pushing force becomes smaller than
The pressure in the pilot chambers 22a, 23a, and 26a of the logic control valves 22, 23, and 26 is reduced, and the logic valve 12 is operated in the opening direction and the logic valves 13 and 16 are operated in the closing direction. This movement is similar to the hydraulic pilot type control valve 2 shown in the embodiment of FIG. 1, and similarly suppresses the increase in rotation of the hydraulic motor 3.
また、吸い込み弁１０．１１はタンク６に通しるタンク
通路６Ｃと油路３ａ、３ｂの間に設けられ、油圧モータ
３への供給油量が不足し駆動側圧力がタンク通路６Ｃの
圧力よりも低くなると、吸い込み弁１０を通して油が供
給されキャビテーション状態になるのを防止する。尚、
ロジック弁１４又は、１６が吸い込み弁を兼ねる場合は
、吸い込み弁１０又は１１は省いても良い。In addition, the suction valve 10.11 is provided between the tank passage 6C that passes through the tank 6 and the oil passages 3a and 3b, and when the amount of oil supplied to the hydraulic motor 3 is insufficient, the drive side pressure becomes lower than the pressure in the tank passage 6C. When it becomes low, oil is supplied through the suction valve 10 to prevent cavitation. still,
If the logic valve 14 or 16 also serves as a suction valve, the suction valve 10 or 11 may be omitted.
本発明は、原動機により駆動される油圧ポンプと、この
油圧ポンプから吐出される油圧により駆動される油圧モ
ータと、非作動時には、油圧モータへの流出入油路を閉
鎖し、作動時には、油圧モータを回転させる圧油の流量
及び方向を制御する油圧パイロット式制御弁と、油圧モ
ータの停止時の高圧発生を防止する逃がし弁と、レバー
操作量に応じたパイロット圧力を前記油圧パイロット弐
制御弁の油圧パイロット室に供給するパイロット弁と、
を有する油圧駆動車両の油圧制御回路において、前記油
圧パイロット弐制御弁の油圧パイロット室とパイロット
弁を継ぐ油路に、パイロット圧とモータ駆動側圧力とが
対抗して作用するパイロット圧力制御弁を設け、このパ
イロット圧力制御弁が、油圧モータ駆動側圧力が作用す
る押力と戻しバネ力との合計の力がパイロット圧が作用
する押力よりも大きい場合は、パイロット弁と油圧パイ
ロット室の油路を開けると共に油圧パイロット室とタン
クとの油路を閉じる位置へと切り換わり、油圧モータ駆
動側圧力が作用する押力と戻しバネ力との合計の力がパ
イロット圧が作用する押力よりよりも小さくなった場合
、押力差に応じて、油圧パイロット室への油路を絞ると
共に油圧パイロット室の油を絞りを介してタンクへ逃す
位置へと切り換わる様にすることによって以下に述べる
効果を奏する。The present invention includes a hydraulic pump driven by a prime mover, a hydraulic motor driven by hydraulic pressure discharged from the hydraulic pump, and an oil passageway into and out of the hydraulic motor when it is not in operation, and which is connected to the hydraulic motor when it is in operation. a hydraulic pilot type control valve that controls the flow rate and direction of the pressure oil that rotates the hydraulic motor; a relief valve that prevents high pressure from being generated when the hydraulic motor is stopped; and a hydraulic pilot type control valve that controls the pilot pressure according to the amount of lever operation. a pilot valve that supplies the hydraulic pilot room;
In the hydraulic control circuit for a hydraulically driven vehicle, a pilot pressure control valve is provided in an oil passage connecting the hydraulic pilot chamber of the second hydraulic pilot control valve and the pilot valve, in which pilot pressure and motor drive side pressure act against each other. If the total force of the pushing force exerted by the hydraulic motor drive side pressure and the return spring force is greater than the pushing force exerted by the pilot pressure, the pilot pressure control valve will close the oil passage between the pilot valve and the hydraulic pilot chamber. At the same time as opening, the oil passage between the hydraulic pilot chamber and the tank is switched to the closed position, and the total force of the pushing force exerted by the hydraulic motor drive side pressure and the return spring force is greater than the pushing force exerted by the pilot pressure. If it becomes smaller, the oil passage to the hydraulic pilot chamber is throttled and the oil in the hydraulic pilot chamber is switched to the position where it is released to the tank via the throttle, depending on the difference in pushing force, thereby achieving the effects described below. play.
油圧モータとポンプとの間に設けた油圧パイロット式制
御弁をメータイン制御又はメータアウト制御とし、この
制御位置の制御をパイロット弁と油圧パイロット式制御
弁の間に設けられたパイロット圧力制御弁で制御し、こ
の制御位置で油圧モータの速度をコントロールする構成
としたので、回路構成が必要最小限となり、回路抵抗が
減少する効果を有する。The hydraulic pilot type control valve installed between the hydraulic motor and the pump is controlled by meter-in or meter-out control, and the control position is controlled by the pilot pressure control valve installed between the pilot valve and the hydraulic pilot type control valve. However, since the speed of the hydraulic motor is controlled at this control position, the circuit configuration is reduced to the necessary minimum, which has the effect of reducing circuit resistance.
第１図は油圧制御回路図、第２図はパイロ、ト圧力制御
弁のメインスプールの開口面積線図、第３図は油圧パイ
ロット式制御弁のメーターイン制御におけるメインスプ
ールの開口面積線図、第４図は油圧パイロット式制御弁
のメーターアウト制御におけるメインスプールの開口面
積線図、第５図は第２の実施例に係る油圧制御回路図、
第６図は従来の油圧制御回路図である。
１・・・油圧ポンプ、
２．１７・・・油圧パイロット式制御弁、２ｄ、２ｅ・
・・油圧パイロット室、
３・・・油圧モータ、
３ａ、３ｂ・・・油路、
４．４′・・・パイロット弁、
４ａ、４ｆ・・・レバー
５・・・パイロットポンプ、６・・・タンク、８．９・
・・パイロット圧力制御弁、
８ｄ ８ｅ・・・パイロット室、
８ｆ・・・戻しバネ、８ｈ・・・絞り。
特許出願人 日本エヤーブレーキ株式会社代理人
弁理士 梶 良 之Fig. 1 is a hydraulic control circuit diagram, Fig. 2 is a diagram of the opening area of the main spool of the pyro-pressure control valve, and Fig. 3 is a diagram of the opening area of the main spool in meter-in control of the hydraulic pilot type control valve. FIG. 4 is a diagram of the opening area of the main spool in meter-out control of a hydraulic pilot type control valve, and FIG. 5 is a hydraulic control circuit diagram according to the second embodiment.
FIG. 6 is a conventional hydraulic control circuit diagram. 1...Hydraulic pump, 2.17...Hydraulic pilot type control valve, 2d, 2e・
...Hydraulic pilot room, 3...Hydraulic motor, 3a, 3b...Oil passage, 4.4'...Pilot valve, 4a, 4f...Lever 5...Pilot pump, 6... Tank, 8.9・
... Pilot pressure control valve, 8d 8e... Pilot chamber, 8f... Return spring, 8h... Throttle. Patent applicant: Japan Air Brake Co., Ltd. Agent
Patent Attorney Yoshiyuki Kaji
Claims (1)
ポンプから吐出される油圧により駆動される油圧モータ
と、非作動時には、油圧モータへの流出入油路を閉鎖し
、作動時には、油圧モータを回転させる圧油の流量及び
方向を制御する油圧パイロット式制御弁と、油圧モータ
の停止時の高圧発生を防止する逃がし弁と、レバー操作
量に応じたパイロット圧力を前記油圧パイロット式制御
弁の油圧パイロット室に供給するパイロット弁と、を有
する油圧駆動車両の油圧制御回路において、 前記油圧パイロット式制御弁の油圧パイロット室とパイ
ロット弁を継ぐ油路に、パイロット圧とモータ駆動側圧
力とが対抗して作用するパイロット圧力制御弁を設けこ
のパイロット圧力制御弁が、油圧モータの駆動側の油圧
による押力と戻しバネ力との合計の力が、パイロット圧
による押力との差に応じて作動し、前記合計の力がパイ
ロット圧による押力より小さい時は、パイロット弁とパ
イロット室間の絞りを小さくし、パイロット室とタンク
の間の絞りを大きくし、前記合計の力がパイロット圧に
よる押力より大きい時は、パイロット弁とパイロット室
間の絞りを大きくし、パイロット室とタンクの間の絞り
を小さくする切換位置を有する事を特徴とする油圧回路
。(1) A hydraulic pump driven by a prime mover and a hydraulic motor driven by the hydraulic pressure discharged from this hydraulic pump. When not in operation, the oil flow passage into and out of the hydraulic motor is closed, and when in operation, the hydraulic motor is closed. A hydraulic pilot type control valve controls the flow rate and direction of the pressurized oil to be rotated, a relief valve prevents generation of high pressure when the hydraulic motor is stopped, and a pilot pressure corresponding to the amount of lever operation is applied to the hydraulic pressure of the hydraulic pilot type control valve. In a hydraulic control circuit for a hydraulically driven vehicle having a pilot valve that supplies a pilot chamber, pilot pressure and motor drive side pressure oppose each other in an oil passage connecting the hydraulic pilot chamber of the hydraulic pilot type control valve and the pilot valve. A pilot pressure control valve is provided, and the pilot pressure control valve operates according to the difference between the total force of the pushing force caused by the hydraulic pressure on the drive side of the hydraulic motor and the force of the return spring, and the pushing force caused by the pilot pressure. , when the total force is smaller than the pushing force due to pilot pressure, reduce the restriction between the pilot valve and the pilot chamber, increase the restriction between the pilot chamber and the tank, and make the total force equal to the pressing force due to the pilot pressure. A hydraulic circuit characterized in that it has a switching position that increases the restriction between the pilot valve and the pilot chamber and decreases the restriction between the pilot chamber and the tank when the amount is larger.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10573790A JPH044304A (en) | 1990-04-20 | 1990-04-20 | Hydraulic control circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10573790A JPH044304A (en) | 1990-04-20 | 1990-04-20 | Hydraulic control circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH044304A true JPH044304A (en) | 1992-01-08 |
Family
ID=14415591
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10573790A Pending JPH044304A (en) | 1990-04-20 | 1990-04-20 | Hydraulic control circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH044304A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006283852A (en) * | 2005-03-31 | 2006-10-19 | Nabtesco Corp | Traveling motor controller of construction machine |
| JP2006283854A (en) * | 2005-03-31 | 2006-10-19 | Nabtesco Corp | Traveling motor controller of construction machine |
| WO2016091528A1 (en) * | 2014-12-08 | 2016-06-16 | Robert Bosch Gmbh | Hydraulic valve arrangement, hydraulic valve block with such a valve arrangement, and hydraulic drive comprising such a valve block |
| JP2019065996A (en) * | 2017-10-03 | 2019-04-25 | 株式会社クボタ | Hydraulic system of work machine |
| US11614808B2 (en) | 2019-04-03 | 2023-03-28 | Wacom Co., Ltd. | Electronic pen |
-
1990
- 1990-04-20 JP JP10573790A patent/JPH044304A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006283852A (en) * | 2005-03-31 | 2006-10-19 | Nabtesco Corp | Traveling motor controller of construction machine |
| JP2006283854A (en) * | 2005-03-31 | 2006-10-19 | Nabtesco Corp | Traveling motor controller of construction machine |
| JP4541211B2 (en) * | 2005-03-31 | 2010-09-08 | ナブテスコ株式会社 | Construction machine travel motor control device |
| WO2016091528A1 (en) * | 2014-12-08 | 2016-06-16 | Robert Bosch Gmbh | Hydraulic valve arrangement, hydraulic valve block with such a valve arrangement, and hydraulic drive comprising such a valve block |
| JP2019065996A (en) * | 2017-10-03 | 2019-04-25 | 株式会社クボタ | Hydraulic system of work machine |
| US11614808B2 (en) | 2019-04-03 | 2023-03-28 | Wacom Co., Ltd. | Electronic pen |
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