JPH08258579A - Transmission for hydrostatic transmission vehicle - Google Patents
Transmission for hydrostatic transmission vehicleInfo
- Publication number
- JPH08258579A JPH08258579A JP6577795A JP6577795A JPH08258579A JP H08258579 A JPH08258579 A JP H08258579A JP 6577795 A JP6577795 A JP 6577795A JP 6577795 A JP6577795 A JP 6577795A JP H08258579 A JPH08258579 A JP H08258579A
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- pressure receiving
- switching valve
- hydraulic motors
- receiving portion
- 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
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
- F16H61/38—Control of exclusively fluid gearing
- F16H61/40—Control of exclusively fluid gearing hydrostatic
- F16H61/42—Control of exclusively fluid gearing hydrostatic involving adjustment of a pump or motor with adjustable output or capacity
- F16H61/423—Motor capacity control by fluid pressure control means
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、油圧ショベルなどの油
圧駆動車の走行用の油圧モータの容量を増減して走行速
度を高速、低速の２段に変速する変速装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission for changing the traveling speed between high speed and low speed by increasing or decreasing the capacity of a hydraulic motor for running a hydraulically driven vehicle such as a hydraulic excavator.
【０００２】[0002]
【従来の技術】油圧駆動車としては油圧ポンプの吐出圧
油を左右の走行用の油圧モータに供給して回転駆動し、
それによって左右の走行体を駆動して走行するものが知
られている。2. Description of the Related Art As a hydraulically driven vehicle, the hydraulic fluid discharged from a hydraulic pump is supplied to left and right traveling hydraulic motors for rotational driving.
It is known that the left and right traveling bodies are driven thereby to travel.
【０００３】このような油圧駆動車において走行速度を
高速、低速の２段に変速する変速装置としては種々のも
のが知られている。例えば、左右の走行用の油圧モータ
を可変容量型の油圧モータとし、その容量を制御する容
量制御部材に圧油を供給する走行速度切換弁と、左右の
走行用の油圧モータの駆動圧を検出する圧力センサと、
前記走行速度切換弁に切換信号を出力するコントローラ
を設け、圧力センサで検出した駆動圧が高圧の時には容
量を大として低速とし、低圧の時には容量を小として高
速としている。Various types of transmissions for changing the traveling speed of the hydraulically driven vehicle to two speeds, high speed and low speed, are known. For example, the left and right traveling hydraulic motors are variable displacement hydraulic motors, and the traveling speed switching valve that supplies pressure oil to the displacement control member that controls the displacement and the driving pressures of the left and right traveling hydraulic motors are detected. Pressure sensor,
A controller that outputs a switching signal to the traveling speed switching valve is provided, and when the driving pressure detected by the pressure sensor is high, the capacity is large and low speed, and when the driving pressure is low, the capacity is small and high speed.
【０００４】つまり、走行用の油圧モータの容量が大で
あると１回転に要する流量が多くなるので、油圧ポンプ
より供給される流量が一定であれば走行用の油圧モータ
は低速回転となって走行速度が低速となり、走行用の油
圧モータの容量が小であると１回転に要する流量が少な
くなるので、油圧ポンプより供給される流量が一定であ
れば走行用の油圧モータは高速回転となって走行速度が
高速となる。That is, if the displacement of the traveling hydraulic motor is large, the flow rate required for one rotation is large. Therefore, if the flow rate supplied from the hydraulic pump is constant, the traveling hydraulic motor will rotate at a low speed. If the traveling speed becomes low and the capacity of the traveling hydraulic motor is small, the flow rate required for one rotation decreases. Therefore, if the flow rate supplied from the hydraulic pump is constant, the traveling hydraulic motor will rotate at high speed. The traveling speed becomes high.
【０００５】[0005]
【発明が解決しようとする課題】かかる変速装置である
と、左右の走行用の油圧モータの駆動圧をコントローラ
に送り、そのコントローラが駆動圧が設定した圧力より
高圧か低圧を判断して切換信号を出力しており、コント
ローラの誤動作などにより走行用の油圧モータの容量が
正しく設定されないことがあって信頼性が悪いものとな
る。In such a transmission, the drive pressure of the left and right traveling hydraulic motors is sent to the controller, and the controller determines whether the drive pressure is higher or lower than the set pressure, and the switching signal is sent. Is output, the capacity of the hydraulic motor for traveling may not be set correctly due to malfunction of the controller, resulting in poor reliability.
【０００６】また、前述のように駆動圧の高圧、低圧を
判断して切換信号を出力するコントローラを必要とし、
そのコントローラは大変高価となるので変速装置が高価
となる。Further, as described above, the controller which judges the high pressure or the low pressure of the driving pressure and outputs the switching signal is required.
The controller is very expensive and therefore the transmission is expensive.
【０００７】そこで、本発明は前述の課題を解決できる
ようにした油圧駆動車の変速装置を提供することを目的
とする。Therefore, an object of the present invention is to provide a transmission device for a hydraulically driven vehicle that can solve the above-mentioned problems.
【０００８】[0008]
【課題を解決するための手段】油圧ポンプ１の吐出圧油
を左・右方向制御弁２，３により走行用の左・右油圧モ
ータ４，５に供給して走行する油圧駆動車において、前
記左・右油圧モータ４，５を可変容量型の油圧モータと
し、受圧室１４に圧油が供給されると左・右油圧モータ
４，５の容量を小とし、受圧室１４の圧油がタンクに流
出すると左・右油圧モータ４，５の容量を大とする左・
右の容量制御シリンダ１２と、制御用油圧ポンプ１５の
吐出圧油を前記左・右の容量制御シリンダ１２の受圧室
１４に供給する供給位置Ｆとその受圧室１４をタンクに
連通するドレーン位置Ｇに切換えられる切換弁と、前記
左・右油圧モータ４，５の駆動圧における高い方の駆動
圧を検出する高圧優先弁３１とを設け、前記切換弁をス
プリング２５で供給位置Ｆに押し、かつ受圧部２８の圧
力でドレーン位置Ｇに押すものとし、その受圧部２８を
前記高圧優先弁３１の出力側に接続した油圧駆動車の変
速装置。[Means for Solving the Problems] In a hydraulically driven vehicle that travels by supplying discharged hydraulic fluid from a hydraulic pump 1 to left and right hydraulic motors 4 and 5 for traveling by means of left and right direction control valves 2 and 3, When the left and right hydraulic motors 4 and 5 are variable displacement hydraulic motors and the pressure oil is supplied to the pressure receiving chamber 14, the left and right hydraulic motors 4 and 5 are reduced in capacity, and the pressure oil in the pressure receiving chamber 14 is stored in the tank. When it leaks to the left / right hydraulic motors 4, 5 increase the capacity of the left /
A supply position F for supplying pressure oil discharged from the right displacement control cylinder 12 and the control hydraulic pump 15 to the pressure receiving chamber 14 of the left and right displacement control cylinders 12 and a drain position G for connecting the pressure receiving chamber 14 to the tank. And a high pressure priority valve 31 for detecting the higher drive pressure of the left and right hydraulic motors 4, 5 are provided, and the change valve is pushed to the supply position F by the spring 25, and A transmission for a hydraulically driven vehicle in which the pressure of the pressure receiving portion is pushed to the drain position G, and the pressure receiving portion is connected to the output side of the high pressure priority valve 31.
【０００９】[0009]
【作 用】左・右油圧モータ４，５の駆動圧が高圧の
時には切換弁がドレーン位置Ｇとなって左・右の容量制
御シリンダ１２の受圧室１４内の圧油がタンクに流出し
て容量が大となり、左・右油圧モータ４，５の駆動圧が
低圧の時には切換弁が供給位置Ｆとなって左右の容量制
御シリンダ１２の受圧室１４に制御用油圧ポンプ１５の
吐出圧油が供給されて容量が小となるから、左・右油圧
モータ４，５の駆動圧が高圧の時には低速回転となって
走行速度が低速となり、低圧の時には高速回転となって
走行速度が高速となる。[Operation] When the driving pressure of the left and right hydraulic motors 4 and 5 is high, the switching valve becomes the drain position G and the pressure oil in the pressure receiving chamber 14 of the left and right capacity control cylinders 12 flows out to the tank. When the displacement becomes large and the driving pressure of the left and right hydraulic motors 4 and 5 is low, the switching valve becomes the supply position F and the discharge pressure oil of the control hydraulic pump 15 is supplied to the pressure receiving chambers 14 of the left and right displacement control cylinders 12. When the driving pressure of the left and right hydraulic motors 4 and 5 is high, the speed is low and the running speed is low, and when the pressure is low, the running speed is low and the running speed is high. .
【００１０】[0010]
【実 施 例】図１に示すように、油圧ポンプ１の吐出
圧油は左・右方向制御弁２，３により走行用の左・右油
圧モータ４，５に供給され、その左・右油圧モータ４，
５により図示しない左・右走行体を駆動して走行するよ
うにしてある。[Example] As shown in Fig. 1, the discharge pressure oil of the hydraulic pump 1 is supplied to the left and right hydraulic motors 4 and 5 for traveling by the left and right direction control valves 2 and 3, and the left and right hydraulic pressures are Motor 4,
The left and right running bodies (not shown) are driven by 5 to run.
【００１１】前記左・右方向制御弁２，３はポンプポー
ト６、タンクポート７、第１アクチュエータポート８、
第２アクチュエータポート９、負荷圧検出ポート１０を
有し、中立位置Ａ、第１圧油供給位置Ｂ、第２圧油供給
位置Ｃにパイロット圧、ソレノイド、手動等によって切
換えられる。The left and right direction control valves 2 and 3 are a pump port 6, a tank port 7, a first actuator port 8,
It has a second actuator port 9 and a load pressure detection port 10, and can be switched to a neutral position A, a first pressure oil supply position B, and a second pressure oil supply position C by pilot pressure, solenoid, manual operation or the like.
【００１２】左・右方向制御弁２，３が中立位置Ａの時
には各ポートが遮断して左・右油圧モータ４，５は停止
する。When the left / right directional control valves 2, 3 are in the neutral position A, the ports are shut off and the left / right hydraulic motors 4, 5 are stopped.
【００１３】左・右方向制御弁２，３が第１圧油供給位
置Ｂの時にはポンプポート６が第１アクチュエータポー
ト８に連通し、かつ絞りを経て負荷圧検出ポート１０に
連通し、第２アクチュエータポート９がタンクポート７
に連通して左・右油圧モータ４，５は一方向に回転駆動
し、その駆動圧が負荷圧検出ポート１０に検出される。When the left / right directional control valves 2 and 3 are in the first pressure oil supply position B, the pump port 6 communicates with the first actuator port 8 and also communicates with the load pressure detection port 10 via the throttle, Actuator port 9 is tank port 7
The left and right hydraulic motors 4 and 5 are driven to rotate in one direction in communication with the load pressure detection port 10.
【００１４】左・右方向制御弁２，３が第２圧油供給位
置Ｃの時にはポンプポート６が第２アクチュエータポー
ト９に連通し、かつ絞りを経て負荷圧検出ポート１０に
連通し、第１アクチュエータポート８がタンクポート７
に連通して左・右油圧モータ４，５は他方向に回転駆動
し、その駆動圧が負荷圧検出ポート１０に検出される。When the left / right directional control valves 2 and 3 are in the second pressure oil supply position C, the pump port 6 communicates with the second actuator port 9, and also communicates with the load pressure detection port 10 via the throttle, Actuator port 8 is tank port 7
The left and right hydraulic motors 4, 5 are rotatably driven in the other direction in communication with the load pressure detection port 10.
【００１５】前記左・右油圧モータ４，５は斜板１１の
傾転角度を変更することで容量が可変となる可変容量型
の油圧モータとなり、その斜板１１は容量制御シリンダ
１２により傾転される。The left and right hydraulic motors 4 and 5 are variable displacement hydraulic motors whose capacities are variable by changing the tilting angle of the swash plate 11. The swash plate 11 is tilted by a capacity control cylinder 12. To be done.
【００１６】前記容量制御シリンダ１２はスプリング１
３により傾転角度大（容量大）方向（矢印ａ）に作動
し、圧力室１４内の圧力で傾転角度小（容量小）方向
（矢印ｂ）に作動し、その受圧室１４内には制御用油圧
ポンプ１５の吐出圧油が供給される。The capacity control cylinder 12 is a spring 1
3 operates in the direction of large tilt angle (large capacity) (arrow a), and in the pressure chamber 14 operates in the direction of small tilt angle (small capacity) (arrow b). Discharge pressure oil of the control hydraulic pump 15 is supplied.
【００１７】前記制御用油圧ポンプ１５の吐出路１６に
は第１切換弁２０と第２切換弁２１が直列に設けてあ
り、第１切換弁２０はスプリング２２でドレーン位置Ｄ
に保持され、ソレノイド２３が励磁すると供給位置Ｅと
なる。A first switching valve 20 and a second switching valve 21 are provided in series in a discharge passage 16 of the control hydraulic pump 15, and the first switching valve 20 is a spring 22 and a drain position D.
When the solenoid 23 is excited, the supply position E is reached.
【００１８】前記第１切換弁２０がドレーン位置Ｄの時
にはポンプ寄り吐出路１６ａを遮断して中間吐出路１６
ｂをタンク２４に連通し、供給位置Ｅの時にはポンプ寄
り吐出路１６ａを中間吐出路１６ｂに連通して制御用油
圧ポンプ１５の吐出圧油を中間吐出路１６ｂに供給す
る。When the first switching valve 20 is at the drain position D, the discharge passage 16a close to the pump is shut off and the intermediate discharge passage 16 is closed.
b is connected to the tank 24, and at the supply position E, the pump-side discharge passage 16a is connected to the intermediate discharge passage 16b to supply the discharge pressure oil of the control hydraulic pump 15 to the intermediate discharge passage 16b.
【００１９】前記第２切換弁２１はスプリング２５とソ
レノイド２６と補助受圧部２７の圧力で供給位置Ｆとな
り、受圧部２８の圧力でドレーン位置Ｇとなり、その受
圧部２８の受圧面積は補助受圧部２７の受圧面積よりも
大きくなっている。The pressure of the spring 25, the solenoid 26, and the auxiliary pressure receiving portion 27 of the second switching valve 21 becomes the supply position F, and the pressure of the pressure receiving portion 28 becomes the drain position G. The pressure receiving area of the pressure receiving portion 28 is the auxiliary pressure receiving portion. It is larger than the pressure receiving area of 27.
【００２０】第２切換弁２１が供給位置Ｆの時には中間
吐出路１６ｂを先端吐出路１６ｃに連通して中間吐出路
１６ｂの圧油を容量制御シリンダ１２の受圧室１４に供
給し、ドレーン位置Ｇの時には先端吐出路１６ｃをタン
ク２４に連通して容量制御シリンダ１２の受圧室１４内
の圧油をタンク２４に流出する。When the second switching valve 21 is in the supply position F, the intermediate discharge passage 16b is connected to the tip discharge passage 16c to supply the pressure oil in the intermediate discharge passage 16b to the pressure receiving chamber 14 of the capacity control cylinder 12, and the drain position G At the time of, the tip discharge passage 16c is communicated with the tank 24, and the pressure oil in the pressure receiving chamber 14 of the capacity control cylinder 12 flows out to the tank 24.
【００２１】前記第１切換弁２０のソレノイド２３と第
２切換弁２１のソレノイド２６は手動・自動切換スイッ
チ２９により通電制御される。例えば手動・自動切換ス
イッチ２９を自動位置ｃとすると第１切換弁２０のソレ
ノイド２３に通電され、かつ第２切換弁２１のソレノイ
ド２６には通電されない、手動・自動切換スイッチ２９
を手動位置ｄとすると第２切換弁２１のソレノイド２６
に通電され、かつ第１切換弁２０のソレノイド２３には
通電されない。The solenoid 23 of the first switching valve 20 and the solenoid 26 of the second switching valve 21 are energized and controlled by a manual / automatic switch 29. For example, when the manual / automatic changeover switch 29 is set to the automatic position c, the solenoid 23 of the first changeover valve 20 is energized and the solenoid 26 of the second changeover valve 21 is not energized.
Is the manual position d, the solenoid 26 of the second switching valve 21
The solenoid 23 of the first switching valve 20 is not energized.
【００２２】前記第１切換弁２０のソレノイド２３は手
動・自動切換スイッチ２９を手動位置ｄとして高速・低
速切換スイッチ３０を高速位置ｅとすると通電され、低
速位置ｆとすると通電されなくなる。The solenoid 23 of the first switching valve 20 is energized when the manual / automatic switching switch 29 is in the manual position d and the high speed / low speed switching switch 30 is in the high speed position e, and is not energized in the low speed position f.
【００２３】前記左・右方向制御弁２，３の負荷圧検出
ポート１０はシャトル弁等の高圧優先弁３１の入口側に
それぞれ接続され、その高圧優先弁３１の出口側は前記
第２切換弁２１の受圧部２８に接続している。The load pressure detection ports 10 of the left / right directional control valves 2 and 3 are respectively connected to the inlet side of a high pressure priority valve 31 such as a shuttle valve, and the outlet side of the high pressure priority valve 31 is the second switching valve. 21 is connected to the pressure receiving portion 28.
【００２４】次に作動を説明する。左・右方向制御弁
２，３を第１圧油供給位置Ｂとして油圧ポンプ１の吐出
圧油を第１アクチュエータポート８より左・右油圧モー
タ４，５に供給して一方向に駆動して車両を前進走行す
る。Next, the operation will be described. The left and right direction control valves 2 and 3 are set to the first pressure oil supply position B, and the discharge pressure oil of the hydraulic pump 1 is supplied from the first actuator port 8 to the left and right hydraulic motors 4 and 5 to be driven in one direction. Drive the vehicle forward.
【００２５】（自動変速時）前述の状態で手動・自動切
換スイッチ２９を自動位置ｃとして第１切換弁２０のソ
レノイド２３に通電して供給位置Ｅとする。この時第２
切換弁２１のソレノイド２６には通電されないから第２
切換弁２１はスプリング２５と補助受圧部２７の圧力に
より供給位置Ｆに押され、受圧部２８の圧力でドレーン
位置Ｇに押される。(During automatic shifting) In the above-described state, the manual / automatic changeover switch 29 is set to the automatic position c to energize the solenoid 23 of the first changeover valve 20 to the supply position E. At this time the second
Since the solenoid 26 of the switching valve 21 is not energized, the second
The switching valve 21 is pushed to the supply position F by the pressure of the spring 25 and the auxiliary pressure receiving portion 27, and is pushed to the drain position G by the pressure of the pressure receiving portion 28.
【００２６】前記第２切換弁２１の受圧部２８には左・
右油圧モータ４，５における高い方の駆動圧が高圧優先
弁３１より供給されて第２切換弁２１をドレーン位置Ｇ
に押す力は駆動圧に見合う力となり、その駆動圧が所定
圧力よりも高圧の時には第２切換弁２１がドレーン位置
Ｇとなって容量制御シリンダ１２の受圧室１４内の圧油
がタンク２４に流出して斜板１１の傾転角度が大となっ
て、左・右油圧モータ４，５が低速回転して走行速度は
低速となる。The pressure receiving portion 28 of the second switching valve 21 has a left
The higher drive pressure in the right hydraulic motors 4, 5 is supplied from the high pressure priority valve 31 to move the second switching valve 21 to the drain position G.
The force pushing against becomes a force commensurate with the driving pressure, and when the driving pressure is higher than a predetermined pressure, the second switching valve 21 becomes the drain position G and the pressure oil in the pressure receiving chamber 14 of the capacity control cylinder 12 is transferred to the tank 24. It flows out, the tilt angle of the swash plate 11 becomes large, the left and right hydraulic motors 4, 5 rotate at low speed, and the traveling speed becomes low.
【００２７】前記左・右油圧モータ４，５の駆動圧が所
定圧力より低圧の時には第２切換弁２１が供給位置Ｆと
なって容量制御シリンダ１２の受圧室１４に制御用油圧
ポンプ１５の吐出圧油が供給されて斜板１１の傾転角度
が小となり、左・右油圧モータ４，５が高速回転して走
行速度は高速となる。When the driving pressure of the left and right hydraulic motors 4 and 5 is lower than a predetermined pressure, the second switching valve 21 becomes the supply position F and the control hydraulic pump 15 discharges the pressure receiving chamber 14 of the displacement control cylinder 12. Pressure oil is supplied, the tilt angle of the swash plate 11 becomes small, the left and right hydraulic motors 4, 5 rotate at high speed, and the traveling speed becomes high.
【００２８】以上のように第２切換弁２１は左・右油圧
モータ４，５の駆動圧が所定圧力よりも高圧となるとド
レーン位置Ｇ、所定圧力よりも低圧となると供給位置Ｇ
となるが、ドレーン位置Ｇから供給位置Ｆに切換わる時
（低速から高速に変速する時）の圧力は供給位置Ｆから
ドレーン位置Ｇに切換わる時（高速から低速に変速する
時）の圧力よりも低圧となる。As described above, the second switching valve 21 has a drain position G when the driving pressure of the left and right hydraulic motors 4, 5 is higher than a predetermined pressure, and a supply position G when the driving pressure is lower than the predetermined pressure.
However, the pressure when switching from the drain position G to the supply position F (when shifting from low speed to high speed) is greater than the pressure when switching from the supply position F to the drain position G (when shifting from high speed to low speed). Becomes low pressure.
【００２９】つまり、第２切換弁２１がドレーン位置Ｇ
の時（低速の時）には先端側吐出路１６ｃはタンク２４
に連通して補助受圧部２７には圧力が生じないから第２
切換弁２１はスプリング２５のみで供給位置Ｆに向けて
押されているので、受圧部２８の圧力がスプリング２５
のばね荷重による押力に見合う圧力Ｐ1 となると第２切
換弁２１が供給位置Ｆとなって高速となる。That is, the second switching valve 21 moves to the drain position G
At the time of (at a low speed), the discharge passage 16c on the tip side is in the tank 24
Since the pressure is not generated in the auxiliary pressure receiving portion 27 by communicating with the second
Since the switching valve 21 is pushed toward the supply position F only by the spring 25, the pressure of the pressure receiving portion 28 is the same as that of the spring 25.
When the pressure P 1 is commensurate with the pressing force due to the spring load, the second switching valve 21 becomes the supply position F and the speed becomes high.
【００３０】また、第２切換弁２１が供給位置Ｆの時
（高速の時）には補助受圧部２７に制御用油圧ポンプ１
５の吐出圧Ｐ0 が作用し、第２切換弁２１はその吐出圧
Ｐ0 と受圧面積の積の大きさの力で供給位置Ｆに押され
るので、その第２切換弁２１を供給位置Ｆに押す力は前
記スプリング２５のばね荷重による押力＋吐出圧Ｐ0 と
受圧面積の積の大きさの力となり、ドレーン位置Ｇの時
よりも大きくなる。Further, when the second switching valve 21 is in the supply position F (at high speed), the auxiliary hydraulic pressure receiving portion 27 is provided with the control hydraulic pump 1.
The discharge pressure P 0 of 5 acts and the second switching valve 21 is pushed to the supply position F by the force of the product of the discharge pressure P 0 and the pressure receiving area. The pushing force is a product of the pushing force due to the spring load of the spring 25 + the discharge pressure P 0 and the pressure receiving area, and is larger than that at the drain position G.
【００３１】このために、受圧部２８の圧力が前述の圧
力Ｐ1 となってもドレーン位置Ｇとならずに、受圧部２
８の圧力が前述の圧力Ｐ1 よりも高い圧力Ｐ2 となると
第２切換弁２１がドレン位置Ｇとなり、図２に示すよう
に高速から低速に変速する時の圧力（切換圧）はＰ
2 で、低速から高速に変速する時の圧力（切換圧）はＰ
1で、Ｐ2 ＞Ｐ1 となる。Therefore, even if the pressure of the pressure receiving portion 28 reaches the above-mentioned pressure P 1 , it does not reach the drain position G, but the pressure receiving portion 2
When the pressure of 8 reaches a pressure P 2 higher than the above-mentioned pressure P 1 , the second switching valve 21 is in the drain position G, and the pressure (shifting pressure) when shifting from high speed to low speed is P as shown in FIG.
2 , the pressure (switching pressure) when shifting from low speed to high speed is P
At 1 , P 2 > P 1 .
【００３２】このように、切換圧をＰ2 とＰ1 としたこ
とにより、第２切換弁２１は駆動圧がその切換圧の差圧
（Ｐ2 −Ｐ1 ）の範囲内で変化した時には初期位置、例
えば供給位置Ｆ、ドレーン位置Ｇに保持されて変速され
ないので、スムーズな走行ができる。Thus, by setting the switching pressures to P 2 and P 1 , the second switching valve 21 is initially set when the driving pressure changes within the range of the differential pressure (P 2 -P 1 ) of the switching pressures. Since the vehicle is held at the position, for example, the supply position F and the drain position G and the gear is not changed, smooth running can be performed.
【００３３】つまり、第２切換弁２１に補助受圧部２７
を設けないと受圧部２８に作用する駆動圧が所定の圧力
となるとドレーン位置Ｇ、所定の圧力より低圧となると
供給位置Ｇとなって駆動圧が所定の圧力より若干変化す
ると高速、低速に変速されてスムーズな走行ができない
が、前述のように駆動圧がＰ2 −Ｐ1 の差圧の範囲内で
変化した時に初期位置に保持して変速しないようにすれ
ばスムーズな走行ができる。That is, the auxiliary pressure receiving portion 27 is attached to the second switching valve 21.
If the drive pressure acting on the pressure receiving portion 28 becomes a predetermined pressure, the drain position G is set, and if the drive pressure is lower than the predetermined pressure, the supply position G is set and the drive pressure slightly changes from the predetermined pressure. As a result, when the driving pressure changes within the range of the differential pressure of P 2 -P 1 as described above, if the driving pressure is held at the initial position so as not to shift, smooth driving can be performed.
【００３４】（手動変速の時）手動・自動切換スイッチ
２９を手動位置ｄとして第２切換弁２１のソレノイド２
６に通電する。これにより第２切換弁２１はソレノイド
２６の推力によっても供給位置Ｆに押されるので、受圧
部２８に最高駆動圧が供給されてもドレーン位置Ｇとな
らない。(During manual shifting) With the manual / automatic changeover switch 29 set to the manual position d, the solenoid 2 of the second changeover valve 21 is set.
Energize 6. As a result, the second switching valve 21 is also pushed to the supply position F by the thrust of the solenoid 26, so that the drain position G is not reached even if the maximum drive pressure is supplied to the pressure receiving portion 28.
【００３５】前述の状態より高速・低速切換スイッチ３
０を高速位置ｅとすると第１切換弁２０のソレノイド２
３に通電されて供給位置Ｅとなって制御用油圧ポンプ１
５の吐出圧油が容量制御シリンダ１２の受圧室１４に供
給されて容量小となり、左・右油圧モータ４，５が高速
回転して走行速度が高速となる。High speed / low speed changeover switch 3 from the above state
When 0 is the high speed position e, the solenoid 2 of the first switching valve 20
3 is energized to the supply position E and the control hydraulic pump 1
The discharge pressure oil of No. 5 is supplied to the pressure receiving chamber 14 of the capacity control cylinder 12 to have a small capacity, and the left and right hydraulic motors 4 and 5 rotate at high speed to increase the traveling speed.
【００３６】前述の状態より高速・低速切換スイッチ３
０を低速位置ｆとすると第１切換弁２０のソレノイド２
３に通電されなくなって第１切換弁２０がドレーン位置
Ｄとなり、容量制御シリンダ１２の受圧室１４の圧油が
タンク２４に流出して容量大となり、左・右油圧モータ
４，５が低速回転して走行速度が低速となる。High speed / low speed changeover switch 3 from the above state
When 0 is set to the low speed position f, the solenoid 2 of the first switching valve 20
3, the first switching valve 20 becomes the drain position D, the pressure oil in the pressure receiving chamber 14 of the capacity control cylinder 12 flows into the tank 24, and the capacity becomes large, so that the left and right hydraulic motors 4 and 5 rotate at a low speed. Then, the traveling speed becomes low.
【００３７】このように、駆動圧に関係なく手動操作に
より高速・低速に変速できる。As described above, the speed can be changed between high speed and low speed by the manual operation regardless of the driving pressure.
【００３８】以上の実施例において自動変速のみとする
場合には第１切換弁２０が不要となり、制御用油圧ポン
プ１５の吐出圧油を第２切換弁２１の入口側に直接供給
し、第２切換弁２１のソレノイド２６が不要となる。In the above embodiment, when only automatic shifting is performed, the first switching valve 20 is not necessary, and the pressure oil discharged from the control hydraulic pump 15 is directly supplied to the inlet side of the second switching valve 21. The solenoid 26 of the switching valve 21 becomes unnecessary.
【００３９】[0039]
【発明の効果】左・右油圧モータ４，５の駆動圧が高圧
の時には切換弁がドレーン位置Ｇとなって左・右の容量
制御シリンダ１２の受圧室１４内の圧油がタンクに流出
して容量が大となり、左・右油圧モータ４，５の駆動圧
が低圧の時には切換弁が供給位置Ｆとなって左右の容量
制御シリンダ１２の受圧室１４に制御用油圧ポンプ１５
の吐出圧油が供給されて容量が小となる。これにより、
左・右油圧モータ４，５の駆動圧が高圧の時には低速回
転となって走行速度が低速となり、低圧の時には高速回
転となって走行速度が高速となるので、油圧駆動車を自
動的に高速・低速の２段に変速できる。When the driving pressure of the left and right hydraulic motors 4 and 5 is high, the switching valve becomes the drain position G and the pressure oil in the pressure receiving chamber 14 of the left and right displacement control cylinders 12 flows out to the tank. When the driving pressure of the left and right hydraulic motors 4 and 5 is low, the switching valve becomes the supply position F and the control hydraulic pump 15 is provided in the pressure receiving chamber 14 of the left and right capacity control cylinders 12.
The discharge pressure oil is supplied to reduce the capacity. This allows
When the driving pressure of the left and right hydraulic motors 4 and 5 is high, the rotation speed is low and the traveling speed is low, and when the driving pressure is low, it is high speed and the traveling speed is high.・ You can shift to two low speeds.
【００４０】また、左・右油圧モータ４，５の駆動圧に
より切換弁を切換えるので、誤動作することがなく正し
く高速・低速に変速できるし、変速装置が安価となる。Further, since the switching valve is switched by the driving pressure of the left and right hydraulic motors 4 and 5, it is possible to correctly shift to a high speed and a low speed without malfunction, and the transmission becomes inexpensive.
【００４１】切換弁を補助受圧部２７の圧力で供給位置
Ｆに押すようにすれば、切換弁が供給位置Ｆからドレー
ン位置Ｇに切換える時の切換圧が高圧で、ドレーン位置
Ｇから供給位置Ｆに切換える時の切換圧が低圧となり、
高速から低速に変速する時の駆動圧が高く、低速から高
速に変速する時の駆動圧が低くなってスムーズな走行が
できる。If the switching valve is pushed to the supply position F by the pressure of the auxiliary pressure receiving portion 27, the switching pressure when the switching valve switches from the supply position F to the drain position G is high, and the drain position G to the supply position F. The switching pressure when switching to becomes low,
The driving pressure when shifting from high speed to low speed is high, and the driving pressure when shifting from low speed to high speed is low, which enables smooth running.
【図１】本発明の実施例を示す線図的構成説明図であ
る。FIG. 1 is a diagrammatic configuration explanatory view showing an embodiment of the present invention.
【図２】変速時の切換圧を示す図表である。FIG. 2 is a chart showing a switching pressure during a shift.
１…油圧ポンプ ２…左方向制御弁 ３…右方向制御弁 ４…左油圧モータ ５…右油圧モータ １２…容量制御シリンダ １３…スプリング １４…受圧室 １５…制御用油圧ポンプ ２０…第１切換弁 ２１…第２切換弁 ２２…スプリング ２３…ソレノイド ２４…タンク ２５…スプリング ２６…ソレノイド ２７…補助受圧部 ２８…受圧部 ３１…高圧優先弁。 1 ... Hydraulic pump 2 ... Left direction control valve 3 ... Right direction control valve 4 ... Left hydraulic motor 5 ... Right hydraulic motor 12 ... Capacity control cylinder 13 ... Spring 14 ... Pressure receiving chamber 15 ... Control hydraulic pump 20 ... 1st switching valve 21 ... 2nd switching valve 22 ... Spring 23 ... Solenoid 24 ... Tank 25 ... Spring 26 ... Solenoid 27 ... Auxiliary pressure receiving part 28 ... Pressure receiving part 31 ... High pressure priority valve.
Claims (2)
御弁２，３により走行用の左・右油圧モータ４，５に供
給して走行する油圧駆動車において、 前記左・右油圧モータ４，５を可変容量型の油圧モータ
とし、 受圧室１４に圧油が供給されると左・右油圧モータ４，
５の容量を小とし、受圧室１４の圧油がタンクに流出す
ると左・右油圧モータ４，５の容量を大とする左・右の
容量制御シリンダ１２と、 制御用油圧ポンプ１５の吐出圧油を前記左・右の容量制
御シリンダ１２の受圧室１４に供給する供給位置Ｆと、
その受圧室１４をタンクに連通するドレーン位置Ｇに切
換えられる切換弁と、 前記左・右油圧モータ４，５の駆動圧における高い方の
駆動圧を検出する高圧優先弁３１とを設け、 前記切換弁をスプリング２５で供給位置Ｆに押し、かつ
受圧部２８の圧力でドレーン位置Ｇに押すものとし、そ
の受圧部２８を前記高圧優先弁３１の出力側に接続した
ことを特徴とする油圧駆動車の変速装置。1. A hydraulically driven vehicle that travels by supplying pressure oil discharged from a hydraulic pump 1 to left and right hydraulic motors 4 and 5 for traveling by means of left and right directional control valves 2 and 3, wherein the left and right hydraulic pressures are The motors 4 and 5 are variable displacement hydraulic motors. When pressure oil is supplied to the pressure receiving chamber 14, the left and right hydraulic motors 4 and 5 are driven.
The discharge pressure of the control hydraulic pump 15 and the left and right displacement control cylinders 12 that increase the displacement of the left and right hydraulic motors 4 and 5 when the pressure oil in the pressure receiving chamber 14 flows out into the tank. A supply position F for supplying oil to the pressure receiving chamber 14 of the left and right displacement control cylinders 12,
A switching valve that switches the pressure receiving chamber 14 to a drain position G that communicates with the tank, and a high pressure priority valve 31 that detects a higher driving pressure of the left and right hydraulic motors 4 and 5 are provided. The hydraulically driven vehicle is characterized in that the valve is pushed to the supply position F by the spring 25 and to the drain position G by the pressure of the pressure receiving portion 28, and the pressure receiving portion 28 is connected to the output side of the high pressure priority valve 31. Gearbox.
部２７の圧力で供給位置Ｆに押し、かつ受圧部２８の圧
力でドレーン位置Ｇに押すものとし、その補助受圧部２
７を切換弁の出力側に接続し、前記受圧部２８を前記高
圧優先弁３１の出力側に接続した請求項１記載の油圧駆
動車の変速装置。2. The switching valve is pushed to the supply position F by the pressure of the spring 25 and the auxiliary pressure receiving portion 27 and to the drain position G by the pressure of the pressure receiving portion 28.
2. The transmission device for a hydraulically driven vehicle according to claim 1, wherein 7 is connected to the output side of the switching valve, and the pressure receiving portion 28 is connected to the output side of the high pressure priority valve 31.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6577795A JPH08258579A (en) | 1995-03-24 | 1995-03-24 | Transmission for hydrostatic transmission vehicle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6577795A JPH08258579A (en) | 1995-03-24 | 1995-03-24 | Transmission for hydrostatic transmission vehicle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08258579A true JPH08258579A (en) | 1996-10-08 |
Family
ID=13296814
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6577795A Pending JPH08258579A (en) | 1995-03-24 | 1995-03-24 | Transmission for hydrostatic transmission vehicle |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08258579A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007092955A (en) * | 2005-09-30 | 2007-04-12 | Kubota Corp | Load control structure of working vehicle |
| CN100347454C (en) * | 2003-10-15 | 2007-11-07 | 纳博特斯克株式会社 | Automatic transmission mechanism of hydraulic motor |
| JP2008082130A (en) * | 2006-09-29 | 2008-04-10 | Kubota Corp | Hydraulic system of backhoe |
| JP2011202805A (en) * | 2010-03-12 | 2011-10-13 | Hans Jensen Lubricators As | Valve arrangement for dosing fluid |
| CN102673362A (en) * | 2012-05-12 | 2012-09-19 | 张庆春 | High-pressure air energy vehicle |
| CN103213494A (en) * | 2013-04-26 | 2013-07-24 | 江苏四明工程机械有限公司 | Self-walking mechanical double-speed walking electro-hydraulic control system |
| JP2019143806A (en) * | 2015-09-08 | 2019-08-29 | 株式会社クボタ | Hydraulic system of work machine |
-
1995
- 1995-03-24 JP JP6577795A patent/JPH08258579A/en active Pending
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100347454C (en) * | 2003-10-15 | 2007-11-07 | 纳博特斯克株式会社 | Automatic transmission mechanism of hydraulic motor |
| JP2007092955A (en) * | 2005-09-30 | 2007-04-12 | Kubota Corp | Load control structure of working vehicle |
| JP4585417B2 (en) * | 2005-09-30 | 2010-11-24 | 株式会社クボタ | Tractor load control structure |
| JP2008082130A (en) * | 2006-09-29 | 2008-04-10 | Kubota Corp | Hydraulic system of backhoe |
| JP2011202805A (en) * | 2010-03-12 | 2011-10-13 | Hans Jensen Lubricators As | Valve arrangement for dosing fluid |
| KR20130044225A (en) * | 2010-03-12 | 2013-05-02 | 한스 옌젠 루브리케이터스 에이/에스 | Valve arrangement for dosing a fluid |
| CN102673362A (en) * | 2012-05-12 | 2012-09-19 | 张庆春 | High-pressure air energy vehicle |
| CN103213494A (en) * | 2013-04-26 | 2013-07-24 | 江苏四明工程机械有限公司 | Self-walking mechanical double-speed walking electro-hydraulic control system |
| CN103213494B (en) * | 2013-04-26 | 2015-08-05 | 江苏四明工程机械有限公司 | The double speed walking electrohydraulic control system of self-walking machinery |
| JP2019143806A (en) * | 2015-09-08 | 2019-08-29 | 株式会社クボタ | Hydraulic system of work machine |
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