JPS63235135A - Travelling speed changeover device of hydraulic travelling vehicle - Google Patents
Travelling speed changeover device of hydraulic travelling vehicleInfo
- Publication number
- JPS63235135A JPS63235135A JP6950087A JP6950087A JPS63235135A JP S63235135 A JPS63235135 A JP S63235135A JP 6950087 A JP6950087 A JP 6950087A JP 6950087 A JP6950087 A JP 6950087A JP S63235135 A JPS63235135 A JP S63235135A
- Authority
- JP
- Japan
- Prior art keywords
- speed
- pressure
- travel
- valve
- pilot
- 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.)
- Granted
Links
- 238000006073 displacement reaction Methods 0.000 claims description 2
- 239000012530 fluid Substances 0.000 abstract 5
- 239000003921 oil Substances 0.000 description 24
- 230000007423 decrease Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 230000005284 excitation Effects 0.000 description 3
- 230000009194 climbing Effects 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000006870 function Effects 0.000 description 2
- 239000010720 hydraulic oil Substances 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000035807 sensation Effects 0.000 description 2
- 230000007935 neutral effect Effects 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
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
Landscapes
- Fluid-Pressure Circuits (AREA)
- Control Of Driving Devices And Active Controlling Of Vehicle (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
この発明は、低速、高速の切換走行ができる油圧走行式
建設・荷役車両の走行速度切換装置に関する。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a travel speed switching device for a hydraulic construction/material handling vehicle that can switch between low and high speeds.
従来の技術
油圧走行式建設・荷役車両が近距離移動するときには、
現場内移動のための強力な低速走行と、現場間移動の高
速走行とを切換えて、走行を行なっている。第２図は、
クローラ式油圧ショベルの従来技術走行モータ駆動用油
圧・電気回路図である。パイロット弁１，１°を単独ま
たは同時操作すると、走行弁２，２°はそれぞれ単独ま
たは同時に切換作動する。そこで、油圧ポンプ３，３゛
からの吐出圧油は、走行モータ４，４°に送油されるの
で、走行モータ４．４°は、同時またはいずれか一方が
正転、逆転する０次に、走行モータ４，４°を低速。Conventional technology When hydraulically propelled construction and material handling vehicles move over short distances,
Travel is performed by switching between powerful low-speed travel for intra-site movement and high-speed travel for inter-site movement. Figure 2 shows
1 is a hydraulic and electrical circuit diagram for driving a conventional travel motor of a crawler type hydraulic excavator. When pilot valves 1 and 1° are operated individually or simultaneously, travel valves 2 and 2° are switched individually or simultaneously. Therefore, the pressure oil discharged from the hydraulic pumps 3 and 3' is sent to the travel motors 4 and 4 degrees, so the travel motors 4 and 4 degrees are 0-order, which rotates forward and reverse at the same time or one of them. , drive motor 4, 4° at low speed.
高速に切換える場合を、走行モータ４側について述べる
。走行モータ４の１回転当り容量を、常時は、傾転角澗
整用シリンダ５内ばねのばね力により所定の大容量側に
設定している。しかし、上記シリンダ５に圧油が作用す
ると、ピストン６は移動し、容量可変レバを小容量側に
傾動させる。シリンダ５より通じる油路７は、速度選択
切換弁８を経て、常時は油タンク９に連通している。ま
た、速度選択切換弁８のパイロット圧受圧部１０とパイ
ロットポンプ１１とを連通ずる油路に、電磁弁１２を設
けている。低速走行を行うときには、電気回路内の速度
選択用スイッチ１３をオフ操作にしておく、そのときに
は、シリンダ５は、油路７、速度選択切換弁８のイ位置
を経て、油タンク９に連通している。走行モータ４は大
容量側に傾転されているので、パイロット弁ｌを操作す
ると、走行モータ４．は、強力な回転力を発して、低速
回転を行う。The case of switching to high speed will be described on the traveling motor 4 side. The capacity per rotation of the travel motor 4 is normally set to a predetermined large capacity side by the spring force of the spring inside the cylinder 5 for adjusting the tilt angle. However, when pressure oil acts on the cylinder 5, the piston 6 moves and tilts the variable capacity lever toward the small capacity side. An oil passage 7 leading from the cylinder 5 is normally in communication with an oil tank 9 via a speed selection switching valve 8. Further, a solenoid valve 12 is provided in an oil passage that communicates the pilot pressure receiving section 10 of the speed selection switching valve 8 with the pilot pump 11. When traveling at low speed, the speed selection switch 13 in the electric circuit is turned off. At that time, the cylinder 5 communicates with the oil tank 9 via the oil passage 7 and the speed selection switching valve 8 at position A. ing. Since the travel motor 4 is tilted to the high capacity side, when the pilot valve l is operated, the travel motor 4. generates strong rotational force and rotates at low speed.
次に、高速走行を行う場合について述べる。スイッチ１
３をオン操作すると、電磁弁１２の励磁コイル１６を通
電するので、電磁弁１２はハ位置より二位置に切換わる
。そうすると、パイロットポンプ１１からの圧油は、油
路１７．１８．１９、電磁弁１２の二位置、油路１５．
１４を経て、速度選択切換弁８のパイロット圧受圧部１
０に作用する。速度選択切換弁８は、イ位置より口位置
に切換わる。そこで、パイロット弁１を操作すると、油
圧ポンプ３からの吐出圧油は、油路２ｏ、２１、走行弁
２、油路２２または２３を経て、走行モータ４に送油さ
れる。そのときに、油路２２または２３内の圧油の一部
が、シャトル弁２４、速度選択切換弁８の口位置、油路
７を経て、シリンダ５のピストン６に作用する。ピスト
ン６は、ばねのばね力に抗して移動し、走行モータ４を
小容量側に傾転させるので、走行モータ４は高速回転を
する。なお、走行モータ４゛側の低速、高速切換は、上
記走行モータ４の場合と同様である。Next, the case of high-speed running will be described. switch 1
When 3 is turned on, the excitation coil 16 of the solenoid valve 12 is energized, so the solenoid valve 12 is switched from the C position to the 2nd position. Then, the pressure oil from the pilot pump 11 is transmitted to the oil passages 17, 18, and 19, to the two positions of the solenoid valve 12, and to the oil passages 15.
14, the pilot pressure receiving part 1 of the speed selection switching valve 8
Acts on 0. The speed selection switching valve 8 is switched from the A position to the Open position. Therefore, when the pilot valve 1 is operated, the pressure oil discharged from the hydraulic pump 3 is sent to the travel motor 4 via the oil passages 2o and 21, the traveling valve 2, and the oil passage 22 or 23. At this time, a portion of the pressure oil in the oil passage 22 or 23 acts on the piston 6 of the cylinder 5 via the shuttle valve 24, the opening position of the speed selection switching valve 8, and the oil passage 7. The piston 6 moves against the spring force of the spring and tilts the travel motor 4 toward the small capacity side, so the travel motor 4 rotates at high speed. Note that switching between low speed and high speed on the travel motor 4' side is the same as in the case of the travel motor 4 described above.
この発明の解決すべき問題点
低速、高速に速度を切換操作できる油圧走行車両におい
では、高速走行は、低速走行に比べて走行速度は速いが
、高速切換状態行モータの回転力が弱い、それで、高速
切換状態で発進すると、その発進の力は弱い、また、高
速走行しているときに停止する場合には、その停止のシ
ョックが大きいので、車両のメンテナンス上好ましくな
いし、運転感覚も不快であった。一方、高速切損時車両
の登はん力や操向力が弱いので、運転者は現場の条件や
目的などに応じて、低速走行と高速走行とを切換操作し
ていた。すなわち、高速走行中に走行負荷が大きく増加
する状態、たとえば坂道などにさしかかると、その度に
高速走行より低速走行に切換操作していた。そして、そ
の走行負荷の大きい場所を通過した後に、再び、低速走
行より高速走行に切換えていた。したがって、その切換
操作がわずられしく、運転者の疲労を増加させていた。Problems to be Solved by this Invention In hydraulic vehicles that can switch speeds between low and high speeds, the traveling speed in high-speed travel is faster than in low-speed travel, but the rotational force of the motor in the high-speed switching state is weak. If the vehicle starts in the high-speed switching state, the starting force will be weak, and if the vehicle stops while driving at high speed, the shock of the stop will be large, which is not desirable in terms of vehicle maintenance, and the driving sensation will be unpleasant. there were. On the other hand, since the vehicle's climbing force and steering force are weak when the vehicle is cut off at high speed, the driver has to switch between low-speed driving and high-speed driving depending on the on-site conditions and purpose. That is, whenever the vehicle encounters a situation where the running load increases significantly during high-speed running, such as on a slope, the vehicle switches from high-speed running to low-speed running each time. Then, after passing through a place with a heavy running load, the vehicle switched from low-speed travel to high-speed travel again. Therefore, the switching operation is cumbersome, increasing driver fatigue.
この発明は上記の問題を解決し、速度選択用スイッチを
オン操作しておけば、発進および停止直前には、自動的
に低速走行に切換わるとともに、高速走行中の車両の走
行負荷が大きくなったときに、自動的に低速走行に切換
作動し、かつ、上記走行負荷が軽減されると、再び、高
速走行に自動復帰する油圧走行車両の走行速度切換装置
を提供することを目的とするものである。This invention solves the above problem, and by turning on the speed selection switch, the vehicle automatically switches to low-speed driving immediately before starting or stopping, and the running load of the vehicle during high-speed driving becomes large. An object of the present invention is to provide a traveling speed switching device for a hydraulic vehicle that automatically switches to low-speed traveling when the vehicle is traveling at a low speed, and automatically returns to high-speed traveling when the traveling load is reduced. It is.
問題点を解決するための手段
前記問題点を解決するために講じたこの発明の手段は
イ、可変容量形走行モータの傾転角調整用シリンダに通
じる油路に速度選択切換弁を連結し、その速度選択切換
弁を速度選択用スイッチで作動し、上記走行モータを低
速または高速回転させるようにした油圧走行車両におい
て、
口、左右走行モータのパイロット圧作用回路にパイロッ
ト圧を検出するパイロット圧用シャトル弁を設け、その
シャトル弁からの圧力信号を速度選択用スイッチ側に導
き、
ハ、かつ、左右走行モータの作動回路に回路圧を検出す
る回路圧用シャトル弁を設け、そのシャトル弁からの圧
力信号を速度選択切換弁と速度選択用ス１インチとの間
に導き、
二、高速操作時の発進および停止直前には低速に切換え
るとともに、走行モータの回路圧力価定圧以上になった
とき、走行モータの速度を低速に切換えるように構成し
た。Means for Solving the Problems The means of the present invention taken to solve the above problems are (a) connecting a speed selection switching valve to an oil passage leading to a tilting angle adjustment cylinder of a variable displacement travel motor; In a hydraulic vehicle in which the speed selection selector valve is operated by a speed selection switch to rotate the travel motor at low speed or high speed, a pilot pressure shuttle detects pilot pressure in the pilot pressure action circuit of the left and right travel motors. A valve is provided, and the pressure signal from the shuttle valve is guided to the speed selection switch side.C. Also, a circuit pressure shuttle valve is provided in the operating circuit of the left and right travel motors to detect the circuit pressure, and the pressure signal from the shuttle valve is provided. 2. Just before starting and stopping during high-speed operation, the speed is switched to low speed, and when the circuit pressure of the travel motor exceeds the fixed pressure, the travel motor The speed of the motor was configured to be switched to a low speed.
作用
イ、油圧走行車両の発進および走行停止直前には、走行
弁のパイロット圧回路のパイロット圧は上昇しない。パ
イロット圧用圧力スイッチはオフ状態となっているので
、速度選択用スイッチをオン操作していても、電気回路
は通電しない。Effect (a) Immediately before the hydraulic vehicle starts and stops traveling, the pilot pressure in the pilot pressure circuit of the travel valve does not rise. Since the pilot pressure switch is in the off state, the electric circuit will not be energized even if the speed selection switch is turned on.
したがって、発進および走行停止直前には、走行モータ
は低速回転をする。Therefore, immediately before starting and stopping the vehicle, the travel motor rotates at a low speed.
口、速度選択用スイッチをオン操作して高速走行してい
るときに、走行負荷が増大した状態になると、回路圧用
シャトル弁から導出された圧力信号の圧力は上昇する。When the vehicle is traveling at high speed with the speed selection switch turned on and the traveling load increases, the pressure of the pressure signal derived from the circuit pressure shuttle valve increases.
そこで、回路圧用圧カスインチは自動的にオフ作動し、
走行モータは、高速回転から低速回転に切換わる。Therefore, the pressure gas inch for circuit pressure is automatically turned off,
The travel motor switches from high speed rotation to low speed rotation.
ハ、上記走行負荷を低速走行にて対処すると、走行負荷
は軽減される。そうすると、回路圧用シャトル弁から導
出されていた圧力信号の圧力は低下し、回路圧用圧力ス
イッチは、オンの状態に復帰する。この場合に、速度選
択用スイッチはオン操作のままにしているので、走行モ
ータは、低速回転から高速回転に自動復帰する。C. If the above running load is dealt with by driving at low speed, the running load will be reduced. Then, the pressure of the pressure signal derived from the circuit pressure shuttle valve decreases, and the circuit pressure pressure switch returns to the on state. In this case, since the speed selection switch remains on, the travel motor automatically returns from low-speed rotation to high-speed rotation.
実施例
以下、この発明にかかる走行速度切換装置を図面に基い
て詳細に説明する。第１図は、この発明にかかる油圧・
電気回路図である。第１図が従来技術第１図と異なる点
は、左、右走行弁２，２°のパイロット圧受圧部３４Ｌ
・３４Ｒ，３４’Ｌ・ ３４°Ｒをそれぞれ連通ずるパ
イロット油路にシャトル弁３５．３５“を設け、さらに
、上記シャトル弁３５゜３５″を連通ずるパイロット油
路にシャトル弁３６を設けている。そして、電気回路内
に設けたパイロット圧用圧力スイッチ３７とシャトル弁
３６とを連通した。また、走行モータ４．４°の作動油
路２２・２３．２２’・２３゛をそれぞれ連通ずる油路
にシャトル弁２５，２５°を設け、さらに、上記シャト
ル弁２５．２５″を連通ずる油路にシャトル弁２６を設
けている。一方、電気回路内に圧力スイッチ２７を設け
、その圧力スイッチ２７とパイロット圧用圧力スイッチ
３７．電磁弁１２用励磁コイル１６．速度選択用スイッ
チ１３および電Ｂ２８とを直列に接続した。それととも
に、圧力スイッチ２７とシャトル弁２６とをスローリタ
ーン弁２９を介して連通した。EXAMPLE Hereinafter, a traveling speed switching device according to the present invention will be explained in detail with reference to the drawings. Figure 1 shows the hydraulic pressure according to this invention.
It is an electrical circuit diagram. The difference between FIG. 1 and the prior art FIG. 1 is that the pilot pressure receiving portion 34L of the left and right traveling valves 2 and 2
・A shuttle valve 35.35" is provided in the pilot oil path that communicates with 34R, 34'L, and 34°R, and a shuttle valve 36 is provided in the pilot oil path that communicates with the shuttle valves 35 and 35". . Then, the pilot pressure pressure switch 37 provided in the electric circuit and the shuttle valve 36 were communicated. In addition, shuttle valves 25 and 25° are provided in the oil passages that communicate the hydraulic oil passages 22, 23, 22', and 23' of the travel motor 4.4°, and furthermore, the oil passages that communicate the shuttle valves 25.25'' and 23' are provided. On the other hand, a pressure switch 27 is provided in the electric circuit, and the pressure switch 27, the pilot pressure pressure switch 37, the excitation coil 16 for the electromagnetic valve 12, the speed selection switch 13, and the electric B28 are connected to each other. were connected in series.At the same time, the pressure switch 27 and shuttle valve 26 were communicated via a slow return valve 29.
この発明にかかる走行速度切換装置は上記のように構成
されているが、その作動機能について述べる。電気回路
内に設けたパイロット圧用圧力スイッチ３７のスプリン
グ３８は、パイロット圧が所定圧力まで上昇したときに
、その圧力スイッチ３７がオン作動するように設定しで
ある。油圧走行車両の発進および走行停止直前には、パ
イロット弁ｌ、１゛用操作レバの傾動角度がきわめて小
さいので、パイロット圧用シャトル弁３６より導出され
るパイロット圧は、圧力スイッチ３７内スプリング３８
の設定圧よりも低圧である。そのために、速度選択用ス
イッチ１３をオン操作して、車両を発進させると、パイ
ロット圧用圧力スイッチ３７はオフ状態であるため、低
速走行となる。しかし、発進後パイロット圧が、上記ス
プリング３８の設定圧以上に上昇すると、そのパイロッ
ト圧は、シャトル弁３６、パイロット油路３９を経て、
圧力スイッチ３７に作用する。圧力スイッチ３７はオン
作動するので、自動的に高速走行に切換わる。また、高
速走行をしているときに、パイロット弁１，１°の操作
レバを中立位置付近に戻すと、パイロット圧は、上記ス
プリング３８の設定圧以下に低下する。そこで、停止直
前には、自動的に低速走行に切換わる。一方、回路圧用
圧力スイッチ２７内スプリング３０のばね力は、油圧ポ
ンプ３．３°用メインリリーフ弁３１，３１°、走行モ
ータ４，４゛用走リリーフ弁３２，３２°のいずれか低
い方のリリーフ設定圧より、若干低圧に設定している。The traveling speed switching device according to the present invention is constructed as described above, and its operational functions will be described below. The spring 38 of the pilot pressure pressure switch 37 provided in the electric circuit is set so that the pressure switch 37 is turned on when the pilot pressure rises to a predetermined pressure. Immediately before starting or stopping a hydraulic vehicle, the tilting angle of the operating levers for pilot valves 1 and 1 is extremely small, so the pilot pressure derived from the pilot pressure shuttle valve 36 is transferred to the spring 38 in the pressure switch 37.
The pressure is lower than the set pressure. For this reason, when the speed selection switch 13 is turned on to start the vehicle, the pilot pressure switch 37 is in the off state, so the vehicle runs at a low speed. However, when the pilot pressure rises above the set pressure of the spring 38 after starting, the pilot pressure passes through the shuttle valve 36 and the pilot oil passage 39, and
Acts on pressure switch 37. Since the pressure switch 37 is turned on, the vehicle automatically switches to high-speed travel. Further, when the operating lever of the pilot valves 1 and 1° is returned to near the neutral position while the vehicle is traveling at high speed, the pilot pressure decreases below the set pressure of the spring 38. Therefore, just before stopping, the vehicle automatically switches to low-speed travel. On the other hand, the spring force of the spring 30 in the pressure switch 27 for circuit pressure is the lower of the main relief valves 31, 31° for the hydraulic pump 3.3° and the travel relief valves 32, 32° for the travel motors 4, 4'. The pressure is set slightly lower than the relief setting pressure.
そのために、速度選択用スイッチ１３をオン操作して高
速走行しているときに、走行負荷が増大した状態になる
と、作動油路２２，２３゜２２’、 ２３’の内いず
れか油路の油圧が昇圧する。For this reason, when the speed selection switch 13 is turned on and traveling at high speed, when the running load increases, the oil pressure in any of the hydraulic oil passages 22, 23, 22', and 23' decreases. increases in pressure.
その圧力信号は、シャトル弁２６、油路３３、スローリ
ターン弁２９を経て、圧力スイッチ２７に作用する。そ
の圧力信号の油圧が、圧力スイッチ２７用スプリング３
０の設定圧をこえると、圧力スイッチ２７はオフ作動す
る。そこで、励磁コイル１６は非通電となり、電磁弁１
２は、二位置よりタンク連通ハ位置に切換ねる。このよ
うにして、走行モータ４．４゛は自動的に高速回転から
低速回転に切換ねるので、回転力の大きな低速走行をし
て、上記の大きな走行負荷に対処する。低速走行により
、走行負荷対処を終了すると、走行負荷は軽減される。The pressure signal acts on the pressure switch 27 via the shuttle valve 26, oil passage 33, and slow return valve 29. The hydraulic pressure of the pressure signal is applied to the spring 3 for the pressure switch 27.
When the set pressure of 0 is exceeded, the pressure switch 27 is turned off. Therefore, the excitation coil 16 is de-energized, and the solenoid valve 1
2 is switched from the 2nd position to the tank communication C position. In this way, the traveling motor 4.4' automatically switches from high-speed rotation to low-speed rotation, so that the vehicle can travel at low speed with a large rotational force to cope with the above-mentioned large traveling load. When the running load has been dealt with by running at low speed, the running load is reduced.
ジ−トル弁２６から導出されていた圧力信号の圧力は低
下し、圧力スイッチ２７は、そのスプリング３０のばね
力によりオンの状態に復帰しようとする。しかし、圧力
スイッチ２７に作用していた圧力信号の作動圧が、スロ
ーリターン弁２９を経て戻るので、圧力スイッチ２７は
若干遅延してオン作動する。しかも、速度選択用スイッ
チ１３はオン操作のままにしているので、走行モータ４
．４゛は、低速回転からスムーズに高速回転に自動復帰
する。The pressure of the pressure signal derived from the jettle valve 26 decreases, and the pressure switch 27 attempts to return to the on state due to the spring force of the spring 30. However, since the operating pressure of the pressure signal acting on the pressure switch 27 returns via the slow return valve 29, the pressure switch 27 is turned on with a slight delay. Moreover, since the speed selection switch 13 is left on, the travel motor 4
．． 4. Automatically returns from low speed rotation to high speed rotation smoothly.
発明の効果
従来技術では、たとえば油圧シラベルが高速切換状態で
発進すると、その発進の力は弱い。また、高速走行して
いるときに停止する場合には、その停止のシリンダが大
きいので、車両のメンテナンス上好ましくないし、運転
感覚も不快であった。Effects of the Invention In the prior art, for example, when a hydraulic cylinder starts in a high-speed switching state, the starting force is weak. Further, when the vehicle stops while traveling at high speed, the cylinder for stopping is large, which is not desirable in terms of maintenance of the vehicle, and the driving sensation is also unpleasant.
一方、高速切換状態両の登はん力や操向力が弱いので、
運転者は現場の条件や目的などに応じて、低速走行と高
速走行とを切換操作していた。したがって、その切換操
作がわずられしく、運転者の疲労を増加させていた。On the other hand, the climbing force and steering force in both high-speed switching states are weak, so
The driver switches between low-speed driving and high-speed driving depending on the site conditions and purpose. Therefore, the switching operation is cumbersome, increasing driver fatigue.
しかし、この発明にかかる走行速度切換装置は、速度選
択用スイッチをオン操作しておけば、発進および停止直
前には、自動的に低速走行に切換わるとともに、高速走
行中の車両の走行負荷が大きくなったときに、自動的に
低速走行に切換作動し、かつ、上記走行負荷が軽減され
ると、再び高速走行に自動復帰する。したがうて、この
発明にかかる′走行速度切換装置は、油圧走行車両のメ
ンテナンス性および走行機能を向上し、かつ、走行操作
における運転者の疲労を軽減させる。However, with the traveling speed switching device according to the present invention, if the speed selection switch is turned on, immediately before starting or stopping, the traveling speed switching device automatically switches to low speed traveling, and the traveling load of the vehicle traveling at high speed is reduced. When the load increases, the vehicle automatically switches to low-speed travel, and when the travel load is reduced, it automatically returns to high-speed travel. Therefore, the travel speed switching device according to the present invention improves the maintainability and travel function of a hydraulic vehicle, and reduces driver fatigue during travel operations.
第１図はこの発明にかかる走行速度切換装置の油圧・電
気回路図、第２図は従来技術の油圧・電気回路図である
。
２．２゛・・・・・・・・・・・左、右走行弁４．４°
・・・・・・・・・・・左、右走行モータ５・・・・・
・・・・・・・・・傾転角調整用シリンダ８・・・・・
・・・・・・・・・速度選択切換弁１２・・・・・・・
・・・・・・電磁弁１３・・・・・・・・・・・・・速
度選択用スイッチ２６．２５，２５°・・・・・シャト
ル弁３６、３５．３５’・・・・・シャトル弁２７．３
７・・・・・・・・・圧力スイッチ以上FIG. 1 is a hydraulic/electrical circuit diagram of a traveling speed switching device according to the present invention, and FIG. 2 is a hydraulic/electrical circuit diagram of a conventional technology. 2.2゛・・・・・・・・・Left and right travel valves 4.4°
......Left and right travel motors 5...
......Cylinder 8 for adjusting tilt angle...
......Speed selection switching valve 12...
... Solenoid valve 13 ... Speed selection switch 26.25, 25° ... Shuttle valve 36, 35.35' ... Shuttle valve 27.3
7・・・・・・・・・Pressure switch or higher
Claims (1)
る油路に速度選択切換弁を連結し、その速度選択切換弁
を速度選択用スイッチで作動し、上記走行モータを低速
または高速回転させるようにした油圧走行車両において
、左右走行モータのパイロット圧作用回路にパイロット
圧を検出するパイロット圧用シャトル弁を設け、そのシ
ャトル弁からの圧力信号を速度選択用スイッチ側に導き
、かつ、左右走行モータの作動回路に回路圧を検出する
回路圧用シャトル弁を設け、そのシャトル弁からの圧力
信号を速度選択切換弁と速度選択用スイッチとの間に導
き、高速操作時の発進および停止直前には低速に切換え
るとともに、走行モータの回路圧が設定圧以上になった
とき、走行モータの速度を低速に切換えることを特徴と
する油圧走行車両の走行速度切換装置。A speed selection changeover valve is connected to an oil passage leading to a tilt angle adjustment cylinder of a variable displacement travel motor, and the speed selection changeover valve is operated by a speed selection switch to rotate the travel motor at a low speed or a high speed. In a hydraulically driven vehicle, a pilot pressure shuttle valve for detecting pilot pressure is provided in the pilot pressure circuit of the left and right travel motors, and the pressure signal from the shuttle valve is guided to the speed selection switch side, and the left and right travel motors are operated. A circuit pressure shuttle valve is provided in the circuit to detect the circuit pressure, and the pressure signal from the shuttle valve is guided between the speed selection selector valve and the speed selection switch, and the speed is switched to low speed immediately before starting and stopping during high-speed operation. Also, a travel speed switching device for a hydraulic vehicle, characterized in that the speed of the travel motor is switched to a low speed when the circuit pressure of the travel motor exceeds a set pressure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6950087A JPH07106690B2 (en) | 1987-03-23 | 1987-03-23 | Travel speed switching device for hydraulic traveling vehicle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6950087A JPH07106690B2 (en) | 1987-03-23 | 1987-03-23 | Travel speed switching device for hydraulic traveling vehicle |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63235135A true JPS63235135A (en) | 1988-09-30 |
| JPH07106690B2 JPH07106690B2 (en) | 1995-11-15 |
Family
ID=13404502
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6950087A Expired - Fee Related JPH07106690B2 (en) | 1987-03-23 | 1987-03-23 | Travel speed switching device for hydraulic traveling vehicle |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07106690B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01203701A (en) * | 1988-02-05 | 1989-08-16 | Kawasaki Heavy Ind Ltd | Speed changeover device of hydraulic motor for vehicle running |
| JPH02195074A (en) * | 1989-01-23 | 1990-08-01 | Kubota Ltd | Hydraulic structure of vehicle |
| WO2007132670A1 (en) | 2006-05-11 | 2007-11-22 | Nabtesco Corporation | Variable hydraulic motor drive device |
| CN102134868A (en) * | 2010-01-22 | 2011-07-27 | 日立建机株式会社 | Hybrid power type engineering machine |
-
1987
- 1987-03-23 JP JP6950087A patent/JPH07106690B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01203701A (en) * | 1988-02-05 | 1989-08-16 | Kawasaki Heavy Ind Ltd | Speed changeover device of hydraulic motor for vehicle running |
| JPH02195074A (en) * | 1989-01-23 | 1990-08-01 | Kubota Ltd | Hydraulic structure of vehicle |
| WO2007132670A1 (en) | 2006-05-11 | 2007-11-22 | Nabtesco Corporation | Variable hydraulic motor drive device |
| US8122714B2 (en) | 2006-05-11 | 2012-02-28 | Nabtesco Corporation | Variable hydraulic motor driving device |
| CN102134868A (en) * | 2010-01-22 | 2011-07-27 | 日立建机株式会社 | Hybrid power type engineering machine |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH07106690B2 (en) | 1995-11-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |