JPH083748Y2 - Control device for hydraulically driven vehicle - Google Patents
Control device for hydraulically driven vehicleInfo
- Publication number
- JPH083748Y2 JPH083748Y2 JP1987024054U JP2405487U JPH083748Y2 JP H083748 Y2 JPH083748 Y2 JP H083748Y2 JP 1987024054 U JP1987024054 U JP 1987024054U JP 2405487 U JP2405487 U JP 2405487U JP H083748 Y2 JPH083748 Y2 JP H083748Y2
- Authority
- JP
- Japan
- Prior art keywords
- hydraulic
- swash plate
- load
- vehicle
- motor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Landscapes
- Motor Power Transmission Devices (AREA)
- Control Of Fluid Gearings (AREA)
Description
【考案の詳細な説明】 〈産業上の利用分野〉 本考案は、荷役車両等の液圧駆動車両の制御装置に関
する。DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a control device for a hydraulically driven vehicle such as a cargo handling vehicle.
〈従来技術〉 従来の荷役用液圧駆動車両（HST車両）において、旋
回するときとか荷を積んで坂を登るときなど、高速レン
ジ（高速度段）のままだとエンジンの回転数が落ちてく
る。このときは、オペレータがマニアル（手動）で液圧
モーターの斜板の傾斜を操作して低速レンジに切換えて
いる。<Prior art> In a conventional hydraulically driven vehicle for cargo handling (HST vehicle), the engine speed drops if the vehicle remains in the high speed range (high speed stage), such as when turning or climbing a hill with a load. come. At this time, the operator manually operates the tilt of the swash plate of the hydraulic motor to switch to the low speed range.
低速レンジから高速レンジへの切換えの場合も同様
に、走行しながらマニアルで切換えている。Similarly, when switching from the low-speed range to the high-speed range, switching is done manually while running.
〈考案が解決しようとする問題点〉 上記の如く、走行中に荷役車両の液圧モーターの斜板
をマニアルでコントロールし、高速レンジや低速レンジ
に切換えるという操作は煩わしいといつた問題点があ
る。<Problems to be solved by the invention> As described above, there is a problem in that the operation of manually controlling the swash plate of the hydraulic motor of the cargo handling vehicle to switch to the high speed range or the low speed range while traveling is troublesome. .
本考案は、上記問題点に鑑み、液圧駆動装置のチヤー
ジ圧を利用してレンジを自動的に切換えることにより、
レンジ切換えの煩わしさを解決し得る液圧駆動車両の制
御装置の提供を目的とする。In view of the above problems, the present invention uses the charge pressure of the hydraulic drive device to automatically switch the range,
An object of the present invention is to provide a control device for a hydraulic drive vehicle that can solve the trouble of range switching.
〈問題点を解決するための手段〉 本考案による問題点解決手段は、第１図の液圧（油
圧）回路図に示す如く、二個の可変容量液圧ポンプP1,P
2と、各液圧ポンプP1,P2からの圧液により駆動される二
個の可変容量液圧モーターM1,M2とを具えた液圧駆動車
両において、各液圧モーターM1,M2の負荷を検出する負
荷検出手段１と、各液圧モーターM1,M2の斜板２に連結
機構を介して連結された斜板切換用の操作シリンダ12
と、少なくともどちらか一方の液圧モーターM1,M2の負
荷が設定値以上のとき各液圧モーターM1,M2の斜板２が
低速方向に傾斜するように前記操作シリンダ12に対する
圧液の流れを変化させる切換弁13とを具えてなる。<Means for Solving Problems> The problem solving means according to the present invention is, as shown in the hydraulic (hydraulic) circuit diagram of FIG. 1, two variable displacement hydraulic pumps P1, P.
Detects the load on each hydraulic motor M1, M2 in a hydraulic drive vehicle that includes 2 and two variable displacement hydraulic motors M1, M2 driven by the hydraulic fluid from each hydraulic pump P1, P2 Load detecting means 1 and the swash plate switching operation cylinder 12 connected to the swash plate 2 of each hydraulic motor M1, M2 via a connecting mechanism.
When the load of at least one of the hydraulic motors M1 and M2 is equal to or greater than the set value, the flow of the hydraulic liquid to the operation cylinder 12 is controlled so that the swash plate 2 of each hydraulic motor M1 and M2 inclines in the low speed direction. And a switching valve (13) for changing.
〈作用〉 上記問題点解決手段において、各液圧ポンプP1,P2か
らの圧液により各液圧モーターM1,M2が駆動して車両は
走行可能となる。<Operation> In the above problem solving means, the hydraulic motors M1 and M2 are driven by the hydraulic fluid from the hydraulic pumps P1 and P2 to enable the vehicle to travel.
各液圧モーターM1,M2の斜板２が高速方向（高速レン
ジ）で走行中、旋回や登坂時に車両にかかる負荷が大き
くなると、両方あるいはどちらか一方の液圧モータM1,M
2の負荷圧力が上昇する。この負荷が設定値以上になる
と、切換弁13が切換わつて操作シリンダ12に対する圧液
の流れが変化し、このときの操作シリンダ12の作動によ
り各液圧モーターM1,M2の斜板２が低速方向に傾斜し
て、自動的に低速レンジに切換わる。If the swash plate 2 of each hydraulic motor M1, M2 is traveling in the high speed direction (high speed range) and the load on the vehicle during turning or climbing becomes large, either or both hydraulic motors M1, M2
The load pressure of 2 rises. When this load exceeds the set value, the switching valve 13 switches to change the flow of the hydraulic fluid to the operating cylinder 12, and the operation of the operating cylinder 12 at this time causes the swash plate 2 of each hydraulic motor M1, M2 to move at a low speed. It tilts in the direction and automatically switches to the low speed range.
〈実施例〉 以下、本考案の一実施例における液圧駆動車両の制御
装置を第１図ないし第３図に基づいて説明する。第１図
は本考案の実施例を示す液圧駆動車両の制御装置の要部
液圧回路図、第２図は同じく全体液圧回路図、第３図は
同じく車両の速度と駆動力の関係を示すグラフである。<Embodiment> A control device for a hydraulically driven vehicle according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 is a hydraulic circuit diagram of a main part of a control device for a hydraulically driven vehicle showing an embodiment of the present invention, FIG. 2 is the same overall hydraulic circuit diagram, and FIG. 3 is a relationship between vehicle speed and driving force. It is a graph which shows.
そして、図示の如く本実施例の制御装置は、二個の可
変容量液圧ポンプＰと、該液圧ポンプＰからの圧液によ
り駆動される二個の可変容量液圧モーターＭとを具えた
液圧駆動車両において、前記液圧モーターＭの負荷を検
出する負荷検出手段１と、該負荷検出手段１からの液圧
信号により前記液圧モーターＭの斜板２の傾斜角度を自
動的に切換える切換手段と、前記液圧モーターＭの負荷
が設定値以上で前記切換手段に斜板低速方向傾斜信号を
出力し前記液圧モーターＭの負荷が設定値以下で前記切
換手段に斜板高速方向傾斜信号を出力する液圧制御回路
３とを具えて成るものである。Then, as shown in the figure, the control device of the present embodiment includes two variable displacement hydraulic pumps P and two variable displacement hydraulic motors M driven by the hydraulic fluid from the hydraulic pumps P. In a hydraulically driven vehicle, load detecting means 1 for detecting the load of the hydraulic motor M, and the inclination angle of the swash plate 2 of the hydraulic motor M are automatically switched by a hydraulic pressure signal from the load detecting means 1. When the load of the switching means and the hydraulic motor M is above a set value, a swash plate low speed direction inclination signal is output to the switching means, and when the load of the hydraulic motor M is below the set value, the swash plate high speed direction is inclined to the switching means. And a hydraulic pressure control circuit 3 for outputting a signal.
前記液圧ポンプＰは第一ポンプP1と第二ポンプP2から
成る。第１図の如く、液圧駆動装置４の主回路５は、前
記第一、第二ポンプP1,P2と、そこに接続されたチヤー
ジポンプP3と、第一モーターM1および第二モーターM2か
ら成る前記液圧モーターＭとを有する。The hydraulic pump P comprises a first pump P1 and a second pump P2. As shown in FIG. 1, the main circuit 5 of the hydraulic drive unit 4 comprises the first and second pumps P1 and P2, the charge pump P3 connected thereto, the first motor M1 and the second motor M2. And a hydraulic motor M.
前記第一ポンプP1のそれぞれの出力端6a,6bが前記第
一モーターM1のそれぞれの入力端7a,7bに主管路８を介
して接続され、前記第二ポンプP2のそれぞれの出力端9
a,9bが前記第二モーターM2のそれぞれの入力端10a,10b
に主管路11を介して接続されている。The respective output terminals 6a, 6b of the first pump P1 are connected to the respective input terminals 7a, 7b of the first motor M1 via the main pipe line 8, and the respective output terminals 9 of the second pump P2 are connected.
a and 9b are the input terminals 10a and 10b of the second motor M2.
To the main pipe line 11.
前記切換手段は、前記チヤージポンプP3からの圧液に
より駆動する斜板切換用の操作シリンダ12から成り、前
記液圧制御回路３は、前記操作シリンダ12と該操作シリ
ンダ12を接続する四ポート二位置切換の液圧パイロツト
切換弁13から成る。The switching means comprises an operating cylinder 12 for switching the swash plate which is driven by the pressure liquid from the charge pump P3, and the hydraulic pressure control circuit 3 includes the operating cylinder 12 and a four-port two-position connecting the operating cylinder 12. It consists of a switching hydraulic pilot switching valve 13.
図において、前記操作シリンダ12のロツド側がロツド
側接続管14aを介して液圧パイロツト切換弁13の第一ポ
ート13aに接続され、テール側がテール側接続管14bを介
して第二ポート13bに接続されている。そして、前記ロ
ツド側接続管14a、テール側接続管14bの管端が共にオイ
ルタンク15まで延長され、前記ロツド側接続管14aの管
端にチエツクバルブ16が接続されている。In the figure, the rod side of the operating cylinder 12 is connected to the first port 13a of the hydraulic pilot switching valve 13 via the rod side connecting pipe 14a, and the tail side is connected to the second port 13b via the tail side connecting pipe 14b. ing. The pipe ends of the rod-side connecting pipe 14a and the tail-side connecting pipe 14b are both extended to the oil tank 15, and the check valve 16 is connected to the pipe end of the rod-side connecting pipe 14a.
前記負荷検出手段１は、前記第一モーターM1および第
二モーターM2のそれぞれの入力端7a,7b,10a,10bに接続
された逆止弁17を有する第一接続管ないし第四接続管1
8,19,20,21と、該各接続管18,19,20,21の圧液を前記液
圧パイロツト切換弁13に導く導管22とから構成される。The load detecting means 1 includes a first connecting pipe to a fourth connecting pipe 1 having a check valve 17 connected to the respective input ends 7a, 7b, 10a, 10b of the first motor M1 and the second motor M2.
It is composed of 8,19,20,21 and a conduit 22 for guiding the pressure liquid of each of the connecting pipes 18,19,20,21 to the hydraulic pressure pilot switching valve 13.
第２図中の30は、前記第一モーターM1および第二モー
ターM2に接続されたネガテイブブレーキ、31は車輪に連
結された減速機である。In FIG. 2, 30 is a negative brake connected to the first motor M1 and the second motor M2, and 31 is a speed reducer connected to the wheels.
32,33はそれぞれ前記第一モーターM1および第二モー
ターM2の出力側に接続された逆止弁である。Reference numerals 32 and 33 are check valves respectively connected to the output sides of the first motor M1 and the second motor M2.
35は荷役具用シリンダ、36は該シリンダ35と前記チヤ
ージポンプP3の間に接続された荷役用制御弁、37は該制
御弁36に設けられたリリーフ弁、38aは前記チヤージポ
ンプP3と前記オイルタンク15の間に接続されたフイル
タ、38bは前記荷役制御弁36と前記第一ポンプP1および
第二ポンプP2の間に接続されたフイルタである。35 is a cargo handling cylinder, 36 is a cargo handling control valve connected between the cylinder 35 and the charge pump P3, 37 is a relief valve provided in the control valve 36, and 38a is the charge pump P3 and the oil tank 15 And 38b is a filter connected between the cargo handling control valve 36 and the first pump P1 and the second pump P2.
39,40はそれぞれ前記主管路8,11上に接続されたリリ
ーフ弁である。Reference numerals 39 and 40 are relief valves connected to the main pipelines 8 and 11, respectively.
41は前記第一ポンプP1と前記オイルタンク15の間に接
続された熱交換器である。Reference numeral 41 is a heat exchanger connected between the first pump P1 and the oil tank 15.
また、43は、前記両ネガテイブブレーキ30と前記オイ
ルタンク15の間および前記チエツクバルブ16と液圧パイ
ロツト切換弁13の中間点42の間に接続された電磁式四ポ
ート二位置切換弁である。Reference numeral 43 denotes an electromagnetic four-port two-position switching valve connected between the both negative brakes 30 and the oil tank 15 and between the check valve 16 and the intermediate point 42 of the hydraulic pilot switching valve 13.
上記構成において、車両の速度レンジの切換を第３図
のグラフに基づいて説明する。Switching of the vehicle speed range in the above configuration will be described with reference to the graph of FIG.
本考案において、液圧ポンプＰからの圧液により液圧
モーターＭが駆動して車両は走行可能となる。そして、
通常、車両は低速レンジから高速レンジとなる。In the present invention, the hydraulic motor M is driven by the hydraulic fluid from the hydraulic pump P so that the vehicle can run. And
Usually, the vehicle goes from the low speed range to the high speed range.
斜板２が高速方向（高速レンジ）で走行中、旋回の場
合、片側の車輪に負荷が掛かると、例えば出力端6a,6b
の圧力が上昇する。このことによつても液圧パイロツト
切換弁13が切換わつて第一液圧モーターM1の斜板２が自
動的に低速方向に切換わる。When the swash plate 2 is traveling in the high speed direction (high speed range) and turning, if a load is applied to one wheel, for example, the output ends 6a, 6b.
Pressure rises. This also causes the hydraulic pilot switching valve 13 to switch, and the swash plate 2 of the first hydraulic motor M1 automatically switches to the low speed direction.
そして、液圧駆動装置４の主回路５のモーターのそれ
ぞれの入口、出口よりパイロツト圧を検出しているので
どの回路に圧が立つても液圧パイロツト切換弁13が作動
する回路となる。そして、これが例えば設定値の200kg/
cm2になると、液圧パイロツト切換弁13が作動し、低速
レンジに切換わる。Since the pilot pressures are detected from the respective inlets and outlets of the motors of the main circuit 5 of the hydraulic drive device 4, the hydraulic pilot switching valve 13 operates regardless of the circuit pressure. And this is, for example, the set value of 200 kg /
When the pressure reaches cm 2 , the hydraulic pilot switching valve 13 operates and switches to the low speed range.
これは、液圧パイロツト切換弁13が液圧により作動す
ると、切換手段としてのシリンダ12に対する圧液の流れ
が変わり、このシリンダ12のピストンロツドと適宜の連
結機構を介して連結されている第一、第二モーターM1,M
2の斜板２が低速方向に傾斜するためである。This is because when the hydraulic pilot switching valve 13 is actuated by hydraulic pressure, the flow of the pressurized liquid to the cylinder 12 as a switching means changes, and the piston rod of this cylinder 12 is connected via a suitable connecting mechanism. Second motor M1, M
This is because the swash plate 2 of 2 inclines in the low speed direction.
すると両ポンプP1,P2の出力端6a,6b,9a,9bの圧力は例
えば100kg/cm2に下降し、さらに負荷が大きくなれば低
速レンジのままリリーフ圧まで上昇する。斜板２が低速
方向（低速レンジ）で走行していて、次第に負荷が下が
り、出力端6a,6b,9a,9bの液圧が例えば100kg/cm2まで下
がると、液圧パイロツト切換弁13が高速の姿勢となり、
斜板２が高速方向に切換わり、自動的に高速レンジに切
換わる。Then, the pressure at the output ends 6a, 6b, 9a, 9b of the two pumps P1, P2 drops to, for example, 100 kg / cm 2 , and when the load further increases, the pressure rises to the relief pressure in the low speed range. When the swash plate 2 is traveling in the low speed direction (low speed range), the load gradually decreases, and the hydraulic pressure at the output ends 6a, 6b, 9a, 9b drops to, for example, 100 kg / cm 2 , the hydraulic pilot switching valve 13 It becomes a high-speed posture,
The swash plate 2 switches to the high speed direction, and automatically switches to the high speed range.
以上の自動切換えは、第３図の一点鎖線で示すような
切換えとなる。第３図は横軸に車速度、縦軸に駆動力を
とつた速度レンジの比較図である。The above automatic switching is the switching shown by the alternate long and short dash line in FIG. FIG. 3 is a comparison diagram of speed ranges in which the vehicle speed is plotted on the horizontal axis and the driving force is plotted on the vertical axis.
図中A,Bで示す実線はそれぞれ低速レンジおよび高速
レンジにおける走行の特徴を示すものであり、双方の交
点Ｃにおける主回路５の圧力は、高速レンジであれば約
200kg/cm2、低速レンジではその1/2（例えば減速比が1/
2にとつてある車両）の約100kg/cm2となる。The solid lines indicated by A and B in the figure show the characteristics of traveling in the low speed range and the high speed range, respectively, and the pressure of the main circuit 5 at the intersection C of the two is about the high speed range.
200kg / cm 2 , 1/2 of that in low speed range (for example, reduction ratio is 1 /
2), which is about 100 kg / cm 2 of the vehicle attached to 2).
なお、本考案は、上記実施例に限定されるものではな
く、本考案の範囲内で上記実施例に多くの修正および変
更を加え得ることは勿論である。It should be noted that the present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.
〈考案の効果〉 以上の説明から明らかな通り、本考案によれば、旋回
や登坂時における車両にかかる負荷に応じて変化する各
液圧モーターの負荷を検出し、自動的に各液圧モーター
の斜板を低速方向に傾斜させて、低速レンジに切換える
ことができるため、従来手動で行つていた速度レンジ切
換えの煩わしさを省くことができる。<Effects of the Invention> As is apparent from the above description, according to the present invention, the load of each hydraulic motor that changes according to the load applied to the vehicle at the time of turning or climbing is detected, and each hydraulic motor is automatically detected. Since it is possible to incline the swash plate in the low speed direction and switch to the low speed range, it is possible to eliminate the troublesomeness of manually changing the speed range that has been conventionally performed.
また、二個の液圧モーターで左右の車輪を夫々回転さ
せる構造としたとき、路面状況やブレーキの片効き等に
より左右の車輪における負荷が異なつて各液圧モーター
の負荷にばらつきが生じた場合であつても、少なくとも
どちらか一方の液圧モーターの負荷が設定値以上のとき
各液圧モーターの斜板が低速方向に傾斜するので、車両
の直進性を保つて安定した走行ができるといつた優れた
効果がある。Also, when the left and right wheels are rotated by two hydraulic motors respectively, and the load on the left and right wheels varies due to the road condition and one-sided braking, etc. Even so, when the load on at least one of the hydraulic motors is greater than the set value, the swash plate of each hydraulic motor inclines in the low speed direction, so it is possible to maintain stable straightness of the vehicle for stable driving. It has an excellent effect.
第１図は本考案の実施例を示す液圧駆動車両の制御装置
の要部液圧回路図、第２図は同じく全体液圧回路図、第
３図は同じく車両の速度と駆動力の関係を示すグラフで
ある。 1:負荷検出手段、2:斜板、3:液圧制御回路、4:液圧駆動
装置、5:主回路、6a,6b,9a,9b:出力端、12:シリンダ、1
2a:ピストンロツド、13:液圧パイロツト切換弁、C:交
点、M:液圧モーター、M1:第一モーター、M2:第二モータ
ー、P:液圧ポンプ。FIG. 1 is a hydraulic circuit diagram of a main part of a control device for a hydraulically driven vehicle showing an embodiment of the present invention, FIG. 2 is the same overall hydraulic circuit diagram, and FIG. 3 is a relationship between vehicle speed and driving force. It is a graph which shows. 1: load detection means, 2: swash plate, 3: hydraulic control circuit, 4: hydraulic drive device, 5: main circuit, 6a, 6b, 9a, 9b: output end, 12: cylinder, 1
2a: Piston rod, 13: Hydraulic pilot switching valve, C: Intersection, M: Hydraulic motor, M1: First motor, M2: Second motor, P: Hydraulic pump.
Claims (1)
プからの圧液により駆動される二個の可変容量液圧モー
ターとを具えた液圧駆動車両において、各液圧モーター
の負荷を検出する負荷検出手段と、各液圧モーターの斜
板に連結機構を介して連結された斜板切換用の操作シリ
ンダと、少なくともどちらか一方の液圧モーターの負荷
が設定値以上のとき各液圧モーターの斜板が低速方向に
傾斜するように前記操作シリンダに対する圧液の流れを
変化させる切換弁とを具えて成る液圧駆動車両の制御装
置。1. A hydraulic drive vehicle comprising two variable displacement hydraulic pumps and two variable displacement hydraulic motors driven by the hydraulic fluid from each hydraulic pump. When the load detection means that detects the load, the operation cylinder for swash plate switching that is connected to the swash plate of each hydraulic motor via the connection mechanism, and the load of at least one of the hydraulic motors is greater than or equal to the set value A control device for a hydraulically driven vehicle, comprising: a switching valve that changes the flow of the hydraulic fluid with respect to the operating cylinder so that the swash plate of each hydraulic motor tilts in the low speed direction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1987024054U JPH083748Y2 (en) | 1987-02-19 | 1987-02-19 | Control device for hydraulically driven vehicle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1987024054U JPH083748Y2 (en) | 1987-02-19 | 1987-02-19 | Control device for hydraulically driven vehicle |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63132158U JPS63132158U (en) | 1988-08-30 |
| JPH083748Y2 true JPH083748Y2 (en) | 1996-01-31 |
Family
ID=30822932
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1987024054U Expired - Lifetime JPH083748Y2 (en) | 1987-02-19 | 1987-02-19 | Control device for hydraulically driven vehicle |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH083748Y2 (en) |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5229381A (en) * | 1975-08-28 | 1977-03-05 | Fujitsu Ltd | Method for sealing chemicals |
-
1987
- 1987-02-19 JP JP1987024054U patent/JPH083748Y2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63132158U (en) | 1988-08-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3978937A (en) | Hydrostatic propulsion system | |
| CN101663515B (en) | Construction vehicle | |
| JPH0882367A (en) | Gear shifter for hydraulic type drive device and gear shift control method therefor | |
| JPH11350539A (en) | Traveling aid hydraulic circuit of hydraulic drive working vehicle | |
| US5653107A (en) | Hydrostatic propulsion drive | |
| JP2711894B2 (en) | Variable displacement pump controller for hydraulically driven vehicles | |
| JPH083748Y2 (en) | Control device for hydraulically driven vehicle | |
| JPH07223419A (en) | Suspension device for wheel type construction vehicle | |
| JPS63258223A (en) | Four-wheel driving system | |
| JPH0658411A (en) | Hst hydraulic pressure running driving device | |
| JP3266348B2 (en) | Hydraulic motor drive circuit for work vehicle traveling | |
| JP2690353B2 (en) | Make-up device for hydraulic circuit using load sensing system | |
| JPH078360Y2 (en) | Running control circuit for construction machinery | |
| JPH0245076Y2 (en) | ||
| JPH0321333Y2 (en) | ||
| US20230279642A1 (en) | Work machine | |
| JP3742941B2 (en) | Braking energy regeneration device | |
| JPH0732240Y2 (en) | Driving speed control device for hydraulically driven vehicle | |
| JPH02195074A (en) | Hydraulic structure of vehicle | |
| JPH02144824U (en) | ||
| JPH0646744Y2 (en) | Work vehicle travel control device | |
| JPS6223892Y2 (en) | ||
| JPH0730778Y2 (en) | Hydraulic circuit of wheeled backhoe work vehicle | |
| JPH11311330A (en) | Power recovery control method for vehicle | |
| JPS5815669Y2 (en) | Double pump flow control device |