JPH0665244B2 - Lifting control device for ground work machine - Google Patents
Lifting control device for ground work machineInfo
- Publication number
- JPH0665244B2 JPH0665244B2 JP60279881A JP27988185A JPH0665244B2 JP H0665244 B2 JPH0665244 B2 JP H0665244B2 JP 60279881 A JP60279881 A JP 60279881A JP 27988185 A JP27988185 A JP 27988185A JP H0665244 B2 JPH0665244 B2 JP H0665244B2
- Authority
- JP
- Japan
- Prior art keywords
- height
- setting device
- working
- depth
- tractor
- 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
- Lifting Devices For Agricultural Implements (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、トラクタに連結されているロータリ耕耘装
置の如き対地作業機の昇降制御装置に関するもので、耕
耘作業における作業高さの調節操作に便利であるように
工夫した昇降制御装置を提案するものであつて、トラク
タに利用できる。Description: TECHNICAL FIELD The present invention relates to a lifting control device for a ground working machine such as a rotary tiller connected to a tractor, and is used for adjusting a working height in a tilling work. It proposes a lift control device devised for convenience and can be used for tractors.
高さ設定器にて設定された高さに対地作業機を昇降制御
できる高さ制御機能と、耕深設定器によつて設定された
耕深にこの対地作業機を制御できるようにした耕深制御
機能を有しているトラクタを用いて耕耘作業を行うと
き、作業前の吊上位置から対地作業機を、高さ設定器に
て設定した高さまで下降させ、次に耕深設定器を操作し
て所望の耕深設定値を設定して、この耕深設定操作によ
つて対地作業機は耕深設定値を目標として下働して耕深
制御が開始されることになる。A height control function that allows the ground work implement to be raised and lowered to the height set by the height setter, and a working depth that allows the ground work implement to be controlled to the working depth set by the tillage depth setter. When performing plowing work using a tractor with a control function, lower the ground work implement from the lifting position before work to the height set by the height setting device, and then operate the plowing depth setting device. Then, a desired plowing depth setting value is set, and by this plowing depth setting operation, the ground work machine works downward with the plowing depth setting value as a target to start plowing depth control.
このように、対地作業機を吊上位置から下降させるに
は、高さ設定器による高さ設定操作に引続いて、耕深設
定操作を必ず行わねばならず、したがつて、耕深制御作
業中に一たん、吊上状態としたときは、必ず再度、耕深
設定操作を必要とすると云う面倒があり、例えば畦際に
おける比較的に高い圃場面では、畦際以外のときの耕耘
爪の位置よりも上位となるように耕耘作業を行つて、畦
際を終つたとき以降は、通常の位置にまで耕耘爪を下降
させることを行う場合、畦際とそれ以外の夫々の区域毎
にその都度、耕深設定操作を設定し直す必要があつて面
倒である。In this way, in order to lower the ground work implement from the hoisting position, the plowing depth setting operation must always be performed following the height setting operation by the height setting device. Once in the suspended state, there is a trouble that it is always necessary to set the working depth again, for example, in a relatively high field scene at the ridge, the plow of the tilling claw at times other than the ridge is When plowing work is performed so that it is higher than the position, and when the tilling claw is lowered to the normal position after finishing the ridge, the ridge and the other area It is troublesome because it is necessary to reset the plowing depth setting operation each time.
この発明は、耕耘作業中では所望の耕深設定を行つた後
は、対地作業機を昇降操作しても再度、耕深設定を行う
必要を省いて操作が容易となるように工夫したものであ
つて、その構成は、作業機連結リンク機構（７）にてト
ラクタ（１）へ連結されている対地作業機（２）が、油
圧昇降機構（９）によつて昇降自在に設けられ、高さ設
定器（I1）にて設定される高さ設定値に、高さセンサ
（S1）にて検出された高さ検出値が一致するように油圧
昇降機構（９）が制御されると共に、耕深設定器（I2）
にて設定される耕深設定値に耕深センサ（S2）にて検出
された耕深検出値が一致するように油圧昇降機構（９）
を制御する制御部（12）を有しているトラクタにおい
て、該トラクタは、作業状態又は非作業状態の何れかを
指定するためのスイッチを備え、該スイッチ（23）の動
作にて作業機が作業状態にあるとき、高さ設定器（I1）
の作業機吊上指示位置から下降方向への操作に伴つて、
この高さ設定器（I1）及び耕深設定器（I2）の何れか高
い位置を設定している設定器によつて指定された設定高
さに油圧昇降機構（９）を下降制御すべく、上記制御部
（12）を構成したことを特徴とする対地作業機の昇降制
御装置である。This invention has been devised so that the operation can be facilitated by omitting the need to set the working depth again after the desired working depth is set during the tilling work, even if the ground work machine is moved up and down. The construction is such that the ground work implement (2) connected to the tractor (1) by the work implement connection link mechanism (7) is provided so as to be able to move up and down by the hydraulic lifting mechanism (9). The hydraulic lifting mechanism (9) is controlled so that the height detection value detected by the height sensor (S 1 ) matches the height setting value set by the height setting device (I 1 ). , Working depth setting device (I 2 )
The hydraulic lifting mechanism (9) so that the tilling depth detection value detected by the tilling depth sensor (S 2 ) matches the tilling depth setting value set at
In a tractor having a control unit (12) for controlling the tractor, the tractor includes a switch for designating either a working state or a non-working state, and the work machine is operated by the operation of the switch (23). Height setting device (I 1 ) when in working condition
With the operation in the descending direction from the working machine lifting instruction position of
The hydraulic lifting mechanism (9) is controlled to descend to the set height designated by the height setting device (I 1 ) or the working depth setting device (I 2 ) whichever is set higher. In view of the above, the above-mentioned control section (12) is configured to provide a lifting control device for a ground work machine.
作業状態切替スイッチ（23）を高さ設定器（I1）を作業
機吊上指示位置から下降方向へ操作すると、制御部（1
2）の指令によつてこの高さ設定器（I1）及び耕深設定
器（I2）の何れか高い位置を設定している設定器によつ
て指定された設定高さに、油圧昇降機構（９）が下降制
御させることになるので畦際以外の耕深設定値を耕深設
定器（I2）によつて設定しておいて、畦際附近では耕深
設定値よりも少し高位の位置を高さ設定器（I1）によつ
て設定指示することによつて耕耘作業を行い、畦際附近
を終えたときに高さ設定器（I1）を例えば最下位位置に
操作すれば、耕深設定器（I2）にて設定された耕深に対
地作業機（２）が制御されることになるものである。When the work status changeover switch (23) is operated by operating the height setting device (I 1 ) in the descending direction from the working machine lifting instruction position, the control unit (1
In accordance with the command of 2 ), the hydraulic lifting / lowering is performed at the set height specified by the height setting device (I 1 ) or the working depth setting device (I 2 ) that is set to the higher position. Since the mechanism (9) will control the descent, the plowing depth setting value other than the ridgeline is set by the plowing depth setter (I 2 ), and it is slightly higher than the plowing depth set value near the ridgeline. by the position performed by connexion tilling to instructs connexion set height setter (I 1), operating the height setter to (I 1) for example to the lowest position when finishing the vicinity when ridges For example, the ground work implement (2) is controlled to the working depth set by the working depth setting device (I 2 ).
次にこの発明の一実施例を図に基づいて説明する。第２
図に示すように、トラクタ（１）の後部に対地作業機
（２）の１例としてのロータリ耕耘装置を左右１対のリ
フトアーム（３）（３）へ、左右のリフトロツド（４）
（４）を介して上下に揺動する左右のロワーリンク
（５）（５）及び、中央上部のトツプリンク（６）から
なる作業機連結リンク機構（７）によつて連結し、この
作業機連結リンク機構（７）は、そのリフトアーム
（３）（３）を、油圧を用いたリフトシリンダ（８）に
よつて昇降回動させる油圧昇降機構（９）によつて昇降
動作をするものである。Next, an embodiment of the present invention will be described with reference to the drawings. Second
As shown in the figure, a rotary tiller, which is an example of a ground working machine (2), is provided at the rear of the tractor (1) to a pair of left and right lift arms (3) (3) and left and right lift rods (4).
The left and right lower links (5) and (5) swinging up and down via (4) and the working machine connecting link mechanism (7) including the top link (6) in the upper center are connected to each other. The connecting link mechanism (7) is moved up and down by a hydraulic lifting mechanism (9) that lifts and lifts its lift arms (3) (3) by a lift cylinder (8) using hydraulic pressure. is there.
高さ制御において、油圧昇降機構（９）を昇降制御する
高さ設定器（I1）は、設定レバー（10）の回動操作によ
つて操作されるポリューム（11）にて構成され、リフト
アーム（３）のリフト軸にその検出軸を連結しているポ
テンシヨメータからなる高さセンサ（S1）によつて検出
された高さ検出値が、設定レバー（10）の回動操作によ
つて高さ設定器（I1）にて設定される高さ設定値に一致
するまで、マイクロコンピユータの如きものにて構成し
ている制御部（12）が油圧昇降機構（９）を制御するも
のであつて、上昇用ソレノイド弁（13）又は下降用ソレ
ノイド弁（14）のオン又はオフ動作を、上昇用駆動部
（15）又は下降用駆動部（16）が制御部（12）の出力指
令に基づいて行うように構成し、耕深制御における油圧
昇降機構（９）の昇降制御を行う耕深設定器（I2）は、
設定ダイヤル（17）の回動操作によつて調節されるボリ
ユーム（18）にて構成され、地表を摺接できるように上
下回動自在に対地作業機機体に螺着されているリヤカバ
ー（19）の上下動作を、ポテンシヨメータからなる耕深
センサ（S2）によつて検出して、この耕深センサ（S2）
によつて検出された耕深検出値が、設定ダイヤル（17）
の回動操作によつて耕深設定機（I2）にて設定される耕
深設定値に一致するまで、制御部（12）が上昇用ソレノ
イド弁（13）又は下降用ソレノイド弁（14）のオン、オ
フ動作を制御するものであり、作業モード切替スイツチ
（20）を高さ制御位置（21）に切替えたときに上記の高
さ制御が行われることになり、耕深制御位置（22）に作
業モード切替スイツチ（20）を置いたときは、耕深制御
が行われるものであり、そして、作業切替スイツチ（2
3）をオン動作して作業状態に切替えた状態では、高さ
設定器（I1）又は耕深設定器（I2）の何れか高い位置を
設定している設定器によつて指定された設定高さに、対
地作業機（２）の昇降制御が行われるように制御部（1
2）を構成したものである。In the height control, the height setting device (I 1 ) for controlling the lifting and lowering of the hydraulic lifting mechanism (9) is composed of a volume (11) which is operated by rotating the setting lever (10). The height detection value detected by the height sensor (S 1 ) consisting of a potentiometer that connects the detection shaft to the lift shaft of the arm (3) is used to rotate the setting lever (10). Therefore, until the height set value set by the height setter (I 1 ) is matched, the control unit (12) constituted by something like a microcomputer controls the hydraulic lifting mechanism (9). The on / off operation of the ascending solenoid valve (13) or the descending solenoid valve (14) is controlled by the ascending drive unit (15) or the descending drive unit (16) output from the control unit (12). Lifting control of hydraulic lifting mechanism (9) in plowing depth control, configured to perform based on commands Tilling depth setting device (I 2) is to perform,
A rear cover (19) which is composed of a volume (18) adjusted by rotating the setting dial (17) and is screwed to the ground work machine body so as to be vertically rotatable so that the ground surface can be slidably contacted. Up and down movements of the machine are detected by a tilling depth sensor (S 2 ) consisting of a potentiometer, and this tilling depth sensor (S 2 )
The working depth detection value detected by the setting dial (17)
The control unit (12) controls the ascending solenoid valve (13) or the descending solenoid valve (14) until the tilling depth setting value set by the tilling depth setting machine (I 2 ) is matched by the turning operation of. It controls the on / off operation of the work mode. When the work mode switching switch (20) is switched to the height control position (21), the above height control is performed, and the working depth control position (22 ), When the work mode switch (20) is placed, the working depth control is performed, and the work switch (2)
When 3) is turned on and switched to the working state, the height setting device (I 1 ) or the working depth setting device (I 2 ) is specified by the setting device that sets the higher position. The control unit (1) controls the ground work implement (2) to be raised and lowered at the set height.
2) is composed.
又、ボリユームの如きものにて構成している上限設定器
（24）の回動操作によつて設定した上限値に、作業切替
スイツチ（23）のオフ動作時には対地作業機（２）が上
昇するように構成している。Further, the ground work implement (2) rises to the upper limit value set by the turning operation of the upper limit setter (24) composed of a volume-like one when the work switching switch (23) is off. Is configured as follows.
高さセンサ（S1）は、上記実施例のほか、例えばロワー
リンク（５）の上下方向回動角或いはトツプリンク
（６）の上下回動角を検出する構造のものを用いても良
く、種々のものを使用できる。The height sensor (S 1 ) may be, for example, one having a structure for detecting the vertical rotation angle of the lower link (5) or the vertical rotation angle of the top link (6) in addition to the above embodiment, Various ones can be used.
尚、上記作業切替スイッチ（23）は、作業状態又は非作
業状態の何れかを指定するスイッチであればよいのであ
り、特定せらるべきではない。The work changeover switch (23) may be any switch that specifies either the work state or the non-working state, and should not be specified.
この発明に係る対地作業機の昇降制御装置は上述のよう
に構成したものであつて、高さ設定器（I1）を作業機吊
上指示位置から下降方向へ操作すると、制御部（12）の
指令によつてこの高さ設定器（I1）及び耕深設定器
（I2）の何れか高い位置を設定している設定器によつて
指定された設定高さに油圧昇降機構（９）が下降制御さ
れることになるので、畦際以外の耕深設定値を耕深設定
器（I2）によつて設定しておいて、畦際附近では耕深設
定値よりも少し高位の位置を高さ設定器（I1）によつて
設定指示することによつて耕耘作業を行い、畦際附近を
終えたときに、高さ設定器（I1）を例えば最下位位置に
操作すれば、耕深設定器（I2）にて設定された耕深に対
地作業機（２）が制御されることになるので、畦際附近
の耕耕作業などにおける対地作業機（２）の昇降操作に
便利となり、或いは又、作業中に土壌抵抗の急増が発生
してエンジン回転数が急に低下したとき、対地作業機
（２）を少し上昇操作して作業負荷を軽減してエンジン
回転を回復した後、高さ設定器（I1）を最下位位置に戻
し操作することによつて上昇操作前の耕深設定値に対地
作業機（２）が再び制御されることになるので、このよ
うに、１時的に対地作業機（２）を上昇操作した後の高
さ制御における操作を極めて容易化できたのである。The elevation control device for a ground work machine according to the present invention is configured as described above, and when the height setter (I 1 ) is operated in the descending direction from the work machine lifting instruction position, the control unit (12). The height setting device (I 1 ) or the working depth setting device (I 2 ) is set to a higher position by the command of the hydraulic setting mechanism (9) to the set height specified by the setting device. ) Will be controlled to be lowered. Therefore, set the tilling depth setting value other than the ridgeline using the tilling depth setter (I 2 ), and set a little higher than the tilling depth setting value near the ridgeline. When the position is set by the height setter (I 1 ), the cultivating work is performed, and when the position near the ridge is finished, the height setter (I 1 ) is operated to the lowest position, for example. if, tilling depth setting device since (I 2) set in the tilling depth in ground working machine (2) is to be controlled, such as in hydroponic farming industry vicinity when ridge It is convenient for raising and lowering the ground work machine (2), or when the engine speed suddenly drops due to a sudden increase in soil resistance during work, raise the ground work machine (2) slightly. After the work load is reduced and the engine speed is restored, the height setting device (I 1 ) is returned to the lowest position so that the ground work implement (2) returns to the working depth setting value before the raising operation. As described above, since the control is performed, the operation in the height control after the temporary lifting operation of the ground work implement (2) can be extremely facilitated.
図はこの発明の一実施例を示し、第１図は制御回路図、
第２図はトラクタの側面図、第３図は第１図における要
部斜視図である。 符号説明 （１）……トラクタ、（２）……対地作業機 （７）……作業機連結リンク機構、（９）……油圧昇降
機構 （12）……制御部、（23）……作業状態切替スイツチ （I1）……高さ設定器、（I2）……耕深設定器 （S1）……高さセンサ、（S2）……耕深センサFIG. 1 shows an embodiment of the present invention, FIG. 1 is a control circuit diagram,
FIG. 2 is a side view of the tractor, and FIG. 3 is a perspective view of an essential part in FIG. Explanation of symbols (1) …… tractor, (2) …… ground work machine (7) …… work machine connecting link mechanism, (9) …… hydraulic lifting mechanism (12) …… control unit, (23) …… work State switching switch (I 1 ) …… Height setting device, (I 2 ) …… Tilling depth setting device (S 1 ) …… Height sensor, (S 2 ) …… Tilling depth sensor
Claims (1)
されている対地作業機が、油圧昇降機構によって昇降自
在に設けられ、高さ設定器にて設定される高さ設定値
に、高さセンサにて検出された高さ検出値が一致するよ
うに油圧昇降機構が制御されると共に、耕深設定器にて
設定される耕深設定値に、耕深センサにて検出された耕
深検出値が一致するように油圧昇降機構を制御する制御
部を有しているトラクタにおいて、該トラクタは作業状
態又は非作業状態の何れかを指定するためのスイッチを
備え、該スイッチの動作にて作業機が作業状態にあると
き、高さ設定器の作業機吊上指示位置から下降方向への
操作に伴って、この高さ設定器及び耕深設定器の何れか
高い位置を設定している設定器によって指定された設定
高さに、油圧昇降機構を下降制御すべく上記制御部を構
成したことを特徴とする対地作業機の昇降制御装置。1. A ground work implement connected to a tractor by a work implement connection link mechanism is provided so as to be movable up and down by a hydraulic lifting mechanism, and has a height set value set by a height setter. The hydraulic lifting mechanism is controlled so that the height detection values detected by the sensor match, and the tilling depth detected by the tilling depth sensor is set to the tilling depth setting value set by the tilling depth setting device. In a tractor that has a control unit that controls the hydraulic lifting mechanism so that the values match, the tractor is equipped with a switch for designating either a working state or a non-working state, and the work is performed by the operation of the switch. When the machine is in the working state, the height setting device or the working depth setting device, whichever is higher, is set as the height setting device is operated in the descending direction from the working machine lifting instruction position. Hydraulic lift to the set height specified by the device Elevation control apparatus for ground working machine, characterized in that constitute the control unit to control lower the.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60279881A JPH0665244B2 (en) | 1985-12-12 | 1985-12-12 | Lifting control device for ground work machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60279881A JPH0665244B2 (en) | 1985-12-12 | 1985-12-12 | Lifting control device for ground work machine |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5117255A Division JP2661859B2 (en) | 1993-05-19 | 1993-05-19 | Hydraulic lifting control of tractor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62138106A JPS62138106A (en) | 1987-06-20 |
| JPH0665244B2 true JPH0665244B2 (en) | 1994-08-24 |
Family
ID=17617236
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60279881A Expired - Lifetime JPH0665244B2 (en) | 1985-12-12 | 1985-12-12 | Lifting control device for ground work machine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0665244B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62272904A (en) * | 1986-05-20 | 1987-11-27 | 株式会社クボタ | Electric type automatic controller of agricultural tractor |
| JPH0657083B2 (en) * | 1986-06-24 | 1994-08-03 | ヤンマーディーゼル株式会社 | Automatic control device for tractor tilling depth |
| JPH0810244Y2 (en) * | 1990-04-06 | 1996-03-29 | 三菱農機株式会社 | Lifting range setting device for working section in work vehicle |
| JPH0615343B2 (en) * | 1990-05-29 | 1994-03-02 | 三菱農機株式会社 | Structure of control operation part in agricultural tractor |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53103804A (en) * | 1977-02-17 | 1978-09-09 | Diesel Kiki Co | Plow position controller of tractor |
| JPS53122505A (en) * | 1977-03-28 | 1978-10-26 | Osaka Koukiyuu Chiyuuzou Tetsu | Automatic depth control device |
| JPS54135104A (en) * | 1978-03-16 | 1979-10-20 | Fujikoshi Kk | Automatic position controller of working machine |
| JPS557070A (en) * | 1978-06-30 | 1980-01-18 | Sato Zoki Co Ltd | Working machine lifting controller of farm tractor |
| JPS5526879A (en) * | 1978-08-17 | 1980-02-26 | Sato Zoki Co Ltd | Working machine lifting and lowering device of power farm machine |
| JPS5554804A (en) * | 1978-10-19 | 1980-04-22 | Diesel Kiki Co | Lifting and lowering controller of working machine for tractor |
| JPS5678504A (en) * | 1979-11-28 | 1981-06-27 | Kubota Ltd | Soil treating machine with automatic lifting control mechanism |
| JPS5847123A (en) * | 1981-09-12 | 1983-03-18 | Mitsubishi Heavy Ind Ltd | Internal combustion engine |
| JPS602002A (en) * | 1983-06-17 | 1985-01-08 | Hitachi Ltd | Position detecting method of transport vehicle |
| JPS6016509A (en) * | 1983-07-08 | 1985-01-28 | 井関農機株式会社 | Earth working controller in tractor |
-
1985
- 1985-12-12 JP JP60279881A patent/JPH0665244B2/en not_active Expired - Lifetime
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53103804A (en) * | 1977-02-17 | 1978-09-09 | Diesel Kiki Co | Plow position controller of tractor |
| JPS53122505A (en) * | 1977-03-28 | 1978-10-26 | Osaka Koukiyuu Chiyuuzou Tetsu | Automatic depth control device |
| JPS54135104A (en) * | 1978-03-16 | 1979-10-20 | Fujikoshi Kk | Automatic position controller of working machine |
| JPS557070A (en) * | 1978-06-30 | 1980-01-18 | Sato Zoki Co Ltd | Working machine lifting controller of farm tractor |
| JPS5526879A (en) * | 1978-08-17 | 1980-02-26 | Sato Zoki Co Ltd | Working machine lifting and lowering device of power farm machine |
| JPS5554804A (en) * | 1978-10-19 | 1980-04-22 | Diesel Kiki Co | Lifting and lowering controller of working machine for tractor |
| JPS5678504A (en) * | 1979-11-28 | 1981-06-27 | Kubota Ltd | Soil treating machine with automatic lifting control mechanism |
| JPS5847123A (en) * | 1981-09-12 | 1983-03-18 | Mitsubishi Heavy Ind Ltd | Internal combustion engine |
| JPS602002A (en) * | 1983-06-17 | 1985-01-08 | Hitachi Ltd | Position detecting method of transport vehicle |
| JPS6016509A (en) * | 1983-07-08 | 1985-01-28 | 井関農機株式会社 | Earth working controller in tractor |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62138106A (en) | 1987-06-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH0779565B2 (en) | Lifting control device for agricultural work machines | |
| JPH0665244B2 (en) | Lifting control device for ground work machine | |
| JP2559696B2 (en) | Lifting control device for tractor | |
| JP2548123B2 (en) | Tractor lifting control | |
| JP2661859B2 (en) | Hydraulic lifting control of tractor | |
| JPH062B2 (en) | Control mode switching device in work equipment control device | |
| JPH0636645Y2 (en) | Rotary depth control device for rotary tiller | |
| JP2855731B2 (en) | Reversing rise control device of rotary tilling device | |
| JPS60192501A (en) | Tractor | |
| JP2510039B2 (en) | Lift control device | |
| JP2827369B2 (en) | Hydraulic control device for powered vehicle | |
| JPH0448649Y2 (en) | ||
| JP3008546B2 (en) | Work machine lift control device | |
| JPH0984411A (en) | Lifting and lowering control device for ground working machine | |
| JPH0387102A (en) | Hydraulic controller of power-driven vehicle | |
| JPH086408Y2 (en) | Downward speed control device for ground work machine | |
| JPH0624445B2 (en) | Tilling depth control device | |
| JP2512955B2 (en) | Ground work machine lifting control | |
| JPH0984410A (en) | Lifting and lowering control device for ground working machine | |
| JPH0622608A (en) | Lift-controlling apparatus of tractor | |
| JP2893909B2 (en) | Hydraulic control unit for ground work machine | |
| JP2527014B2 (en) | Hydraulic control of tractor | |
| JPH0536325Y2 (en) | ||
| JP2508663B2 (en) | Down valve cutting device for ground work machine | |
| JP2559696C (en) |