JPH0795881B2 - Agricultural machine hydraulic lift device - Google Patents
Agricultural machine hydraulic lift deviceInfo
- Publication number
- JPH0795881B2 JPH0795881B2 JP63074487A JP7448788A JPH0795881B2 JP H0795881 B2 JPH0795881 B2 JP H0795881B2 JP 63074487 A JP63074487 A JP 63074487A JP 7448788 A JP7448788 A JP 7448788A JP H0795881 B2 JPH0795881 B2 JP H0795881B2
- Authority
- JP
- Japan
- Prior art keywords
- valve
- solenoid valve
- hydraulic
- lift device
- turned
- 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
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- Fluid-Pressure Circuits (AREA)
- Lifting Devices For Agricultural Implements (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は移動農機の油圧リフト装置に関し、詳しくは、
作動油の粘性抵抗が大きい低温時でも誤動作しないよう
にした移動農機の油圧リフト装置に関するものである。The present invention relates to a hydraulic lift device for a mobile agricultural machine, and more specifically,
The present invention relates to a hydraulic lift device for a mobile agricultural machine which prevents malfunctions even at low temperatures where the viscous resistance of hydraulic oil is large.
第８図に示す従来の油圧回路図において、作動油はフイ
ルタ１→ポンプ２→リリーフ弁３→分流弁４→コントロ
ール装置５→降下速度調整弁６→作業機昇降用油圧シリ
ンダ７の順に流れ、リフト装置が上昇する。そしてコン
トロール機構５には上昇用電磁弁14に接続する上昇用パ
イロツト弁10と、下降用電磁弁16に接続する下降用パイ
ロツト弁15とが配設されており、上昇用電磁弁14および
下降用電磁弁16は、第２図のようにマイコン35からの指
令信号により作動するよう構成されている。In the conventional hydraulic circuit diagram shown in FIG. 8, hydraulic fluid flows in the order of filter 1 → pump 2 → relief valve 3 → shunt valve 4 → control device 5 → descent speed adjusting valve 6 → work machine lifting hydraulic cylinder 7. Lifting device rises. The control mechanism 5 is provided with an ascending pilot valve 10 connected to the ascending solenoid valve 14 and a descending pilot valve 15 connected to the descending solenoid valve 16, and the ascending solenoid valve 14 and the descending solenoid valve 15 are provided. The solenoid valve 16 is configured to operate in response to a command signal from the microcomputer 35 as shown in FIG.
ところで、上述した従来の油圧回路では、作動油の粘性
抵抗が大きい低温時に、マイコン35よりの指令信号が中
立状態、または下降状態にあるにもかかわらず、リフト
装置30が上昇するという問題があつた。By the way, in the above-mentioned conventional hydraulic circuit, there is a problem that the lift device 30 moves up even when the command signal from the microcomputer 35 is in the neutral state or in the lowered state at a low temperature where the viscous resistance of the hydraulic oil is large. It was
つまり、中立状態では、上昇用電磁弁14が中立位置に切
換えられるので、パイロツト弁10が押し下げられて開放
された弁頭部を通つた作動油がドレン回路11を通りタン
ク12へ逃げるのが正常であるが、作動油の粘性が高い場
合には、弁10を押し下げようとしても、弁10の下方に残
つている油が抜けず弁10が押し下げられないので、作動
油は油路Ａから逆止弁13を押し上げて油圧シリンダ７側
に流れ、リフト装置30が上昇してしまうという欠点があ
つた。In other words, in the neutral state, the solenoid valve 14 for raising is switched to the neutral position, so that it is normal for the hydraulic oil passing through the valve head opened by pushing down the pilot valve 10 to escape to the tank 12 through the drain circuit 11. However, when the viscosity of the hydraulic oil is high, even if an attempt is made to push down the valve 10, the oil remaining below the valve 10 does not escape and the valve 10 cannot be pushed down. There is a drawback that the stop valve 13 is pushed up to flow to the hydraulic cylinder 7 side, and the lift device 30 rises.
そして、下降状態では、下降用電磁弁16が下降位置に切
換えられるので、パイロツト弁15が押し上げられて開放
された弁頭部を通つた作動油がドレン回路17を通りタン
ク12へ逃げるのが正常であるが、作動油の粘性が高い場
合には、弁15を押し上げようとしても、弁15の上方に残
つている油が抜けず弁15が押し上げられないので、中立
位置にある上昇用電磁弁14に影響され逆止弁13を押し上
げて流れた作動油が油圧シリンダ７側に流れ、リフト装
置30が上昇してしまうという欠点があつた。Then, in the descending state, the descending solenoid valve 16 is switched to the descending position, so that it is normal for the hydraulic oil passing through the valve head opened by pushing up the pilot valve 15 to escape to the tank 12 through the drain circuit 17. However, when the viscosity of the hydraulic oil is high, even if you try to push up the valve 15, the oil remaining above the valve 15 does not escape and the valve 15 cannot be pushed up, so the solenoid valve for rising in the neutral position There was a drawback that the hydraulic fluid that was influenced by 14 and pushed up the check valve 13 and flowed to the hydraulic cylinder 7 side raised the lift device 30.
この欠点は、リフト装置に重量がある作業機が装着され
リフト装置側の負荷が作動油の粘性抵抗よりも大きい場
合には発生しないが、リフト装置側の負荷が小さい場合
に発生することが多く、また、上昇用電磁弁14をONにし
た上昇状態では特に問題とはならないという特徴があ
る。This drawback does not occur when a heavy work implement is attached to the lift device and the load on the lift device side is larger than the viscous resistance of the hydraulic oil, but it often occurs when the load on the lift device side is small. In addition, there is a feature that it does not cause any particular problem in the ascending state in which the ascending solenoid valve 14 is turned on.
そこで、本発明は上述した従来の実情に鑑み、その欠点
を解消すべく創案されたもので、上昇用電磁弁をONにし
た上昇状態にある場合を除き、作動油の粘性抵抗が大き
い低温時に油圧リフト装置が誤作動しないようにした移
動農機の油圧リフト装置を提供することを目的として実
施するものである。Therefore, in view of the above-mentioned conventional circumstances, the present invention was devised in order to eliminate the drawbacks, except when the rising solenoid valve is in the ON state in an ascending state, at a low temperature when the viscous resistance of the hydraulic oil is large. The purpose of the present invention is to provide a hydraulic lift device for a mobile agricultural machine in which the hydraulic lift device does not malfunction.
上記目的を達成する本発明は、リフト装置に接続された
油圧シリンダとポンプとの間の油路に配設した上昇用パ
イロット弁と下降用パイロット弁とを、マイコンにより
制御される上昇用電磁弁および下降用電磁弁に夫々接続
し、上記両パイロット弁より前位の油路に、粘性抵抗が
大きい作動油のみをタンクに還流せしめる戻し機構を配
設し、前記上昇用電磁弁をONにした場合にこの戻し機構
を非作動状態にすると共に、上昇用電磁弁をOFFにした
場合にこの戻し機構を作動状態とするように制御する前
記マイコンを設けてなるものである。The present invention that achieves the above object is to provide a rising solenoid valve and a lowering pilot valve, which are arranged in an oil passage between a hydraulic cylinder connected to a lift device and a pump, with a rising solenoid valve controlled by a microcomputer. And a solenoid valve for lowering, respectively, and in the oil passage in front of both pilot valves, a return mechanism for returning only the hydraulic oil with large viscous resistance to the tank was placed, and the solenoid valve for rising was turned on. In this case, the return mechanism is inactivated, and the microcomputer for controlling the return mechanism to operate when the solenoid valve for raising is turned off is provided.
したがつて、油圧シリンダ７とポンプ２との間の油路に
配設した上昇用パイロツト弁10と下降用パイロツト弁15
とを、マイコン35により制御される上昇用電磁弁14およ
び下降用電磁弁16により夫々制御するようにした農機の
リフト装置にあつても、この両パイロツト弁よりも前位
の油路に粘性抵抗が高い作動油のみをタンク12に還流せ
しめる戻し機構37を配設し、しかも、上昇用電磁弁14を
ONにした場合には、戻し機構37を非作動状態にする一
方、上昇用電磁弁14をOFFにした場合には、戻し機構37
を作動状態とするように制御することにより、上昇用電
磁弁14をOFFにした下降状態又は中立状態にある場合に
は、粘性抵抗が高い作動油が両パイロツト弁まで送られ
ないので、従来の作動油の粘性抵抗が高い低温時にコン
トロール機構５としてのパイロツト弁10または15が誤作
動し、中立、または下降指令であるにもかかわらずリフ
ト装置30が上昇してしまうという問題を解消し得る。Therefore, the ascending pilot valve 10 and the descending pilot valve 15 arranged in the oil passage between the hydraulic cylinder 7 and the pump 2.
Even in the case of a lift device of an agricultural machine in which and are controlled by the ascending solenoid valve 14 and the descending solenoid valve 16 controlled by the microcomputer 35, respectively, viscous resistance is applied to the oil passage in front of both pilot valves. A return mechanism 37 is provided to recirculate only the hydraulic oil having a high flow rate into the tank 12, and the solenoid valve 14 for raising is installed.
When it is turned on, the return mechanism 37 is deactivated, while when the lift solenoid valve 14 is turned off, the return mechanism 37 is turned off.
By controlling so as to be in an operating state, when the ascending solenoid valve 14 is turned off or in a descending state or a neutral state, hydraulic oil with high viscous resistance cannot be sent to both pilot valves. It is possible to solve the problem that the pilot valve 10 or 15 as the control mechanism 5 malfunctions at a low temperature where the viscous resistance of the hydraulic oil is high, and the lift device 30 rises despite a neutral or down command.
以下、本発明を一実施例として示す図面について、上述
した第８図との重複を避けて説明する。Hereinafter, a drawing showing the present invention as an embodiment will be described while avoiding duplication with FIG. 8 described above.
第５図に示す如く、20は前部にエンジン21が配設され、
運転席22の側部にポテンシヨメータからなる設定器23付
のポジシヨンレバー24を設けた農用トラクタであつて、
後部にロータリ耕耘部等の作業機（図外）がアツパーリ
ンク25および左右一対のロアリンク26により昇降可能に
連結され、リフト機構30のリフトアーム29は左右一対の
リフトロツド27にて前記ロアリンク26に連結されてお
り、上記リフトアーム29および受動アーム31と一体に回
動するリフト軸32にはリフトアーム29の角度を検出する
リフトセンサ33が付設されている。As shown in FIG. 5, an engine 21 is provided at the front of the 20,
An agricultural tractor provided with a position lever 24 with a setting device 23 consisting of a potentiometer on the side of the driver's seat 22,
A working machine (not shown) such as a rotary tiller is connected to the rear part so as to be able to move up and down by an upper link 25 and a pair of left and right lower links 26. A lift sensor 33 that detects an angle of the lift arm 29 is attached to a lift shaft 32 that is connected to the lift arm 29 and rotates integrally with the lift arm 29 and the passive arm 31.
第６図に示すように受動アーム31が油圧ケース34の後壁
に接当した際、油路の昇圧はリリーフ弁３によりタンク
12に還流される。上記リフト軸32は油圧ケース34の後部
寄りに支承され、その受動アーム31は上昇用電磁弁14と
下降用電磁弁16のON、OFFにより伸縮作動する油圧シリ
ンダ７内のピストンロツド7aに連結されている。また、
前記設定器23の設定値とリフトセンサ33の検出値とは第
２図の如くマイコン35に入力され、マイコン35はそれら
の入力をデーター処理して上昇用電磁弁14および下降用
電磁弁16にON、OFF信号を指令する。As shown in FIG. 6, when the passive arm 31 contacts the rear wall of the hydraulic case 34, the relief valve 3 is used to increase the pressure in the oil passage.
Reflux to 12. The lift shaft 32 is supported near the rear of the hydraulic case 34, and its passive arm 31 is connected to the piston rod 7a in the hydraulic cylinder 7 which is expanded and contracted by turning on and off the ascending solenoid valve 14 and the descending solenoid valve 16. There is. Also,
The set value of the setter 23 and the detected value of the lift sensor 33 are input to the microcomputer 35 as shown in FIG. 2, and the microcomputer 35 processes the data to the rising solenoid valve 14 and the lowering solenoid valve 16. Command ON and OFF signals.
したがつて、ポジシヨンレバー24を上方側へ一杯操作す
ると、その設定値はリフトセンサ33の検出値より大きい
ので、上昇用電磁弁14がONとなりパイロツト弁10に通ず
るドレン回路11が閉鎖され、作動油は通路Ｘから逆止弁
13を押圧げて油圧シリンダ７に供給されることで、ピス
トンロツド7aが伸長してリフトアーム29が上昇する。Therefore, when the position lever 24 is fully operated upward, the set value is larger than the detection value of the lift sensor 33, so the solenoid valve 14 for raising is turned on and the drain circuit 11 leading to the pilot valve 10 is closed, Check the hydraulic oil from the passage X
By pushing 13 and supplying it to the hydraulic cylinder 7, the piston rod 7a extends and the lift arm 29 rises.
また、ポジシヨンレバー24を下方側へ操作すると、その
設定値はリフトセンサ33の検出値より大きいので、下降
用電磁弁16がONとなりパイロット弁15に通ずるドレン回
路17が開放され、逆止弁13を押圧げて流れる作動油およ
び油圧シリンダ７内の作動油がドレン回路17からタンク
12内へ戻されることで、ピストンロツド7aが押し戻され
てリフトアーム29が下降する。When the position lever 24 is operated downward, the set value is larger than the value detected by the lift sensor 33, so the solenoid valve 16 for downward movement is turned on, the drain circuit 17 communicating with the pilot valve 15 is opened, and the check valve is opened. The hydraulic oil flowing by pressing 13 and the hydraulic oil in the hydraulic cylinder 7 are discharged from the drain circuit 17 to the tank.
By being returned to the inside of 12, the piston rod 7a is pushed back and the lift arm 29 descends.
第１図に示す如く、フイルタ１とポンプ２との間の油路
に負圧センサ36が配設され、この負圧センサ36は油路を
流れる負圧が例えば、−0.3kg/cm2以上となると戻し機
構としての電磁切換弁37がＡポートに切換えられるの
で、ポンプ２からの作動油は分流弁４に至る以前にタン
ク兼用のミツシヨンケース12内へ還流される。この還流
によつて、作動油の粘性抵抗が大きい低温時に、ポンプ
２へ至る回路が負圧となるのを利用して作動油がパイロ
ツト弁10を経由して油圧シリンダ７に至り、リフト装置
30が上昇してしまうという誤動作を解消できる。As shown in FIG. 1, a negative pressure sensor 36 is provided in an oil passage between the filter 1 and the pump 2, and the negative pressure sensor 36 has a negative pressure of −0.3 kg / cm 2 or more in the oil passage. In this case, the electromagnetic switching valve 37 as a return mechanism is switched to the A port, so that the hydraulic oil from the pump 2 is returned to the tank case which also serves as a tank before reaching the flow dividing valve 4. Due to this recirculation, the hydraulic oil reaches the hydraulic cylinder 7 via the pilot valve 10 by utilizing the fact that the circuit to the pump 2 becomes negative pressure at low temperature when the viscous resistance of the hydraulic oil is large, and the lift device
The malfunction that 30 goes up can be solved.
上記したタンク12への還流作用により粘性抵抗が少なく
なつた作動油は、ポンプ２へ至る回路の負圧が−0.3kg/
m2未満となると、電磁切換弁37はＢポートへ自動的に切
換えられるので、作動油が上昇用パイロツト弁10まで流
れる通常状態に切換えられる。With the hydraulic oil whose viscous resistance has been reduced by the above-described reflux action to the tank 12, the negative pressure of the circuit leading to the pump 2 is -0.3 kg /
When it becomes less than m 2 , the electromagnetic switching valve 37 is automatically switched to the B port, so that the operating oil is switched to the normal state in which the hydraulic oil flows to the raising pilot valve 10.
しかし、負圧が−0.3kg/cm2以上と高い場合でも、マイ
コン35により上昇用電磁弁14がONとなつた場合、電磁切
換弁37が自動的にＢポートへ切換えられ、リフトアーム
29は上昇できる。However, even if the negative pressure is as high as −0.3 kg / cm 2 or more, when the ascending solenoid valve 14 is turned on by the microcomputer 35, the solenoid switching valve 37 is automatically switched to the B port and the lift arm.
29 can rise.
第１図に示す例では、電磁切換弁37をポンプ２とリリー
フ弁３との間で分流弁４よりも前の油路に配設するよう
にしているが、分流弁４とコントロール弁５との間に配
設してコントロール弁５に入る前の油路に配設してあれ
ばよい。また、図示しないが、上記負圧センサ36は温度
センサとしてもよい。温度センサとした場合には油路を
流れる作動油温度が＋10℃未満となつたら電磁切換弁37
をＡポートに、＋10℃以上となつたらＢポートに切換る
ようにするが、作動油温度が＋10℃未満でも、マイコン
35からの上げ信号が出ている場合、自動的にＢポートに
切換えられ、リフトアーム29は上昇できる。温度センサ
にした場合には作動油中の塵埃詰り等による誤動作を少
なくできる利点がある。In the example shown in FIG. 1, the electromagnetic switching valve 37 is arranged in the oil passage between the pump 2 and the relief valve 3 and in front of the diversion valve 4, but the diversion valve 4 and the control valve 5 are It suffices to dispose it in the oil passage before it enters the control valve 5 by being disposed between the two. Although not shown, the negative pressure sensor 36 may be a temperature sensor. When the temperature sensor is used, the solenoid valve 37
Is switched to the A port, and when it reaches + 10 ℃ or more, it is switched to the B port.
When the raising signal from 35 is output, it is automatically switched to the B port and the lift arm 29 can be raised. When the temperature sensor is used, there is an advantage that malfunction due to clogging of dust in the hydraulic oil can be reduced.
第１図中、符号18は左右に設けたリフトロツド27の内、
片側のリフトロツド27の長手方向略中間部に設けられた
作業機の水平姿勢制御用の油圧シリンダで、例えば農用
トラクタ20が左右に傾斜した場合でも、油圧シリンダ18
の伸縮により作業機を水平姿勢に保持できるが、この油
圧シリンダ18は電磁式切換弁19の切換えにより制御され
る。In FIG. 1, reference numeral 18 indicates one of the lift rods 27 provided on the left and right,
A hydraulic cylinder for horizontal attitude control of a working machine provided at a substantially middle portion in the longitudinal direction of the lift rod 27 on one side. For example, even when the agricultural tractor 20 tilts left and right, the hydraulic cylinder 18
Although the work machine can be held in a horizontal posture by expanding and contracting, the hydraulic cylinder 18 is controlled by switching the electromagnetic switching valve 19.
また、第７図に示すように、ポンプ２はエンジン21前部
に装備されたタイミングケース41の側方に取付けられ、
ポンプ軸2aにスプライン嵌合したポンプ歯車43が図外の
タイミング歯車に噛合する中間歯車44により駆動され
る。このポンプ歯車43の両端に内径が嵌合する玉軸受45
および46は、その外径がタイミングケース41の支承部に
支承されるが、シール付きの玉軸受となつている。Further, as shown in FIG. 7, the pump 2 is attached to the side of the timing case 41 mounted on the front part of the engine 21,
A pump gear 43 that is spline-fitted to the pump shaft 2a is driven by an intermediate gear 44 that meshes with a timing gear (not shown). Ball bearings 45 whose inner diameter fits on both ends of this pump gear 43
The outer diameters of the bearings 46 and 46 are supported by the bearing portion of the timing case 41, but are ball bearings with a seal.
そして、ポンプ２内圧力が異常高圧となりポンプ軸オイ
ルシール47が抜けても、作動油はシール付き玉軸受45お
よび46にシールされ、タイミングケース41内を通りエン
ジン21内に侵入するのが阻止されるが、これと同時に安
全装置55を作動させ、自動的にエンジン21を停止でき
る。この安全装置55は、スプライン嵌合部を通り点線で
示す矢印方向に流れ出た作動油が空間部49で昇圧される
が、この昇圧により空間部49に臨む圧力センサ50がONと
なることで、作動するリレー51によつて接点52が切換
り、始動スイツチ53をOFF状態にすると同時に、ソレノ
イド54が励磁され燃料噴射ポンプ56による燃料供給を停
止し、エンジン21を自動的に停止させる。Then, even if the pump 2 internal pressure becomes abnormally high and the pump shaft oil seal 47 comes off, the hydraulic oil is sealed by the sealed ball bearings 45 and 46, and is prevented from passing through the timing case 41 and entering the engine 21. However, at the same time, the safety device 55 is activated to automatically stop the engine 21. In this safety device 55, the hydraulic oil flowing through the spline fitting portion in the direction of the arrow indicated by the dotted line is boosted in the space 49, but the pressure sensor 50 facing the space 49 is turned on by this boosting, The contact 52 is switched by the relay 51 that operates to turn off the starting switch 53, and at the same time, the solenoid 54 is excited to stop the fuel supply by the fuel injection pump 56 and automatically stop the engine 21.
また、圧力センサ50により異常状態を警報ランプ、また
はブザー等で警報するようにしてもよい。Further, the pressure sensor 50 may warn of an abnormal state by an alarm lamp or a buzzer.
このポンプ２はサクシヨンパイプ57によりタンク兼用の
ミツシヨンケース12に接続され、プレツシヤパイプ59に
より油圧ケース34に接続されている。The pump 2 is connected by a suction pipe 57 to the storage case 12 that also serves as a tank, and is connected to a hydraulic case 34 by a compression pipe 59.
以上に説明してきたように本発明は、リフト装置に接続
された油圧シリンダとポンプとの間の油路に配設した上
昇用パイロット弁と下降用パイロット弁とを、マイコン
により制御される上昇用電磁弁および下降用電磁弁に夫
々接続し、上記両パイロット弁より前位の油路に、粘性
抵抗が大きい作動油のみをタンクに還流せしめる戻し機
構を配設し、前記上昇用電磁弁をONにした場合にこの戻
し機構を非作動状態にすると共に、上昇用電磁弁をOFF
にした場合にこの戻し機構を作動状態とするように制御
する前記マイコンを設けてなるので、以下の効果を奏す
ることができる。As described above, according to the present invention, the ascending pilot valve and the descending pilot valve, which are arranged in the oil passage between the hydraulic cylinder connected to the lift device and the pump, are provided for ascending by a microcomputer. Connected to the solenoid valve and the solenoid valve for lowering respectively, a return mechanism is installed in the oil passage in front of both pilot valves to return only the hydraulic oil with large viscous resistance to the tank, and the solenoid valve for rising is turned on. When this is set, the return mechanism is deactivated and the lift solenoid valve is turned off.
In the case of the above, since the microcomputer for controlling the return mechanism to operate is provided, the following effects can be obtained.
上昇用電磁弁がOFFに切り替えられている場合、低温で
あるが故に粘性抵抗が高い作動油が両パイロツト弁まで
送られないので、従来の作動油の粘性抵抗が高い低温時
にコントロール機構としての上昇用パイロツト弁または
下降用パイロツト弁が誤作動し、中立または下降指令で
あるにもかかわらずリフト装置が上昇してしまうという
問題を解消できる。When the solenoid valve for raising is switched to OFF, hydraulic oil with high viscous resistance cannot be sent to both pilot valves because it is at low temperature. It is possible to solve the problem that the lifting pilot valve or the lowering pilot valve malfunctions and the lift device rises despite the neutral or lowering command.
また、上昇用電磁弁がONに切り替えられている場合に
は、前記戻し機構を非作動状態にすることができるの
で、粘性抵抗が高い作動油であってもタンクに戻され
ず、速やかに油圧シリンダを上昇させることができる。Also, when the solenoid valve for raising is switched on, the return mechanism can be deactivated, so even hydraulic oil with high viscous resistance will not be returned to the tank, and the hydraulic cylinder can be quickly operated. Can be raised.
第１図〜第７図は本発明の一実施例を示し、第１図は要
部の油圧回路図、第２図は要部の制御回路、第３図はフ
ローチヤート図、第４図は他例におけるフローチヤート
図、第５図は農用トラクタの概略側面図、第６図はリフ
ト装置の上昇姿勢を示す断面図、第７図はポンプ取付部
の詳細図である。第８図は従来例を示す油圧回路図であ
る。 １…フイルタ、２…ポンプ、５…コントロール機構、７
…油圧シリンダ、10…パイロツト弁、15…パイロツト
弁、14…上昇用電磁弁、16…下降用電磁弁、35…マイコ
ン、36…負圧センサ、37…電磁切換弁（戻し機構）。1 to 7 show an embodiment of the present invention. FIG. 1 is a hydraulic circuit diagram of a main part, FIG. 2 is a control circuit of the main part, FIG. 3 is a flow chart, and FIG. 5 is a flow chart of another example, FIG. 5 is a schematic side view of an agricultural tractor, FIG. 6 is a cross-sectional view showing a lifted posture of a lifting device, and FIG. 7 is a detailed view of a pump mounting portion. FIG. 8 is a hydraulic circuit diagram showing a conventional example. 1 ... Filter, 2 ... Pump, 5 ... Control mechanism, 7
... hydraulic cylinder, 10 ... pilot valve, 15 ... pilot valve, 14 ... solenoid valve for raising, 16 ... solenoid valve for lowering, 35 ... microcomputer, 36 ... negative pressure sensor, 37 ... solenoid switching valve (return mechanism).
フロントページの続き (72)発明者 堀内 淳 島根県八束郡東出雲町大字揖屋町667番地 １ 三菱農機株式会社内 (56)参考文献 特開 昭62−204（ＪＰ，Ａ) 特開 昭59−89811（ＪＰ，Ａ) 実開 昭61−40806（ＪＰ，Ｕ)Continuation of front page (72) Atsushi Horiuchi Atsushi 667 Isuya-cho, Higashi-Izumo-cho, Yatsuka-gun, Shimane Prefecture 1 Inside Mitsubishi Agricultural Machinery Co., Ltd. (56) Reference JP-A-62-204 (JP, A) JP-A-59- 89811 (JP, A) Actually opened 61-40806 (JP, U)
Claims (1)
ンプとの間の油路に配設した上昇用パイロット弁と下降
用パイロット弁とを、マイコンにより制御される上昇用
電磁弁および下降用電磁弁に夫々接続し、上記両パイロ
ット弁より前位の油路に、粘性抵抗が大きい作動油のみ
をタンクに還流せしめる戻し機構を配設し、前記上昇用
電磁弁をONにした場合にこの戻し機構を非作動状態にす
ると共に、上昇用電磁弁をOFFにした場合にこの戻し機
構を作動状態とするように制御する前記マイコンを設け
てなる農機の油圧リフト装置。1. A rising solenoid valve and a lowering solenoid valve, which are controlled by a microcomputer, are provided with a raising pilot valve and a lowering pilot valve arranged in an oil passage between a hydraulic cylinder connected to a lift device and a pump. A return mechanism is installed in each of the oil passages in front of the pilot valves to return only the hydraulic oil with large viscous resistance to the tank, and the return solenoid is turned on when the solenoid valve for raising is turned on. A hydraulic lift device for an agricultural machine, which is provided with the microcomputer for controlling the return mechanism to be in an activated state when the raising solenoid valve is turned off while the mechanism is inactivated.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63074487A JPH0795881B2 (en) | 1988-03-30 | 1988-03-30 | Agricultural machine hydraulic lift device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63074487A JPH0795881B2 (en) | 1988-03-30 | 1988-03-30 | Agricultural machine hydraulic lift device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01247002A JPH01247002A (en) | 1989-10-02 |
| JPH0795881B2 true JPH0795881B2 (en) | 1995-10-18 |
Family
ID=13548695
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63074487A Expired - Lifetime JPH0795881B2 (en) | 1988-03-30 | 1988-03-30 | Agricultural machine hydraulic lift device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0795881B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5441452B2 (en) * | 2009-03-10 | 2014-03-12 | ヤンマー株式会社 | Work vehicle |
| CN105035261A (en) * | 2015-06-03 | 2015-11-11 | 长江南京航道局 | Combined mechanism for measuring depth of longitudinal flow bow ship |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5989811A (en) * | 1982-11-15 | 1984-05-24 | Iseki & Co Ltd | Hydraulic control device for power car |
| JPS6140806U (en) * | 1984-08-17 | 1986-03-15 | 株式会社 神崎高級工機製作所 | Agricultural tractor work equipment control device |
| JPS62204A (en) * | 1985-06-24 | 1987-01-06 | 株式会社クボタ | Drive control mechanism for working device of working machine |
-
1988
- 1988-03-30 JP JP63074487A patent/JPH0795881B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01247002A (en) | 1989-10-02 |
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