JPH018084Y2 - - Google Patents
Info
- Publication number
- JPH018084Y2 JPH018084Y2 JP986382U JP986382U JPH018084Y2 JP H018084 Y2 JPH018084 Y2 JP H018084Y2 JP 986382 U JP986382 U JP 986382U JP 986382 U JP986382 U JP 986382U JP H018084 Y2 JPH018084 Y2 JP H018084Y2
- Authority
- JP
- Japan
- Prior art keywords
- valve
- circuit
- horizontal control
- lifting
- cylinder
- 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
Links
- 238000011144 upstream manufacturing Methods 0.000 claims description 3
- 230000008602 contraction Effects 0.000 description 3
- 230000003028 elevating effect Effects 0.000 description 3
- 230000007246 mechanism Effects 0.000 description 3
- 230000001174 ascending effect Effects 0.000 description 2
- 230000007935 neutral effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000008713 feedback mechanism Effects 0.000 description 1
Landscapes
- Lifting Devices For Agricultural Implements (AREA)
- Fluid-Pressure Circuits (AREA)
Description
【考案の詳細な説明】
本考案は、トラクタの油圧回路に関し、作業機
の昇降動作、特に上昇動作中でも、水平制御回路
が確実に動作するようにしたものである。[Detailed Description of the Invention] The present invention relates to a hydraulic circuit for a tractor, and is designed to ensure that the horizontal control circuit operates reliably even during the lifting and lowering operations of the working machine, especially during the lifting operation.
トラクタに三点リンク機構を介して作業機を装
着すると共に、作業機昇降用の昇降シリンダの左
右一対のリフトアームと三点リンク機構の左右一
対のロアーリンクとを連結する一対のリフトロツ
ドの内、何れか一方を油圧シリンダにより構成
し、この油圧シリンダ(リフトロツドシリンダ)
を水平センサーに応動する電磁弁により伸縮させ
て、トラクタの傾斜に関係なく作業機を常に水平
に制御するようにした技術がある。このリフトロ
ツドシリンダ及び電磁弁を含む水平制御回路は、
昇降シリンダ及びその制御弁を含む昇降回路と共
に分流弁を介して油圧ポンプに接続し、1台の油
圧ポンプを昇降用と水平制御用とに兼用するのが
通常であり、また水平制御の使用頻度は限られて
いるため、水平制御回路の戻り油を直接タンクに
戻すようにすれば、その流量が常に無駄になるの
で、戻り油路をチエツク弁を介して昇降回路に合
流させる回路構成を採用し、合流後の油で昇降シ
リンダを作動させるようにしている。しかし、こ
のような回路構成にすると、両者回路の動作時の
回路内圧力を考えた場合、作業機上昇時の昇降回
路の圧力が水平制御時の水平制御回路の圧力より
も大であるため、作業機の上昇中には戻り油の流
れが断たれて水平制御回路が動作しなくなると云
う問題が生ずる。従つて、牽引負荷の変動を感知
して昇降シリンダを動作させるドラフト制御を行
ないながら、同時に作業機の水平制御を行なう場
合には、作業機の昇降動作後に作業機の水平制御
動作が始まることになり、水平制御の意義が大き
く損なわれる結果となる。 A pair of lift rods are attached to the tractor via a three-point link mechanism, and connect a pair of left and right lift arms of a lifting cylinder for raising and lowering the work machine and a pair of left and right lower links of the three-point link mechanism; Either one is composed of a hydraulic cylinder, and this hydraulic cylinder (lift rod cylinder)
There is a technology in which the tractor is expanded and contracted using a solenoid valve that responds to a horizontal sensor, so that the work equipment is always controlled horizontally regardless of the inclination of the tractor. The horizontal control circuit including this lift rod cylinder and solenoid valve is
Normally, a lifting circuit including a lifting cylinder and its control valve is connected to a hydraulic pump via a diversion valve, and one hydraulic pump is used for both lifting and horizontal control, and the frequency of use for horizontal control is Since the flow rate is limited, if the return oil from the horizontal control circuit were returned directly to the tank, the flow rate would always be wasted, so a circuit configuration was adopted in which the return oil path merges into the lifting circuit via a check valve. The oil after merging is used to operate the lifting cylinder. However, with such a circuit configuration, considering the pressure in the circuit when both circuits are in operation, the pressure in the lifting circuit when the work equipment is raised is greater than the pressure in the horizontal control circuit during horizontal control. A problem arises in that the flow of return oil is cut off while the work implement is being raised, causing the horizontal control circuit to become inoperable. Therefore, when horizontal control of the work equipment is performed at the same time as draft control is performed to operate the lifting cylinder by sensing fluctuations in the traction load, the horizontal control operation of the work equipment starts after the work equipment lifts/lowers. This results in a significant loss of the significance of horizontal control.
本考案は、このような従来の問題点を解消する
ことを目的としたものであつて、その特徴とする
処は、作業機の昇降回路と作業機の水平制御回路
とを分流弁を介して油圧ポンプに接続し、水平制
御回路の戻り油路をチエツク弁を介して昇降回路
に合流させたトラクタの油圧回路において、戻り
油路のチエツク弁より上流側に、水平制御動作時
に水平制御回路のパイロツト圧により該戻り油路
を開放する開閉弁を介装した点にある。 The purpose of this invention is to solve these conventional problems, and its feature is that the lifting circuit of the work equipment and the horizontal control circuit of the work equipment are connected via a shunt valve. In a tractor hydraulic circuit that is connected to a hydraulic pump and has the return oil path of the horizontal control circuit merge into the lifting circuit via a check valve, the horizontal control circuit is connected upstream of the check valve in the return oil path during horizontal control operation. An on-off valve is provided to open the return oil passage using pilot pressure.
以下、図示の実施例について本考案を詳述する
と、第1図において、1はトラクタで、後部に作
業機を昇降させるための単動型の昇降シリンダ2
が搭載され、またその昇降シリンダ2は左右一対
のリフトアーム3を有する。4は作業機の一例を
示すプラウであつて、トラクタ1後方に三点リン
ク機構5を介して装着され、また左右一対のリフ
トロツド6及びリフトアーム3を介して昇降シリ
ンダ2により昇降せしめられる。左右一対のリフ
トロツド6の内、一方は伸縮自在なリフトロツド
シリンダ6aにより構成されており、このリフト
ロツドシリンダ6aの伸縮によつてトラクタ1の
傾斜に関係なくプラウ4を水平に制御可能であ
る。 Hereinafter, the present invention will be described in detail with reference to the illustrated embodiment. In FIG. 1, reference numeral 1 denotes a tractor, and a single-acting lifting cylinder 2 for raising and lowering a working machine at the rear.
is mounted, and the elevating cylinder 2 has a pair of left and right lift arms 3. Reference numeral 4 denotes a plow, which is an example of a working machine, and is attached to the rear of the tractor 1 via a three-point linkage mechanism 5, and is raised and lowered by a lift cylinder 2 via a pair of left and right lift rods 6 and a lift arm 3. One of the pair of left and right lift rods 6 is composed of a telescopic lift rod cylinder 6a, and by expanding and contracting the lift rod cylinder 6a, the plow 4 can be controlled horizontally regardless of the inclination of the tractor 1. be.
第2図は昇降シリンダ2及びリフトロツドシリ
ンダ6aを含む油圧回路を示す。第2図において
7はエンジン、8はエンジン7により駆動される
油圧ポンプであつて、この油圧ポンプ8はタンク
9内の油を吸込んで分流弁10側に吐出する。分
流弁10は油圧ポンプ8から供給される油を昇降
回路11と水平制御回路12との入側油路13,
14に分流するためのものであつて、水平制御回
路12側に優先的に分流すべく構成されている。
昇降回路11は昇降シリンダ2の他、この昇降シ
リンダ2を制御するように制御弁15、チエツク
弁16、絞り弁17及びアンロード弁18を備え
て成り、またその制御弁15は図外の油圧制御レ
バー、フイードバツク機構等を介してスプール1
9を軸心方向に往復動作させることによりポジシ
ヨン制御、ドラフト制御用として動作する。水平
制御回路12はリフトロツドシリンダ6a、電磁
弁20及びチエツク弁21を備えて成り、その電
磁弁20はプラウ側の水平センサーの出力によつ
て駆動される一対のソレノイド22,23を有
し、この各ソレノイド22,23の選択的励磁に
よりプラウ4が水平となるようにリフトロツドシ
リンダ6aを伸縮制御すべく構成されている。こ
の水平制御回路12の戻り油路24はチエツク弁
25を介して昇降回路11の入側油路13に合流
すべく接続され、またこの戻り油路24には電磁
弁20とチエツク弁25との間に、該戻り油路2
4を開放するための開閉弁26が介装されてい
る。開閉弁26はパイロツト型であつて、そのパ
イロツト回路27は、リフトロツドシリンダ6a
の伸縮動作時に水平制御回路12のパイロツト圧
により開閉弁26を開放するように、リフトロツ
ドシリンダ6aと電磁弁20とを結ぶ油路28,
29の一方に接続されている。30,31はリリ
ーフ弁、32は安全弁である。 FIG. 2 shows a hydraulic circuit including the lifting cylinder 2 and the lift rod cylinder 6a. In FIG. 2, 7 is an engine, and 8 is a hydraulic pump driven by the engine 7. This hydraulic pump 8 sucks oil in a tank 9 and discharges it to the flow dividing valve 10 side. The diversion valve 10 transfers oil supplied from the hydraulic pump 8 to the inlet oil passage 13 between the lifting circuit 11 and the horizontal control circuit 12.
14, and is configured to preferentially divert the flow to the horizontal control circuit 12 side.
In addition to the lifting cylinder 2, the lifting circuit 11 includes a control valve 15, a check valve 16, a throttle valve 17, and an unloading valve 18 to control the lifting cylinder 2. Spool 1 via control lever, feedback mechanism, etc.
By reciprocating 9 in the axial direction, it operates for position control and draft control. The horizontal control circuit 12 includes a lift rod cylinder 6a, a solenoid valve 20, and a check valve 21, and the solenoid valve 20 has a pair of solenoids 22 and 23 driven by the output of a horizontal sensor on the plow side. By selectively energizing the solenoids 22 and 23, the lift rod cylinder 6a is controlled to expand and contract so that the plow 4 is horizontal. A return oil passage 24 of the horizontal control circuit 12 is connected to the inlet oil passage 13 of the lifting circuit 11 via a check valve 25, and a solenoid valve 20 and a check valve 25 are connected to the return oil passage 24. In between, the return oil path 2
An on-off valve 26 for opening 4 is interposed. The on-off valve 26 is of a pilot type, and its pilot circuit 27 connects to the lift rod cylinder 6a.
An oil passage 28 connects the lift rod cylinder 6a and the solenoid valve 20 so that the opening/closing valve 26 is opened by the pilot pressure of the horizontal control circuit 12 during the expansion and contraction operation of the lift rod cylinder 6a.
29. 30 and 31 are relief valves, and 32 is a safety valve.
次に作用を説明する。油圧ポンプ8を駆動する
と、タンク9の油を吸込んで分流弁10側に吐出
し、その油は分流弁10で昇降回路11と水平制
御回路12とに分流され、その入側油路13,1
4へと供給されて行く。そして制御弁15が中立
状態の時には、アンロード弁18が開き、昇降回
路11側に供給された油は入側油路13からアン
ロード弁18を介してタンク9へと戻され、また
制御弁15を上昇側に切換えると、アンロード弁
18が閉じ、チエツク弁16が開くため、油はチ
エツク弁16を介して昇降シリンダ2へと供給さ
れて行き、昇降シリンダ2が作動してプラウ4を
持上げる。 Next, the effect will be explained. When the hydraulic pump 8 is driven, oil from the tank 9 is sucked in and discharged to the diversion valve 10 side.
It is supplied to 4. When the control valve 15 is in the neutral state, the unload valve 18 opens, and the oil supplied to the lifting circuit 11 side is returned from the inlet oil path 13 to the tank 9 via the unload valve 18, and the control valve 15 to the lifting side, the unload valve 18 closes and the check valve 16 opens, so oil is supplied to the lifting cylinder 2 via the check valve 16, and the lifting cylinder 2 operates to move the plow 4. Lift up.
一方、水平制御の停止時或いはプラウ4が水平
の時には電磁弁20が中立状態にあるため、水平
制御回路12の入側油路14に供給された油は、
電磁弁20から戻り油路24の開閉弁26、及び
チエツク弁25を介して昇降回路11の入側油路
13に合流し、従つて、水平制御回路12に分流
した油を昇降回路11の昇降シリンダ2の作動用
として使用でき、油の無駄を防止できる。 On the other hand, when the horizontal control is stopped or the plow 4 is horizontal, the solenoid valve 20 is in a neutral state, so the oil supplied to the inlet oil path 14 of the horizontal control circuit 12 is
The oil that flows from the electromagnetic valve 20 to the inlet oil passage 13 of the lifting circuit 11 via the on-off valve 26 of the return oil passage 24 and the check valve 25, and is branched to the horizontal control circuit 12, is used for the lifting circuit 11. It can be used to operate the cylinder 2, preventing wastage of oil.
プラウ4が傾斜し水平センサーがそれを検出す
ると、電磁弁20が上昇又は下降側に切換わり、
リフトロツドシリンダ6aの伸縮によりプラウ4
を水平姿勢に戻すように動作する。今、ソレノイ
ド23が励磁して電磁弁20が上昇側に切換わつ
たとすると、水平制御回路12の入側油路14の
油が電磁弁20、油路28、チエツク弁21を経
てリフトロツドシリンダ6aの下側のシリンダ室
へと供給されると共に、リフトロツドシリンダ6
aの上側のシリンダ室の油が油路29、電磁弁2
0を経て戻り油路24へと戻されて行き、リフト
ロツドシリンダ6aが収縮動作としてプラウ4を
水平に戻す。この時、昇降シリンダ2が上昇動作
中以外であれば、昇降回路11の入側油路13内
の圧力が高圧とはなつていないので、戻り油は戻
り油路24からチエツク弁25を経て入側油路1
3に合流する。またドラフト制御等で昇降シリン
ダ2が上昇動作中であれば、入側油路13の圧力
が高いため、チエツク弁25は開かず、従つて戻
り油は入側回路13には合流しない。しかし、こ
の時には水平制御回路12の油路28側の圧力が
開閉弁26の設定されたパイロツト圧以上に上昇
し、この開閉弁26が開放するので、戻り油は開
閉弁26からタンク9へと戻されて行き、リフト
ロツドシリンダ6aは円滑かつ確実に収縮動作を
する。 When the plow 4 tilts and the horizontal sensor detects this, the solenoid valve 20 switches to the upward or downward side,
The plow 4 is moved by the expansion and contraction of the lift rod cylinder 6a.
It moves to return to a horizontal position. Now, if the solenoid 23 is energized and the solenoid valve 20 is switched to the upward side, the oil in the inlet oil passage 14 of the horizontal control circuit 12 passes through the solenoid valve 20, the oil passage 28, and the check valve 21, and then reaches the lift rod. It is supplied to the lower cylinder chamber of the cylinder 6a, and the lift rod cylinder 6
The oil in the upper cylinder chamber of a is connected to the oil passage 29 and the solenoid valve 2.
0 and returns to the return oil path 24, and the lift rod cylinder 6a returns the plow 4 to the horizontal position as a contraction operation. At this time, if the lifting cylinder 2 is not in the ascending operation, the pressure in the inlet oil passage 13 of the lifting circuit 11 is not high pressure, so the return oil enters from the return oil passage 24 via the check valve 25. Side oil passage 1
Join 3. Further, if the lifting cylinder 2 is in the ascending operation due to draft control or the like, the pressure in the inlet oil passage 13 is high, so the check valve 25 does not open, and therefore the return oil does not join the inlet circuit 13. However, at this time, the pressure on the oil passage 28 side of the horizontal control circuit 12 rises above the pilot pressure set by the on-off valve 26, and this on-off valve 26 opens, so the return oil flows from the on-off valve 26 to the tank 9. As it is returned, the lift rod cylinder 6a retracts smoothly and reliably.
リフトロツドシリンダ6aの伸長動作の時にも
同様である。 The same holds true when the lift rod cylinder 6a is extended.
なお上記実施例では、昇降シリンダ2の上昇中
でかつリフトロツドシリンダ6aが伸縮動作した
時にのみ開閉弁26が開放するようにしたが、開
閉弁26のパイロツト圧の設定値を変えることに
より、リフトロツドシリンダ6aの伸縮動作時に
は、昇降シリンダ2の上昇動作に関係なく、必ず
開閉弁26が開放するようにしても良い。 In the above embodiment, the on-off valve 26 is opened only when the lift cylinder 2 is being raised and the lift rod cylinder 6a is extended or retracted. However, by changing the set value of the pilot pressure of the on-off valve 26, The opening/closing valve 26 may be always opened when the lift rod cylinder 6a is extended or contracted, regardless of the raising operation of the elevating cylinder 2.
本考案は、戻り油路のチエツク弁より上流側
に、水平制御動作時に水平制御回路のパイロツト
圧により該戻り油路を開放する開閉弁を介装して
いるので、水平制御回路の戻り油を昇降回路に合
流させる構成を採つているにも拘らず、昇降回路
の動作中でも水平制御回路を確実に動作させるこ
とができ、従つて、牽引負荷に応じて作業機を昇
降させるドラフト制御を行ないながら、作業機の
水平制御を同時に行なう場合にも、作業機の水平
制御に遅れが発生することがなく、その実用的価
値は極めて大である。 The present invention has an on-off valve installed upstream of the check valve in the return oil path, which opens the return oil path using the pilot pressure of the horizontal control circuit during horizontal control operation. Even though the horizontal control circuit is configured to merge into the lifting circuit, it is possible to operate the horizontal control circuit reliably even when the lifting circuit is in operation. Even when the horizontal control of the working machine is performed at the same time, there is no delay in the horizontal control of the working machine, and its practical value is extremely great.
図面は本考案の一実施例を例示するものであつ
て、第1図は側面図、第2図は油圧回路図であ
る。
1……トラクタ、2……昇降シリンダ、4……
プラウ、6a……リフトロツドシリンダ、8……
油圧ポンプ、10……分流弁、11……昇降回
路、12……水平制御回路、13,14……入側
油路、24……戻り油路、26……開閉弁。
The drawings illustrate one embodiment of the present invention, with FIG. 1 being a side view and FIG. 2 being a hydraulic circuit diagram. 1...Tractor, 2...Lifting cylinder, 4...
Plow, 6a... Lift rod cylinder, 8...
Hydraulic pump, 10...Diversion valve, 11...Elevating circuit, 12...Horizontal control circuit, 13, 14...Inlet oil path, 24...Return oil path, 26...Opening/closing valve.
Claims (1)
分流弁を介して油圧ポンプに接続し、水平制御回
路の戻り油路をチエツク弁を介して昇降回路に合
流させたトラクタの油圧回路において、戻り油路
のチエツク弁より上流側に、水平制御動作時に水
平制御回路のパイロツト圧により該戻り油路を開
放する開閉弁を介装したことを特徴とするトラク
タの油圧回路。 In the hydraulic circuit of a tractor, the lifting circuit of the working equipment and the horizontal control circuit of the working equipment are connected to a hydraulic pump via a diversion valve, and the return oil path of the horizontal control circuit is joined to the lifting circuit via a check valve. 1. A hydraulic circuit for a tractor, characterized in that an on-off valve is installed upstream of a check valve in a return oil path to open the return oil path using pilot pressure of the horizontal control circuit during horizontal control operation.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP986382U JPS58113311U (en) | 1982-01-26 | 1982-01-26 | tractor hydraulic circuit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP986382U JPS58113311U (en) | 1982-01-26 | 1982-01-26 | tractor hydraulic circuit |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS58113311U JPS58113311U (en) | 1983-08-03 |
JPH018084Y2 true JPH018084Y2 (en) | 1989-03-03 |
Family
ID=30022473
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP986382U Granted JPS58113311U (en) | 1982-01-26 | 1982-01-26 | tractor hydraulic circuit |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS58113311U (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6087702A (en) * | 1983-10-18 | 1985-05-17 | 井関農機株式会社 | Hydraulic controller of tractor |
JPH0522009Y2 (en) * | 1986-07-07 | 1993-06-07 |
-
1982
- 1982-01-26 JP JP986382U patent/JPS58113311U/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS58113311U (en) | 1983-08-03 |
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