JPS6221127Y2 - - Google Patents
Info
- Publication number
- JPS6221127Y2 JPS6221127Y2 JP18180580U JP18180580U JPS6221127Y2 JP S6221127 Y2 JPS6221127 Y2 JP S6221127Y2 JP 18180580 U JP18180580 U JP 18180580U JP 18180580 U JP18180580 U JP 18180580U JP S6221127 Y2 JPS6221127 Y2 JP S6221127Y2
- Authority
- JP
- Japan
- Prior art keywords
- valve
- switching
- directional control
- directional
- control valve
- 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
- 238000003780 insertion Methods 0.000 claims description 12
- 230000037431 insertion Effects 0.000 claims description 12
- 230000001965 increasing effect Effects 0.000 claims description 11
- 230000007935 neutral effect Effects 0.000 claims description 7
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000003028 elevating effect Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
Landscapes
- Operation Control Of Excavators (AREA)
- Mechanically-Actuated Valves (AREA)
- Fluid-Pressure Circuits (AREA)
Description
【考案の詳細な説明】
本考案は単動型アクチエータにより駆動される
コンクリート破砕機（ブレーカー）や鑚孔機等を
アタツチメントとして取付けたパワーシヨベルや
クレーン車のような作業車両の油圧制御装置に関
する。[Detailed Description of the Invention] The present invention relates to a hydraulic control system for a work vehicle such as a power shovel or a crane truck to which a concrete crusher (breaker), a drilling machine, etc. driven by a single-acting actuator is attached as an attachment.
本考案は複動型アクチエータが常時略一方向の
負荷を受けているため、該複動型アクチエータを
負荷作用方向に駆動する場合は増速する必要がな
い点に着目して、単動型アクチエータ用３位置方
向切換弁の不使用位置を複動型アクチエータの負
荷に抗した方向の作動の増速制御に利用して、油
圧制御装置の制御弁数を節減することを目的とす
る。 The present invention focuses on the fact that since a double-acting actuator is always subjected to a load in approximately one direction, there is no need to increase the speed when driving the double-acting actuator in the direction in which the load is applied. The purpose of this invention is to reduce the number of control valves in a hydraulic control device by utilizing the unused position of a three-position directional control valve to increase the speed of the operation of a double-acting actuator in a direction against the load.
本考案は夫々異なる油圧ポンプの吐出口に接続
され、常時中立位置に復帰賦勢される２個の３位
置の方向切換弁４，７のスプール摺動杆と１個の
操作杆３９との間に、一方の方向切換弁４を先に
切換えた後に他方の方向切換弁７を切換える機構
を介装して、一方向に負荷が作用する複動型アク
チエータ１４を方向切換弁４の出力側に接続し、
該複動型アクチエータの負荷作用側油室に方向切
換弁４と協同してポンプ吐出圧油を供給する増速
用油路１２を、方向切換弁７の出力側に接続した
作業車両において、増速用油路１２にポンプ吐出
圧油を供給する増速用切換位置と反対側の切換位
置に方向切換弁７を切換えた時に駆動される単動
型アクチエータを、該方向切換弁７の出力側に接
続して、その戻り油路１６に一方向弁１９を、又
増速用油路１２に一方向弁２０を夫々挿入し、方
向切換弁７を前記反対側切換位置に切換え可能な
一方向作動の操作装置を該方向切換弁のスプール
摺動杆２５に連動連結し、該スプール摺動杆２５
と、これを操作杆３９に連動連結すべきリンク３
５のピン挿入筒部分３５ａとを挿脱自在なピン３
４で連結して、増速用切換位置とその反対側の切
換位置とに方向切換弁７を切換え得るように、該
ピン挿入筒部分３５ａの移動範囲を限定する長孔
４１を操作杆や方向切換弁の取付台側に設け、中
立位置の方向切換弁７を前記反対側の切換位置に
切換える方向にピン挿入筒部分３５ａを長孔４１
に沿い移動させる際は、ピン３４がスプール摺動
杆２５に対し空動きするように、該スプール摺動
杆に設けたピン孔を長孔３３に構成したことを特
徴とする。 The present invention is designed between the spool sliding rods of two 3-position directional control valves 4 and 7, which are connected to the discharge ports of different hydraulic pumps, and which are always biased to return to the neutral position, and one operating rod 39. In addition, a mechanism is installed to first switch one directional valve 4 and then switch the other directional valve 7, and a double-acting actuator 14 on which a load acts in one direction is placed on the output side of the directional valve 4. connection,
In a work vehicle, a speed increasing oil passage 12 for supplying pump discharge pressure oil to the load application side oil chamber of the double-acting actuator in cooperation with the directional control valve 4 is connected to the output side of the directional control valve 7. A single-acting actuator that is driven when the directional control valve 7 is switched to the switching position opposite to the speed increasing switching position that supplies pump discharge pressure oil to the speed oil passage 12 is connected to the output side of the directional switching valve 7. A one-way valve 19 is inserted into the return oil passage 16, and a one-way valve 20 is inserted into the speed-increasing oil passage 12, so that the directional switching valve 7 can be switched to the opposite switching position. An operating device is operatively connected to the spool sliding rod 25 of the directional control valve, and the spool sliding rod 25
and the link 3 that should be linked to the operating rod 39.
The pin 3 can be freely inserted into and removed from the pin insertion tube portion 35a of No. 5.
4, and the long hole 41 that limits the movement range of the pin insertion cylinder portion 35a is connected to the operating rod or the direction so that the directional control valve 7 can be switched between the speed increasing switching position and the opposite switching position. The pin insertion cylinder portion 35a is provided on the mounting base side of the switching valve, and the pin insertion cylinder portion 35a is inserted into the long hole 41 in the direction of switching the directional switching valve 7 from the neutral position to the switching position on the opposite side.
It is characterized in that the pin hole provided in the spool sliding rod 25 is formed into a long hole 33 so that the pin 34 moves idly relative to the spool sliding rod 25 when moving along the spool sliding rod 25.
以下単動型アクチエータをブーム俯仰シリンダ
に、又単動型アクチエータをブレーカー駆動モー
タにした油圧パワーシヨベルに本考案を適用した
図示実施例について説明する。 An illustrated embodiment in which the present invention is applied to a hydraulic power shovel in which a single-acting actuator is used as a boom elevation cylinder and a single-acting actuator is used as a breaker drive motor will be described below.
１，２は車載エンジンにより同時駆動される油
圧ポンプ、３，４，５は油圧ポンプ１より圧油を
供給される多連弁、６，７，８，９は油圧ポンプ
２より圧油を供給される多連弁、Ｔはタンクを示
し、該各多連弁は夫々中立位置に常時復帰賦勢さ
れる同構成の３位置方向切換弁である。３位置方
向切換弁４の両出力側ポートは夫々油路１０，１
１を介して一組の複動型アクチエータ（ブーム俯
仰シリンダ）１４に接続され、その負荷作用側油
室（下部油室）１４ａに接続された油路１０には
スローリタン弁１３が挿入されている。又３位置
方向切換弁７の両出力側ポートは夫々油路１５，
１６を介して単動型アクチエータ（ブレーカー駆
動モータ）１７に接続され、油路１６が戻り油路
となる。 1 and 2 are hydraulic pumps driven simultaneously by the on-vehicle engine; 3, 4, and 5 are multiple valves supplied with pressure oil from the hydraulic pump 1; and 6, 7, 8, and 9 are supplied with pressure oil from the hydraulic pump 2. T indicates a tank, and each of the multiple valves is a three-position directional control valve of the same construction that is always energized to return to its neutral position. Both output ports of the 3-position directional control valve 4 are connected to oil passages 10 and 1, respectively.
A slow return valve 13 is inserted into an oil passage 10 that is connected to a set of double-acting actuators (boom elevation cylinders) 14 through a hydraulic cylinder 1 and a load action side oil chamber (lower oil chamber) 14a thereof. . Also, both output ports of the 3-position directional control valve 7 are connected to oil passages 15 and 15, respectively.
It is connected to a single-acting actuator (breaker drive motor) 17 via an oil passage 16, and the oil passage 16 serves as a return oil passage.
戻り油路１６と負荷作用側油室１４ａの間は増
速用油路１２で連通連結され、該増速用油路１２
中には戻り油路１６より負荷作用側油室１４ａへ
の油の流れのみを許す一方向弁（チエツク弁）２
０が挿入される。又単動型アクチエータ１７と増
速用油路１２の連結部との間の戻り油路１６中に
は、その戻り油の流れのみを許す一方向弁（チエ
ツク弁）１９が挿入される。尚一方向弁１９，２
０はシーケンス弁にしてもよいことは勿論であ
る。 The return oil passage 16 and the load action side oil chamber 14a are connected to each other by a speed increasing oil passage 12, and the speed increasing oil passage 12
There is a one-way valve (check valve) 2 that only allows oil to flow from the return oil path 16 to the load action side oil chamber 14a.
0 is inserted. A one-way valve (check valve) 19 is inserted into the return oil passage 16 between the single-acting actuator 17 and the connection portion of the speed-increasing oil passage 12 to allow only the return oil to flow. Furthermore, one-way valve 19, 2
Of course, 0 may be a sequence valve.
第１図中２３は油圧ポンプ１側油圧回路のリリ
ーフ弁、２４は油圧ポンプ２側油圧回路のリリー
フ弁を示し、３，６は夫々両側走行モータ制御用
方向切換弁、５はアーム回動シリンダ用方向切換
弁、８はバケツト回動シリンダ用方向切換弁、９
は旋回モータ制御用方向切換弁である。 In Fig. 1, reference numeral 23 indicates a relief valve for the hydraulic circuit on the hydraulic pump 1 side, 24 indicates a relief valve for the hydraulic circuit on the hydraulic pump 2 side, 3 and 6 indicate directional switching valves for controlling both traveling motors, and 5 indicates an arm rotation cylinder. 8 is a directional valve for bucket rotary cylinder, 9 is a directional valve for bucket rotation cylinder.
is a directional switching valve for controlling a swing motor.
第２図及び第３図は方向切換弁４，７の操作装
置の一例を示し、方向切換弁７のスプール摺動杆
２５の先端は、順次くの字状リンク２６、ベルク
ランク２７を介してパワーシヨベルの旋回台２８
に摺動自在に支持されたロツド２９に連動連結さ
れ、該ロツド２９の上端と後述の作用を達成する
間隔をおいて、旋回台２８に枢架３０された単動
型アクチエータ１７操作用のペダル３１が圧縮ば
ね３２により弾力支持される。一方スプール摺動
杆２５の先端部に穿設した該スプール摺動方向の
長孔３３の先端に抜差自在のピン３４を介して連
結されたリンク３５の先端と、方向切換弁４のス
プール摺動杆３６の先端とをレバー３７の両端に
夫々連結して、旋回台２８に枢架３８したブーム
俯仰シリンダ１４制御用の操作杆３９の下端と該
レバー３７の中間部の間をリンク４０で連結し、
該リンク両側におけるレバー３７のアーム長さの
間に差を持たせることにより、各方向切換弁の中
立位置復帰ばねと協同して、操作杆３９のＡ方向
回転により方向切換弁４が第１図の上位置に切換
えられた後に方向切換弁７が同図の上位置に切換
えられるようにする。又リンク３５のピン挿入筒
部分３５ａを旋回台２８に穿設したスプール変位
限定用の長孔４１に常時係合させるなどして、該
リンク３５を長孔３３への連結位置に保持させる
ことは勿論である。 FIGS. 2 and 3 show an example of an operating device for the directional control valves 4 and 7, and the tip of the spool sliding rod 25 of the directional control valve 7 is connected sequentially through a dogleg-shaped link 26 and a bell crank 27. Power shovel swivel base 28
A pedal for operating the single-acting actuator 17 is connected to a rod 29 that is slidably supported on the swivel base 28, and is pivoted 30 on the swivel base 28 at a distance from the upper end of the rod 29 to achieve the function described below. 31 is elastically supported by a compression spring 32. On the other hand, the tip of a link 35 connected via a removable pin 34 to the tip of a long hole 33 in the spool sliding direction bored in the tip of the spool sliding rod 25 and the spool slide of the directional control valve 4. The tip of the moving rod 36 is connected to both ends of a lever 37, respectively, and a link 40 is connected between the lower end of the operating rod 39 for controlling the boom elevation cylinder 14, which is pivoted on the swivel table 28, and the middle part of the lever 37. connect,
By creating a difference between the arm lengths of the levers 37 on both sides of the link, in cooperation with the neutral position return springs of each directional control valve, the directional control valve 4 is moved to the position shown in FIG. 1 by rotation of the operating rod 39 in the A direction. After being switched to the upper position in the figure, the directional control valve 7 is switched to the upper position in the figure. Further, it is possible to maintain the link 35 in the connecting position to the elongated hole 33 by constantly engaging the pin insertion tube portion 35a of the link 35 with the elongated hole 41 for limiting spool displacement formed in the swivel base 28. Of course.
上記構成によれば、図示のようにリンク３５の
ピン挿入筒部分３５ａに挿着したピン３４を長孔
３３に係合させた状態において、操作杆３９のＡ
方向回転量を調節することにより、方向切換弁４
だけを第１図の上位置に切換え、負荷作用側油室
１４ａに油圧ポンプ１の吐出圧油を供給し、一方
その上部油室１４ｂをタンクＴに連通してブーム
仰起方向にブーム俯仰シリンダ１４を作動させる
ことも、或いは方向切換弁４，７を共に第１図の
上位置に切換えてブーム俯仰シリンダを油圧ポン
プ１，２の吐出圧油でブーム仰起方向に増速作動
させることもできる。この増速作動の際は、油路
１６の一方向弁１９が閉じてアクチエータ１７へ
の圧油の供給を阻止するから、油圧ポンプ２の吐
出圧油はその全量が一方向弁２０を開いて油路１
２よりブーム俯仰シリンダ１４の負荷作用側油室
１４ａに供給される。一方方向切換弁７の上位置
切換に連動してロツド２９が上昇するが、該ロツ
ドとペダル３１の間には隙間があるから、該ペダ
ルが回動される恐れはない。 According to the above configuration, when the pin 34 inserted into the pin insertion cylinder portion 35a of the link 35 is engaged with the elongated hole 33 as shown in the figure, the A of the operating rod 39 is
By adjusting the amount of directional rotation, the directional switching valve 4
1 to the upper position in FIG. 1, the discharge pressure oil of the hydraulic pump 1 is supplied to the load action side oil chamber 14a, and the upper oil chamber 14b is communicated with the tank T to move the boom elevation cylinder in the boom elevation direction. 14, or by switching both the directional control valves 4 and 7 to the upper position in FIG. can. During this speed-increasing operation, the one-way valve 19 of the oil passage 16 closes and prevents the supply of pressure oil to the actuator 17, so the entire amount of pressure oil discharged from the hydraulic pump 2 is released when the one-way valve 20 is opened. Oil road 1
2 to the load acting side oil chamber 14a of the boom elevation cylinder 14. The rod 29 rises in conjunction with the switching of the one-way switching valve 7 to the upper position, but since there is a gap between the rod and the pedal 31, there is no fear that the pedal will be rotated.
又操作杆３９をＢ方向に操作した時は、先ずピ
ン３４が長孔３３内を空動きしながら、リンク３
５のピン挿入筒部分３５ａが長孔４１の第２図右
端まで摺動して、レバー３７の該リンク連結部分
が旋回台２８に支持された後に、方向切換弁４の
スプール摺動杆３６がその中立位置復帰ばねに抗
して第１図の下位置に切換えられ、ブーム俯仰シ
リンダ１４の上部油室１４ｂが油圧ポンプ１の吐
出口に連通し、又下部油室或いは負荷作用側油室
１４ａがタンクＴに連通して、該ブーム俯仰シリ
ンダは油圧ポンプ１の吐出圧油だけでブーム倒伏
方向に作動させられる。 Also, when the operating rod 39 is operated in the direction B, the pin 34 moves idly within the elongated hole 33 and the link 3
After the pin insertion tube portion 35a of the directional control valve 4 slides to the right end of the elongated hole 41 in FIG. It is switched to the lower position in FIG. 1 against the neutral position return spring, and the upper oil chamber 14b of the boom elevation cylinder 14 communicates with the discharge port of the hydraulic pump 1, and the lower oil chamber or the load application side oil chamber 14a. is in communication with the tank T, and the boom elevating cylinder is operated in the boom lowering direction only by the pressure oil discharged from the hydraulic pump 1.
アクチエータ１７を作動させるに際しては、リ
ンク３５よりピン３４を抜取つて該リンクとスプ
ール摺動杆２５の連結を解いた後にペダル３１を
踏むことにより、ロツド２９を摺動させて、順次
ベルクランク２７、くの字状リンク２６を介しス
プール摺動杆２５或いは方向切換弁７を第１図の
下位置に切換えれば、油圧ポンプ２の吐出圧油が
一方向弁１９を開きながら順次油路１５、単動型
アクチエータ１７、油路１６を経てタンクＴに戻
り、該アクチエータを駆動する。この場合増速用
油路１２の一方向弁２０は負荷作用側油室１４ａ
の油圧により閉じてブーム俯仰シリンダ１４の縮
小を拘束するから、ブームが不時に倒伏する恐れ
はない。 To operate the actuator 17, remove the pin 34 from the link 35 to disconnect the link from the spool sliding rod 25, and then step on the pedal 31 to slide the rod 29 and sequentially move the bell crank 27, If the spool sliding rod 25 or the directional control valve 7 is switched to the lower position in FIG. It returns to the tank T via the single-acting actuator 17 and the oil path 16, and drives the actuator. In this case, the one-way valve 20 of the speed increasing oil passage 12 is in the load action side oil chamber 14a.
Since the cylinder 14 is closed by the hydraulic pressure and restrains contraction of the boom elevation cylinder 14, there is no fear that the boom will collapse unexpectedly.
又この単動型アクチエータ駆動中にブームを俯
仰させる場合は、操作杆３９をＡ方向或いはＢ方
向に操作して、ピン挿入筒部分３５ａを長孔４１
の前後何れかの端末に係合させた後のレバー３７
の揺動により、方向切換弁４を第１図の上位置或
いは下位置に切換えればよく、この場合も一方向
弁２０が閉じてブーム俯仰シリンダ側油圧回路と
単動型アクチエータ側油圧回路の間を遮断するこ
とは明らかである。 If the boom is to be raised or lowered while this single-acting actuator is being driven, operate the operating rod 39 in the A direction or B direction to insert the pin insertion tube portion 35a into the elongated hole 41.
Lever 37 after being engaged with either the front or rear terminals of
The directional control valve 4 can be switched to the upper position or the lower position in FIG. It is clear that there is a gap between
本考案によれば、長孔４１に常時係合している
ピン挿入筒部分３５ａにピン３４を挿脱するだけ
で、方向切換弁４による複動型アクチエータの制
御を何等妨げることなくして、方向切換弁７が複
動型アクチエータを負荷に抗して増速する位置
か、或いは単動型アクチエータを駆動する位置か
に切換えられるように構成し、且つ方向切換弁７
の出力側を複動型アクチエータと単動型アクチエ
ータに連結する油路中に一方向弁１９，２０を設
けて、該方向切換弁の出力側を該両アクチエータ
の何れか一方に連結し替える面倒な配管取付け作
業を無くしたから、作業現場内において複動型ア
クチエータの増速駆動と、該複動型アクチエータ
及び単動型アクチエータの同時駆動とを迅速且つ
容易に切替えることができ、作業車両の作業能率
を向上できる効果がある。 According to the present invention, by simply inserting and removing the pin 34 into the pin insertion cylinder portion 35a that is always engaged with the elongated hole 41, the control of the double-acting actuator by the directional control valve 4 is not hindered in any way. The switching valve 7 is configured to be able to switch between a position where the double-acting actuator is accelerated against a load or a position where the single-acting actuator is driven;
One-way valves 19 and 20 are provided in the oil passages connecting the output side of the directional control valve to the double-acting actuator and the single-acting actuator, and the output side of the directional control valve is connected to either one of the two actuators. Since the need for piping installation work is eliminated, it is possible to quickly and easily switch between increased speed driving of the double-acting actuator and simultaneous driving of the double-acting actuator and single-acting actuator at the work site, which improves the speed of the work vehicle. It has the effect of improving work efficiency.
第１図は本考案一実施例の油圧回路図、第２図
は方向切換弁操作装置の斜視図、第３図はその一
部の分解斜視図である。
１，２……油圧ポンプ、４，７……３位置方向
切換弁、１０，１１……油路、１２……増速用油
路、１４……ブーム俯仰シリンダ、１５，１６…
…油路、１７……単動型アクチエータ、１９，２
０……一方向弁。
FIG. 1 is a hydraulic circuit diagram of an embodiment of the present invention, FIG. 2 is a perspective view of a directional control valve operating device, and FIG. 3 is an exploded perspective view of a portion thereof. 1, 2... Hydraulic pump, 4, 7... 3-position directional switching valve, 10, 11... Oil passage, 12... Oil passage for speed increase, 14... Boom elevation cylinder, 15, 16...
...Oil passage, 17...Single acting actuator, 19,2
0...One-way valve.
Claims (1)
時中立位置に復帰賦勢される２個の３位置の方向
切換弁４，７のスプール摺動杆と１個の操作杆３
９との間に、一方の方向切換弁４を先に切換えた
後に他方の方向切換弁７を切換える機構を介装し
て、一方向に負荷が作用する複動型アクチエータ
１４を方向切換弁４の出力側に接続し、該複動型
アクチエータの負荷作用側油室に方向切換弁４と
協同してポンプ吐出圧油を供給する増速用油路１
２を、方向切換弁７の出力側に接続した作業車両
において、増速用油路１２にポンプ吐出圧油を供
給する増速用切換位置と反対側の切換位置に方向
切換弁７を切換えた時に駆動される単動型アクチ
エータを、該方向切換弁７の出力側に接続して、
その戻り油路１６に一方向弁１９を、又増速用油
路１２に一方向弁２０を夫々挿入し、方向切換弁
７を前記反対側切換位置に切換え可能な一方向作
動の操作装置を該方向切換弁のスプール摺動杆２
５に連動連結し、該スプール摺動杆２５と、これ
を操作杆３９に連動連結すべきリンク３５のピン
挿入筒部分３５ａとを挿脱自在なピン３４で連結
して、増速用切換位置とその反対側の切換位置と
に方向切換弁７を切換え得るように、該ピン挿入
筒部分３５ａの移動範囲を限定する長孔４１を操
作杆や方向切換弁の取付台側に設け、中立位置の
方向切換弁７を前記反対側の切換位置に切換える
方向にピン挿入筒部分３５ａを長孔４１に沿い移
動させる際は、ピン３４がスプール摺動杆２５に
対し空動きするように、該スプール摺動杆に設け
たピン孔を長孔３３に構成したことを特徴とする
作業車両の油圧制御装置。 Spool sliding rods of two 3-position directional control valves 4 and 7, which are connected to the discharge ports of different hydraulic pumps and are always activated to return to the neutral position, and one operating rod 3.
A mechanism is interposed between the directional switching valve 9 and the directional switching valve 4 to switch the double-acting actuator 14 on which a load acts in one direction from the directional switching valve 4 to the directional switching valve 9. speed increasing oil passage 1 connected to the output side of the double-acting actuator and supplying pump discharge pressure oil to the load action side oil chamber of the double-acting actuator in cooperation with the directional control valve 4;
2 is connected to the output side of the directional control valve 7, and the directional control valve 7 is switched to a switching position opposite to the speed increasing switching position that supplies pump discharge pressure oil to the speed increasing oil path 12. A single-acting actuator that is driven at the same time is connected to the output side of the directional control valve 7,
A one-way valve 19 is inserted into the return oil passage 16, and a one-way valve 20 is inserted into the speed-increasing oil passage 12, thereby providing a one-way operating operating device capable of switching the directional switching valve 7 to the opposite switching position. Spool sliding rod 2 of the directional control valve
5, the spool sliding rod 25 and the pin insertion cylinder portion 35a of the link 35 which is to be interlocked and connected to the operating rod 39 are connected by a removable pin 34, and the speed increasing switching position is established. In order to switch the directional control valve 7 between the neutral position and the opposite switching position, an elongated hole 41 is provided on the operating rod or the mounting base of the directional control valve to limit the movement range of the pin insertion cylinder portion 35a. When moving the pin insertion cylinder portion 35a along the elongated hole 41 in the direction of switching the direction switching valve 7 to the opposite switching position, the spool is moved so that the pin 34 moves idly relative to the spool sliding rod 25. A hydraulic control device for a work vehicle, characterized in that a pin hole provided in a sliding rod is formed into a long hole 33.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18180580U JPS6221127Y2 (en) | 1980-12-19 | 1980-12-19 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18180580U JPS6221127Y2 (en) | 1980-12-19 | 1980-12-19 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57105402U JPS57105402U (en) | 1982-06-29 |
| JPS6221127Y2 true JPS6221127Y2 (en) | 1987-05-29 |
Family
ID=29979611
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18180580U Expired JPS6221127Y2 (en) | 1980-12-19 | 1980-12-19 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6221127Y2 (en) |
-
1980
- 1980-12-19 JP JP18180580U patent/JPS6221127Y2/ja not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57105402U (en) | 1982-06-29 |
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