JPS6244849Y2 - - Google Patents
Info
- Publication number
- JPS6244849Y2 JPS6244849Y2 JP1981012285U JP1228581U JPS6244849Y2 JP S6244849 Y2 JPS6244849 Y2 JP S6244849Y2 JP 1981012285 U JP1981012285 U JP 1981012285U JP 1228581 U JP1228581 U JP 1228581U JP S6244849 Y2 JPS6244849 Y2 JP S6244849Y2
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- valve
- hydraulic transmission
- pilot
- variable displacement
- 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
- 230000005540 biological transmission Effects 0.000 claims description 46
- 238000006073 displacement reaction Methods 0.000 claims description 16
- 230000007246 mechanism Effects 0.000 claims description 3
- 239000003921 oil Substances 0.000 description 4
- 230000007935 neutral effect Effects 0.000 description 3
- 230000001360 synchronised effect Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 1
- 239000010720 hydraulic oil Substances 0.000 description 1
Landscapes
- Control Of Fluid Gearings (AREA)
- Non-Deflectable Wheels, Steering Of Trailers, Or Other Steering (AREA)
Description
【考案の詳細な説明】
本考案は、油圧ポンプと油圧モータとを閉回路
接続した油圧伝動装置（油圧トランスミツシヨ
ン）を、左右独立に備えた油圧駆動装置に関する
ものである。[Detailed Description of the Invention] The present invention relates to a hydraulic drive device that is equipped with left and right independent hydraulic transmissions in which a hydraulic pump and a hydraulic motor are connected in a closed circuit.
従来、この種の油圧駆動装置にあつては低負荷
直進走行時に、左右の油圧伝動装置の効率の相違
等によつて曲つてしまうことがある。 Conventionally, in this type of hydraulic drive system, during low-load straight-ahead running, the steering wheel may bend due to differences in efficiency between the left and right hydraulic transmission devices.
そこで、特開昭51−50132号公報に示す如く左
右の油圧伝動装置を油圧伝動装置の圧力が低い時
には連通し圧力が高い時には遮断する同調バルブ
を介して短絡し、低負荷直進時には左右の油圧伝
動装置が短絡して効率の相違等があつても直進で
きるようにしたものが提案されている。 Therefore, as shown in Japanese Patent Application Laid-Open No. 51-50132, the left and right hydraulic transmission devices are short-circuited via a synchronized valve that communicates when the pressure of the hydraulic transmission device is low and shuts off when the pressure is high. A vehicle has been proposed that allows the vehicle to travel straight even if there is a difference in efficiency due to a short circuit in the transmission device.
しかし、前述の同調バルブは、バネ力でスプー
ルを連通位置に保持しかつ左右の油圧伝動装置の
圧力によつてスプールをバネ力に抗して遮断位置
に切換える構造であるから、次の不具合を有す
る。 However, the above-mentioned synchronized valve has a structure in which the spring force holds the spool in the communicating position, and the pressure of the left and right hydraulic transmission devices switches the spool to the shut-off position against the spring force, which causes the following problems. have
同調バルブが連通位置の時にステアリング操
作、例えば左操向操作すると（つまり、右油圧
伝動装置を高速回転状態とすると）同調バルブ
のスプールが連通位置であるから、右油圧伝動
装置の高圧側管路から作動油が左油圧伝動装置
の高圧側管路に流れ込んでしまうから、左油圧
伝動装置が高速回転となつてしまい左操向しな
くなつてしまう。 When the tuning valve is in the communicating position, if you perform a steering operation, for example, to the left (that is, if the right hydraulic transmission is in a high-speed rotation state), the spool of the tuning valve is in the communicating position, so the high-pressure side pipe of the right hydraulic transmission is Since the hydraulic oil flows into the high-pressure side conduit of the left hydraulic transmission, the left hydraulic transmission rotates at high speed, making it impossible to steer to the left.
また、右油圧伝動装置の高圧側管路の作動油
が左油圧伝動装置の高圧側管路に流れ込むこと
によつて右油圧伝動装置の低圧側管路への右モ
ータからの戻り流量が減少しチヤージポンプの
チヤージ流量でこの減少分を補なえなくなつた
場合にはキヤビテーシヨンが発生してしまう。 Additionally, as the hydraulic fluid in the high-pressure side pipe of the right hydraulic transmission device flows into the high-pressure side pipe line of the left hydraulic transmission device, the return flow rate from the right motor to the low-pressure side pipe of the right hydraulic transmission device is reduced. Cavitation occurs when the charge flow rate of the charge pump cannot compensate for this decrease.
したがつて、チヤージポンプの流量を大きく
しなければならず馬力損失が増大してしまう。 Therefore, the flow rate of the charge pump must be increased, resulting in increased horsepower loss.
前述のの状態からさらに左操向操作する
と、右油圧駆動装置の高圧側管路の圧力が左油
圧伝動装置の抵抗により上昇して同調バルブの
スプールをバネ力に抗して急激に遮断位置とす
るので、車両は急激に左旋回し非常に危険であ
る。 When the left steering operation is performed from the above-mentioned state, the pressure in the high-pressure side pipe of the right hydraulic drive device increases due to the resistance of the left hydraulic transmission device, and the spool of the synchronized valve suddenly moves to the shutoff position against the spring force. This causes the vehicle to turn sharply to the left, which is extremely dangerous.
以上のことを要約すると、ステアリング操作開
始段階では車両が旋回せずにある程度ステアリン
グ操作した時に車両が急激に旋回するので非常に
危険であると共に、ステアリング操作した時にキ
ヤビテーシヨンが発生して油圧駆動装置の寿命な
どに悪影響を与えるとの不具合を有する。 To summarize the above, the vehicle does not turn at the beginning of the steering operation, but when the steering wheel is operated to a certain extent, the vehicle suddenly turns, which is extremely dangerous, and cavitation occurs when the steering wheel is operated, causing damage to the hydraulic drive system. It has a problem that has a negative impact on its lifespan.
なお、特開昭54−71260号公報や特開昭54−
71262号公報に記載されたように、右油圧伝動装
置の第１、第２主管路と左油圧伝動装置の第１、
第２主管路を直進補償弁で断通すると共に、この
直進補償弁を車両が直進する時には連通位置とな
り、かつ操向する時には遮断位置となるようにし
た油圧駆動装置が知られているが、この油圧駆動
装置であると重負荷で直進している時に右左油圧
伝動装置に加わる負荷が大きく異なると高負荷側
の油圧伝動装置の高圧油が直進補償弁を通つて低
負荷側の油圧伝動装置に流入し、高負荷側のモー
タ回転数が減少すると共に、低負荷側のモータの
回転数が増加して左右のモータ回転数差が拡大し
て、直進補償弁によつて左右の油圧伝動装置の第
１、第２主管路を短絡したことによつて、かえつ
て車両が大きく曲進して直進できなくなつてしま
う。 In addition, JP-A-54-71260 and JP-A-54-
As described in Publication No. 71262, the first and second main pipes of the right hydraulic transmission and the first and second main pipes of the left hydraulic transmission
A hydraulic drive device is known in which the second main pipe is disconnected by a straight-line compensation valve, and the straight-line compensation valve is set in a communicating position when the vehicle is traveling straight, and in a blocking position when the vehicle is steering. With this hydraulic drive system, when the load applied to the right and left hydraulic transmission devices differs greatly when traveling straight under heavy load, high pressure oil from the hydraulic transmission device on the high load side passes through the straight travel compensation valve to the hydraulic transmission device on the low load side. The rotational speed of the motor on the high-load side decreases, and the rotational speed of the motor on the low-load side increases, increasing the difference in the rotational speed of the left and right motors. By short-circuiting the first and second main pipes, the vehicle ends up making a large turn and is unable to go straight.
本考案は上記の事情に鑑みなされたものであ
り、その目的は低負荷時の直進を補償できると共
に、ステアリング操作すると直ちに滑らかに旋回
操向し、さらには小容量のチヤージポンプを用い
てキヤビテーシヨンが発生し難くできると共に、
重負荷直進時に右左油圧伝動装置に加わる負荷の
差が大であつても車両が大きく曲進することがな
いようにした油圧駆動装置を提供することであ
る。 This invention was developed in view of the above circumstances, and its purpose is to compensate for straight-line driving under low load, to smoothly turn the steering wheel immediately after steering operation, and to prevent cavitation by using a small-capacity charge pump. It can be difficult to do, and
To provide a hydraulic drive device which prevents a vehicle from making a large turn even if there is a large difference in loads applied to right and left hydraulic transmission devices when moving straight with a heavy load.
以下図面を参照して本考案の実施例を説明す
る。 Embodiments of the present invention will be described below with reference to the drawings.
Ａは右油圧伝動装置、Ｂは左油圧伝動装置であ
り、Ｃはチヤージポンプ、Ｄはパイロツトポンプ
である。 A is a right hydraulic transmission, B is a left hydraulic transmission, C is a charge pump, and D is a pilot pump.
前記油圧伝動装置Ａは次のように構成してあ
る。 The hydraulic transmission device A is constructed as follows.
つまり、右可変容量形ポンプ１と右可変容量形
モータ２とを第1.第２主管路３，４で閉回路接続
すると共に、第1.第２主管路３，４間にシヤツト
ルバルブ５が設けてある。 That is, the right variable displacement pump 1 and the right variable displacement motor 2 are connected in a closed circuit through the first and second main lines 3 and 4, and the shuttle valve 5 is connected between the first and second main lines 3 and 4. is provided.
該シヤツトルバルブ５は第1.第２主管路３，４
の圧力が等しい時には第1.第２主管路３，４を遮
断する中立位置Ｎとなり、第１主管路３の圧力が
高い時には第２主管路４をリリーフ弁７を備えた
ドレーン路８に接続する第１位置となり、第２
主管路４へ圧力が高い時には第１主管路３をドレ
ーン路８に接続する第２位置となる構造であ
る。 The shuttle valve 5 is connected to the first and second main pipes 3 and 4.
When the pressures are equal, the first and second main pipes 3 and 4 are cut off at the neutral position N, and when the pressure of the first main pipe 3 is high, the second main pipe 4 is connected to the drain pipe 8 equipped with the relief valve 7. the first position, and the second
The structure is such that when the pressure in the main pipe line 4 is high, the first main pipe line 3 is connected to the drain line 8 in a second position.
前記チヤージポンプＣの吐出路C1は逆止弁
９，１０を介して第1.第２主管路３，４に接続し
ていると共に、第1.第２主管路３，４はリリーフ
弁１１，１２を介して前記吐出路C1に接続して
ある。 The discharge passage C 1 of the charge pump C is connected to the first and second main pipes 3 and 4 via check valves 9 and 10, and the first and second main pipes 3 and 4 are connected to relief valves 11 and 10, respectively. It is connected to the discharge passage C1 via 12.
前記左油圧伝動装置Ｂは次のように構成してあ
る。 The left hydraulic transmission device B is constructed as follows.
つまり、左可変容量形ポンプ２１と右可変容量
形モータ２２とを第1.第２主管路２３，２４で閉
回路接続すると共に、第1.第２主管路２３，２４
間にシヤツトルバルブ２５が設けてある。 That is, the left variable displacement pump 21 and the right variable displacement motor 22 are connected in a closed circuit through the first and second main conduits 23 and 24, and the first and second main conduits 23 and 24 are connected in a closed circuit.
A shuttle valve 25 is provided between them.
該シヤツトルバルブ２５は第1.第２主管路２
３，２４の圧力が等しい時には第1.第２主管路２
３，２４を遮断する中立位置Ｎとなり、第１主管
路２３の圧力が高い時には第２主管路２４をリリ
ーフ弁２７を備えたドレーン路２８に接続する第
１位置となり、第２主管路２４の圧力が高い時
には第１主管路２３をドレーン路２８に接続する
第２位置となる構造である。 The shuttle valve 25 is connected to the first and second main pipes 2.
When the pressures of 3 and 24 are equal, the first and second main pipes 2
3 and 24, and when the pressure in the first main line 23 is high, it becomes the first position where the second main line 24 is connected to the drain line 28 equipped with the relief valve 27, and the second main line 24 is in the first position. When the pressure is high, the first main pipe line 23 is connected to the drain line 28 in a second position.
前記チヤージポンプＣの吐出路C1は逆止弁２
９，３０を介して第1.第２主管路２３，２４に接
続していると共に、第１、第２主管路２３，２４
はリリーフ弁３１，３２を介して前記吐出路C1
に接続してある。 The discharge passage C1 of the charge pump C is a check valve 2.
9, 30 to the first and second main pipes 23, 24, and the first and second main pipes 23, 24.
is the discharge passage C 1 via the relief valves 31 and 32.
It is connected to.
前記各第１主管路３，２３は第１連通路６で短
絡され、第２主管路４，２４は第２連通路２６で
短絡されていると共に、第1.第２連通路６，２６
には開閉弁２０が設けてある。 The first main pipes 3 and 23 are short-circuited by a first communication path 6, and the second main pipes 4 and 24 are short-circuited by a second communication path 26, and the first and second communication paths 6, 26 are short-circuited.
is provided with an on-off valve 20.
該開閉弁２０はバネ２０ａで遮断位置に保持
され、受圧部２０ｂのパイロツト圧力で連通位置
に切換る構造となつている。 The on-off valve 20 is held in a closed position by a spring 20a, and is switched to a communicating position by pilot pressure from a pressure receiving portion 20b.
そして、パイロツト路４０は前記パイロツトポ
ンプＤの吐出路D1に接続してあり、パイロツト
路４０には第1.第２切換弁４１，４２が設けてあ
る。 The pilot passage 40 is connected to the discharge passage D1 of the pilot pump D, and the pilot passage 40 is provided with first and second switching valves 41 and 42.
該第１切換弁４１はバネ４１ａでドレーン位置
イに保持され、受圧部４１ｂの圧力で連通位置ロ
に切換るものであり、第２切換弁４２は連通位置
ハとドレーン位置ニとを備え、バネ４２ａで連通
位置ハに保持してある。 The first switching valve 41 is held in a drain position A by a spring 41a, and is switched to a communicating position B by the pressure of a pressure receiving part 41b, and the second switching valve 42 has a communicating position C and a drain position D, It is held in the communicating position C by a spring 42a.
前記パイロツトポンプＤの吐出路D1は圧力補
償式の操作弁４３を介して第1.第２パイロツト管
路４４，４５のどちらか一方に供給制御され、第
1.第２パイロツト管路４４，４５は右．左操向弁
４６，４７を介して右．右可変容量形ポンプ１，
２１の容量制御用サーボ機構１ａ，２１ａ及び
右．左可変容量形モータ２，２２の容量制御用サ
ーボ機構２ａ，２２ａにパイロツト圧として供給
制御され、パイロツトポンプＤの吐出圧油を容量
制御シリンダ１ｂ，２ｂ，２１ｂ，２２ｂに圧送
制御するようにしてある。 The discharge path D1 of the pilot pump D is controlled to be supplied to either the first or second pilot pipe 44, 45 via a pressure-compensated operation valve 43, and the
1. The second pilot pipes 44 and 45 are on the right. right via left steering valves 46 and 47. Right variable displacement pump 1,
21 capacity control servo mechanisms 1a, 21a and the right. The pilot pressure is controlled to be supplied to the displacement control servomechanisms 2a and 22a of the left variable displacement motors 2 and 22, and the pressure oil discharged from the pilot pump D is controlled to be pumped to the displacement control cylinders 1b, 2b, 21b and 22b. be.
前記操作弁４３は吐出路D1を遮断する中立位
置Ｎ、第１パイロツト管路４４に接続する第１位
置、第２パイロツト管路４５に接続する第２位
置とを備え、レバ４３ａで切換えられると共
に、レバ４３ａの操作ストロークに応じた圧油が
第１あるいは第２パイロツト管路４４，４５に生
じるように構成してある。 The operation valve 43 has a neutral position N that blocks the discharge passage D1 , a first position that connects to the first pilot line 44, and a second position that connects to the second pilot line 45, and is switched by a lever 43a. At the same time, pressure oil is generated in the first or second pilot pipes 44, 45 in accordance with the operating stroke of the lever 43a.
そして、第1.第２パイロツト管路４４，４５は
シヤツトル弁４８を介して前記第１切換弁４１の
受圧部４１ｂに接続され、その圧力が所定圧力P1
以上となると連通位置ロに切換るようにしてあ
る。 The first and second pilot pipes 44 and 45 are connected to the pressure receiving part 41b of the first switching valve 41 via a shuttle valve 48, and the pressure thereof is set to a predetermined pressure P1.
When this happens, the communication position is switched to the communication position B.
前記右．左操向弁４６，４７はポンプモータの
容量を零とする中立位置Ｎ、正転方向とする正転
位置ホ、逆転方向とする逆転位置ヘとを備え、レ
バ４６ａ，４７ａで切換えられると共に、レバ４
６ａ，４７ａはリンク機構４９，５０を介して前
記第２切換弁４２に、右．左操向弁４６，４７と
逆方向位置に操作するとドレーン位置ニに切換る
ように連結してある。 Said right. The left steering valves 46 and 47 have a neutral position N where the capacity of the pump motor is zero, a normal rotation position H where the pump motor rotates in the forward direction, and a reverse position where the pump motor rotates in the reverse direction, and are switched by levers 46a and 47a. lever 4
6a and 47a are connected to the second switching valve 42 via link mechanisms 49 and 50, respectively. It is connected to the left steering valves 46 and 47 so that when the valve is operated in the opposite direction, the drain position is switched to the drain position N.
次に作動を説明する。 Next, the operation will be explained.
車両が直進．前進する時。 The vehicle goes straight. Time to move forward.
操作弁４３を第１位置、右．左操向弁４
６，４７を正転位置ホとして各ポンプ・モータ
を正転駆動させる。 Set the operating valve 43 to the first position, right. Left steering valve 4
6 and 47 are set as normal rotation position E, and each pump motor is driven in normal rotation.
これにより、右．左油圧伝動装置A.Bの第１
主管路３，２３は第２主管路４，２４よりも高
圧となる。つまり、差圧△Ｐが生じる。 With this, the right. 1st of left hydraulic transmission AB
The main lines 3 and 23 have a higher pressure than the second main lines 4 and 24. In other words, a differential pressure ΔP is generated.
ここで、前記差圧△Ｐは可変容量ポンプ１，
２１の入力軸馬力が一定のとき可変容量モータ
２，２２の回転数に関して第２図に示す表図の
ごとくになる。 Here, the differential pressure ΔP is the variable displacement pump 1,
When the input shaft horsepower of the motor 21 is constant, the rotational speed of the variable displacement motors 2 and 22 is as shown in the table shown in FIG.
つまり、所定の回転数N1で容量が最大とな
り、それよりも低速回転或N′（高負荷状態）
では差圧が順次高くなつてある回転数N2で最
高となりそれ以後は差圧が同じとなると共に、
所定の回転数N1よりも高速回転或N″（軽負荷
状態）では差圧が等圧となる。 In other words, the capacity is maximum at a predetermined rotation speed N 1 , and at lower speeds or N′ (high load state)
Then, the differential pressure gradually increases until it reaches a maximum at a certain rotation speed N 2 , and thereafter the differential pressure remains the same, and
At a rotation speed higher than the predetermined rotation speed N1 (a light load state), the differential pressure becomes equal.
一方、第1.第２パイロツト管路４４，４５の
差圧△P′はレバ４３ａの操作ストロークに比例
しストローク大（負荷小）ならば大きく、スト
ローク小（負荷大）ならば小さくなる。 On the other hand, the differential pressure ΔP' between the first and second pilot pipes 44 and 45 is proportional to the operating stroke of the lever 43a, and increases if the stroke is large (small load) and becomes small if the stroke is small (large load).
ここで、所定回転数N1のときの差圧△P1と
前記差圧△P′とが△P′＞△P1の時（軽負荷時）
にはバネ４１ａの力に抗して第１切換弁４１が
連通位置ロとなり、△P′＜△P1の時（重負荷
時）にはバネ４１ａの力で第１切換弁４１がド
レーン位置イとなるように設定する。 Here, when the differential pressure △P 1 at the predetermined rotation speed N 1 and the differential pressure △P′ are △P′>△P 1 (during light load)
, the first switching valve 41 moves to the communication position B against the force of the spring 41a, and when △P'<△P 1 (during heavy load), the first switching valve 41 moves to the drain position due to the force of the spring 41a. Set it so that
したがつて、前述の直進．前進状態におい
て、軽負荷であればパイロツトポンプＤの吐出
圧油がパイロツト路４０を介して開閉弁２０の
受圧部２０ｂに供給されて連通位置となるか
ら、右左の第１主管路３，２３及び第２主管路
４，２４がそれぞれ短絡連通し右油圧伝動装置
Ａの効率と左油圧伝動装置Ｂの効率とが相違し
ても第１主管路３，２３は等圧となつて車両は
直進する。 Therefore, go straight as mentioned above. In the forward movement state, if the load is light, the discharge pressure oil of the pilot pump D is supplied to the pressure receiving part 20b of the on-off valve 20 through the pilot passage 40, and the opening/closing valve 20 is in a communicating position. Even if the second main pipes 4 and 24 are short-circuited and the efficiency of the right hydraulic transmission device A and the efficiency of the left hydraulic transmission device B are different, the pressure in the first main pipes 3 and 23 becomes equal, and the vehicle moves straight. .
また、前述の状態で重負荷となると△P1＞△
P′となつて第１切換弁４１はドレーン位置イと
なるから開閉弁２０はバネ力で遮断位置とな
り、第１主管路３，２３及び第２主管路４，２
４は遮断される。 Also, if the load becomes heavy under the above conditions, △P 1 > △
P' and the first switching valve 41 is in the drain position A, so the on-off valve 20 is in the cutoff position due to the spring force, and the first main pipes 3, 23 and the second main pipes 4, 2
4 is blocked.
したがつて、重負荷状態で車両を稼動させる
場合には左右の油圧伝動装置A.Bが独立とな
り、負荷によつて車両が大きく曲がることはな
い。 Therefore, when the vehicle is operated under a heavy load, the left and right hydraulic transmission devices AB become independent, and the vehicle does not bend significantly due to the load.
車両を左右に操向させる場合。 When steering the vehicle left or right.
第1.第２操向弁４６，４７を異なる位置ホ．
ヘに切換えて車両を操向するので、第２切換弁
４２はドレーン位置ニに切換り負荷に関係なく
開閉弁２０は遮断位置となるから左右の油圧
伝動装置A.Bは独立し車両を滑らかに旋回操向
できる。 The first and second steering valves 46 and 47 are moved to different positions.
Since the vehicle is steered by switching to F, the second switching valve 42 switches to drain position N, and the on-off valve 20 is in the cutoff position regardless of the load, so the left and right hydraulic transmission devices AB are independent and the vehicle can be turned smoothly. Can be steered.
本考案は以上の様になり、右油圧伝動装置Ａの
第１、第２主管路３，４と左油圧伝動装置Ｂの第
１、第２主管路３，４は開閉弁２０で断通される
と共に、その開閉弁２０はバネ力で遮断位置に
保持され、かつ受圧部２０ｂのパイロツト圧で連
通位置となり、しかも受圧部２０ｂにパイロツ
ト圧を供給する第１切換弁４１は、操作弁４３の
操作ストロークが小さく第１、第２パイロツト管
路４４，４５の差圧が所定圧力以下の時、つまり
油圧伝動装置の負荷が小さく高速回転している時
には連通位置となり、かつ差圧が所定圧力以上の
時、つまり油圧伝動装置の負荷が大きく低速回転
している時にドレーン位置となり、第２切換弁４
１はステアリング操作操向する時にはドレーン位
置となる。 The present invention is as described above, and the first and second main pipes 3 and 4 of the right hydraulic transmission device A and the first and second main pipes 3 and 4 of the left hydraulic transmission device B are disconnected by the on-off valve 20. At the same time, the opening/closing valve 20 is held in the shutoff position by the spring force and is brought into the communicating position by the pilot pressure of the pressure receiving part 20b. When the operating stroke is small and the differential pressure between the first and second pilot pipes 44 and 45 is below a predetermined pressure, that is, when the load on the hydraulic transmission is small and it is rotating at high speed, the communication position is reached, and the differential pressure is above the predetermined pressure. , that is, when the load on the hydraulic transmission device is large and it is rotating at a low speed, it is in the drain position, and the second switching valve 4 is in the drain position.
1 becomes the drain position when performing steering operation.
したがつて、低負荷で直進する時には第１切換
弁４１が連通位置で、第２切換弁４２が連通位置
となるから開閉弁２０の受圧部２０ｂにパイロツ
ト圧が供給されて開閉弁２０は連通位置となつ
て左右油圧伝動装置Ａ，Ｂの第１主管路３，２３
及び第２主管路４，２４がそれぞれ短絡連通して
右油圧伝動装置Ａの効率と左油圧伝動装置Ｂの効
率が相違しても車両を直進できる。 Therefore, when traveling straight under low load, the first switching valve 41 is in the communicating position and the second switching valve 42 is in the communicating position, so pilot pressure is supplied to the pressure receiving part 20b of the on-off valve 20, and the on-off valve 20 is in the communicating position. The first main pipes 3, 23 of the left and right hydraulic transmission devices A, B
The second main pipes 4 and 24 are short-circuited, allowing the vehicle to travel straight even if the efficiency of the right hydraulic transmission device A and the efficiency of the left hydraulic transmission device B are different.
また、重負荷で直進すると時には第１切換弁４
１がドレーン位置となつて第２切換弁４２が連通
位置であつても開閉弁２０の受圧部２０ｂにパイ
ロツト圧が供給されずに開閉弁２０は遮断位置
となり、右左油圧伝動装置Ａ，Ｂは独立となつて
右左油圧伝動装置Ａ，Ｂに加わる負荷の差により
車両が大きく曲進することがない。 In addition, when traveling straight with a heavy load, sometimes the first switching valve 4
1 is in the drain position and the second switching valve 42 is in the communication position, pilot pressure is not supplied to the pressure receiving part 20b of the on-off valve 20, and the on-off valve 20 is in the cutoff position, and the right and left hydraulic transmission devices A and B are The vehicle does not move significantly due to the difference in the loads applied to the right and left hydraulic transmission devices A and B independently.
また、車両を左右に操向する時には第２切換弁
４２がドレーン位置となつて第１切換弁４１が連
通位置であつても開閉弁２０の受圧部２０ｂにパ
イロツト圧が供給されずに開閉弁２０は遮断位置
となるので、右左油圧伝動装置Ａ，Ｂは独立し、
従来のように一方の油圧伝動装置の高圧側主管路
から他方の油圧伝動装置の高圧側主管路に作動油
が流入することがなく車両を滑らかに旋回操向で
きると共に、一方の油圧伝動装置の低圧側主管路
へ戻り流量が減少するこがなく小容量のチヤージ
ポンプを用いてキヤビテーシヨン発生を防止でき
る。 Furthermore, when steering the vehicle left and right, even if the second switching valve 42 is in the drain position and the first switching valve 41 is in the communicating position, pilot pressure is not supplied to the pressure receiving part 20b of the on-off valve 20, and the on-off valve is closed. 20 is the cutoff position, so the right and left hydraulic transmission devices A and B are independent.
Unlike in the past, hydraulic fluid does not flow from the high-pressure side main line of one hydraulic transmission to the high-pressure side main line of the other hydraulic transmission, allowing the vehicle to turn and steer smoothly. Cavitation can be prevented by using a small-capacity charge pump without reducing the flow rate returning to the low-pressure side main pipe.
第１図は本考案の実施例を示す線図的構成説明
図で、第２図は差圧とモータ回転数との関係を示
す表図である。
Ａは右油圧伝動装置、Ｂは左油圧伝動装置、Ｃ
はチヤージポンプ、１は右ポンプ、２は右モー
タ、３，４は第1.第２主管路、６は連通路、２０
は開閉弁、２１は左ポンプ、２２は左モータ、２
３，２４は第1.第２主管路、２６は連通路、４０
はパイロツト路、４１，４２は第1.第２切換弁。
FIG. 1 is a diagrammatic configuration explanatory diagram showing an embodiment of the present invention, and FIG. 2 is a table diagram showing the relationship between differential pressure and motor rotation speed. A is the right hydraulic transmission, B is the left hydraulic transmission, C
1 is the charge pump, 1 is the right pump, 2 is the right motor, 3 and 4 are the 1st and 2nd main pipes, 6 is the communication path, 20
is the on-off valve, 21 is the left pump, 22 is the left motor, 2
3 and 24 are first and second main pipes, 26 is a communication path, 40
is the pilot path, and 41 and 42 are the first and second switching valves.
Claims (1)
とを第１、第２主管路３，４で閉回路接続した右
油圧伝動装置Ａ及び左可変容量形ポンプ２１と左
可変容量形モータ２２とを第１、第２主管路２
３，２４で閉回路接続した左油圧駆動装置Ｂを備
えた油圧駆動装置において、前記右油圧伝動装置
Ａの第１、第２主管路３，４と前記左油圧伝動装
置Ｂの第１、第２連通路６，２６を介してそれぞ
れ短絡連通し、該第１、第２連通路６，２６に、
バネ力で遮断位置となり受圧部２０ｂのパイロ
ツト圧で連通位置となる開閉弁２０を設けると
共に、該開閉弁２０の受圧部２０ｂに接続したパ
イロツト路４０に第１、第２切換弁４１，４２を
直列に設け、さらに前記各可変容量形ポンプ、モ
ータの容量制御用サーボ機構に接続した第１、第
２パイロツト管路４４，４５のどちらか一方に操
作ストロークに応じた圧油を選択的に供給する操
作弁４３を設けると共に、前記第１切換弁４１を
第１、第２パイロツト管路４４，４５の差圧が所
定圧力以上となるドレーン位置イとなり、かつ所
定圧力以下となると連通位置ロとなる構成とする
と共に、前記第２切換弁４２を、ステアリング操
作すると連通位置ヘからドレーン位置ニに切換る
構成としたことを特徴とする油圧駆動装置。 Right variable displacement pump 1 and right variable displacement motor 2
The right hydraulic transmission device A, which is connected in a closed circuit with the first and second main pipes 3 and 4, and the left variable displacement pump 21 and the left variable displacement motor 22 are connected to the first and second main pipes 2.
In a hydraulic drive device including a left hydraulic drive device B connected in a closed circuit at 3 and 24, the first and second main pipes 3 and 4 of the right hydraulic transmission device A and the first and first main pipes of the left hydraulic transmission device B are connected to each other in a closed circuit. Short-circuit communication is provided through the two communication passages 6 and 26, respectively, and the first and second communication passages 6 and 26 are
An on-off valve 20 is provided which is placed in a cutoff position by a spring force and placed in a communication position by a pilot pressure of a pressure receiving part 20b, and first and second switching valves 41 and 42 are provided in a pilot path 40 connected to the pressure receiving part 20b of the on-off valve 20. Pressure oil is selectively supplied according to the operating stroke to either one of the first and second pilot pipes 44 and 45 which are arranged in series and further connected to the servo mechanism for controlling the displacement of each of the variable displacement pumps and motors. At the same time, the first switching valve 41 is set to the drain position A when the pressure difference between the first and second pilot pipes 44 and 45 is above a predetermined pressure, and to the communication position B when the pressure is below a predetermined pressure. A hydraulic drive device characterized in that the second switching valve 42 is switched from a communication position to a drain position N when a steering wheel is operated.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1981012285U JPS6244849Y2 (en) | 1981-02-02 | 1981-02-02 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1981012285U JPS6244849Y2 (en) | 1981-02-02 | 1981-02-02 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57127059U JPS57127059U (en) | 1982-08-07 |
| JPS6244849Y2 true JPS6244849Y2 (en) | 1987-11-28 |
Family
ID=29810399
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1981012285U Expired JPS6244849Y2 (en) | 1981-02-02 | 1981-02-02 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6244849Y2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1274748A (en) * | 1987-02-19 | 1990-10-02 | Steven Harold Johnson | Balanced hydraulic propulsion system |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5471260A (en) * | 1977-11-18 | 1979-06-07 | Komatsu Ltd | Controlling device in oil pressure driving device |
| JPS5471262A (en) * | 1977-11-18 | 1979-06-07 | Komatsu Ltd | Controlling device in oil pressure device |
-
1981
- 1981-02-02 JP JP1981012285U patent/JPS6244849Y2/ja not_active Expired
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5471260A (en) * | 1977-11-18 | 1979-06-07 | Komatsu Ltd | Controlling device in oil pressure driving device |
| JPS5471262A (en) * | 1977-11-18 | 1979-06-07 | Komatsu Ltd | Controlling device in oil pressure device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57127059U (en) | 1982-08-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4075841A (en) | Control system for hydrostatic transmission | |
| US4324098A (en) | Hydraulic circuit for a hydraulically driven vehicle | |
| US3803841A (en) | Steering actuated motor displacement control valve | |
| GB2320314A (en) | Hydrostatic transmission control system | |
| JP2004027706A (en) | Hydraulic circuit device for construction machinery | |
| JPS6244849Y2 (en) | ||
| US4583371A (en) | Hydrostatic drive arrangement | |
| JPS6313979Y2 (en) | ||
| JPS5854305B2 (en) | Seiatsukudo Souchi | |
| JP2716607B2 (en) | Hydraulic circuit of construction machinery | |
| JPH03282063A (en) | Hydraulic circuit for closed circuit hydraulic transmission | |
| DE102010048891A1 (en) | Drive system for mobile machine, particularly ground conveyor, has hydraulic fan drive for producing cooling air flow at heat exchanger unit | |
| JP2749611B2 (en) | Hydraulic drive using load sensing system | |
| JPH0618820Y2 (en) | Running hydraulic circuit of wheel type construction machine | |
| SU1611778A1 (en) | Integrated hydraulic system for steering gear and additional user for vehicle | |
| EP0028448A2 (en) | Fluid motor control system | |
| JP2594686Y2 (en) | Traveling hydraulic circuit | |
| JPH0674054B2 (en) | Straight traveling control circuit device for hydraulic traveling vehicle | |
| JPH04173478A (en) | Hydraulic drive unit for working vehicle | |
| SU1085860A1 (en) | Hydraulic system of vehicle with positive-displacement hydraulic transmission | |
| JP2919120B2 (en) | Tractor transmission | |
| JP4076436B2 (en) | Flow rate support circuit to HST circuit | |
| JP3218299B2 (en) | Travel speed control circuit for construction machinery | |
| SU1255467A1 (en) | Hydraulic torque converter for vehicle | |
| JPH0370684A (en) | Hydraulic steering device with variable displacement oil hydraulic motor |