JP7053446B2

JP7053446B2 - Tractor

Info

Publication number: JP7053446B2
Application number: JP2018237061A
Authority: JP
Inventors: 武二田中; 直樹内田; 智典須山; 恵三内田
Original assignee: Mitsubishi Mahindra Agricultural Machinery Co Ltd
Current assignee: Mitsubishi Mahindra Agricultural Machinery Co Ltd
Priority date: 2018-12-19
Filing date: 2018-12-19
Publication date: 2022-04-12
Anticipated expiration: 2038-12-19
Also published as: JP2020098008A

Description

本発明は、前進用油圧クラッチ及び後進用油圧クラッチを備えるトラクタに関する。 The present invention relates to a tractor including a forward hydraulic clutch and a reverse hydraulic clutch.

走行機体の前後進を切り換える前進用油圧クラッチ及び後進用油圧クラッチと、前後進切換操作具の操作に応じて前進用油圧クラッチ及び後進用油圧クラッチを昇圧制御して走行機体を前進又は後進させる制御装置と、を備えるトラクタが知られている（例えば、特許文献１、２参照）。 Control to boost or control the forward hydraulic clutch and reverse hydraulic clutch that switch the forward / backward movement of the traveling aircraft, and the forward hydraulic clutch and reverse hydraulic clutch according to the operation of the forward / backward switching operation tool to move the traveling aircraft forward or backward. A tractor comprising the device is known (see, for example, Patent Documents 1 and 2).

特許第４０９８９０３号公報Japanese Patent No. 4098903 特開２００２－８１５３９号公報Japanese Unexamined Patent Publication No. 2002-81539

しかしながら、特許文献１、２に記載のトラクタは、主変速レバーの操作位置を検出する主変速検出手段と、副変速レバーの操作位置を検出する副変速検出手段と、を備えるとともに、制御装置が、主変速レバーや副変速レバーの操作位置に応じて前進用油圧クラッチ及び後進用油圧クラッチの昇圧パターンを変化させるので、レバー位置検出スイッチなどの検出部品が増加するだけでなく、制御が複雑になる虞があった。 However, the tractor described in Patent Documents 1 and 2 includes a main shift detecting means for detecting the operating position of the main shifting lever and an auxiliary shifting detecting means for detecting the operating position of the auxiliary shifting lever, and the control device includes the control device. Since the boost pattern of the forward hydraulic clutch and the reverse hydraulic clutch is changed according to the operation position of the main shift lever and the auxiliary shift lever, not only the number of detection parts such as the lever position detection switch increases, but also the control becomes complicated. There was a risk of becoming.

本発明は、上記の如き実情に鑑みこれらの課題を解決することを目的として創作されたものであって、請求項１の発明は、走行機体と、前記走行機体の走行動力を段階的に変速する走行変速機構と、前記走行機体の前後進を切り換える前進用油圧クラッチ及び後進用油圧クラッチと、前後進切換操作具の操作に応じて前記前進用油圧クラッチ又は前記後進用油圧クラッチを昇圧制御して前記走行機体を前進又は後進させる制御装置と、を備えるトラクタであって、前記前後進切換操作具の操作を検出する前後進操作検出手段と、前記走行機体の車速を検出する車速検出手段と、を備え前記制御装置は、前記前後進切換操作具が前進操作又は後進操作されたとき、前記走行変速機構の変速段に拘わらず前記前進用油圧クラッチ又は前記後進用油圧クラッチを所定の昇圧パターンで昇圧制御するクラッチ接続制御手段と、前記昇圧制御中の検出車速に基づいて前記走行機体の加速度を判断し、該加速度が増加方向に変化したと判断した場合、前記前進用油圧クラッチ又は前記後進用油圧クラッチの昇圧を抑制する昇圧抑制手段と、前記昇圧制御中の検出車速に基づいて前記走行機体の車速が目標速度に到達したと判断した場合、前記前進用油圧クラッチ又は前記後進用油圧クラッチの昇圧を促進させる昇圧促進手段と、を備えることを特徴とするトラクタである。
また、請求項２の発明は、前記昇圧促進手段は、前記昇圧制御中の検出車速に基づいて前記走行機体の車速が安定したと判断した場合、前記走行機体の車速が目標速度に到達したと判断することを特徴とする請求項１に記載のトラクタである。 The present invention has been created for the purpose of solving these problems in view of the above circumstances, and the invention of claim 1 gradually shifts the traveling machine and the traveling power of the traveling machine. The traveling speed change mechanism, the forward hydraulic clutch and the reverse hydraulic clutch for switching the forward / backward movement of the traveling machine, and the forward hydraulic clutch or the reverse hydraulic clutch are boosted and controlled according to the operation of the forward / backward switching operation tool. A tractor including a control device for moving the traveling vehicle forward or backward, a forward / backward operation detecting means for detecting the operation of the forward / backward switching operation tool, and a vehicle speed detecting means for detecting the vehicle speed of the traveling aircraft. When the forward / backward switching operation tool is operated forward or backward, the control device sets the forward hydraulic clutch or the reverse hydraulic clutch in a predetermined step-up pattern regardless of the shift stage of the traveling speed change mechanism. When the acceleration of the traveling aircraft is determined based on the clutch connection control means for boosting control and the detected vehicle speed during boosting control and it is determined that the acceleration has changed in the increasing direction, the forward hydraulic clutch or the reverse movement is performed. When it is determined that the vehicle speed of the traveling aircraft has reached the target speed based on the boost suppression means for suppressing the boosting of the hydraulic clutch and the detected vehicle speed during the boost control, the forward hydraulic clutch or the reverse hydraulic clutch is used. It is a tractor characterized by comprising a boosting promotion means for promoting the boosting of the clutch.
Further, according to the second aspect of the present invention, when the boosting promoting means determines that the vehicle speed of the traveling aircraft is stable based on the detected vehicle speed during the boosting control, the vehicle speed of the traveling aircraft has reached the target speed. The tractor according to claim 1, wherein the tractor is determined.

請求項１の発明によれば、制御装置は、前後進切換操作具が前進操作又は後進操作されたとき、走行変速機構の変速段に拘わらず前進用油圧クラッチ又は後進用油圧クラッチを所定の昇圧パターンで昇圧制御するクラッチ接続制御手段を備えるので、主変速レバーや副変速レバーの操作位置を検出するレバー位置検出スイッチを不要にして部品点数を削減できるだけでなく、制御を簡略化できる。また、制御装置は、昇圧制御中の検出車速に基づいて走行機体の加速度を判断し、該加速度が増加方向に変化したと判断した場合、前進用油圧クラッチ又は後進用油圧クラッチの昇圧を抑制する昇圧抑制手段を備えるので、過剰な圧力で走行機体が急発進することも防止できる。
また、制御装置は、昇圧制御中の検出車速に基づいて走行機体の車速が目標速度に到達したと判断した場合、前進用油圧クラッチ又は後進用油圧クラッチの昇圧を促進させる昇圧促進手段を備えるので、昇圧制御の所要時間を短縮できるだけでなく、目標速度に到達した後の負荷で車速が落ちることを防止できる。
また、請求項２の発明によれば、昇圧促進手段は、昇圧制御中の検出車速に基づいて走行機体の車速が安定したと判断した場合、走行機体の車速が目標速度に到達したと判断するので、主変速レバー及び副変速レバーの操作位置に基づいて目標速度を算出しなくても、目標速度への到達を判断することができる。 According to the invention of claim 1, when the forward / backward switching operation tool is operated forward or backward, the control device raises the forward hydraulic clutch or the reverse hydraulic clutch by a predetermined pressure regardless of the shift stage of the traveling speed change mechanism. Since the clutch connection control means for boosting control by the pattern is provided, not only the number of parts can be reduced by eliminating the need for the lever position detection switch for detecting the operation position of the main shift lever and the auxiliary shift lever, but also the control can be simplified. Further, the control device determines the acceleration of the traveling aircraft based on the detected vehicle speed during the boost control, and when it is determined that the acceleration has changed in the increasing direction, the control device suppresses the boosting of the forward hydraulic clutch or the reverse hydraulic clutch. Since the booster suppressing means is provided, it is possible to prevent the traveling aircraft from suddenly starting due to excessive pressure.
Further , the control device includes a boosting promoting means for promoting boosting of the forward hydraulic clutch or the reverse hydraulic clutch when it is determined that the vehicle speed of the traveling machine has reached the target speed based on the detected vehicle speed during boost control. Therefore, not only the time required for boost control can be shortened, but also the vehicle speed can be prevented from dropping due to the load after reaching the target speed.
Further, according to the invention of claim 2 , when it is determined that the vehicle speed of the traveling vehicle is stable based on the detected vehicle speed during the boosting control, the boosting promoting means determines that the vehicle speed of the traveling vehicle has reached the target speed. Therefore, it is possible to determine the arrival at the target speed without calculating the target speed based on the operating positions of the main shift lever and the auxiliary shift lever.

本発明の一実施形態に係るトラクタの側面図である。It is a side view of the tractor which concerns on one Embodiment of this invention. 走行動力伝達経路を示すブロック図である。It is a block diagram which shows the traveling power transmission path. 運転部を上方から見た斜視図である。It is a perspective view which looked at the driving part from above. 制御部の入出力を示すブロック図である。It is a block diagram which shows the input / output of a control part. クラッチ接続制御手段の説明図である。It is explanatory drawing of the clutch connection control means. 昇圧抑制手段の説明図であり、（ａ）は昇圧抑制なしの場合を示す説明図、（ｂ）は昇圧抑制ありの場合を示す説明図である。It is explanatory drawing of the boost suppression means, (a) is an explanatory diagram which shows the case without boost suppression, and (b) is an explanatory diagram which shows the case with boost suppression. 昇圧促進手段の説明図である。It is explanatory drawing of the step-up promotion means. クラッチ接続制御の処理手順を示すフローチャートである。It is a flowchart which shows the processing procedure of a clutch connection control.

以下、本発明の実施の形態について、図面に基づいて説明する。図１において、１はトラクタＴの走行機体であって、該走行機体１は、機体前部に搭載されるエンジン２（図２参照）と、エンジン２の動力を変速するトランスミッションケース３と、トランスミッションケース３から供給される走行動力で回転駆動される前輪４及び後輪５と、図示しない作業機を昇降可能に連結する作業機連結部６と、作業者が乗車する運転部７と、を備える。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a traveling machine of a tractor T, which is an engine 2 mounted on the front portion of the body (see FIG. 2), a transmission case 3 for shifting the power of the engine 2, and a transmission. It includes front wheels 4 and rear wheels 5 that are rotationally driven by traveling power supplied from the case 3, a work machine connecting unit 6 that connects work machines (not shown) so as to be able to move up and down, and a driving unit 7 on which an operator rides. ..

図２に示すように、トランスミッションケース３内には、メインクラッチ機構８の他、主変速機構９、前後進変速機構１０、副変速機構１１などの変速機構が設けられている。前後進変速機構１０は、走行機体１の前後進を切り換える前進用油圧クラッチ１２及び後進用油圧クラッチ１３を備えており、前進用油圧クラッチ１２及び後進用油圧クラッチ１３を切断した中立状態と、前進用油圧クラッチ１２を接続し、且つ後進用油圧クラッチ１３を切断した前進状態と、前進用油圧クラッチ１２を切断し、且つ後進用油圧クラッチ１３を接続した後進状態と、に切り換えられる。 As shown in FIG. 2, in addition to the main clutch mechanism 8, a transmission mechanism such as a main speed change mechanism 9, a forward / backward speed change mechanism 10, and an auxiliary speed change mechanism 11 is provided in the transmission case 3. The forward / backward speed change mechanism 10 includes a forward hydraulic clutch 12 and a reverse hydraulic clutch 13 for switching the forward / backward movement of the traveling machine body 1, and is in a neutral state in which the forward hydraulic clutch 12 and the reverse hydraulic clutch 13 are disconnected and forward. It is switched between a forward state in which the hydraulic clutch 12 is connected and the reverse hydraulic clutch 13 is disengaged, and a reverse state in which the forward hydraulic clutch 12 is disengaged and the reverse hydraulic clutch 13 is connected.

前進用油圧クラッチ１２及び後進用油圧クラッチ１３は、それぞれ、比例減圧弁からなる前進用油圧バルブ１４（図４参照）及び後進用油圧バルブ１５（図４参照）の動作に応じて接続／切断される。 The forward hydraulic clutch 12 and the reverse hydraulic clutch 13 are connected / disconnected according to the operation of the forward hydraulic valve 14 (see FIG. 4) and the reverse hydraulic valve 15 (see FIG. 4), which are proportional pressure reducing valves, respectively. Ru.

図３に示すように、運転部７には、作業者が座る運転座席１６の他に、前輪４を操舵するステアリングホイール１７、主変速機構９を操作する主変速レバー１８、副変速機構１１を操作する副変速レバー１９、前後進変速機構１０を操作する前後進切換レバー２０（前後進切換操作具）、メインクラッチ機構８を操作するクラッチペダル２１、左右のブレーキ機構（図示せず）を個別に操作する左右のブレーキペダル２２、２３、左右のブレーキペダル２２、２３を連結する連結操作具２４、ブレーキペダル２２、２３を踏み込み位置に固定保持する駐車ブレーキレバー２５などの操作具や、各種の状態表示を行うモニタパネル２６が設けられている。 As shown in FIG. 3, in addition to the driver's seat 16 on which the operator sits, the driver unit 7 includes a steering wheel 17 for steering the front wheels 4, a main shift lever 18 for operating the main shift mechanism 9, and an auxiliary shift mechanism 11. The auxiliary shift lever 19 to be operated, the forward / backward switching lever 20 to operate the forward / backward shifting mechanism 10 (forward / backward switching operating tool), the clutch pedal 21 to operate the main clutch mechanism 8, and the left and right brake mechanisms (not shown) are individually separated. Various operating tools such as the left and right brake pedals 22 and 23, the connecting operating tool 24 that connects the left and right brake pedals 22 and 23, and the parking brake lever 25 that holds the brake pedals 22 and 23 fixedly at the stepped position. A monitor panel 26 for displaying a status is provided.

図４に示すように、走行機体１には、前後進切換制御を行う制御装置２８が設けられている。制御装置２８の入力側には、前後進切換レバー２０の前進操作を検出する前進操作検出スイッチ２９（前後進操作検出手段）と、前後進切換レバー２０の中立操作を検出する中立操作検出スイッチ３０（前後進操作検出手段）と、前後進切換レバー２０の後進操作を検出する後進操作検出スイッチ３１（前後進操作検出手段）と、駐車ブレーキレバー２５の入り操作を検出する駐車ブレーキスイッチ３２と、前進用油圧クラッチ１２及び後進用油圧クラッチ１３を作動させる作動油の油温を検出する油温センサ３３と、エンジン２の回転を検出するエンジン回転センサ３４と、走行機体１の車速を検出する車速センサ３５（車速検出手段）と、が接続される一方、制御装置２８の出力側には、前述した前進用油圧バルブ１４及び後進用油圧バルブ１５が接続されている。 As shown in FIG. 4, the traveling machine body 1 is provided with a control device 28 that performs forward / backward switching control. On the input side of the control device 28, a forward operation detection switch 29 (forward / backward operation detection means) for detecting the forward operation of the forward / backward switching lever 20 and a neutral operation detection switch 30 for detecting the neutral operation of the forward / backward switching lever 20. (Forward operation detection means), reverse operation detection switch 31 (forward / backward operation detection means) for detecting the reverse operation of the forward / backward switching lever 20, parking brake switch 32 for detecting the entry operation of the parking brake lever 25, and An oil temperature sensor 33 that detects the oil temperature of the hydraulic oil that operates the forward hydraulic clutch 12 and the reverse hydraulic clutch 13, an engine rotation sensor 34 that detects the rotation of the engine 2, and a vehicle speed that detects the vehicle speed of the traveling machine 1. While the sensor 35 (vehicle speed detecting means) is connected, the forward hydraulic valve 14 and the reverse hydraulic valve 15 described above are connected to the output side of the control device 28.

制御装置２８は、ハードウェアとソフトウェアとの協働により実現される機能的な構成として、前後進切換レバー２０が前進操作又は後進操作されたとき、主変速機構９や副変速機構１１の変速段に拘わらず前進用油圧クラッチ１２又は後進用油圧クラッチ１３を所定の昇圧パターンで昇圧制御するクラッチ接続制御手段と、昇圧制御中の検出車速に基づいて走行機体１の加速度を判断し、該加速度が増加方向に変化したと判断した場合、前進用油圧クラッチ１２又は後進用油圧クラッチ１３の昇圧を抑制する昇圧抑制手段と、昇圧制御中の検出車速に基づいて走行機体１の車速が目標速度に到達したと判断した場合、前進用油圧クラッチ１２又は後進用油圧クラッチ１３の昇圧を促進させる昇圧促進手段と、を備える。 As a functional configuration realized by the cooperation of hardware and software, the control device 28 has a shift stage of the main shift mechanism 9 and the auxiliary shift mechanism 11 when the forward / reverse switching lever 20 is operated forward or backward. Regardless of this, the acceleration of the traveling machine 1 is determined based on the clutch connection control means for boosting and controlling the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 with a predetermined boosting pattern and the detected vehicle speed during boosting control, and the acceleration is determined. When it is determined that the vehicle speed has changed in the increasing direction, the vehicle speed of the traveling machine 1 reaches the target speed based on the boost suppression means for suppressing the pressure increase of the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 and the detected vehicle speed during the boost control. If it is determined that the clutch has been increased, the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 is provided with a boosting promoting means for promoting the boosting.

図５に示すように、クラッチ接続制御手段が用いる所定の昇圧パターンには、接続させる前進用油圧クラッチ１２又は後進用油圧クラッチ１２に対し、一定の所定圧力で所定時間作動油を充填する油充填工程と、油充填工程が完了した後、接続させる前進用油圧クラッチ１２又は後進用油圧クラッチ１３に対し、所定の第１上昇傾斜で圧力を上昇させながら作動油を充填するミート工程と、ミート工程が完了した後、接続させる前進用油圧クラッチ１２又は後進用油圧クラッチ１３に対し、所定の第２上昇傾斜で圧力を上昇させながら作動油を充填する昇圧工程と、が含まれる。 As shown in FIG. 5, the predetermined boosting pattern used by the clutch connection control means is filled with oil for a predetermined time to fill the forward hydraulic clutch 12 or the reverse hydraulic clutch 12 to be connected with hydraulic oil at a constant predetermined pressure. After the step and the oil filling step are completed, the meet step and the meet step of filling the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 to be connected with hydraulic oil while increasing the pressure at a predetermined first ascending inclination. The step of filling the hydraulic oil for the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 to be connected with hydraulic oil while increasing the pressure at a predetermined second ascending inclination is included.

クラッチ接続制御手段は、油充填工程によって前進用油圧クラッチ１２又は後進用油圧クラッチ１３がミート（クラッチ接続開始）する直前まで作動油を充填し、ミート工程において前進用油圧クラッチ１２又は後進用油圧クラッチ１３をミートさせる。ミート工程における第１上昇傾斜及び作動油充填時間は、主変速機構９及び副変速機構１１の最低速変速段（ＳＬ）から最高速変速段（Ｈ）までの変速荷重を網羅し、いずれの変速段でも大きな変速ショックが生じないように設定されている。そして、クラッチ接続制御手段は、前進用油圧クラッチ１２又は後進用油圧クラッチ１３がミートした後、昇圧工程において所定の第２上昇傾斜で圧力を上昇させながら作動油を充填することで前進用油圧クラッチ１２又は後進用油圧クラッチ１３を安定した接続状態に移行させる。このようなクラッチ接続制御手段によれば、主変速レバー１８や副変速レバー１９の操作位置を検出するレバー位置検出スイッチを不要にして部品点数を削減できるだけでなく、制御を簡略化できる。 The clutch connection control means fills the hydraulic oil until just before the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 meets (starts clutch connection) in the oil filling step, and in the meet step, the forward hydraulic clutch 12 or the reverse hydraulic clutch Meet 13 The first ascending inclination and hydraulic oil filling time in the meet process cover the shift load from the lowest speed shift stage (SL) to the highest speed shift stage (H) of the main transmission mechanism 9 and the auxiliary transmission mechanism 11, and any shift. It is set so that a large shift shock does not occur even in the gear. Then, after the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 meets, the clutch connection control means fills the hydraulic oil with hydraulic oil while increasing the pressure at a predetermined second ascending inclination in the boosting step. 12 or the reverse hydraulic clutch 13 is shifted to a stable connection state. According to such a clutch connection control means, not only the number of parts can be reduced by eliminating the need for the lever position detection switch for detecting the operation position of the main shift lever 18 and the sub shift lever 19, but also the control can be simplified.

図６の（ａ）に示すように、走行変速段に拘わらず所定の昇圧パターンで前進用油圧クラッチ１２又は後進用油圧クラッチ１３を接続すると、走行変速段によってはクラッチミート後の昇圧が過剰になり、走行機体１が急加速する現象が発生する可能性がある。図６の（ｂ）に示すように、昇圧抑制手段は、このような急加速現象を回避するために、昇圧工程中の検出車速に基づいて走行機体１の加速度を判断し、該加速度が増加方向に変化したと判断した場合、第２上昇傾斜を小さくすることで、前進用油圧クラッチ１２又は後進用油圧クラッチ１３の昇圧を抑制する。このような昇圧抑制手段によれば、過剰なクラッチ昇圧によって走行機体１が急発進する現象を防止できる。なお、本実施形態では、加速度の増加に応じた昇圧抑制処理を昇圧工程中においてのみ実行しているが、ミート工程中においても、検出車速に基づいて走行機体１の加速度を判断し、該加速度が増加方向に変化したと判断した場合、第１上昇傾斜を小さくすることで、前進用油圧クラッチ１２又は後進用油圧クラッチ１３の昇圧を抑制してもよい。 As shown in FIG. 6A, when the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 is connected in a predetermined boosting pattern regardless of the traveling gear, the boosting after the clutch meet is excessive depending on the traveling gear. Therefore, there is a possibility that the traveling machine 1 may suddenly accelerate. As shown in FIG. 6B, the boosting suppression means determines the acceleration of the traveling machine 1 based on the detected vehicle speed during the boosting process in order to avoid such a sudden acceleration phenomenon, and the acceleration increases. When it is determined that the vehicle has changed in the direction, the boosting of the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 is suppressed by reducing the second ascending inclination. According to such a boosting suppression means, it is possible to prevent the traveling machine body 1 from suddenly starting due to excessive clutch boosting. In the present embodiment, the boosting suppression process according to the increase in acceleration is executed only during the boosting process, but even during the meet process, the acceleration of the traveling machine 1 is determined based on the detected vehicle speed, and the acceleration is determined. If it is determined that the number has changed in the increasing direction, the pressure increase of the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 may be suppressed by reducing the first ascending inclination.

一方、図７に示すように、走行変速段に拘わらず所定の昇圧パターンで前進用油圧クラッチ１２又は後進用油圧クラッチ１３を接続すると、走行変速段によってはクラッチミート後の昇圧が不足し、走行機体１が目標速度に到達した後も長時間に亘ってクラッチ接続が完了しない可能性がある。昇圧促進手段は、このような現象を回避するために、昇圧工程中の検出車速に基づいて走行機体１の車速が目標速度に到達したと判断した場合、第２上昇傾斜を大きくすることで、前進用油圧クラッチ１２又は後進用油圧クラッチ１３の昇圧を促進させる。このような昇圧促進手段によれば、昇圧工程の所要時間を短縮できるだけでなく、目標速度に到達した後の負荷で車速が落ちることを防止できる。 On the other hand, as shown in FIG. 7, when the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 is connected in a predetermined boosting pattern regardless of the traveling gear, the boosting after the clutch meet is insufficient depending on the traveling gear, and the vehicle travels. Even after the aircraft 1 reaches the target speed, the clutch connection may not be completed for a long time. In order to avoid such a phenomenon, the boosting promoting means increases the second ascending slope when it is determined that the vehicle speed of the traveling machine 1 has reached the target speed based on the detected vehicle speed during the boosting process. The boosting of the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 is promoted. According to such a boosting promotion means, not only the time required for the boosting process can be shortened, but also the vehicle speed can be prevented from dropping due to the load after reaching the target speed.

また、昇圧促進手段は、昇圧工程中の検出車速に基づいて走行機体１の車速が安定したと判断した場合、走行機体１の車速が目標速度に到達したと判断する。具体的には、車速の変化率を検出し、該変化率が所定値以下となったとき車速が安定したと判断するとともに、車速が目標速度に到達したと判断している。このような昇圧促進手段によれば、主変速レバー１８及び副変速レバー１９の操作位置に基づいて目標速度を算出しなくても、目標速度への到達を判断することができる。 Further, when the boosting promotion means determines that the vehicle speed of the traveling machine 1 is stable based on the detected vehicle speed during the boosting process, it determines that the vehicle speed of the traveling machine 1 has reached the target speed. Specifically, the rate of change in vehicle speed is detected, and when the rate of change becomes equal to or less than a predetermined value, it is determined that the vehicle speed is stable, and it is determined that the vehicle speed has reached the target speed. According to such a boosting promoting means, it is possible to determine the arrival at the target speed without calculating the target speed based on the operating positions of the main speed change lever 18 and the auxiliary speed change lever 19.

つぎに、クラッチ接続制御手段、昇圧抑制手段及び昇圧促進手段の処理手順を含むクラッチ接続制御について図８を参照して説明する。 Next, the clutch connection control including the processing procedure of the clutch connection control means, the boost suppression means, and the boost promotion means will be described with reference to FIG.

図８に示すように、制御装置２８は、クラッチ接続制御において、まず、前後進切換レバー２０の前進操作又は後進操作を判断し（Ｓ１）、この判断結果がＹＥＳの場合は、接続させる前進用油圧クラッチ１２又は後進用油圧クラッチ１２に対し、一定の所定圧力で所定時間作動油を充填する油充填工程に移行する（Ｓ２）。 As shown in FIG. 8, in the clutch connection control, the control device 28 first determines the forward operation or the reverse operation of the forward / backward switching lever 20 (S1), and if the determination result is YES, the forward / backward switching lever 20 is connected. The process shifts to an oil filling step of filling the hydraulic clutch 12 or the reverse hydraulic clutch 12 with hydraulic oil at a constant predetermined pressure for a predetermined time (S2).

制御装置２８は、油充填工程を実行しつつ、油充填工程の完了（所定時間の経過）を判断し（Ｓ３）、この判断結果がＹＥＳの場合は、接続させる前進用油圧クラッチ１２又は後進用油圧クラッチ１３に対し、所定の第１上昇傾斜で圧力を上昇させながら作動油を充填するミート工程に移行する（Ｓ４）。 The control device 28 determines the completion of the oil filling process (elapsed of a predetermined time) while executing the oil filling process (S3), and if the determination result is YES, the forward hydraulic clutch 12 or the reverse hydraulic clutch 12 to be connected is used. The process shifts to the meet step of filling the hydraulic clutch 13 with hydraulic oil while increasing the pressure at a predetermined first ascending inclination (S4).

制御装置２８は、ミート工程を実行しつつ、ミート工程の完了（所定時間の経過）を判断し（Ｓ５）、この判断結果がＹＥＳの場合は、接続させる前進用油圧クラッチ１２又は後進用油圧クラッチ１３に対し、所定の第２上昇傾斜で圧力を上昇させながら作動油を充填する昇圧工程に移行する（Ｓ６）。 The control device 28 determines the completion of the meet process (elapsed of a predetermined time) while executing the meet process (S5), and if the determination result is YES, the forward hydraulic clutch 12 or the reverse hydraulic clutch to be connected is connected. In contrast to 13, the process shifts to a pressure increasing step of filling the hydraulic oil while increasing the pressure at a predetermined second ascending slope (S6).

制御装置２８は、昇圧工程を実行しつつ、加速度の増加（Ｓ７）、目標速度への到達（Ｓ９）、及び昇圧工程の完了（Ｓ１１：目標電流値への到達）を判断し、加速度が増加傾向であると判断した場合は、第２上昇傾斜を小さくすることで、前進用油圧クラッチ１２又は後進用油圧クラッチ１３の昇圧を抑制し（Ｓ８）、目標速度へ到達したと判断した場合は、第２上昇傾斜を大きくすることで、前進用油圧クラッチ１２又は後進用油圧クラッチ１３の昇圧を促進し（Ｓ１０）、昇圧工程の完了を判断した場合は、今回のクラッチ接続制御を終わる。 While executing the boosting process, the control device 28 determines that the acceleration increases (S7), reaches the target speed (S9), and completes the boosting process (S11: reaches the target current value), and the acceleration increases. If it is determined that there is a tendency, the pressure increase of the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 is suppressed by reducing the second ascending inclination (S8), and if it is determined that the target speed has been reached. By increasing the second ascending inclination, the boosting of the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 is promoted (S10), and when it is determined that the boosting process is completed, the current clutch connection control is ended.

叙述の如く構成された本実施形態によれば、走行機体１と、走行機体１の走行動力を段階的に変速する主変速機構９及び副変速機構１１と、走行機体１の前後進を切り換える前進用油圧クラッチ１２及び後進用油圧クラッチ１３と、前後進切換レバー２０の操作に応じて前進用油圧クラッチ１２又は後進用油圧クラッチ１３を昇圧制御して走行機体１を前進又は後進させる制御装置２８と、を備えるトラクタＴであって、前後進切換レバー２０の操作を検出する前進操作検出スイッチ２９、中立操作検出スイッチ３０及び後進操作検出スイッチ３１と、走行機体１の車速を検出する車速センサ３５と、を備え、制御装置２８は、前後進切換レバー２０が前進操作又は後進操作されたとき、主変速機構９及び副変速機構１１の変速段に拘わらず前進用油圧クラッチ１２又は後進用油圧クラッチ１３を所定の昇圧パターンで昇圧制御するクラッチ接続制御手段を備えるので、主変速レバー１８や副変速レバー１９の操作位置を検出するレバー位置検出スイッチを不要にして部品点数を削減できるだけでなく、制御を簡略化できる。 According to the present embodiment configured as described above, the traveling machine 1, the main speed change mechanism 9 and the auxiliary speed change mechanism 11 that gradually change the running power of the traveling machine 1, and the forward movement of the traveling machine 1 are switched. A hydraulic clutch 12 and a reverse hydraulic clutch 13, and a control device 28 that boosts and controls the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 according to the operation of the forward / backward switching lever 20 to move the traveling machine 1 forward or backward. A tractor T including the When the forward / backward switching lever 20 is operated forward or backward, the control device 28 comprises a forward hydraulic clutch 12 or a reverse hydraulic clutch 13 regardless of the shift stage of the main transmission mechanism 9 and the auxiliary transmission mechanism 11. Since it is equipped with a clutch connection control means for boosting control with a predetermined boost pattern, it is possible not only to reduce the number of parts by eliminating the need for a lever position detection switch for detecting the operation position of the main shift lever 18 and the auxiliary shift lever 19, but also to control the control. Can be simplified.

また、制御装置２８は、昇圧制御中の検出車速に基づいて走行機体１の加速度を判断し、該加速度が増加方向に変化したと判断した場合、前進用油圧クラッチ１２又は後進用油圧クラッチ１３の昇圧を抑制する昇圧抑制手段を備えるので、過剰な圧力で走行機体１が急発進することも防止できる。 Further, the control device 28 determines the acceleration of the traveling machine body 1 based on the detected vehicle speed during the boost control, and when it is determined that the acceleration has changed in the increasing direction, the forward hydraulic clutch 12 or the reverse hydraulic clutch 13 is used. Since the booster suppressing means for suppressing the booster pressure is provided, it is possible to prevent the traveling machine body 1 from suddenly starting due to excessive pressure.

また、制御装置２８は、昇圧制御中の検出車速に基づいて走行機体１の車速が目標速度に到達したと判断した場合、前進用油圧クラッチ１２又は後進用油圧クラッチ１３の昇圧を促進させる昇圧促進手段を備えるので、昇圧制御の所要時間を短縮できるだけでなく、目標速度に到達した後の負荷で車速が落ちることを防止できる。 Further, when the control device 28 determines that the vehicle speed of the traveling machine 1 has reached the target speed based on the detected vehicle speed during the boost control, the control device 28 promotes the boosting of the forward hydraulic clutch 12 or the reverse hydraulic clutch 13. Since the means is provided, not only the time required for boost control can be shortened, but also the vehicle speed can be prevented from dropping due to the load after reaching the target speed.

また、昇圧促進手段は、昇圧制御中の検出車速に基づいて走行機体１の車速が安定したと判断した場合、走行機体１の車速が目標速度に到達したと判断するので、主変速レバー１８及び副変速レバー１９の操作位置に基づいて目標速度を算出しなくても、目標速度への到達を判断することができる。 Further, when the boosting promoting means determines that the vehicle speed of the traveling vehicle 1 is stable based on the detected vehicle speed during the boosting control, it determines that the vehicle speed of the traveling vehicle 1 has reached the target speed. It is possible to determine the arrival at the target speed without calculating the target speed based on the operation position of the auxiliary shift lever 19.

Ｔトラクタ
１走行機体
９主変速機構
１０前後進変速機構
１１副変速機構
１２前進用油圧クラッチ
１３後進用油圧クラッチ
１４前進用油圧バルブ
１５後進用油圧バルブ
１８主変速レバー
１９副変速レバー
２０前後進切換レバー
２８制御装置
２９前進操作検出スイッチ
３０中立操作検出スイッチ
３１後進操作検出スイッチ
３５車速センサ
T tractor 1 Traveling machine 9 Main transmission mechanism 10 Forward / backward transmission mechanism 11 Sub-transmission mechanism 12 Forward hydraulic clutch 13 Reverse hydraulic clutch 14 Forward hydraulic valve 15 Reverse hydraulic valve 18 Main shift lever 19 Sub-transmission lever 20 Forward / backward switching Lever 28 Control device 29 Forward operation detection switch 30 Neutral operation detection switch 31 Reverse operation detection switch 35 Vehicle speed sensor

Claims

With the traveling aircraft,
A traveling speed change mechanism that gradually shifts the traveling power of the traveling machine,
The forward hydraulic clutch and the reverse hydraulic clutch that switch the forward / backward movement of the traveling machine,
A tractor including a control device for boosting control of the forward hydraulic clutch or the reverse hydraulic clutch to move the traveling machine forward or backward according to the operation of the forward / backward switching operation tool.
A forward / backward operation detecting means for detecting the operation of the forward / backward switching operation tool,
A vehicle speed detecting means for detecting the vehicle speed of the traveling machine is provided.
The control device is
A clutch connection control means for boosting control of the forward hydraulic clutch or the reverse hydraulic clutch in a predetermined boost pattern when the forward / backward switching operation tool is forwarded or reverse operated, regardless of the shift stage of the traveling speed change mechanism. When,
When the acceleration of the traveling machine is determined based on the detected vehicle speed during the boost control and it is determined that the acceleration has changed in the increasing direction, the boost suppression that suppresses the boosting of the forward hydraulic clutch or the reverse hydraulic clutch is suppressed. Means and
When it is determined that the vehicle speed of the traveling aircraft has reached the target speed based on the detected vehicle speed during the boost control, the boosting promoting means for promoting the boosting of the forward hydraulic clutch or the reverse hydraulic clutch is provided.
A tractor characterized by being equipped with.

The claim is characterized in that, when it is determined that the vehicle speed of the traveling aircraft is stable based on the detected vehicle speed during the boosting control, the boosting promoting means determines that the vehicle speed of the traveling aircraft has reached the target speed. The tractor according to 1 .