JP5839075B2

JP5839075B2 - Driving transmission device for work vehicle

Info

Publication number: JP5839075B2
Application number: JP2014089183A
Authority: JP
Inventors: 小野　弘喜; 弘喜小野
Original assignee: Iseki and Co Ltd
Current assignee: Iseki and Co Ltd
Priority date: 2014-04-23
Filing date: 2014-04-23
Publication date: 2016-01-06
Anticipated expiration: 2031-07-20
Also published as: JP2014134291A

Description

本発明は、多段の走行変速制御を行う作業車両の走行伝動装置に関するものである。 The present invention relates to a travel transmission device for a work vehicle that performs multi-stage travel shift control.

特許文献１の作業車両の多段変速式走行伝動装置は、高低速変速機構、前後進切替機構および多段変速用の主変速機構を直列してエンジン動力を走行車輪に変速伝動する変速伝動系を構成し、また、変速制御部を備えて変速レバー等の順次式変速指示具を操作することにより、作業に合わせた車速調節を可能とする。 A multi-speed shift type traveling transmission device for a work vehicle disclosed in Patent Document 1 includes a high-speed transmission mechanism, a forward / reverse switching mechanism, and a main transmission mechanism for multi-speed shifting that form a shift transmission system that shifts engine power to traveling wheels. In addition, by providing a shift control unit and operating a sequential shift indicator such as a shift lever, the vehicle speed can be adjusted according to the work.

特開２００４−２５１３５１号公報JP 2004-251351 A

しかしながら、上記走行伝動装置は、変速指示具による変速操作が終了した時点でその指示位置と対応する変速段に変速伝動系を切替えることから、車速を大きく変更する場合において、変速指示具の操作中は元の走行車速が維持され、操作の終了時に指示位置の変速段に切替わるので、急変速による走行ショックを招くという問題があった。 However, the travel transmission device switches the transmission system to the gear position corresponding to the instruction position when the transmission operation by the transmission instruction tool is completed. Since the original traveling vehicle speed is maintained and the operation position is switched to the gear position at the end of the operation, there is a problem that a traveling shock due to a sudden shift is caused.

その一方で、ショック緩和のために一定の切替え時間で順次的に変速段を切替える変速制御を構成した場合は、車速を大きく変更する際に変速完了まで長時間を要することとなり、いずれにおいても、変速指示具の操作に対する走行機体の変速動作について違和感が避けられないという問題があった。 On the other hand, when the shift control is configured to sequentially switch the gear stage at a constant switching time for shock relaxation, it takes a long time to complete the shift when greatly changing the vehicle speed. There was a problem that a sense of incongruity was inevitable with respect to the speed change operation of the traveling machine body with respect to the operation of the speed change indicator.

本発明の目的は、変速指示具による変速操作に際し、変速ショックを招くことなく、かつ、変速操作と対応して迅速で違和感のない変速を可能とする作業車両の走行伝動装置を提供することにある。 SUMMARY OF THE INVENTION An object of the present invention is to provide a travel transmission device for a work vehicle that does not cause a shift shock when performing a shift operation with a shift instruction tool, and enables a speedy and comfortable shift corresponding to the shift operation. is there.

請求項１に係る発明は、エンジン出力を受けて走行車輪（２，３）に多段変速伝動する変速伝動系と、この変速伝動系を走行操作具の操作信号に応じて変速制御する変速制御部（Ｃ）とからなり、上記変速伝動系は、切替えクラッチにより高低速２段変速伝動する高低速変速機構（１１）と、複数段変速伝動する主変速機構（１２）と、切替えクラッチにより正逆切替伝動する前後進切替機構（１３）とによって構成し、上記走行操作具として、クラッチペダル（２１）と、順次式変速指示具（２２）と、正逆転切替具（２３）とを備える作業車両の走行伝動装置において、
変速指示具（２２）により複数段以上の変速指示変化幅で変速操作が行われた場合に、操作開始とともに、変速指示具（２２）の操作途中と操作終了との操作区分を所定の基準によって判定し、操作途中と判定された中間変速位置の変速段に順次切替え、その切替の完了に続いて操作終了と判定された変速位置の変速段に切替える構成とし、
前記操作区分は、変速指示具（２２）の操作速度によって判定し、
変速指示具（２２）には、複数の変速段位置と中立位置を設け、
変速指示具（２２）が変速段位置に操作され、かつ正逆転切替具（２３）を中立位置に操作して停車中のときは、主変速機構（１２）を変速指示具（２２）の操作位置に対応した伝動可能状態にすると共に高低速変速機構（１１）と前後進切替機構（１３）を中立にし、その後、正逆転切替具（２３）を正転側又は逆転側に操作すると、主変速機構（１２）を変速指示具（２２）の操作位置に対応した伝動可能状態に維持したまま、高低速変速機構（１１）と前後進切替機構（１３）を伝動制御して走行を開始する構成とし、
前記高低速変速機構（１１）は２系統に並列構成してエンジン出力を共に受け、前記主変速機構（１２）は２系統に構成して上記高低速変速機構（１１）の出力を系統別に受けるとともに、全変速段を互いに異なる変速比で、変速比順位が隣接する変速段を互いに他の系統に構成し、前記２系統の出力側に共通する前記前後進切替機構（１３）を直列に配置して変速伝動系を構成し、前記変速指示具（２２）の変速段操作範囲の低速端に中立変速位置（Ｎ）を設け、この中立変速位置（Ｎ）にすると、上記高低速変速機構（１１）と前後進切替機構（１３）とを共に伝動遮断するとともに、主変速機構（１２）の２系統を所定の変速段に伝動制御することを特徴とする。 The invention according to claim 1 is a transmission transmission system that receives engine output and performs multi-stage transmission to the traveling wheels (2, 3), and a transmission control unit that performs transmission control of the transmission transmission system according to an operation signal of the traveling operation tool. (C), and the shift transmission system includes a high and low speed transmission mechanism (11) that transmits high and low speeds to two speeds by a switching clutch, a main transmission mechanism (12) that transmits multiple speeds, and a switching clutch. A work vehicle comprising a forward / reverse switching mechanism (13) that performs switching transmission, and including a clutch pedal (21), a sequential shift instruction tool (22), and a forward / reverse switching tool (23) as the travel operation tool. In the traveling transmission device of
When a shift operation is performed with a shift instruction change width of a plurality of stages or more by the shift instruction tool (22), the operation classification between the operation middle of the shift instruction tool (22) and the end of the operation is determined according to a predetermined reference. Determining, sequentially switching to the gear position of the intermediate shift position determined to be in the middle of operation, and switching to the gear position of the shift position determined to be the end of operation following completion of the switching,
The operation classification is determined by the operation speed of the shift instruction tool (22),
The shift indicator (22) is provided with a plurality of shift positions and neutral positions,
When the gear shift indicator (22) is operated to the gear position and the forward / reverse rotation switch (23) is operated to the neutral position to stop the vehicle, the main transmission mechanism (12) is operated to the gear shift indicator (22). When the transmission state corresponding to the position is set and the high / low speed transmission mechanism (11) and the forward / reverse switching mechanism (13) are made neutral, and then the forward / reverse switching tool (23) is operated to the forward rotation side or the reverse rotation side, While the transmission mechanism (12) is maintained in a transmission enabled state corresponding to the operation position of the transmission instruction tool (22), the high-low speed transmission mechanism (11) and the forward / reverse switching mechanism (13) are transmission controlled to start traveling. With configuration,
The high / low speed transmission mechanism (11) is configured in parallel in two systems to receive engine output together, and the main transmission mechanism (12) is configured in two systems to receive the output of the high / low speed transmission mechanism (11) for each system. At the same time, all the gears are configured with different gear ratios, the gears adjacent to each other in the gear ratio order are configured in another system, and the forward / reverse switching mechanism (13) common to the output sides of the two systems is arranged in series. Thus, a shift transmission system is configured, and a neutral shift position (N) is provided at the low speed end of the shift speed operation range of the shift indicator (22). When the neutral shift position (N) is set, the high and low speed shift mechanism ( 11) and the forward / reverse switching mechanism (13) are both cut off from transmission, and the transmission of the two systems of the main transmission mechanism (12) is controlled to a predetermined gear stage.

上記変速制御部は、高低速変速機構、主変速機構、および前後進切替機構から構成される変速伝動系を変速指示具の変速位置に応じて前後進について多段の変速段に切替え、また、変速指示具の操作途中と操作終了との操作区分を所定の基準によって判定し、操作途中と判定された中間変速位置の変速段に順次切替え、その切替の完了に続いて操作終了と判定された変速位置の変速段に切替える。
上記操作区分は、変速指示具の操作速度によって判定される。
また、変速指示具が変速段位置に操作され、かつ正逆転切替具を中立位置に操作して停車中のときは、主変速機構を変速指示具の操作位置に対応した伝動可能状態にすると共に高低速変速機構と前後進切替機構を中立にする。その後、正逆転切替具を正転側又は逆転側に操作すると、主変速機構を変速指示具の操作位置に対応した伝動可能状態に維持したまま、高低速変速機構と前後進切替機構を伝動制御して走行を開始する。
高低速変速機構は２系統に並列構成してエンジン出力を共に受け、主変速機構は２系統に構成して高低速変速機構の出力を系統別に受けるとともに、全変速段を互いに異なる変速比で、変速比順位が隣接する変速段を互いに他の系統に構成する。
前記２系統の出力側に共通する前後進切替機構を直列に配置して変速伝動系を構成し、変速指示具の変速段操作範囲の低速端に中立変速位置を設け、この中立変速位置にすると、高低速変速機構と前後進切替機構とを共に伝動遮断するとともに、主変速機構の２系統を所定の変速段に伝動制御する。 The shift control unit, high and low speed transmission mechanism, the main transmission mechanism, and a reverse Switching multistage gear before depending on the shift position of the forward-reverse switching mechanism shift instructing device the constructed variable transmission system from also shift The operation division between the operation of the pointing tool and the end of the operation is determined based on a predetermined reference, and the gear is sequentially switched to the gear position of the intermediate shift position determined to be in the middle of the operation, and the shift determined to be the operation end after the completion of the switching. Switch to the gear position position.
The operation classification is determined by the operation speed of the shift instruction tool.
In addition, when the gear shift indicator is operated to the gear position and the forward / reverse switch is operated to the neutral position and the vehicle is stopped, the main transmission mechanism is brought into a transmission enabled state corresponding to the operation position of the gear shift indicator. Neutralize high / low speed transmission mechanism and forward / reverse switching mechanism. After that, when the forward / reverse switching tool is operated to the forward rotation side or the reverse rotation side, transmission control is performed for the high / low speed transmission mechanism and the forward / reverse switching mechanism while the main transmission mechanism is maintained in the transmission enabled state corresponding to the operation position of the shift instruction tool. And start running.
The high and low speed transmission mechanism is configured in two systems in parallel to receive the engine output, the main transmission mechanism is configured in two systems and receives the output of the high and low speed transmission mechanism for each system, and all the shift speeds are different from each other. The gear stages having adjacent gear ratio orders are configured in different systems.
When a forward / reverse switching mechanism common to the two output sides is arranged in series to form a shift transmission system, a neutral shift position is provided at the low speed end of the shift stage operation range of the shift indicator, and this neutral shift position is set. The transmission of both the high and low speed transmission mechanism and the forward / reverse switching mechanism is cut off, and transmission control of the two systems of the main transmission mechanism to a predetermined gear stage is performed.

請求項２に係る発明は、請求項１の構成において、変速伝動系の操作具である変速指示具（２２）及び正逆転切替具（２３）のうち、変速指示具（２２）を中立位置にすると、高低速変速機構（１１）と前後進切替機構（１３）を共に中立に伝動制御するとともに主変速機構（１２）の２系統をそれぞれ低速側の変速段に伝動制御することを特徴とする。 According to a second aspect of the present invention, in the configuration of the first aspect , the shift indicator (22) of the shift transmission system operating tool and the forward / reverse switching tool (23) is set to the neutral position. Then, both the high and low speed transmission mechanism (11) and the forward / reverse switching mechanism (13) are neutrally controlled, and the two systems of the main transmission mechanism (12) are respectively controlled to be transmitted to the low speed side gear. .

主変速機構の２系統をそれぞれ低速側の変速段に伝動制御することによる主変速機構の二重噛みと、高低速変速機構と前後進切替機構の伝動遮断とにより、つき回り動力による走行車輪への伝動が遮断される。 The main transmission mechanism is driven to the running wheel by the follow-up power by the double meshing of the main transmission mechanism by controlling the transmission to the low speed gear stage and the transmission interruption of the high / low speed transmission mechanism and the forward / reverse switching mechanism . Is interrupted.

請求項１に係る発明により、変速指示具により複数段以上の変速指示変化幅で変速操作が行われた場合に、操作開始とともに、変速指示具の操作途中と操作終了との操作区分を所定の基準によって判定し、操作途中と判定された中間変速位置の変速段に順次切替え、その切替の完了に続いて操作終了と判定された変速位置の変速段に切替える。
したがって、多段の変速段の一部を選択して中間変速段を設定することにより、変速指示具を大きく操作する場合にあっても操作開始とともに迅速に変速段の切替えが開始され、また、変速指示具を急速に操作した場合にあっても、操作終了時の変速段まで順次的な切替えを経て変速ショック無しに円滑な変速が可能となる。 According to the first aspect of the present invention , when a shift operation is performed with a shift instruction change width of a plurality of stages or more by the shift instruction tool, the operation classification between the middle of operation of the shift instruction tool and the end of the operation is set as predetermined. It is determined according to the reference, and is sequentially switched to the gear position of the intermediate shift position determined to be in the middle of the operation, and is switched to the gear position of the shift position determined to be the end of the operation following completion of the switching.
Therefore, by selecting a part of the multiple shift speeds and setting the intermediate shift speed, even when the gear shift indicator is operated greatly, the shift speed switching is started as soon as the operation is started. Even when the pointing tool is operated rapidly, a smooth shift without shifting shock is possible through sequential switching up to the gear position at the end of the operation.

また、変速指示具の操作速度によって操作途中と操作終了の操作区分を判定することができ、作業者が違和感なく操作することができる。
また、変速指示具が変速段位置に操作され、かつ正逆転切替具を中立位置に操作して停車中のときは、主変速機構を変速指示具の操作位置に対応した伝動可能状態にすると共に高低速変速機構と前後進切替機構を中立にする。これにより、速やかな発進ができる。 Furthermore, Ki out to determine the operation section of the course and operation end operation by operating the speed of the gear shift instruction device, create skilled in the art may be operated without discomfort.
In addition, when the gear shift indicator is operated to the gear position and the forward / reverse switch is operated to the neutral position and the vehicle is stopped, the main transmission mechanism is brought into a transmission enabled state corresponding to the operation position of the gear shift indicator. Neutralize high / low speed transmission mechanism and forward / reverse switching mechanism. Thereby, a quick start can be performed.

また、高低速変速機構は２系統に並列構成してエンジン出力を共に受け、主変速機構は２系統に構成して高低速変速機構の出力を系統別に受けるとともに、全変速段を互いに異なる変速比で、変速比順位が隣接する変速段を互いに他の系統に構成し、前記２系統の出力側に共通する前後進切替機構を直列に配置して変速伝動系を構成し、変速指示具の変速段操作範囲の低速端に中立変速位置を設け、この中立変速位置にすると、高低速変速機構と前後進切替機構とを共に伝動遮断するとともに、主変速機構の２系統を所定の変速段に伝動制御するので、変速指示具による変速操作が開始されると、変速動作の応答性を向上することができる。 In addition, the high and low speed transmission mechanism is configured in parallel in two systems to receive engine output, the main transmission mechanism is configured in two systems to receive the output of the high and low speed transmission mechanism for each system, and all the gear positions are different from each other. Thus, the speed ratios adjacent to each other are configured in different systems, and a forward / reverse switching mechanism common on the output side of the two systems is arranged in series to form a transmission system. A neutral shift position is provided at the low speed end of the step operation range. When this neutral shift position is set, transmission of both the high / low speed transmission mechanism and the forward / reverse switching mechanism is cut off, and two systems of the main transmission mechanism are transmitted to a predetermined shift stage. Since the control is performed, the response of the speed change operation can be improved when the speed change operation by the speed change indicator is started.

請求項２に係る発明により、主変速機構の２系統をそれぞれ低速側の変速段に伝動制御することによる主変速機構の二重噛みと、高低速変速機構と前後進切替機構の伝動遮断とにより、つき回り動力による走行車輪への伝動が遮断されて機体の安定を確保することができる。主変速機構の２系統をそれぞれ低速側の変速段にすることで、つき回りしにくくなる。 According to the second aspect of the present invention, the double transmission of the main transmission mechanism by controlling transmission of the two systems of the main transmission mechanism to the low speed side gear stage, and the transmission interruption of the high / low speed transmission mechanism and the forward / reverse switching mechanism, respectively. it is blocked transmission of the traveling wheel by rotation power moon it is possible to secure stable aircraft. By setting the two systems of the main transmission mechanism to the low speed side, it becomes difficult to turn around.

トラクタの全体側面図Overall side view of tractor 走行伝動装置の伝動系統展開図Transmission system development diagram of traveling transmission 変速伝動系の変速段別伝動構成リストTransmission configuration list for each gear stage of the transmission system 変速制御のシステムブロック図System block diagram of shift control 主変速レバーのレバーガイドの見取図Sketch of the lever guide for the main gearshift lever 停車時（ａ）と発進操作時（ｂ）の変速制御の伝動構成リストTransmission configuration list for shifting control during stop (a) and start operation (b) 前後進レバー操作による発進時のタイミングチャートTiming chart when starting with forward / reverse lever operation クラッチペダル操作による発進時のタイミングチャートTiming chart when starting with clutch pedal operation 走行中の変速制御の伝動構成リスト１Transmission configuration list 1 for shifting control during traveling 走行中の変速制御の伝動構成リスト２Transmission configuration list 2 for shifting control during traveling 走行中の変速操作例１のタイミングチャートTiming chart of shifting operation example 1 during traveling 走行中の変速操作例２のタイミングチャートTiming chart of shifting operation example 2 while traveling 走行中の変速操作例３のタイミングチャートTiming chart of shifting operation example 3 while traveling 変速パターン別のクラッチの油圧制御（ａ）〜（ｅ）Hydraulic control of clutch according to shift pattern (a) to (e)

上記技術思想に基づいて具体的に構成された実施の形態について以下に図面を参照しつつ説明する。
図１は、本発明の適用対象となる作業車両の一例として示すトラクタの全体側面図である。この作業車両１は、前後の走行車輪２，３によって圃場作業可能に機体を支持し、機体前部のエンジン４の動力を受けて走行車輪２，３に変速伝動する変速伝動系を内設した走行伝動装置５であるトランスミッションを備える。この走行伝動装置５は、また、ＰＴＯと略称される作業動力供給部６に伝動する作業機伝動系を内設し、後部ヒッチに装着したロータリ等の作業機Ｗを駆動可能に構成される。 Embodiments specifically configured based on the above technical idea will be described below with reference to the drawings.
FIG. 1 is an overall side view of a tractor shown as an example of a work vehicle to which the present invention is applied. This work vehicle 1 supports the machine body by front and rear traveling wheels 2 and 3 so as to be able to work on the field, and has a shift transmission system that receives the power of the engine 4 at the front of the machine body and performs transmission transmission to the traveling wheels 2 and 3. A transmission which is the traveling transmission device 5 is provided. The traveling transmission device 5 is also provided with a work machine transmission system that is transmitted to the work power supply unit 6, which is abbreviated as PTO, and is capable of driving a work machine W such as a rotary mounted on the rear hitch.

走行伝動装置５は、図２の伝動系統展開図に示すように、高低速の２つの伝動要素をそれぞれのクラッチにより２段変速伝動する２つの高低速変速機構１１，１１と、複数速の伝動要素をパワーシンクロシフトにより多段変速伝動する２つの主変速機構１２，１２と、正逆転の２つの伝動要素をそれぞれのクラッチにより正逆切替伝動する前後進切替機構１３と、ギヤシフトによって多段に変速可能な副変速機構１４とを直列に介設して多段変速可能にエンジン動力を変速伝動する走行用の変速伝動系を備え、また、作業機伝動系としてＰＴＯ変速伝動部１５を設けてその作業クラッチ入力軸である作業入力軸１５ａを高低速変速機構１１，１１と共にエンジン動力を受け、ＰＴＯ軸１５ｂを介して作業動力供給部６に伝動する。 As shown in the development diagram of the transmission system in FIG. 2, the traveling transmission device 5 includes two high- and low-speed transmission mechanisms 11 and 11 that transmit two high- and low-speed transmission elements by two clutches using respective clutches, and a multi-speed transmission. Two main transmission mechanisms 12 and 12 that transmit multi-stage transmission by power synchro shift, forward / reverse switching mechanism 13 that transmits forward and reverse transmission elements by respective clutches, and multi-speed transmission by gear shift And a sub-transmission mechanism 14 connected in series to provide a transmission gear transmission system for shifting the engine power so as to be capable of multi-stage shifting, and a PTO transmission gear transmission 15 is provided as a work machine transmission system, and the working clutch The work input shaft 15a, which is an input shaft, receives engine power together with the high and low speed transmission mechanisms 11, 11, and is transmitted to the work power supply unit 6 via the PTO shaft 15b.

高低速変速機構１１，１１は、２系統に並列配置してエンジン出力軸４ａから共通入力軸１１ａを介してそれぞれ高低速軸１１ｂ，１１ｂに高低出力を伝動し、また、主変速機構１２，１２は、高低速変速機構１１，１１の出力側にそれぞれ系統別に構成して主変速軸１２ｂに共通に伝動出力し、直列配置の前後進切替機構１３の前後進軸１３ｂから４段変速の副変速機構１４を介して前後輪２，３に伝動する。 The high and low speed transmission mechanisms 11 and 11 are arranged in parallel in two systems to transmit high and low outputs from the engine output shaft 4a to the high and low speed shafts 11b and 11b via the common input shaft 11a, respectively, and the main transmission mechanisms 12 and 12 Are configured separately on the output side of the high and low speed transmission mechanisms 11 and 11, respectively, and transmit transmission power in common to the main transmission shaft 12b, and the four-speed sub-shift from the forward / reverse shaft 13b of the forward / reverse switching mechanism 13 arranged in series. It is transmitted to the front and rear wheels 2 and 3 via the mechanism 14.

主変速機構１２，１２は、２系統のそれぞれの上下流両側をクラッチ式の高低速変速機構１１，１１と前後進切替機構１３とによって挟まれることから、これら上下流両側の変速機構１１，１３のクラッチによりエンジン４と走行車輪２，３の両方からの回転伝達の遮断が可能となり、エンジン回転と車速との回転差を受けることがないので、小容量のシンクロ機構によって迅速に変速切替えができる。したがって、上記走行伝動装置５は、走行中における変速切替性を確保した上で、主変速機構１２，１２の小型化によるトランスミッション全長の短縮化が可能となり、それに伴う車両のコンパクト化によって作業車両の小回り性の向上に寄与することができる。 The main transmission mechanisms 12 and 12 are sandwiched between the clutch type high / low speed transmission mechanisms 11 and 11 and the forward / reverse switching mechanism 13 on both the upstream and downstream sides of the two systems. The clutch of the engine 4 can cut off the rotation transmission from both the engine 4 and the traveling wheels 2 and 3, and since it does not receive the rotation difference between the engine rotation and the vehicle speed, the gear change can be quickly performed by a small-capacity synchro mechanism. . Therefore, the traveling transmission device 5 can reduce the total length of the transmission by reducing the size of the main transmission mechanisms 12 and 12 while ensuring the shift changeability during traveling. It can contribute to the improvement of the turning ability.

前後進切替機構１３は、前進ギヤと後進ギヤをクラッチにより切替え可能に構成することによりコンパクト化できるので、クラッチの前或いは後にギヤシフト式の前後進切替機構を設ける場合より、必要な前後長寸法を短縮して構成することができる。 Since the forward / reverse switching mechanism 13 can be made compact by configuring the forward gear and the reverse gear to be switched by a clutch, the required forward / backward length dimension can be increased as compared with the case where a gear shift type forward / backward switching mechanism is provided before or after the clutch. It can be configured by shortening.

高低速変速機構１１，１１の切替え駆動は切替弁によってクラッチを作動させ、また、前後進切替機構１３の切替え駆動は比例圧力制御弁によって伝動力制御可能に構成することにより、圧力制御の際に、クラッチやバルブ、制御部の駆動回路のそれぞれの特性のバラツキに対応した安定化が可能となる。すなわち、変速時のクラッチ駆動中に常にどちらか接続状態となる側のクラッチ圧力コントロールすることで、個々の比例弁制御が不要となり、製品間の変速特性のバラツキを小さく抑えて低コストで安定したシステムを構成することができる。 The switching drive of the high and low speed transmission mechanisms 11, 11 operates the clutch by the switching valve, and the switching driving of the forward / reverse switching mechanism 13 is configured to be able to control the power transmission by the proportional pressure control valve, thereby performing the pressure control. In addition, stabilization corresponding to variations in the characteristics of the clutch, the valve, and the drive circuit of the control unit can be achieved. In other words, by controlling the clutch pressure on the side that is always connected while the clutch is being driven at the time of shifting, individual proportional valve control is not required, and variation in shifting characteristics between products is minimized and stable at low cost. The system can be configured.

また、作業入力軸１５ａは、高低速変速機構１１，１１と共にエンジン動力を受けて作業機動力制御用のＰＴＯ変速伝動部１５を設けることにより、高低速変速機構１１，１１と作業入力軸１５ａに常時エンジン動力が供給されることから、最小限の伝動構成によって走行系と作業系にエンジン動力を供給する走行変速伝動装置５を構成することができる。 Further, the work input shaft 15a is provided with the PTO transmission transmission unit 15 for receiving power from the engine together with the high and low speed transmission mechanisms 11 and 11 to control the work machine power, so that the high and low speed transmission mechanisms 11 and 11 and the work input shaft 15a are provided. Since the engine power is always supplied, the traveling speed change transmission device 5 that supplies the engine power to the traveling system and the working system can be configured with a minimum transmission configuration.

高低速変速機構１１，１１の２系統の高低の変速段は互いに共通に構成し、かつ、主変速機構１２，１２の２系統の全変速段は互いに異なる変速比に構成し、変速比の順位が隣接する２つの変速段は別々の系統に構成する。具体的には、図例の主変速機構１２，１２について、変速比の順位が２系統の一方に第１と第３の変速比による１速と３速の減速ギヤ列、他方に第２と第４の変速比による２速と４速の減速ギヤ列をそれぞれ切替え可能に全４速に構成する。 The two high and low gear stages of the high and low speed transmission mechanisms 11 and 11 are configured in common with each other, and all the two gear stages of the main transmission mechanisms 12 and 12 are configured with different gear ratios. Are arranged in separate systems. Specifically, with respect to the main transmission mechanisms 12 and 12 in the figure, the speed ratio rank is one of the two systems, and the first and third speed reduction gear trains according to the first and third speed ratios, and the other is the second and second speed reduction gear trains. All the 4th speed gears are configured to be switchable between the 2nd speed and 4th speed reduction gear trains according to the fourth gear ratio.

上記構成の変速伝動系の具体的な伝動構成は、図３の変速段別リストに示すように、低速Ｌと高速Ｈを切替える高低速変速機構１１，１１の一方を主変速機構１２，１２の１速−３速の切替えによる１Ｌ、１Ｈ、３Ｌ、３Ｈの４変速段、他方を２速−４速の切替えによる２Ｌ、２Ｈ、４Ｌ、４Ｈの４変速段が選択でき、前進Ｆと後進Ｒを切替える前後進切替機構１３の組合わせにより、前後進についてそれぞれ８速の多段変速が可能となる。また、主変速機構１２，１２の系統別に不連続の変速段を切替え構成することにより、両系統を同時に変速駆動することが可能となることから、１段ずつの順次変速の際に最小限の伝動遮断で円滑な変速が可能となる。 The specific transmission configuration of the above-described transmission transmission system is as follows. One of the high and low speed transmission mechanisms 11 and 11 for switching between the low speed L and the high speed H is the same as that of the main transmission mechanism 12 and 12, as shown in the shift stage list in FIG. Four shift stages of 1L, 1H, 3L and 3H can be selected by switching between 1st and 3rd speeds, and 4L can be selected as 2L, 2H, 4L and 4H by switching between the 2nd and 4th speeds. Forward F and Reverse R With the combination of the forward / reverse switching mechanism 13 for switching the forward / reverse travel, it is possible to perform 8-speed multi-speed shifting for forward / reverse travel. Further, by switching the discontinuous shift stages for each system of the main transmission mechanisms 12 and 12, it is possible to drive both systems at the same time. Smooth transmission can be achieved by interrupting transmission.

上記構成の走行伝動装置５は、変速を含む走行制御のための操作具と変速制御用の制御部Ｃを備えて走行伝動装置を構成し、操作具として、踏込操作用のクラッチペダル２１、順次式変速指示具である主変速レバー２２、前後進選択用の前後進レバー２３を設け、図４のシステムブロック図に示すように、操作具それぞれの操作センサ２１ｓ…および各機器の動作センサ１２ｓ…、回転センサ４ｒ，１３ｒ等の信号を制御部Ｃに入力して各変速機器の駆動部１１ｄ…を制御可能な変速制御システムを構成する。 The travel transmission device 5 having the above-described configuration includes an operation tool for travel control including a shift and a control unit C for shift control, and configures the travel transmission device. As the operation tool, a clutch pedal 21 for stepping operation is sequentially provided. 4 is provided with a main transmission lever 22 which is a type of shift instruction tool, and a forward / reverse lever 23 for forward / reverse selection. As shown in the system block diagram of FIG. 4, operation sensors 21s for each operation tool and motion sensors 12s for each device. , And the rotation sensors 4r, 13r, etc., are input to the control unit C to constitute a shift control system capable of controlling the drive units 11d of the transmission devices.

クラッチペダル２１は、クラッチペダルセンサ２１ｓからの踏込量信号を制御部Ｃに入力し、踏込操作に応じて高低速変速機構１１，１１と前後進切替機構１３とを共に中立に伝動遮断制御し、また、主変速レバー２２は、図５のレバーガイドの見取図に示すように、ポジション１から８までの変速段ポジションとニュートラルＮおよびアクセル変速用の自動変速ＡＴのポジションを設け、ニュートラルＮのポジションで高低速変速機構１１，１１と前後進切替機構１３の伝動を共に中立とするとともに、主変速機構１２，１２の両系統をいずれかの変速段に切替え伝動制御することにより、エンジン側と走行車輪側のいずれについてもクラッチのつき回りによる動力伝達が防止され、また、変速済みの主変速機構１２，１２により、クラッチペダル２１の戻し操作に応じて動力伝達が開始されることから、主変速機構１２，１２のシンクロ動作特性によることなく、応答性を確保することができる。 The clutch pedal 21 inputs a depression amount signal from the clutch pedal sensor 21 s to the control unit C, and controls transmission cut-off control of the high / low speed transmission mechanisms 11, 11 and the forward / reverse switching mechanism 13 neutrally according to the depression operation, Further, as shown in the sketch of the lever guide in FIG. 5, the main transmission lever 22 is provided with a gear position from positions 1 to 8, a neutral N position and an automatic transmission AT position for accelerator transmission, and at the neutral N position. The transmission of the high and low speed transmission mechanisms 11 and 11 and the forward / reverse switching mechanism 13 are both neutral, and both the main transmission mechanisms 12 and 12 are switched to one of the gear stages to perform transmission control, so that the engine side and the traveling wheel can be controlled. On either side, power transmission due to the clutch is prevented, and the main transmission mechanisms 12 and 12 that have already been shifted are used to Since the power transmission is started in response to returning operation of the pedal 21, without by synchro operation characteristics of the main transmission mechanism 12, 12 can be ensured response.

主変速機構１２，１２は、非伝動側の系統についても変速を完了状態に保持するように構成し、主変速レバー２２の指示に応じて異なる変速位置に保持する。例えば、主変速レバー２２の指示がポジション２の場合は、１速−３速の系統の高低速変速機構１１を高速Ｈ側、１速―３速の主変速機構１２を１速に変速制御し、前後進切替機構１３を伝動制御し、この時、他の２速―４速の系統は、高低速変速機構１１を中立、主変速機構１２を２速に変速制御した状態に保持することにより、レバー操作で変速した時は主変速機構１２が既に変速済みであることから、多くの場合において変速操作と連動した切替えが不要となるので、変速時の機器動作を少なくして変速完了までの時間を最小限に短縮することができる。 The main transmission mechanisms 12 and 12 are configured to hold the shift in the non-transmission-side system in a completed state, and are held at different shift positions according to instructions from the main transmission lever 22. For example, when the instruction of the main transmission lever 22 is position 2, the high / low speed transmission mechanism 11 of the 1st to 3rd system is shifted to the high speed H side, and the 1st to 3rd main transmission mechanism 12 is controlled to the 1st speed. The transmission control of the forward / reverse switching mechanism 13 is controlled, and at this time, the other 2nd to 4th speed systems are maintained by shifting the high / low speed transmission mechanism 11 to the neutral and the main transmission mechanism 12 to the second speed. When shifting by lever operation, the main transmission mechanism 12 has already been shifted, so in many cases there is no need to switch in conjunction with the shifting operation. Time can be reduced to a minimum.

主変速レバー２２の変速指示位置と主変速機構１２，１２の変速位置の関係は、少なくとも以下の如くに制御する。すなわち、主変速レバー２２の指示位置が１〜３速の場合は両系統の変速段を１速と２速とし、指示が６〜８速の場合は変速段を３速と４速とし、指示が４，５速の場合はいずれかの変速段に変速することにより、変速制御処理のアルゴリズムが簡単になり、変速操作と連動したシンクロシフト式の変速部の変速動作を少なくすることができる。 The relationship between the shift instruction position of the main transmission lever 22 and the shift positions of the main transmission mechanisms 12 and 12 is controlled at least as follows. That is, when the indicated position of the main shift lever 22 is 1st to 3rd speed, the shift speeds of both systems are 1st speed and 2nd speed, and when the instruction is 6th to 8th speed, the gear speed is 3rd speed and 4th speed. In the case of 4th and 5th gears, shifting to any one of the shift speeds simplifies the algorithm of the shift control processing, and the shift operation of the synchro shift type shift unit linked to the shift operation can be reduced.

変速の際の詳細な制御は、主変速機構１２，１２の変速が完了してから動力伝達できるようにクラッチ伝動を制御し、高低速変速機構１１，１１は変速後のクラッチのミート位置までのピストン移動時間を加味し、クラッチを変速前のポジションに伝動状態で保持するように制御することで、動力遮断を極力少なくすることができる。 The detailed control at the time of shifting is such that the clutch transmission is controlled so that power can be transmitted after the shifting of the main transmission mechanisms 12 and 12 is completed, and the high and low speed shifting mechanisms 11 and 11 reach the meet position of the clutch after shifting. By taking into account the piston movement time and controlling the clutch to be held in the transmission state at the position before the shift, the power interruption can be minimized.

また、変速前に高低速変速機構１１，１１の中立動作とほぼ同時に前後進切替機構１３を減圧側に駆動し、変速後に高低速変速機構１１，１１のクラッチの推定ミートタイミングに合わせて減圧側から徐々に接続トルクを大きくする側（昇圧）に駆動することにより、変速した際の動力遮断が少なく、二重噛みなしに制御できるので、変速のフィーリングを改善することができる。 Further, the forward / reverse switching mechanism 13 is driven to the pressure reducing side almost simultaneously with the neutral operation of the high / low speed transmission mechanisms 11 and 11 before shifting, and the pressure reducing side is synchronized with the estimated meet timing of the clutch of the high and low speed shifting mechanisms 11 and 11 after shifting. By gradually driving to the side where the connection torque is gradually increased (step-up), there is less power interruption at the time of shifting, and control can be performed without double meshing, so that the feeling of shifting can be improved.

変速指示変化幅が複数段以上の場合は中間変速段への変速を介して最終変速目標位置に変速するように、主変速レバー２２による変速位置の変化量によって変速方式を変更する。例えば、１速から８速などの車速差が大きい場合は、一気に変速するとその車速差に応じた加速度が発生して変速ショックが大きくなるので、複数段の変速の際は、１変速段から２変速段を間に置いた中間変速位置を入れて変速することで、車速差を少なくした変速によって変速ショックを和らげることができる。 When the shift instruction change width is a plurality of stages or more, the shift method is changed according to the change amount of the shift position by the main shift lever 22 so as to shift to the final shift target position through the shift to the intermediate shift stage. For example, when the vehicle speed difference such as 1st to 8th is large, if the gear is shifted all at once, the acceleration corresponding to the vehicle speed difference is generated and the shift shock becomes large. By changing the speed by inserting an intermediate speed position with a gear position in between, the speed change shock can be reduced by a speed change with a reduced vehicle speed difference.

主変速レバー２２の変速位置は、ポテンショメータ等のアナログ量で検出し、検出刻み量をほぼ一定にした刻み幅の範囲で変速指示位置を決定するように構成することにより、指示位置毎に幅を設けて変速指示位置を容易に確定することができる。また、検出値をアナログ量とすることで操作を継続しているのか完了したのか判断でき、例えば、１速から４速に変速している過程における２速位置なのか、１速から２速までの操作の完了による２速なのか、その判断が可能となる。 The shift position of the main shift lever 22 is detected by an analog amount such as a potentiometer, and the shift instruction position is determined within a range of a step width in which the detected step amount is substantially constant. It is possible to easily determine the shift instruction position. In addition, it can be determined whether the operation is continued or completed by setting the detected value as an analog amount, for example, whether it is the second speed position in the process of shifting from the first speed to the fourth speed, or from the first speed to the second speed. It is possible to determine whether the speed is the second speed upon completion of the operation.

この場合において、操作方向に対して、変速指示位置範囲にヒステリシスを設ける等の方策により、変速制御の安定化を図ることができる。例えば、１速と２速の検出が繰り返し変化する等の切替わりの位置での検出のチャタリング的な検出を防止することができる。
（中間変速段制御）
次に、中間変速段による変速制御について説明する。 In this case, the shift control can be stabilized by a measure such as providing hysteresis in the shift instruction position range with respect to the operation direction. For example, it is possible to prevent chattering detection of detection at a switching position where the detection of the first speed and the second speed is repeatedly changed.
(Intermediate shift speed control)
Next, the shift control by the intermediate shift stage will be described.

変速制御部Ｃの制御処理により、変速指示具２２の操作途中と操作終了との操作区分を所定の基準によって判定し、操作途中の判定であれば、全変速段から選択した所定の中間変速段の通過により、通過した中間変速段に順次切替え、その終了に続いて操作終了の判定による変速段に切替える。 According to the control processing of the shift control unit C, the operation classification between the operation in progress and the operation end of the shift instruction tool 22 is determined based on a predetermined reference, and if the determination is in the middle of the operation, a predetermined intermediate gear selected from all the gears Are sequentially switched to the intermediate speed stage that has passed, and then the speed is changed to the speed stage based on the determination of the end of the operation following the end of the intermediate speed stage.

このように変速制御を構成することにより、高低速変速機構１１、主変速機構１２、および前後進切替機構１３からなる変速伝動系を変速指示具２２の操作に応じて変速制御部Ｃにより前後進の多段の変速段に切替えができ、また、変速指示具の操作状況について操作途中と操作終了の操作区分を判別し、操作終了までの中間変速段の切替を経て操作終了の判定による変速段に切替えられる。したがって、多段の変速段の一部を選択して中間変速段を設定することにより、変速指示具を大きく操作する場合にあっても操作開始とともに迅速に変速段の切替えが開始され、また、変速指示具を急速に操作した場合にあっても、操作終了時の変速段まで中間変速段の順次切替えを経て変速ショック無しに円滑な変速が可能となる。 By configuring the speed change control in this way, the speed change transmission system including the high / low speed speed change mechanism 11, the main speed change mechanism 12, and the forward / reverse switching mechanism 13 is moved forward and backward by the speed change control unit C according to the operation of the speed change indicator 22. It is possible to switch to multiple gears, and the operation status of the gear change indicator is determined during operation and when the operation is completed. Switched. Therefore, by selecting a part of the multiple shift speeds and setting the intermediate shift speed, even when the gear shift indicator is operated greatly, the shift speed switching is started as soon as the operation is started. Even when the pointing tool is operated rapidly, a smooth shift can be performed without a shift shock by sequentially switching the intermediate shift stage until the shift stage at the end of the operation.

変速指示具２２の操作途中と操作終了の操作区分は、変速指示具の操作速度に基づいて操作状況を判定することができ、この判定区分により、変速指示具を一気に操作した場合は操作終了時を含む中間点毎に変速され、また、操作を低速で継続した場合は１段ずつの変速となり、いずれも操作に対応して制御動作されることから、作業者が違和感なく操作することができる。
（レバー中立制御）
変速指示具２２を中立Ｎにポジション操作した場合については、高低速変速機構１１，１１と前後進切替機構１３とを共にクラッチオフして伝動遮断するとともに、主変速機構１２，１２の両系統をそれぞれの低速側の変速段に伝動制御することにより、次に変速指示具２２による変速操作が開始された際に、主変速機構１２，１２のシンクロ動作を要することなく、上下流両側の変速機構１１，１３のクラッチの伝動動作とともに変速伝動が可能となるので、変速動作の応答性を向上することができる。
（伝動中立制御）
副変速１４の中立操作を除く変速伝動系の中立制御は、高低速変速機構１１，１１と前後進切替機構１３を共に中立に伝動制御するとともに、主変速機構１２，１２の両系統を所定の変速段に伝動制御することにより、二重噛み状態の主変速機構１２，１２がその上下流両側で伝動遮断状態となることから、つき回り動力による走行車輪への伝動が遮断されて機体の安定を確保することができる。
（変速制御例）
次に、変速制御動作の具体例について説明する。 The operation classification of the middle of the operation of the shift instruction tool 22 and the operation end of the operation can determine the operation status based on the operation speed of the shift instruction tool, and when the shift instruction tool is operated at once by this determination classification, In addition, if the operation is continued at a low speed, the gears are shifted one step at a time, and each is controlled according to the operation, so that the operator can operate without a sense of incongruity. .
(Lever neutral control)
When the gear change indicator 22 is operated to the neutral N position, the high and low speed transmission mechanisms 11 and 11 and the forward / reverse switching mechanism 13 are both clutched off to cut off transmission, and both the main transmission mechanisms 12 and 12 are connected. By performing transmission control to the respective low-speed gears, the transmission mechanism on both the upstream and downstream sides is not required without requiring the main transmission mechanisms 12 and 12 to be synchronized when the shift operation by the shift indicator 22 is started next time. Since the transmission of the clutches 11 and 13 can be performed together with the transmission operation of the clutches 13 and 13, the responsiveness of the transmission operation can be improved.
(Transmission neutral control)
The neutralization control of the transmission system excluding the neutral operation of the auxiliary transmission 14 controls the transmission of the high and low speed transmission mechanisms 11 and 11 and the forward / reverse switching mechanism 13 to be neutral and controls both the main transmission mechanisms 12 and 12 to a predetermined level. By performing transmission control to the shift stage, the double-geared main transmission mechanisms 12 and 12 are in the transmission cut-off state on both the upstream and downstream sides thereof, so that the transmission to the traveling wheels by the follow-up power is cut off and the body is stabilized. Can be secured.
(Example of shift control)
Next, a specific example of the shift control operation will be described.

まず、停車時の変速伝動系の変速伝動制御は、図６（ａ）の伝動構成リストに示すように、２系統の高低速変速機構１１，１１と前後進切替機構１３をオフに制御するとともに、２系統の主変速機構１２，１２については、主変速レバー２２の位置と対応した位置に伝動制御する。 First, as shown in the transmission configuration list of FIG. 6A, the transmission transmission control of the transmission transmission system when the vehicle is stopped is performed by turning off the two high-speed transmission mechanisms 11 and 11 and the forward / reverse switching mechanism 13. For the two systems of the main transmission mechanisms 12 and 12, transmission control is performed to a position corresponding to the position of the main transmission lever 22.

例えば、前後進レバー２３を中立のＮ位置に操作して停車中のときは、主変速レバー２２が１速位置であれば、２系統の主変速機構１２，１２のみを準備のために立ち上げて１速オンと２速オンに伝動制御する。また、クラッチペダル２１を踏込み位置に操作して停車中のときは、主変速レバー２２が１速位置であれば、同様に、２系統の主変速機構１２，１２のみを準備のために立ち上げて１速オンと２速オンに伝動制御する。 For example, when the vehicle is stopped by operating the forward / reverse lever 23 to the neutral N position, if the main transmission lever 22 is in the first speed position, only the two main transmission mechanisms 12, 12 are started up for preparation. To control transmission to 1st speed on and 2nd speed on. When the clutch pedal 21 is operated to the depressed position and the vehicle is stopped, if only the main transmission lever 22 is in the first speed position, similarly, only the two main transmission mechanisms 12, 12 are started up for preparation. To control transmission to 1st speed on and 2nd speed on.

また、発進操作時の変速伝動系の変速伝動制御は、図６（ｂ）の伝動構成リストに示すように、前後進レバー２３または、クラッチペダル２１の操作と対応して高低速変速機構１１と前後進切替機構１３をクラッチにより伝動制御する一方で、２系統の主変速機構１２，１２についてはその伝動状態を維持する。 Further, the transmission transmission control of the transmission transmission system at the time of the start operation corresponds to the operation of the high / low speed transmission mechanism 11 corresponding to the operation of the forward / reverse lever 23 or the clutch pedal 21 as shown in the transmission configuration list of FIG. While transmission control of the forward / reverse switching mechanism 13 is performed by a clutch, the transmission state of the two main transmission mechanisms 12 and 12 is maintained.

この発進時の変速制御の詳細は、前後進レバー２３による発進の場合を図７のタイミングチャートに示すように、クラッチペダル２１を戻して開放し、主変速レバー２２を１速位置とし、前後進レバーを中立位置で停車している場合に、この前後進レバー２３を前進位置に操作すると、Ｈｉ−Ｌｏクラッチ（１−３）をオフからＬ（１）オンに制御し、同時に前後進切替機構１３のクラッチをオフから前進に所定の油圧カーブで昇圧して接続し、この間、Ｈｉ−Ｌｏクラッチ（２−４）をオフ、主変速（１−３）を１速オン、主変速（２−４）を準備のために２速オンに立ち上げたままに伝動状態を維持する。この場合、クラッチピストンはそれぞれの移動時間ｔ１、ｔ２を経て接続動作を開始する。 As for the details of the shift control at the time of starting, as shown in the timing chart of FIG. 7, the case of starting by the forward / reverse lever 23 is returned and released, the main transmission lever 22 is set to the first speed position, and the forward / backward movement is performed. When the lever is stopped at the neutral position, if the forward / reverse lever 23 is operated to the forward position, the Hi-Lo clutch (1-3) is controlled from OFF to L (1), and at the same time, the forward / reverse switching mechanism. 13 clutches are connected from off to forward with a predetermined hydraulic curve, and during this time, the Hi-Lo clutch (2-4) is turned off, the main transmission (1-3) is turned on at the first speed, and the main transmission (2- 4) In preparation, maintain the transmission state with the second speed on. In this case, the clutch piston starts the connection operation after the respective movement times t1 and t2.

このように、前後進レバー２３を中立位置から前進位置に操作して発進する際は、主変速レバー２２位置と対応する伝動系統の主変速機構１２をそのままで高低速変速機構１１と前後進切替機構１３の該当側のクラッチを昇圧して動力を伝達する一方で、待機系統の高低速変速機構１１は中立のままで主変速機構１２を準備のためにその伝動状態を維持する。 As described above, when the vehicle is started by operating the forward / reverse lever 23 from the neutral position to the forward position, the main transmission mechanism 12 of the transmission system corresponding to the position of the main transmission lever 22 is left as it is, and the high / low speed transmission mechanism 11 and forward / reverse switching are performed. While the clutch on the corresponding side of the mechanism 13 is boosted to transmit power, the high / low speed transmission mechanism 11 of the standby system remains neutral and maintains the transmission state of the main transmission mechanism 12 for preparation.

また、クラッチペダル２１による発進の場合を図８のタイミングチャートに示すように、前後進レバー２３を中立位置、主変速レバー２２を１速位置とし、クラッチペダル２１を踏込んで停車している場合に、このクラッチペダル２１を戻し操作すると、Ｈｉ−Ｌｏクラッチ（１−３）をオフからＬ（１）オンに制御し、同時に前後進切替機構１３のクラッチをオフから前進にクラッチペダル２１の戻し操作に応じた油圧カーブで昇圧して接続し、この間、Ｈｉ−Ｌｏクラッチ（２−４）をオフ、主変速（１−３）を１速オン、主変速（２−４）を準備のために２速オンに立ち上げたままに伝動制御する。この場合、クラッチピストンはそれぞれの移動時間ｔ１、ｔ２を経て接続動作を開始する。 As shown in the timing chart of FIG. 8, when the clutch pedal 21 is started, the forward / reverse lever 23 is set to the neutral position, the main transmission lever 22 is set to the first speed position, and the clutch pedal 21 is depressed to stop the vehicle. When the clutch pedal 21 is returned, the Hi-Lo clutch (1-3) is controlled from OFF to L (1), and at the same time, the clutch of the forward / reverse switching mechanism 13 is changed from OFF to forward. The hydraulic curve is increased according to the pressure and connected. During this time, the Hi-Lo clutch (2-4) is turned off, the main transmission (1-3) is turned on at the first speed, and the main transmission (2-4) is prepared. Transmission control is performed with the second speed on. In this case, the clutch piston starts the connection operation after the respective movement times t1 and t2.

このように、クラッチペダル２１の戻し操作によって発進する際は、主変速レバー２２位置と対応する伝動系統高低速変速機構１１と前後進切替機構１３の該当側のクラッチを昇圧して動力伝達を開始する一方で、待機系統の高低速変速機構１１を中立のままで主変速機構１２を準備のためにその伝動状態を維持する。 As described above, when starting by returning the clutch pedal 21, the transmission side high / low speed transmission mechanism 11 and the forward / reverse switching mechanism 13 corresponding to the position of the main transmission lever 22 are boosted to start power transmission. On the other hand, the transmission state of the main transmission mechanism 12 is maintained for preparation while the high-low speed transmission mechanism 11 of the standby system remains neutral.

次に、走行中の変速伝動制御については、主変速レバー２２が４速以下のポジションの場合と５速以上のポジションの場合を図９の伝動構成リスト１と図１０の伝動構成リスト２にそれぞれ示すように、主変速レバー２２の操作に伴い、変速操作幅が大きい場合は括弧書きの中間変速段を経て、２系統の主変速機構１２，１２について主変速レバー２２の位置と対応した位置に伝動制御を行う。 Next, regarding the transmission transmission control during travel, the transmission configuration list 1 in FIG. 9 and the transmission configuration list 2 in FIG. 10 are respectively shown when the main transmission lever 22 is in the position of the fourth speed or less and in the position of the fifth speed or more. As shown in the drawing, when the speed change operation width is large as the main speed change lever 22 is operated, the two speed main transmission mechanisms 12 and 12 are moved to positions corresponding to the positions of the main speed change lever 22 through the intermediate speed stage in parentheses. Perform transmission control.

この変速伝動制御について詳細に説明すると、図１１の走行中の変速操作例１のタイミングチャートに示すように、クラッチペダル２１を開放、前後進レバー２３を前進、主変速レバー２２をポジション１で前進走行中においてポジション２に操作した場合は、Ｈｉ−Ｌｏクラッチ（１−３）はＬ（１）オンからＨ（３）オンに切換え、前後進クラッチを前進でＬ（１）オフのタイミングで一旦動力伝達しない程度の低い圧力まで減圧し、徐々に昇圧する一方、Ｈｉ−Ｌｏクラッチ（２−４）はオフ、主変速機構１２（１−３）は、１速オンで使用のまま、主変速（２−４）は２速オンに準備のため立ち上げる。この場合、レバー操作時間ｔ３には移動速度による操作完了判定時間ｔ４を含み、レバー操作時間ｔ３とクラッチピストンの移動時間ｔ１を経て高低速変速機構１１の該当クラッチが接続開始し、その一定時間ｔ５前（略１０ミリ秒前）に前後進クラッチをオフして二重噛みを防止する。 This shift transmission control will be described in detail. As shown in the timing chart of the shifting operation example 1 during traveling in FIG. 11, the clutch pedal 21 is released, the forward / reverse lever 23 is moved forward, and the main shift lever 22 is moved forward at position 1. When operated to position 2 during traveling, the Hi-Lo clutch (1-3) is switched from L (1) on to H (3) on, and the forward / reverse clutch is moved forward and once at L (1) off timing. While the pressure is reduced to a low pressure that does not transmit power and the pressure is gradually increased, the Hi-Lo clutch (2-4) is turned off and the main transmission mechanism 12 (1-3) is used with the first speed on and the main speed change. (2-4) starts up to prepare for turning on the second gear. In this case, the lever operation time t3 includes an operation completion determination time t4 based on the moving speed, and the clutch of the high / low speed transmission mechanism 11 starts to be connected after the lever operation time t3 and the clutch piston moving time t1, and the fixed time t5 The forward / reverse clutch is turned off forward (approximately 10 milliseconds before) to prevent double biting.

このように、主変速レバー２２をポジション１で前進走行中にポジション２に操作した時は、伝動側の系統の高低速変速機構１１の伝動要素を低速から高速に切替制御し、その際に、前後進切替機構１３を一時的に減圧して所定の油圧カーブの昇圧により伝動接続する。 Thus, when the main speed change lever 22 is operated to position 2 during forward traveling at position 1, the transmission element of the high / low speed transmission mechanism 11 of the transmission side system is switched from low speed to high speed, The forward / reverse switching mechanism 13 is temporarily depressurized and connected in transmission by increasing a predetermined hydraulic curve.

また、図１２の走行中の変速操作例２のタイミングチャートに示すように、クラッチペダル２１を開放、前後進レバー２３を前進、主変速レバー２２をポジション１で前進走行中においてポジション５に操作した場合は、Ｈｉ−Ｌｏクラッチ（１−３）はＬ（１）オンからオフに切換えて再びＬ（１）オン、Ｈｉ−Ｌｏクラッチ（２−４）はオフからＬ（２）オンに切換えて再びオフ、主変速クラッチ（１−３）は１速オンの使用からオフにして３速オンで使用、主変速クラッチ（２−４）は２速オンのまま準備で立ち上げておき、前後進クラッチは前進維持でＨｉ−Ｌｏクラッチ切替えの都度減圧して徐々に昇圧する。この場合、レバー操作時間ｔ３は、ポジション３以上への変速操作により確定された時点であり、その時点からポジション３の変速伝動制御が開始され、また、主変速の切替えは、所定の中立保持時間ｔ６を確保する。 12, the clutch pedal 21 is released, the forward / reverse lever 23 is moved forward, and the main shift lever 22 is moved to position 5 while moving forward at position 1 as shown in the timing chart of shifting operation example 2 during traveling. In this case, the Hi-Lo clutch (1-3) is switched from L (1) on to off and L (1) is turned on again, and the Hi-Lo clutch (2-4) is switched from off to L (2) on. Turn off again, the main transmission clutch (1-3) is turned off from the use of the 1st speed and is used at the 3rd speed on, the main transmission clutch (2-4) is started up with the 2nd speed on and ready to start The clutch keeps moving forward and depressurizes and gradually increases each time the Hi-Lo clutch is switched. In this case, the lever operation time t3 is a time point determined by the shift operation to the position 3 or higher, the shift transmission control of the position 3 is started from that time point, and the switching of the main shift is performed for a predetermined neutral holding time. t6 is secured.

このように、主変速レバー２２をポジション１で前進走行中の場合においてポジション５に操作した時は、ポジション３の中間変速段制御を間に挟んで伝動制御し、また、高低速変速機構１１の切替の都度、前後進切替機構１３を一時的に減圧して所定の油圧カーブで昇圧する。 As described above, when the main transmission lever 22 is operated to the position 5 while the vehicle is traveling forward at the position 1, the transmission control is performed with the intermediate speed control of the position 3 interposed therebetween, and the high / low speed transmission mechanism 11 Each time switching is performed, the forward / reverse switching mechanism 13 is temporarily depressurized to increase the pressure with a predetermined hydraulic curve.

また、図１３の走行中の変速操作例３のタイミングチャートに示すように、主変速レバー２２をポジション２で前進走行中においてポジション７に操作した場合において、変速位置や車両転がり条件によってポジション４と５を中間変速段とする例については、ポジション４以上への変速操作により、変速完了が未確定のまま４速への切替え動作を開始し、また、７速確定操作によって５速への変速を行うとともに、その変速の終了に続いて事前に主変速（２―４）を切替える。 In addition, as shown in the timing chart of the shifting operation example 3 in FIG. 13, when the main transmission lever 22 is operated to the position 7 while traveling forward at the position 2, the position 4 is changed depending on the shift position and the vehicle rolling condition. For an example in which 5 is an intermediate shift stage, a shifting operation to position 4 or higher starts a shift operation to 4th speed without completing shifting, and a shift to 5th speed is performed by 7th speed finalizing operation. And the main shift (2-4) is switched in advance following the end of the shift.

次に、変速時の伝動切替えのクラッチ油圧制御について説明する。
クラッチの油圧制御について、図１４に示すように、ポジション１から２への変速例（ａ）は、動力遮断の無い変速で、高低速変速機構１１のクラッチ切換えのみの場合であり、二重噛みしないように、また、油温が低い場合は被らないように制御する。このような変速パターンのポジション移行は、１→２、２→１、３→４、４→３、５→６、６→５、７→８、８→７が該当する。 Next, clutch hydraulic pressure control for transmission switching at the time of shifting will be described.
Regarding the hydraulic control of the clutch, as shown in FIG. 14, the shift example (a) from position 1 to 2 is a shift without power interruption and only the clutch switching of the high / low speed transmission mechanism 11, and double engagement. In addition, control is performed so as not to cover when the oil temperature is low. The shift pattern position shift corresponds to 1 → 2, 2 → 1, 3 → 4, 4 → 3, 5 → 6, 6 → 5, 7 → 8, and 8 → 7.

また、ポジション１から５への変速例（ｂ）は、一気に変速すると動力遮断する変速（使わない）で、主変速機構１２のみ切換の場合である。このような変速パターンのポジション移行は、１→５、５→１、２→６、６→２、３→７、７→３、４→８、８→４が該当する。 Further, the example of shifting from position 1 to 5 (b) is a shifting (not used) in which the power is cut off when shifting at a stroke, and only the main transmission mechanism 12 is switched. Such shift of the shift pattern position corresponds to 1 → 5, 5 → 1, 2 → 6, 6 → 2, 3 → 7, 7 → 3, 4 → 8, and 8 → 4.

また、ポジション２から３への変速例（ｃ）は、動力遮断の無い変速で、高低速変速機構１１のクラッチ切換えと主変速機構１２，１２の系統切換えの場合であり、油温が低い場合は被らないように制御する。このような変速パターンのポジション移行は、１→４，７，８、２→３，４，７，８、３→１，２，５，６、４→１，２，５，６、５→３，４，７，８、６→３，４，７，８、７→１，２，５，６、８→１，２，５，６が該当する。 Further, the shift example (c) from position 2 to 3 is a shift without power interruption, in the case of clutch switching of the high / low speed transmission mechanism 11 and system switching of the main transmission mechanisms 12 and 12, where the oil temperature is low. Is controlled so as not to wear. The shift of the shift pattern position is 1 → 4, 7, 8, 2 → 3,4, 7, 8, 3 → 1, 2, 5, 6, 4 → 1, 2, 5, 6, 5 → 3, 4, 7, 8, 6 → 3, 4, 7, 8, 7 → 1, 2, 5, 6, 8 → 1, 2, 5, 6

また、ポジション１から６への変速例（ｄ）は、一気に変速すると動力遮断する変速（使わない）で、主変速機構１２と高低速変速機構１１のクラッチ切換の場合である。このような変速、パターンのポジション移行は、１→６、２→５、３→８、４→７、６→１、５→２、８→３、７→４が該当する。この場合において、同一主変速機構１２を変速する際は、中立保持後、１００ミリ秒程度待ち時間を確保する。 In addition, the shift example (d) from position 1 to position 6 is a shift (not used) in which the power is cut off when the shift is performed at once, and is a case where the main transmission mechanism 12 and the high / low speed transmission mechanism 11 are switched. Such shifts and shifts in pattern position correspond to 1 → 6, 2 → 5, 3 → 8, 4 → 7, 6 → 1, 5 → 2, 8 → 3, 7 → 4. In this case, when shifting the same main transmission mechanism 12, a waiting time of about 100 milliseconds is secured after the neutral holding.

また、ポジション４から５への変速例（ｅ）は、動力遮断の無い変速で、変速する際にシンクロ式の主変速部を切換える必要がある変速の場合で、高低速変速機構１１のクラッチピストンイニシャル時間（ミート時間）が主変速切換時間より短い場合は、その時間の経過時を変速先の入りタイミングとする。すなわち、主変速切換に十分時間をとってから高低切替え変速を行う。
（動作確認）
次に、変速機器の動作確認制御について説明する。 An example of shifting from position 4 to position (e) is a shift without power interruption, and is a shift that requires switching of the synchro-type main transmission when shifting, and the clutch piston of the high / low speed transmission mechanism 11 When the initial time (meet time) is shorter than the main shift switching time, the passage of the time is set as the shift destination entering timing. In other words, the high / low switching shift is performed after a sufficient time has elapsed for the main shift switching.
(Operation check)
Next, the operation confirmation control of the transmission device will be described.

変速機器の動作確認のための制御として、副変速機構１４が中立状態にあるときは、その上流側の高低速変速機構１１、主変速機構１２、および前後進切替機構１３からなる変速伝動系を変速操作と連動した変速挙動をするように制御することにより、メンテナンスにおける機器動作チェック等において、クラッチ式やシンクロシフト式の各変速機構の挙動を、走行停止状態で確認することができる。 As a control for confirming the operation of the transmission device, when the sub-transmission mechanism 14 is in a neutral state, a transmission system comprising a high / low-speed transmission mechanism 11, a main transmission mechanism 12, and a forward / reverse switching mechanism 13 on the upstream side is used. By performing control so as to have a shift behavior linked to the shift operation, it is possible to check the behavior of each clutch-type or synchro-shift type shift mechanism in the travel stop state in a device operation check or the like during maintenance.

また、クラッチ調整のためにクラッチのピストンを測定する調整モードを設け、各クラッチ出力軸より下流側に回転センサを設け、調整モードにより各クラッチを駆動した時の回転変化によってピストンストロークを測定するように構成することにより、変速時の動力遮断を少なくし、かつ、回転センサにより確実にミートポイントまでのストロークを検出することができる。 In addition, an adjustment mode for measuring the piston of the clutch is provided for clutch adjustment, a rotation sensor is provided downstream from each clutch output shaft, and the piston stroke is measured by a change in rotation when each clutch is driven in the adjustment mode. With this configuration, it is possible to reduce the power interruption at the time of shifting, and to reliably detect the stroke up to the meet point by the rotation sensor.

この場合において、作動油の油温Ｔが規定温度以上であることをピストンストロークの測定条件として牽制制御することにより、オイル粘性に応じた圧力損失による流量変化誤差を防止することができる。 In this case, the flow rate change error due to the pressure loss corresponding to the oil viscosity can be prevented by controlling the control that the oil temperature T of the hydraulic oil is equal to or higher than the specified temperature as the measurement condition of the piston stroke.

また、回転センサは、前後進切替機構１３の出力軸である前後進軸１３ｂより下流に設けた１個のセンサ１３ｒにより、各クラッチの駆動順位を変えながら検出することにより、各クラッチ室の圧力を個別に検出するセンサを要することなく、確実なミートポイントが検出できるとともに、低コスト化が可能となる。 The rotation sensor detects the pressure of each clutch chamber by changing the driving order of each clutch by one sensor 13r provided downstream of the forward / reverse shaft 13b, which is the output shaft of the forward / reverse switching mechanism 13. A reliable meet point can be detected and a cost reduction can be achieved without the need for a sensor for individually detecting the.

また、回転センサは、副変速機構１４のギヤ切換による回転数変化が発生しない部位に設置することにより、副変速機構１４を中立にして停車状態で調整作業が可能となることから、走行スペースがとれない狭い場所でも実施することができる。 In addition, the rotation sensor is installed in a portion where the rotation speed change due to the gear switching of the auxiliary transmission mechanism 14 does not occur, so that the auxiliary transmission mechanism 14 can be neutralized and adjustment work can be performed in a stopped state. It can be carried out even in a narrow place where it cannot be taken.

ピストンストロークの測定は、駆動バルブをほぼ最大流量になる開度で駆動してクラッチのピストンストローク相当の時間（クラッチピストンが初期位置からミートポイントまで規定の駆動方法で動く時間）を測定することにより安定した測定が可能となる。 Piston stroke is measured by driving the drive valve at an opening at which the maximum flow rate is reached, and measuring the time equivalent to the piston stroke of the clutch (the time during which the clutch piston moves from the initial position to the meet point using the specified drive method). Stable measurement is possible.

また、ピストンストローク相当の時間は、該当するクラッチ測定時の検出位置（回転センサ位置）での減速比回転数を測定中のエンジン回転数から演算し、この減速比回転数に対し、検出回転数が規定割合以上になったポイントまでの時間で求め、ピストンストローク基準時間として各クラッチ制御に使用するように構成する。このように、チェックモードで測定時、測定中のエンジン回転数と減速比で演算した回転数と比較して検出することにより、測定時のエンジン回転合わせをラフに行っても正しい検出ができる。 Also, the time corresponding to the piston stroke is calculated from the engine speed being measured at the detection position (rotation sensor position) at the time of measurement of the corresponding clutch from the engine speed being measured. Is determined by the time until the point at which the value becomes equal to or greater than the specified ratio, and is used for each clutch control as the piston stroke reference time. As described above, when the measurement is performed in the check mode, the detection is performed by comparing the engine rotation speed being measured with the rotation speed calculated by the reduction ratio, so that correct detection can be performed even when the engine rotation is roughly adjusted.

測定した高低速変速機構１１のピストンストローク基準データは、変速先のクラッチがミートする直前に変速元のクラッチをオフするタイミングを決めるデータとして変速先のピストンストローク基準データを元に演算使用し、測定ピストンストローク基準データに対し、若干少ない時間で変速元のクラッチをオフするように構成することにより、二重噛みを起こさないように駆動し、クラッチの耐久性を向上することができる。 The measured piston stroke reference data of the high / low speed transmission mechanism 11 is calculated and used based on the shift destination piston stroke reference data as data for determining the timing of turning off the shift source clutch immediately before the shift destination clutch meets. By configuring the transmission source clutch to be turned off in a little less time with respect to the piston stroke reference data, it is possible to drive so as not to cause double engagement and improve the durability of the clutch.

測定した前後進切替機構１３のピストンストローク基準データは、前後進操作やクラッチピストン操作で動力伝達開始する際の前進クラッチ或いは後進クラッチのクラッチミートまでの時間を素早く行うとともに、クラッチミート時の初期圧力を走行変速位置などの条件に応じて適正なものでコントロールするための比例制御弁での初期大電流（流量大）駆動時間として使用し、測定時ピストンストローク基準データに対し、バルブおよびバルブ駆動回路の応答遅れを考慮した若干短い時間で制御データに使用する。このように、ミート時初期圧力を安定的に出すため、バルブの応答性により駆動圧力が高めにならないように、少し短めのイニシャル時間として制御に使用することで、安定的なフィーリングの良いクラッチ制御が可能となる。 The measured piston stroke reference data of the forward / reverse switching mechanism 13 is used to quickly perform the time until the clutch meet of the forward clutch or the reverse clutch when the power transmission is started by the forward / reverse operation or the clutch piston operation, and the initial pressure at the clutch meet. Is used as the initial large current (large flow rate) drive time for the proportional control valve to control with the appropriate one according to the conditions such as the running shift position, and the valve and valve drive circuit against the piston stroke reference data during measurement It is used for the control data in a slightly short time considering the response delay. In this way, in order to stably output the initial pressure at the time of meeting, the clutch is used for control with a slightly shorter initial time so that the drive pressure does not increase due to the responsiveness of the valve. Control becomes possible.

また、主変速機構１２，１２（主１−３、主２−６）は、測定するクラッチの間に位置することから、調整モードでクラッチピストンストローク測定中に、少なくとも前後進切替機構１３のクラッチ測定中１回の測定が終了して暫くの間変速状態を保持しておくように制御処理を構成する。 Further, since the main transmission mechanisms 12, 12 (main 1-3, main 2-6) are located between the clutches to be measured, at least the clutch of the forward / reverse switching mechanism 13 during the clutch piston stroke measurement in the adjustment mode. The control process is configured so that the shift state is maintained for a while after one measurement is completed during the measurement.

例えば、前進クラッチ測定を終了し、後進クラッチ測定を実施する場合、クラッチケースが前後進一体で構成してあるため、測定後の回転停止が遅いと次の測定開始が遅くなり、ピストンストローク測定がトータルで長時間を要することになる。本案では、例えば、前進クラッチ測定後に同クラッチ出力をオフすることで主変速切替機構１２でブレーキを掛けてクラッチケースの回転を早めに停止させることができ、調整モードのトータル時間を短縮することができる。 For example, when the forward clutch measurement is completed and the reverse clutch measurement is performed, the clutch case is configured to be integrated forward and backward, so if the rotation stop after measurement is slow, the start of the next measurement is delayed and the piston stroke measurement is delayed. It will take a long time in total. In the present plan, for example, by turning off the clutch output after measuring the forward clutch, the brake can be braked by the main transmission switching mechanism 12 to stop the rotation of the clutch case early, and the total time of the adjustment mode can be shortened. it can.

測定の回数は個々のクラッチ毎に複数回行い、その全結果の中より基準データを決める構成とし、また、クラッチのピストンが初期ポジションに戻るのを待ってから駆動する必要があることから、同一クラッチを複数回継続して測定する場合は、調整モードに長時間を要することとなるので、その測定の順番は、同一クラッチの連続測定を避け、例えば、前進クラッチと後進クラッチを交互に行う等、少なくとも、異なるクラッチを挟んで順次行うように構成することで、トータル時間を短縮することができる。
（伝動開始操作）
伝動開始操作においては、クラッチペダル２１を踏込み操作している場合における主変速レバー２２の操作時は、前記同様に主変速レバー２２の操作途中或いは操作終了を判定できるように構成し、操作途中の場合は中間変速位置を通過した際に主変速切替機構１２のみを変速し、操作終了時は操作終了に基づき主変速切替機構１２のみ動作するように構成する。このように、主変速機構１２，１２の変速は主変速レバー２２の操作時と同様に必要なポジションに動かすように構成することにより、クラッチペダル２１を徐々に戻す操作を開始したときに、直ぐに応答することができる。 The measurement is performed multiple times for each clutch, and the reference data is determined from all the results. In addition, it is necessary to wait for the clutch piston to return to the initial position before driving, so it is the same. When measuring the clutch continuously several times, it takes a long time for the adjustment mode, so the order of measurement avoids continuous measurement of the same clutch, for example, alternately forward clutch and reverse clutch, etc. At least, the total time can be shortened by performing the sequential operation with different clutches interposed therebetween.
(Transmission start operation)
In the transmission start operation, when the main speed change lever 22 is operated when the clutch pedal 21 is depressed, it is possible to determine whether the operation of the main speed change lever 22 or the end of the operation can be determined as described above. In this case, only the main shift switching mechanism 12 is shifted when passing through the intermediate shift position, and only the main shift switching mechanism 12 is operated when the operation is completed. As described above, the main transmission mechanisms 12 and 12 are configured to move to the necessary positions in the same manner as when the main transmission lever 22 is operated, so that the operation of gradually returning the clutch pedal 21 is started immediately. Can respond.

その他の変速操作具により中立ポジションをとっている場合の主変速レバー２２の操作でも、上記クラッチペダル２１の踏込み時と同様に、主変速レバー２２の操作途中或いは操作終了を判定できるように構成し、操作途中の場合は中間変速位置を通過した際に主変速切替機構１２のみを変速し、操作終了時は操作終了に基づき主変速機構１２のみ動作するように構成することにより、前後進レバー２３等の変速操作開始時に応答性良く動かすことができる。 Even when the main speed change lever 22 is operated in the neutral position with other speed change operation tools, it is possible to determine whether or not the main speed change lever 22 is being operated or has ended, as in the case where the clutch pedal 21 is depressed. In the middle of the operation, only the main shift switching mechanism 12 is shifted when passing the intermediate shift position, and at the end of the operation, only the main transmission mechanism 12 is operated based on the end of the operation. It is possible to move with good responsiveness at the start of shifting operation such as.

１作業車両
２走行車輪
３走行車輪
４エンジン
４ａエンジン出力軸
５走行伝動機（走行伝動装置）
６作業動力供給部
１１高低速変速機構（クラッチ）
１１ａ共通入力軸
１２主変速機構
１３前後進切替機構（クラッチ）
１４副変速機構
１５ＰＴＯ変速伝動部
１５ａ作業入力軸
２１クラッチペダル
２２主変速レバー（変速指示具）
２３前後進レバー（正逆転切替具）
Ｃ変速制御部
Ｎ中立変速位置
Ｗ作業機
ｔ１ピストン移動時間
ｔ２ピストン移動時間
ｔ３レバー操作時間
ｔ４操作完了判定時間
ｔ５一定時間
ｔ６中立保持時間 DESCRIPTION OF SYMBOLS 1 Work vehicle 2 Traveling wheel 3 Traveling wheel 4 Engine 4a Engine output shaft 5 Traveling transmission (traveling transmission device)
6 Working power supply unit 11 High and low speed transmission mechanism (clutch)
11a Common input shaft 12 Main transmission mechanism 13 Forward / reverse switching mechanism (clutch)
14 Sub-transmission mechanism 15 PTO transmission transmission unit 15a Work input shaft 21 Clutch pedal 22 Main transmission lever (transmission indicator)
23 Forward / backward lever (forward / reverse selector)
C Shift control unit N Neutral shift position W Working machine t1 Piston movement time t2 Piston movement time t3 Lever operation time t4 Operation completion determination time t5 Constant time t6 Neutral holding time

Claims

A transmission transmission system that receives engine output and performs multi-stage transmission to the traveling wheels (2, 3), and a transmission control unit (C) that performs transmission control of the transmission transmission system according to an operation signal of the traveling operation tool, The transmission transmission system includes a high / low speed transmission mechanism (11) that transmits high and low speeds through a switching clutch, a main transmission mechanism (12) that transmits multiple speeds, and a forward / reverse switching mechanism (forward / reverse switching transmission using a switching clutch). 13), and as the travel operation tool, a travel transmission device for a work vehicle comprising a clutch pedal (21), a sequential shift instruction tool (22), and a forward / reverse switching tool (23).
When a shift operation is performed with a shift instruction change width of a plurality of stages or more by the shift instruction tool (22), the operation classification between the operation middle of the shift instruction tool (22) and the end of the operation is determined according to a predetermined reference. Determining, sequentially switching to the gear position of the intermediate shift position determined to be in the middle of operation, and switching to the gear position of the shift position determined to be the end of operation following completion of the switching,
The operation classification is determined by the operation speed of the shift instruction tool (22),
The shift indicator (22) is provided with a plurality of shift positions and neutral positions,
When the gear shift indicator (22) is operated to the gear position and the forward / reverse rotation switch (23) is operated to the neutral position to stop the vehicle, the main transmission mechanism (12) is operated to the gear shift indicator (22). When the transmission state corresponding to the position is set and the high / low speed transmission mechanism (11) and the forward / reverse switching mechanism (13) are made neutral, and then the forward / reverse switching tool (23) is operated to the forward rotation side or the reverse rotation side, While the transmission mechanism (12) is maintained in a transmission enabled state corresponding to the operation position of the transmission instruction tool (22), the high-low speed transmission mechanism (11) and the forward / reverse switching mechanism (13) are transmission controlled to start traveling. With configuration,
The high / low speed transmission mechanism (11) is configured in parallel in two systems to receive engine output together, and the main transmission mechanism (12) is configured in two systems to receive the output of the high / low speed transmission mechanism (11) for each system. At the same time, all the gears are configured with different gear ratios, the gears adjacent to each other in the gear ratio order are configured in another system, and the forward / reverse switching mechanism (13) common to the output sides of the two systems is arranged in series. Thus, a shift transmission system is configured, and a neutral shift position (N) is provided at the low speed end of the shift speed operation range of the shift indicator (22). When the neutral shift position (N) is set, the high and low speed shift mechanism ( 11) and the forward / reverse switching mechanism (13) are both cut off from transmission, and the transmission system of the work vehicle is characterized in that transmission control of the two systems of the main transmission mechanism (12) is performed to a predetermined gear stage.

Of the shift indicator (22) and the forward / reverse switching tool (23), which are transmission gear operating tools, when the shift indicator (22) is set to the neutral position, the high / low speed transmission mechanism (11) and the forward / reverse switching mechanism ( 13. The traveling transmission device for a work vehicle according to claim 1 , wherein both the transmission system 13) is neutrally controlled and the transmission of the two systems of the main transmission mechanism (12) is respectively controlled to the low speed side gear stage .