JP5492038B2

JP5492038B2 - Tractor transmission

Info

Publication number: JP5492038B2
Application number: JP2010205887A
Authority: JP
Inventors: 実平岡; 篤史林; 勝安藤; 真和日野
Original assignee: Kubota Corp
Current assignee: Kubota Corp
Priority date: 2010-09-14
Filing date: 2010-09-14
Publication date: 2014-05-14
Anticipated expiration: 2030-09-14
Also published as: JP2012062926A

Description

本発明は、エンジンからの駆動力を入力する静油圧式無段変速部と、前記静油圧式無段変速部が出力する駆動力とエンジンからの駆動力を合成して出力する遊星伝動部と、前記遊星伝動部の出力を走行装置に伝動する走行伝動部とを備えたトラクタの伝動装置に関する。 The present invention includes a hydrostatic continuously variable transmission unit that inputs driving force from an engine, and a planetary transmission unit that combines and outputs the driving force output from the hydrostatic continuously variable transmission unit and the driving force from the engine. The present invention also relates to a transmission device for a tractor including a traveling transmission unit that transmits an output of the planetary transmission unit to a traveling device.

上記したトラクタの伝動装置として、従来、たとえば特許文献１に記載されたものがあった。特許文献１に記載されたものでは、遊星伝動部からの出力を入力する変速出力部、及びこの変速出力部からの出力を入力する前後進切換え装置を備えて、走行伝動部が構成されている。
つまり、特許文献１に記載されたものでは、変速出力部は、１速クラッチ、２速クラッチ、３速クラッチ及び４速クラッチを備えて構成され、静油圧式無段変速部の変速制御に伴って１速クラッチ、２速クラッチ、３速クラッチ及び４速クラッチが適切に入り状態と切り状態に切換え制御されることにより、遊星伝動部からの出力が１速レンジから４速レンジの４段階の速度レンジに段階分けして、かつ各速度レンジにおいて無段階に変速して前後進切換え装置を介して走行装置に伝達される。そして、前後進切換え装置は、前進クラッチ及び後進クラッチを備えて構成され、前進クラッチが入り状態に切換え操作されることにより、変速出力部からの出力を前進側の駆動力に変換して走行装置に伝達し、後進クラッチが入り状態に切換え操作されることにより、変速出力部からの出力を後進側の駆動力に変換して走行装置に伝達する。 Conventionally, as a transmission device for the tractor described above, for example, there has been one described in Patent Document 1. In the one described in Patent Document 1, a traveling transmission unit is configured including a shift output unit that inputs an output from the planetary transmission unit and a forward / reverse switching device that inputs an output from the shift output unit. .
That is, in the one described in Patent Document 1, the shift output unit is configured to include a first speed clutch, a second speed clutch, a third speed clutch, and a fourth speed clutch, and accompanying the shift control of the hydrostatic continuously variable transmission unit. The 1st speed clutch, 2nd speed clutch, 3rd speed clutch and 4th speed clutch are appropriately switched between the on state and the disengaged state, so that the output from the planetary transmission unit is in 4 stages from the 1st speed range to the 4th speed range. The speed range is divided into stages, and the speed is steplessly changed in each speed range and transmitted to the traveling device via the forward / reverse switching device. The forward / reverse switching device includes a forward clutch and a reverse clutch. When the forward clutch is switched to an engaged state, the output from the speed change output unit is converted into a driving force on the forward side. When the reverse clutch is switched to the engaged state, the output from the shift output portion is converted into the reverse drive force and transmitted to the traveling device.

特開２００８−２５８０３号公報JP 2008-25803 A

上記した従来の技術を適用することにより、走行装置の前進駆動と後進駆動を可能にした場合、遊星伝動部からの出力が複数段の速度レンジに段階分けして走行装置に伝達されるように遊星伝動部からの出力を変速する変速処理部としての速度レンジ設定部を備える他に、走行装置に伝動される駆動力が前進用の駆動力になるように伝動作用する前進伝動状態と走行装置に伝動される駆動力が後進用の駆動力になるように伝動作用する後進伝動状態とに切換え操作自在な前後進切換え装置を備えねばならず、コスト高になっていた。 By applying the above-described conventional technology, when the traveling device can be driven forward and backward, the output from the planetary transmission unit is divided into a plurality of speed ranges and transmitted to the traveling device. In addition to having a speed range setting section as a speed change processing section for shifting the output from the planetary transmission section, the forward transmission state and the traveling apparatus are used for transmission so that the driving force transmitted to the traveling apparatus becomes the forward driving force. Therefore, it is necessary to provide a forward / reverse switching device which can be switched to a reverse transmission state for transmission so that the driving force transmitted to the reverse driving force becomes high, and the cost is high.

静油圧式無段変速部が逆回転方向の駆動力を出力する機能を、走行装置に後進用の駆動力を伝動する機能として使用するよう構成すれば、前後進切換え装置を備えずに、走行装置に後進用の駆動力を伝動することが可能になる。この場合、静油圧式無段変速部の伝動効率があまり良くないことから、動力ロスが大きくなりがちであった。 If the hydrostatic continuously variable transmission section is configured to use the function of outputting the driving force in the reverse rotation direction as a function of transmitting the driving force for the reverse travel to the traveling device, the traveling without the forward / reverse switching device is provided. It is possible to transmit a reverse driving force to the apparatus. In this case, the power loss tends to be large because the transmission efficiency of the hydrostatic continuously variable transmission is not very good.

本発明の目的は、走行装置に変速範囲が広い前進用の駆動力を変速途中での出力途切れが生じにくい状態で伝動することができながら、走行装置に後進用の駆動力を安価にかつ伝動効率が良い状態で伝動することができるとともに構造面でも有利に得られるトラクタの伝動装置を提供することにある。 It is an object of the present invention to transmit a forward drive force having a wide shift range to a traveling device in a state where output interruption during the shift is unlikely to occur and to transmit a reverse drive force to the travel device at low cost. It is an object of the present invention to provide a transmission device for a tractor that can be transmitted in a state of high efficiency and can be advantageously obtained in terms of structure.

本第１発明は、エンジンからの駆動力を入力する静油圧式無段変速部と、前記静油圧式無段変速部が出力する駆動力とエンジンからの駆動力を合成して出力する遊星伝動部と、前記遊星伝動部の出力を走行装置に伝動する走行伝動部とを備えたトラクタの伝動装置において、
前記遊星伝動部を、前記静油圧式無段変速部を構成するポンプ及びモータに対して伝動方向下手側に配置するとともに前記静油圧式無段変速部が正回転方向の駆動力を出力する正回転変速状態と逆回転方向の駆動力を出力する逆回転変速状態のいずれに変速された状態においても一定の回転方向の駆動力を出力するように構成し、
前記走行伝動部に、前記遊星伝動部が出力する一定の回転方向の駆動力を複数段の速度レンジに段階分けして出力する複数段の変速伝動状態と伝動を停止する中立状態とに変速操作自在な速度レンジ設定部、及び、前記遊星伝動部が出力する一定の回転方向の駆動力を後進用の駆動力に変換して出力する後進伝動状態と伝動を停止する中立状態とに切換え操作自在な後進伝動部を設け、
前記遊星伝動部を構成するサンギヤ、キャリヤ及びリングギヤに各別に連動されたサンギヤ連動の合成力出力軸、キャリヤ連動の合成力出力軸及びリングギヤ連動の合成力出力軸を、前記遊星伝動部から前記静油圧式無段変速部が位置する側とは反対側に向けて同一の軸芯まわりに相対回転自在に延出させ、
前記リングギヤ連動の合成力出力軸に一体回転自在に設けた１速入力ギヤと、その１速入力ギヤに噛み合う前進１速伝動ギヤと、前記サンギヤ連動の合成力出力軸に一体回転自在に設けた２速入力ギヤと、その２速入力ギヤに噛み合う前進２速伝動ギヤと、前記キャリヤ連動の合成力出力軸に一体回転自在に設けた３速入力ギヤと、その３速入力ギヤに噛み合う前進３速伝動ギヤと、前記前進１速伝動ギヤ、前記前進２速伝動ギヤ及び前記前進３速伝動ギヤの回転軸芯が一直線状に並ぶ状態で前記前進１速伝動ギヤ、前記前進２速伝動ギヤ及び前記前進３速伝動ギヤを相対回転自在に支持する出力軸と、前記前進１速伝動ギヤを前記出力軸に一体回転自在に連結する１速クラッチと、前記前進２速伝動ギヤを前記出力軸に一体回転自在に連結する２速クラッチと、前記前進３速伝動ギヤを前記出力軸に一体回転自在に連結する３速クラッチとを備えて、前記速度レンジ設定部を構成し、
前記リングギヤ連動の合成力出力軸に一体回転自在に設けた入力ギヤと、その入力ギヤに逆転ギヤを介して連動される後進伝動ギヤとを備え、前記後進伝動ギヤを、この後進伝動ギヤの回転軸芯が前記前進１速伝動ギヤ、前記前進２速伝動ギヤ及び前記前進３速伝動ギヤの回転軸芯と一直線状に並ぶ状態で前記出力軸に相対回転自在に支持させて、かつ前記後進伝動ギヤを前記出力軸に一体回転自在に連結する後進伝動クラッチを備えて、前記後進伝動部を構成してある。 According to the first aspect of the present invention, a hydrostatic continuously variable transmission unit that inputs driving force from an engine, and a planetary transmission that combines and outputs the driving force output from the hydrostatic continuously variable transmission unit and the driving force from the engine. A transmission device for a tractor including a traveling portion for transmitting the output of the planetary transmission portion to a traveling device,
The planetary transmission unit is disposed on the lower side in the transmission direction with respect to the pump and motor constituting the hydrostatic continuously variable transmission unit, and the hydrostatic continuously variable transmission unit outputs a driving force in the forward rotation direction. It is configured to output a driving force in a constant rotational direction in either the rotational speed changing state or the reverse rotational speed changing state in which the driving force in the reverse rotational direction is output.
A shift operation is performed on the traveling transmission unit between a multi-stage shift transmission state in which the driving force in the constant rotational direction output from the planetary transmission unit is output in stages into a plurality of speed ranges and a neutral state in which the transmission is stopped. Flexible speed range setting unit, and can be switched between a reverse transmission state in which the driving force in the constant rotation direction output from the planetary transmission unit is converted into a reverse driving force and a neutral state in which the transmission is stopped A reverse gearing,
A sun gear interlocking combined force output shaft, a carrier interlocking combined force output shaft, and a ring gear interlocking combined force output shaft that are individually linked to the sun gear, the carrier, and the ring gear constituting the planetary transmission unit are connected to the static transmission unit from the static transmission unit. Extending relative to the same axis about the side opposite to the side where the hydraulic continuously variable transmission is located,
A first-speed input gear provided integrally with the ring gear-linked synthetic force output shaft, a forward first-speed transmission gear meshing with the first-speed input gear, and a sun gear-linked synthetic force output shaft provided integrally rotatable. A two-speed input gear, a forward two-speed transmission gear meshing with the two-speed input gear, a three-speed input gear provided integrally with the combined force output shaft coupled with the carrier, and a forward three meshing with the three-speed input gear speed and transmission gear, the first forward speed transmission gear, the forward second speed transmission gear and the forward third speed transmission gear of the rotation axis is the forward first speed transmission gear in a state arranged in a straight line, the forward second speed transmission gear and an output shaft for supporting the forward third speed transmission gear relatively rotatably, a first speed clutch integrally rotatably connected to the forward first speed transmission gear to the output shaft, the second forward speed transmission gear to said output shaft Integrally rotatable That a second speed clutch, and a third speed clutch integrally rotatably connected to the forward third speed transmission gear to said output shaft, constitute the speed range setting unit,
An input gear provided integrally with the ring gear interlocking force output shaft and a reverse transmission gear linked to the input gear via a reverse gear, and the reverse transmission gear is rotated by the reverse transmission gear. The shaft is supported by the output shaft so as to be relatively rotatable in a state where the shaft is aligned with the rotation shafts of the forward first speed transmission gear, the forward second speed transmission gear, and the forward third speed transmission gear, and the reverse transmission. A reverse transmission clutch for connecting the gear to the output shaft so as to be integrally rotatable is provided, and the reverse transmission portion is configured.

本第１発明の構成によると、後進伝動クラッチが切り状態に切換え操作されると共に静油圧式無段変速部の変速制御に伴って１速クラッチ、２速クラッチ及び３速クラッチが入り状態と切り状態に適切に切換え制御されることにより、遊星伝動部によってエンジンからの駆動力と静油圧式無段変速部からの駆動力を合成して出力される一定の回転方向の駆動力が１速レンジから３速レンジの３段階の速度レンジに段階分けして、かつ各速度レンジにおいて無段階に変速した前進用の駆動力として出力軸から出力され、この１速レンジから３速レンジに亘ると共に各速度レンジにおいて無段階に変速する前進用の出力が走行装置に伝動される。後進伝動クラッチが入り状態に切換え操作されると共に静油圧式無段変速部の変速制御にかかわらず１速クラッチ、２速クラッチ及び３速クラッチが切り状態に維持されることにより、遊星伝動部によってエンジンからの駆動力と静油圧式無段変速部からの駆動力を合成して出力される一定の回転方向の駆動力が後進伝動クラッチによって後進用の駆動力に変換して出力軸から出力され、この後進用の駆動力が走行装置に伝達される。 According to the configuration of the first aspect of the invention, the reverse transmission clutch is switched to the disengaged state, and the first speed clutch, the second speed clutch, and the third speed clutch are engaged and disengaged along with the shift control of the hydrostatic continuously variable transmission. By appropriately switching to the state, the planetary transmission unit combines the driving force from the engine and the driving force from the hydrostatic continuously variable transmission unit so that a constant rotational driving force is output in the first speed range. Is output from the output shaft as a forward driving force that is steplessly shifted in each speed range and is shifted stepwise in each speed range. A forward output that is steplessly shifted in the speed range is transmitted to the traveling device. The reverse transmission clutch is switched to the engaged state, and the first speed clutch, the second speed clutch, and the third speed clutch are maintained in the disengaged state regardless of the shift control of the hydrostatic continuously variable transmission unit, thereby the planetary transmission unit The driving force in the constant rotational direction, which is output by combining the driving force from the engine and the driving force from the hydrostatic continuously variable transmission, is converted to the driving force for the reverse by the reverse transmission clutch and output from the output shaft. The reverse driving force is transmitted to the traveling device.

遊星伝動部を構成するサンギヤ、キャリヤ及びリングギヤに各別に連動されたサンギヤ連動の合成力出力軸、キャリヤ連動の合成力出力軸及びリングギヤ連動の合成力出力軸を、遊星伝動部から静油圧式無段変速部が位置する側とは反対側に向けて同一の軸芯まわりに相対回転自在に延出させ、リングギヤ連動の合成力出力軸とサンギヤ連動の合成力出力軸とキャリヤ連動の合成力出力軸に分散させて連動させた前進１速伝動ギヤ、前進２速伝動ギヤ及び前進３速伝動ギヤと、前進１速伝動ギヤ、前進２速伝動ギヤ及び前進３速伝動ギヤの回転軸芯が一直線状に並ぶ状態で前進１速伝動ギヤ、前進２速伝動ギヤ及び前進３速伝動ギヤを相対回転自在に支持する出力軸と、前進１速伝動ギヤを出力軸に一体回転自在に連結する１速クラッチと、前進２速伝動ギヤを出力軸に一体回転自在に連結する２速クラッチと、前進３速伝動ギヤを出力軸に一体回転自在に連結する３速クラッチとを備えて、速度レンジ設定部を構成してあるから、１速レンジと２速レンジが切り換わる点において、１速クラッチと２速クラッチが共に入り状態になる過程を経て１速クラッチ及び２速クラッチが入り状態と切り状態の一方から他方に切り換わるようにクラッチ切り換え制御を行なわせることができ、２速レンジと３速レンジが切り換わる点において、２速クラッチと３速クラッチが共に入り状態になる過程を経て２速クラッチ及び３速クラッチが入り状態と切り状態の一方から他方に切り換わるようにクラッチ切り換え制御を行なわせることができて、１速レンジと２速レンジが切り換わる点での変速も２速レンジと３速レンジが切り換わる点での変速も出力途切れが発生しない状態で行なわせられる。 The sun gear interlocking combined force output shaft, the carrier interlocking combined force output shaft, and the ring gear interlocking combined force output shaft individually linked to the sun gear, carrier and ring gear constituting the planetary transmission unit are connected to the planetary transmission unit from the hydrostatic type. The ring gear interlocking combined force output shaft, the sun gear interlocking combined force output shaft, and the carrier interlocking combined force output are extended so as to be relatively rotatable around the same shaft center toward the side opposite to the side where the step transmission is located. The shafts of the forward 1-speed transmission gear, the forward 2-speed transmission gear, and the forward 3-speed transmission gear that are dispersed and interlocked with the shaft are aligned with the rotational axis of the forward 1-speed transmission gear, the forward 2-speed transmission gear, and the forward 3-speed transmission gear. An output shaft that supports the forward 1-speed transmission gear, the forward 2-speed transmission gear, and the forward 3-speed transmission gear in a relatively rotatable manner, and a first speed that connects the forward 1-speed transmission gear to the output shaft so as to be integrally rotatable. Clutch, A speed range setting unit is configured with a two-speed clutch that connects the forward second-speed transmission gear to the output shaft so as to be integrally rotatable, and a three-speed clutch that integrally connects the forward third-speed transmission gear to the output shaft. Therefore, at the point where the 1st speed range and the 2nd speed range are switched, the 1st speed clutch and the 2nd speed clutch go through the process of entering and entering both, and the 1st speed clutch and the 2nd speed clutch are engaged and disengaged from one to the other. The clutch switching control can be performed so that the second speed range and the third speed range are switched, and the second speed clutch and the third speed clutch are changed through a process in which the second speed clutch and the third speed clutch are engaged together. The clutch switching control can be performed so that the clutch is switched from one of the engaged state and the disengaged state to the other, and the first speed range and the second speed range are switched. Speed is also brought in a state where shift is also interrupted output does not occur at the point of switching the second speed range and the third speed range.

本第１発明の構成によると、１速クラッチ、２速クラッチ、３速クラッチ及び後進伝動クラッチを、遊星伝動部に対して静油圧式無段変速部が位置する側とは反対側に同一の出力軸にまとめて支持させて配置することができ、各クラッチを切換え操作する操作機構を遊星伝動部に対して伝動方向下手側に位置する個所にまとめて配備することができる。 According to the configuration of the first invention, the first speed clutch, the second speed clutch, the third speed clutch, and the reverse transmission clutch are the same on the opposite side of the planetary transmission portion from the side where the hydrostatic continuously variable transmission portion is located. The output shaft can be collectively supported and arranged, and an operation mechanism for switching the clutches can be collectively arranged at a position located on the lower side in the transmission direction with respect to the planetary transmission unit.

従って、走行装置に前進用の駆動力を３段階の速度レンジに亘る広い変速範囲で無段変速して、かつ１速レンジと２速レンジが切り換わる変速時点においても２速レンジと３速レンジが切り換わる変速時点においても出力途切れがない状態で伝動して作業や走行箇所に適応した走行速度をスムーズに変速して現出させやすいものでありながら、静油圧式無段変速部に後進用の駆動力を現出される機能を備えさせずに後進伝動部を備えるだけで走行装置に後進用の駆動力を伝動することができて、後進走行を伝動効率が良い状態でかつ安価に行なわせることができる。さらに、各クラッチのための操作機構をコンパクトに組み込むことができて、この面からも安価に得ることができる。 Therefore, the forward driving force is continuously shifted to the traveling device over a wide speed range over the three speed ranges, and the second speed range and the third speed range are also changed at the time of shifting when the first speed range and the second speed range are switched. Even at the time of shifting, the output is not interrupted, and it is easy to make it appear smoothly by shifting the traveling speed adapted to the work and travel location. It is possible to transmit the reverse drive force to the traveling device simply by providing the reverse transmission unit without providing the function for displaying the drive force of the vehicle, and the reverse drive is performed with good transmission efficiency and at low cost. Can be made. Furthermore, the operation mechanism for each clutch can be incorporated in a compact manner, and this aspect can also be obtained at a low cost.

本第２発明は、前記サンギヤ連動の合成力出力軸に一体回転自在に設けた４速入力ギヤと、その４速入力ギヤに噛み合い前記出力軸に相対回転自在に支持された前進４速伝動ギヤと、この前進４速伝動ギヤを前記出力軸に一体回転自在に連結する４速クラッチを、前記速度レンジ設定部に備えてある。 The second aspect of the present invention is a four-speed input gear that is provided so as to rotate integrally with the sun gear-linked composite force output shaft, and a forward four-speed transmission gear that meshes with the four-speed input gear and is supported relatively rotatably on the output shaft. And a four-speed clutch for connecting the forward four-speed transmission gear to the output shaft so as to be integrally rotatable .

本第２発明の構成によると、静油圧式無段変速部の変速制御に伴う１速クラッチ、２速クラッチ及び３速クラッチの切換え制御に併せて、４速クラッチが適切に切換え制御されることにより、遊星伝動部によってエンジンからの駆動力と静油圧式無段変速部からの駆動力を合成して出力される一定の回転方向の駆動力が１速レンジから４速レンジの４段階の速度レンジに段階分けし、かつ各速度レンジにおいて無段階に変速した前進用の駆動力として出力軸から出力され、この１速レンジから４速レンジに亘ると共に各速度レンジにおいて無段階に変速する前進用の出力が走行装置に伝動される。 According to the configuration of the second aspect of the invention, in addition to the switching control of the first speed clutch, the second speed clutch, and the third speed clutch accompanying the shift control of the hydrostatic continuously variable transmission, the fourth speed clutch is appropriately switched and controlled. Thus, the driving force in the constant rotational direction outputted by combining the driving force from the engine and the driving force from the hydrostatic continuously variable transmission unit by the planetary transmission unit is a four-stage speed from the first speed range to the fourth speed range. The forward drive force is output from the output shaft as a forward drive force that is stepped in each range and steplessly shifted in each speed range. The forward drive speed is steplessly changed in each speed range from the first speed range to the fourth speed range. Is transmitted to the traveling device.

リングギヤ連動の合成力出力軸とサンギヤ連動の合成力出力軸とキャリヤ連動の合成力出力軸のうち、前進３速伝動ギヤが連動しない合成力出力軸に連動されるとともに出力軸に相対回転自在に支持される前進４速伝動ギヤ、及びこの前進４速伝動ギヤを出力軸に一体回転自在に連結する４速クラッチを、速度レンジ設定部に備えてあるから、３速クラッチと４速クラッチが共に入り状態になる過程を経て３速クラッチ及び４速クラッチが入り状態と切り状態の一方から他方に切り換わるようにクラッチ切り換え制御を行なわせることができて、３速レンジと４速レンジが切り換わる点での変速を出力途切れが発生しない状態で行なわせることができ、かつ、４速クラッチを切換え操作する操作機構を、１速から３速クラッチを切換え操作する操作機構と共に遊星伝動部に対して伝動方向下手側に位置する個所にまとめて配備することができる。 Of the combined output shaft of the ring gear, the combined force output shaft of the sun gear, and the combined force output shaft of the carrier, the forward three-speed transmission gear is linked to the uncoupled combined force output shaft and is relatively rotatable to the output shaft. Since the speed range setting section includes a supported forward 4-speed transmission gear and a 4-speed clutch that connects the forward 4-speed transmission gear to the output shaft so as to be integrally rotatable, both the 3-speed clutch and the 4-speed clutch are provided. Through the process of entering the engaged state, the clutch switching control can be performed so that the 3rd speed clutch and the 4th speed clutch are switched from one of the engaged state and the disengaged state to the other, and the 3rd speed range and the 4th speed range are switched. Shift operation at a point can be performed in a state where output interruption does not occur, and an operation mechanism that switches a 4-speed clutch is operated by switching a 1-speed to 3-speed clutch. Together with the operation mechanism may be deployed together in places located in the transmitting direction downstream side with respect to the planetary transmission section.

従って、走行装置に前進用の駆動力を４段階の速度レンジに亘る広い変速範囲で無段変速して、かつ１速レンジと２速レンジが切り換わる変速時点及び２速レンジと３速レンジが切り換わる変速時点の他に３速レンジと４速レンジが切り換わる変速時点においても出力途切れがない状態で伝動して作業や走行箇所に適応した走行速度をスムーズに変速して現出させやすい。４速クラッチの操作機構も１速クラッチから３速クラッチの操作機構と共にまとめてコンパクトに組み込むことができて安価に得ることができる。 Therefore, the driving force for forward travel is continuously variable over a wide speed range over a four-step speed range, and the shifting time point when the first speed range and the second speed range are switched, and the second speed range and the third speed range are determined. In addition to the shifting time point when the gears are switched, transmission is performed without interruption of the output at the shifting time point when the 3rd speed range and the 4th speed range are switched. The operation mechanism of the 4-speed clutch can be integrated together with the operation mechanism of the 1-speed clutch to the 3-speed clutch in a compact manner and can be obtained at low cost.

トラクタの全体を示す側面図である。It is a side view which shows the whole tractor. 伝動装置を示すスケルトン図である。It is a skeleton figure which shows a transmission device. 遊星伝動部を示す断面図である。It is sectional drawing which shows a planetary transmission part. 静油圧式無段変速部の変速状態と自走車の走行速度の関係を示す説明図である。It is explanatory drawing which shows the relationship between the shifting state of a hydrostatic continuously variable transmission part, and the traveling speed of a self-propelled vehicle. 後進伝動クラッチ、１速クラッチ、２速クラッチ、３速クラッチ及び４速クラッチの操作状態と自走車の走行方向及び速度レンジとの関係を示す説明図である。It is explanatory drawing which shows the relationship between the operating state of a reverse transmission clutch, a 1st speed clutch, a 2nd speed clutch, a 3rd speed clutch, and a 4th speed clutch, and the running direction and speed range of a self-propelled vehicle. 変速操作装置を示すブロック図である。It is a block diagram which shows a speed change operation apparatus.

以下、本発明の実施の形態を図面に基づいて説明する。
図１は、トラクタの全体を示す側面図である。この図に示すように、トラクタは、左右一対の操向操作及び駆動自在な前車輪１，１と左右一対の駆動自在な後車輪２，２によって自走する自走車と、この自走車の車体前部に設けたエンジン３が装備された原動部と、車体後部に設けた運転座席４が装備された搭乗型の運転部と、自走車の車体フレーム５の後部を構成するミッションケースに揺動昇降操作自在に取り付けた左右一対のリフトアーム６ａ，６ａを有したリンク機構６と、前記ミッションケースから車体後方向きに突出する動力取り出し軸７とを備えて構成してある。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a side view showing the entire tractor. As shown in this figure, the tractor is composed of a self-propelled vehicle that is self-propelled by a pair of left and right steering operations and front wheels 1, 1 that can be driven and a pair of left and right driveable rear wheels 2, 2. A transmission case equipped with an engine 3 provided at the front of the vehicle body, a riding-type driving unit equipped with a driver seat 4 provided at the rear of the vehicle, and a rear part of the body frame 5 of the self-propelled vehicle A link mechanism 6 having a pair of left and right lift arms 6a, 6a attached to be freely swingable up and down, and a power take-out shaft 7 protruding rearward from the transmission case toward the vehicle body.

このトラクタは、車体後部にリンク機構６を介して昇降操作自在にロータリ耕耘装置が連結され、かつエンジン３が出力する駆動力を動力取り出し軸７からロータリ耕耘装置に伝達するように構成されることによって乗用型耕耘機を構成するなど、車体後部に各種の作業装置が昇降操作及び駆動自在に連結されることにより、各種の乗用型作業機を構成する。 This tractor is configured so that a rotary tiller is connected to the rear part of the vehicle body via a link mechanism 6 so as to be movable up and down, and the driving force output from the engine 3 is transmitted from the power take-out shaft 7 to the rotary tiller. Various working devices are connected to the rear portion of the vehicle body so as to be movable up and down and can be driven, such as a riding type tiller.

図２は、エンジン３が出力する駆動力を走行装置としての左右一対の前車輪１，１及び左右一対の後車輪２，２と、動力取り出し軸７に伝動するように自走車に設けられた伝動装置Ｄを示すスケルトン図である。この図に示すように、伝動装置Ｄは、エンジン３の出力軸３ａからの駆動力を、エンジン３の後部に設けられた主クラッチ機構１０の出力軸１０ａから静油圧式無段変速部１１及び遊星伝動部３０に入力するとともにこの遊星伝動部３０から走行伝動部Ｓに伝動してこの走行伝動部Ｓから後輪差動機構１２及び前輪差動機構１３に伝動することによって左右一対の後車輪２，２及び左右一対の前車輪１，１に伝動する走行用の伝動装置部Ｄ１と、エンジン３の出力軸３ａからの駆動力を、主クラッチ機構１０の出力軸１０ａから回転伝動軸２５及び回転伝動軸１４ａを介して作業クラッチ１４に入力するとともにこの作業クラッチ１４から作業変速部１５に伝動してこの作業変速部１５から動力取り出し軸７に伝動する作業用の伝動装置部Ｄ２とを備えている。 FIG. 2 is provided in a self-propelled vehicle so that the driving force output from the engine 3 is transmitted to a pair of left and right front wheels 1 and 1 and a pair of left and right rear wheels 2 and 2 as a traveling device and a power take-out shaft 7. FIG. 6 is a skeleton diagram showing a transmission device D. As shown in this figure, the transmission device D transmits the driving force from the output shaft 3a of the engine 3 from the output shaft 10a of the main clutch mechanism 10 provided at the rear of the engine 3 to the hydrostatic continuously variable transmission unit 11 and A pair of left and right rear wheels are input to the planetary transmission unit 30 and transmitted from the planetary transmission unit 30 to the traveling transmission unit S and transmitted from the traveling transmission unit S to the rear wheel differential mechanism 12 and the front wheel differential mechanism 13. 2 and 2 and a pair of left and right front wheels 1 and 1 for driving transmission D1 and the driving force from the output shaft 3a of the engine 3 from the output shaft 10a of the main clutch mechanism 10 to the rotary transmission shaft 25 and A work transmission device D that is input to the work clutch 14 via the rotation transmission shaft 14 a and is transmitted from the work clutch 14 to the work transmission unit 15 and transmitted from the work transmission unit 15 to the power take-out shaft 7. It is equipped with a door.

作業変速部１５は、複数個のシフトギヤによって複数段の変速状態に変速可能であり、作業クラッチ１４から入力して変速した駆動力を出力軸１５ａから作業伝動軸１９を介して動力取り出し軸７に伝動する。 The work transmission unit 15 can be shifted to a plurality of shift states by a plurality of shift gears, and the drive force input and shifted from the work clutch 14 is transferred from the output shaft 15 a to the power take-out shaft 7 via the work transmission shaft 19. Be transmitted.

走行用の伝動装置部Ｄ１について説明する。
図２に示すように、走行用の伝動装置部Ｄ１は、主クラッチ機構１０の出力軸１０ａに入力ギヤ機構２０を介して入力軸１１ａが連動されている静油圧式無段変速部１１と、主クラッチ機構１０の出力軸１０ａに遊星連動機構２４を介して入力側リングギヤ３３ａが連動されている遊星伝動部３０と、遊星伝動部３０から速度レンジ設定部４０あるいは後進伝動部５０に入力するとともに速度レンジ設定部４０と後進伝動部５０のいずれに入力した場合も出力軸４０ａから後輪差動機構１２及び前輪差動機構１３に伝動する走行伝動部Ｓとを備えて構成してある。 The traveling transmission device D1 will be described.
As shown in FIG. 2, the traveling transmission device D1 includes a hydrostatic continuously variable transmission 11 having an input shaft 11a linked to an output shaft 10a of the main clutch mechanism 10 via an input gear mechanism 20, The planetary transmission unit 30 is connected to the output shaft 10a of the main clutch mechanism 10 via the planetary interlocking mechanism 24 via the planetary interlocking mechanism 24, and the planetary transmission unit 30 inputs the speed range setting unit 40 or the reverse transmission unit 50. When input to either the speed range setting unit 40 or the reverse transmission unit 50, the traveling transmission unit S is configured to transmit from the output shaft 40 a to the rear wheel differential mechanism 12 and the front wheel differential mechanism 13.

主クラッチ機構１０の出力軸１０ａと静油圧式無段変速部１１の入力軸１１ａを連動させる入力ギヤ機構２０は、主クラッチ機構１０の出力軸１０ａに一体回転自在に設けた出力軸ギヤ２１と、この出力軸ギヤ２１に噛合う状態で静油圧式無段変速部１１の入力軸１１ａに一体回転自在に設けた入力軸ギヤ２２とによって構成してある。 An input gear mechanism 20 that interlocks the output shaft 10a of the main clutch mechanism 10 and the input shaft 11a of the hydrostatic continuously variable transmission unit 11 includes an output shaft gear 21 that is rotatably provided integrally with the output shaft 10a of the main clutch mechanism 10. The input shaft gear 22 is provided so as to be integrally rotatable with the input shaft 11a of the hydrostatic continuously variable transmission 11 while being engaged with the output shaft gear 21.

主クラッチ機構１０の出力軸１０ａと遊星伝動部３０の入力側リングギヤ３３ａを連動させる遊星連動機構２４は、主クラッチ機構１０の出力軸１０ａに一体回転自在に形成された回転伝動軸２５と、この回転伝動軸２５に一体回転自在に設けた伝動ギヤ２６と、この伝動ギヤ２６に噛合う状態で入力側リングギヤ３３ａに一体回転自在に設けた入力ギヤ２７とによって構成してある。 The planetary interlocking mechanism 24 that interlocks the output shaft 10a of the main clutch mechanism 10 and the input side ring gear 33a of the planetary transmission unit 30 includes a rotation transmission shaft 25 that is integrally rotatable with the output shaft 10a of the main clutch mechanism 10, and The transmission gear 26 is provided so as to be rotatable integrally with the rotary transmission shaft 25, and the input gear 27 is provided so as to be rotatable integrally with the input side ring gear 33a in a state of meshing with the transmission gear 26.

静油圧式無段変速部１１は、入力軸１１ａをポンプ軸として備えた油圧式のポンプ１１Ｐ（以下、油圧ポンプ１１Ｐと呼称する。）と、この油圧ポンプ１１Ｐに駆動回路を介して接続された油圧式のモータ１１Ｍ（以下、油圧モータ１１Ｍと呼称する。）とを備えて構成してある。油圧ポンプ１１Ｐは、アキシャルプランジャ形で可変容量形の油圧ポンプによって構成し、油圧モータ１１Ｍは、アキシャルプランジャ形の油圧モータによって構成してある。 The hydrostatic continuously variable transmission unit 11 is connected to a hydraulic pump 11P (hereinafter referred to as a hydraulic pump 11P) having an input shaft 11a as a pump shaft, and the hydraulic pump 11P via a drive circuit. A hydraulic motor 11M (hereinafter referred to as a hydraulic motor 11M) is provided. The hydraulic pump 11P is constituted by an axial plunger type variable displacement type hydraulic pump, and the hydraulic motor 11M is constituted by an axial plunger type hydraulic motor.

従って、静油圧式無段変速部１１は、入力軸１１ａに遊星連動機構２０及び主クラッチ機構１０を介してエンジン３から入力した駆動力によって油圧ポンプ１１Ｐを駆動し、油圧ポンプ１１Ｐによって油圧を油圧モータ１１Ｍに供給して油圧モータ１１Ｍを駆動してモータ軸１１ｂから出力する。静油圧式無段変速部１１は、油圧ポンプ１１Ｐの斜板角の変更操作が行なわれることにより、正回転変速状態と中立状態と逆回転変速状態とに変速される。静油圧式無段変速部１１は、正回転変速状態に変速されると、正回転方向の駆動力をモータ軸１１ｂから出力し、中立状態に変速されると、モータ軸１１ｂからの出力を停止し、逆回転変速状態に変速されると、モータ軸１１ｂから逆回転方向の駆動力を出力する。静油圧式無段変速部１１は、正回転変速状態と逆回転変速状態のいずれに変速された場合においても、油圧ポンプ１１Ｐの斜板角の変更操作が行なわれることにより、モータ軸１１ｂからの出力速度を無段階に変速する。 Therefore, the hydrostatic continuously variable transmission unit 11 drives the hydraulic pump 11P by the driving force input from the engine 3 to the input shaft 11a via the planetary interlocking mechanism 20 and the main clutch mechanism 10, and the hydraulic pump 11P supplies the hydraulic pressure to the hydraulic pressure. The motor 11M is supplied to drive the hydraulic motor 11M to output from the motor shaft 11b. The hydrostatic continuously variable transmission unit 11 is shifted to a forward rotation state, a neutral state, and a reverse rotation state by changing the swash plate angle of the hydraulic pump 11P. The hydrostatic continuously variable transmission unit 11 outputs a driving force in the forward rotation direction from the motor shaft 11b when the gear is shifted to the forward rotation speed change state, and stops the output from the motor shaft 11b when the gear shift is performed in the neutral state. When the speed is changed to the reverse rotation speed change state, the driving force in the reverse rotation direction is output from the motor shaft 11b. The hydrostatic continuously variable transmission 11 is operated from the motor shaft 11b by changing the swash plate angle of the hydraulic pump 11P regardless of whether the transmission is in the forward rotation or reverse rotation. Change the output speed steplessly.

図３は、遊星伝動部３０を示す断面図である。図２，３に示すように、遊星伝動部３０は、静油圧式無段変速部１１を構成する油圧ポンプ１１Ｐ及び油圧モータ１１Ｍに対して伝動方向下手側に配置してある。遊星伝動部３０は、静油圧式無段変速部１１のモータ軸１１ｂに一体回転自在に連動された入力側サンギヤ３４ａ、及び主クラッチ機構１０の出力軸１０ａに遊星連動機構２４を介して連動された入力側リングギヤ３３ａを有した入力側遊星ギヤ機構３０Ａと、この入力側遊星ギヤ機構３０Ａに対して伝動方向下手側に位置した出力側遊星ギヤ機構３０Ｂとを備えて構成してある。入力側遊星ギヤ機構３０Ａの入力側遊星ギヤ３５ａを支持する入力側キャリヤ３６ａと、出力側遊星ギヤ機構３０Ｂの出力側遊星ギヤ３５ｂを支持する出力側キャリヤ３６ｂとは、一体のキャリヤ３６に構成されている。つまり、遊星伝動部３０は、入力側遊星ギヤ機構３０Ａと出力側遊星ギヤ機構３０Ｂの一対の遊動ギヤ機構、及び入力側遊星ギヤ機構３０Ａを構成する入力側遊星ギヤ３５ａと出力側遊星ギヤ機構３０Ｂを構成する出力側遊星ギヤ３５ｂを連動させるギヤ連動機構３７を備えて成る複合遊星ギヤ機構によって構成してある。ギヤ連動機構３７は、入力側遊星ギヤ３５ａに一体形成することによって入力側遊星ギヤ３５ａと一連かつ同外径の構造になったギヤ３７ａと、出力側遊星ギヤ３５ｂに一体形成することによって出力側遊星ギヤ３５ｂと一連かつ同外径の構造になったギヤ３７ｂとを噛み合い連動させることによって構成してある。なお、入力側遊星ギヤ３５ａとは別体に形成するとともに入力側遊星ギヤ３５ａに連結軸などによって一体回転自在に連結したギヤと、出力側遊星ギヤ３５ｂとは別体に形成するとともに出力側遊星ギヤ３５ｂに連結軸などによって一体回転自在に連結したギヤとを噛み合い連動させることによってギヤ連動機構３７を構成してもよい。 FIG. 3 is a cross-sectional view showing the planetary transmission unit 30. As shown in FIGS. 2 and 3, the planetary transmission unit 30 is disposed on the lower side in the transmission direction with respect to the hydraulic pump 11 </ b> P and the hydraulic motor 11 </ b> M constituting the hydrostatic continuously variable transmission unit 11. The planetary transmission unit 30 is linked via the planetary linkage mechanism 24 to the input-side sun gear 34a that is linked to the motor shaft 11b of the hydrostatic continuously variable transmission unit 11 so as to be integrally rotatable, and to the output shaft 10a of the main clutch mechanism 10. The input side planetary gear mechanism 30A having the input side ring gear 33a and the output side planetary gear mechanism 30B positioned on the lower side in the transmission direction with respect to the input side planetary gear mechanism 30A are provided. The input side carrier 36a that supports the input side planetary gear 35a of the input side planetary gear mechanism 30A and the output side carrier 36b that supports the output side planetary gear 35b of the output side planetary gear mechanism 30B are configured as an integral carrier 36. ing. That is, the planetary transmission unit 30 includes a pair of planetary gear mechanisms of the input planetary gear mechanism 30A and the output planetary gear mechanism 30B, and the input planetary gear 35a and the output planetary gear mechanism 30B constituting the input planetary gear mechanism 30A. Is constituted by a compound planetary gear mechanism comprising a gear interlocking mechanism 37 for interlocking the output side planetary gear 35b constituting the. The gear interlocking mechanism 37 is integrally formed with the input side planetary gear 35a by being integrally formed with the input side planetary gear 35a, and the output side planetary gear 35b is integrally formed with the output side planetary gear 35b. The planetary gear 35b and a gear 37b having a structure having the same outer diameter are meshed and interlocked with each other. The input side planetary gear 35a is formed separately from the input side planetary gear 35a and is integrally connected to the input side planetary gear 35a by a connecting shaft or the like, and the output side planetary gear 35b is formed separately from the output side planetary gear 35a. The gear interlocking mechanism 37 may be configured by meshing and interlocking with a gear 35b that is connected to the gear 35b by a connecting shaft or the like so as to be integrally rotatable.

遊星伝動部３０を構成する出力側遊星ギヤ機構３０Ａが位置する部位から静油圧式無段変速部１１が位置する側とは反対側に向けて３つの合成力出力軸３８ａ，３８ｂ，３８ｃを同一の軸芯まわりに相対回転するように三重軸構造に構成して延出してある。三重軸構造の３つの合成力出力軸３８ａ，３８ｂ，３８ｃのうちの最も内側に位置する合成力出力軸３８ｃは、キャリヤ３６に一体回転自在に連動されている。三重軸構造の３つの合成力出力軸３８ａ，３８ｂ，３８ｃのうちの中間に位置する合成力出力軸３８ｂは、出力側遊星ギヤ機構３０Ｂを構成する出力側サンギヤ３４ｂに一体回転自在に連動されている。三重軸構造の３つの合成力出力軸３８ａ，３８ｂ，３８ｃのうちの最も外側に位置する合成力出力軸３８ａは、出力側遊星ギヤ機構３０Ｂを構成する出力側リングギヤ３３ｂに一体回転自在に連動されている。 The three combined force output shafts 38a, 38b, and 38c are the same from the portion where the output side planetary gear mechanism 30A constituting the planetary transmission unit 30 is located to the side opposite to the side where the hydrostatic continuously variable transmission unit 11 is located. It is configured and extended in a triple-axis structure so as to relatively rotate around the axis of the shaft. Of the three combined force output shafts 38 a, 38 b, 38 c of the triple shaft structure, the combined force output shaft 38 c located on the innermost side is linked to the carrier 36 so as to be integrally rotatable. The combined force output shaft 38b located in the middle of the three combined force output shafts 38a, 38b, 38c of the triple shaft structure is linked to the output side sun gear 34b constituting the output side planetary gear mechanism 30B so as to be integrally rotatable. Yes. Out of the three combined force output shafts 38a, 38b, 38c of the triple shaft structure, the combined force output shaft 38a located on the outermost side is linked to the output side ring gear 33b constituting the output side planetary gear mechanism 30B so as to be integrally rotatable. ing.

遊星伝動部３０は、エンジン３が出力する駆動力を主クラッチ機構１０及び遊星連動機構２４を介して入力側リングギヤ３３ａに入力し、静油圧式無段変速部１１がモータ軸１１ｂから出力する駆動力を入力側サンギヤ３４ａに入力し、エンジン３から入力した駆動力と静油圧式無段変速部１１から入力した駆動力を入力側遊星機構３０Ａと出力側遊星機構３０Ｂによって合成し、合成した駆動力をキャリヤ連動の合成力出力軸３８ｃ、サンギヤ連動の合成力出力軸３８ｂ及びリングギヤ連動の合成力出力軸３８ａから出力する。遊星伝動部３０は、静油圧式無段変速部１１が正回転変速状態と逆回転変速状態のいずれに変速された状態においても、後進用の駆動力は合成せずに、前進用の駆動力（一定の回転方向の駆動力）のみを合成してキャリヤ連動の合成力出力軸３８ｃ、サンギヤ連動の合成力出力軸３８ｂ及びリングギヤ連動の合成力出力軸３８ａから出力する。 The planetary transmission unit 30 inputs the driving force output from the engine 3 to the input side ring gear 33a via the main clutch mechanism 10 and the planetary interlocking mechanism 24, and the hydrostatic continuously variable transmission unit 11 outputs from the motor shaft 11b. Force is input to the input-side sun gear 34a, and the driving force input from the engine 3 and the driving force input from the hydrostatic continuously variable transmission unit 11 are combined by the input-side planetary mechanism 30A and the output-side planetary mechanism 30B. The force is output from the combined force output shaft 38c linked to the carrier, the combined force output shaft 38b linked to the sun gear, and the combined force output shaft 38a linked to the ring gear. The planetary transmission unit 30 does not synthesize the reverse driving force and does not synthesize the forward driving force regardless of whether the hydrostatic continuously variable transmission unit 11 is shifted to either the forward rotational speed state or the reverse rotational speed state. Only (the driving force in a certain rotational direction) is combined and output from the combined force output shaft 38c linked to the carrier, the combined force output shaft 38b linked to the sun gear, and the combined force output shaft 38a linked to the ring gear.

走行伝動部Ｓを構成する速度レンジ設定部４０は、三重軸構造の３つの合成出力軸３８ａ，３８ｂ，３８ｃと平行に設けた出力軸４０ａ、及び、出力軸４０ａに伝動下手側が連動された１速レンジ設定部４０Ａと２速レンジ設定部４０Ｂと３速レンジ設定部４０Ｃと４速レンジ設定部４０Ｄを備えて構成してある。 The speed range setting unit 40 constituting the traveling transmission unit S includes an output shaft 40a provided in parallel with the three composite output shafts 38a, 38b, and 38c having a triple shaft structure, and a transmission lower side linked to the output shaft 40a. A speed range setting unit 40A, a second speed range setting unit 40B, a third speed range setting unit 40C, and a fourth speed range setting unit 40D are provided.

１速レンジ設定部４０Ａは、リングギヤ連動の合成力出力軸３８ａに一体回転自在に設けた１速入力ギヤ４１ａと、この１速入力ギヤ４１ａに噛み合うことによってリングギヤ連動の合成力出力軸３８ａに連動する状態にあり、この連動状態で出力軸４０ａに相対回転自在に支持される前進１速伝動ギヤ４１ｂと、この前進１速伝動ギヤ４１ｂと出力軸４０ａにわたって設けた多板式でかつ油圧操作式の摩擦クラッチで成る１速クラッチ４１ｃとを備えている。 The first speed range setting unit 40A is interlocked with the first gear input gear 41a provided integrally with the ring gear interlocking combined force output shaft 38a and the first gear input gear 41a so as to be interlocked with the combined force output shaft 38a associated with the ring gear. In this interlocking state, the forward first-speed transmission gear 41b that is rotatably supported by the output shaft 40a, and the multi-plate type and hydraulically operated type provided across the forward first-speed transmission gear 41b and the output shaft 40a. And a first speed clutch 41c formed of a friction clutch.

２速レンジ設定部４０Ｂは、３つの合成力出力軸３８ａ，３８ｂ，３８ｃのうちの１速入力ギヤ４１ａが連動しないサンギヤ連動の合成力出力軸３８ｂに一体回転自在に設けた２速入力ギヤ４２ａと、この２速入力ギヤ４２ａに噛み合うことによってサンギヤ連動の合成力出力軸３８ｂに連動する状態にあり、この連動状態で出力軸４０ａに相対回転自在に支持される前進２速伝動ギヤ４２ｂと、この前進２速伝動ギヤ４２ｂと出力軸４０ａにわたって設けた多板式でかつ油圧操作式の摩擦クラッチで成る２速クラッチ４２ｃとを備えている。 The two-speed range setting unit 40B is a two-speed input gear 42a that is provided so as to be integrally rotatable with a combined force output shaft 38b that is coupled to a sun gear that does not interlock with the first-speed input gear 41a of the three combined force output shafts 38a, 38b, and 38c. And a second forward transmission gear 42b that is supported by the output shaft 40a so as to be relatively rotatable in this interlocked state by being engaged with the sun gear interlocking synthetic force output shaft 38b by meshing with the second speed input gear 42a, The forward second-speed transmission gear 42b and a two-speed clutch 42c formed of a multi-plate and hydraulically operated friction clutch provided over the output shaft 40a are provided.

３速レンジ設定部４０Ｃは、３つの合成力出力軸３８ａ，３８ｂ，３８ｃのうちの２速入力ギヤ４２ａが連動しないキャリヤ連動の合成力出力軸３８ｃに一体回転自在に設けた３速入力ギヤ４３ａと、この３速入力ギヤ４３ａに噛み合うことによってキャリヤ連動の合成力出力軸３８ｃに連動する状態にあり、この連動状態で出力軸４０ａに相対回転自在に支持される前進３速伝動ギヤ４３ｂと、この前進３速伝動ギヤ４３ｂと出力軸４０ａにわたって設けた多板式でかつ油圧操作式の摩擦クラッチで成る３速クラッチ４３ｃとを備えている。 The three-speed range setting unit 40C is a three-speed input gear 43a provided so as to be integrally rotatable on a carrier-coupled synthetic force output shaft 38c that does not interlock with the two-speed input gear 42a of the three synthetic force output shafts 38a, 38b, 38c. A forward three-speed transmission gear 43b that is supported by the output shaft 40a so as to be relatively rotatable in this interlocked state. The forward third-speed transmission gear 43b and a three-speed clutch 43c formed of a multi-plate and hydraulically operated friction clutch provided over the output shaft 40a are provided.

４速レンジ設定部４０Ｄは、３つの合成力出力軸３８ａ，３８ｂ，３８ｃのうちの３速入力ギヤ４３ａが連動しないサンギヤ連動の合成力出力軸３８ｂに一体回転自在に設けた４速入力ギヤ４４ａと、この４速入力ギヤ４４ａに噛合うことによってサンギヤ連動の合成力出力軸３８ｃに連動する状態にあり、この連動状態で出力軸４０ａに相対回転自在に支持される前進４速伝動ギヤ４４ｂと、この前進４速伝動ギヤ４４ｂと出力軸４０ａにわたって設けた多板式で油圧操作式の摩擦クラッチで成る４速クラッチ４４ｃとを備えている。 The four-speed range setting unit 40D is a four-speed input gear 44a provided so as to be rotatable integrally with a sun gear-linked synthetic force output shaft 38b that is not linked to the three-speed input gear 43a of the three combined force output shafts 38a, 38b, 38c. And a forward four-speed transmission gear 44b that is supported by the output shaft 40a so as to be relatively rotatable in this interlocked state by engaging with the four-speed input gear 44a. The forward four-speed transmission gear 44b and the four-speed clutch 44c, which is a multi-plate hydraulically operated friction clutch provided over the output shaft 40a, are provided.

前進１速伝動ギヤ４１ｂと前進２速伝動ギヤ４２ｂと前進３速伝動ギヤ４３ｂと前進４速伝動ギヤ４４ｂは、出力軸４０ａの軸芯方向に並んで出力軸４０ａに相対回転自在に支持されており、前進１速伝動ギヤ４１ｂと前進２速伝動ギヤ４２ｂと前進３速伝動ギヤ４３ｂと前進４速伝動ギヤ４４ｂのそれぞれは、出力軸４０ａの軸芯を回転軸芯として回転し、前進１速伝動ギヤ４１ｂと前進２速伝動ギヤ４２ｂと前進３速伝動ギヤ４３ｂと前進４速伝動ギヤ４４ｂの回転軸芯が一直線状に並んでいる。出力軸４０ａは、出力軸４０ａの後端部に一体回転自在に設けた出力ギヤ４５と、この出力ギヤ４５に噛み合う状態で後輪差動機構１２の入力軸１２ａに一体回転自在に設けた伝動ギヤ４６とを介して後輪差動機構１２の入力軸１２ａに連動されている。出力軸４０ａは、出力ギヤ４５、伝動ギヤ４６、後輪差動機構１２の入力軸１２ａ、この入力軸１２ａに一体回転自在に設けた伝動ギヤ４８ａ、この伝動ギヤ４８ａに噛合う状態で前輪用出力軸４７に一体回転自在に設けた伝動ギヤ４８、前輪用出力軸４７、及び回転軸４９を介して前輪差動機構１３の入力軸１３ａに連動されている。 The forward 1-speed transmission gear 41b, the forward 2-speed transmission gear 42b, the forward 3-speed transmission gear 43b, and the forward 4-speed transmission gear 44b are lined up in the axial direction of the output shaft 40a and supported by the output shaft 40a so as to be relatively rotatable. The forward first-speed transmission gear 41b, the forward second-speed transmission gear 42b, the forward third-speed transmission gear 43b, and the forward fourth-speed transmission gear 44b rotate about the axis of the output shaft 40a as the rotation axis, respectively. The rotational axes of the transmission gear 41b, the forward second-speed transmission gear 42b, the forward third-speed transmission gear 43b, and the forward fourth-speed transmission gear 44b are aligned in a straight line. The output shaft 40a is provided with an output gear 45 provided at the rear end portion of the output shaft 40a so as to be integrally rotatable, and a transmission provided so as to be integrally rotatable with the input shaft 12a of the rear wheel differential mechanism 12 while being engaged with the output gear 45. It is linked to the input shaft 12 a of the rear wheel differential mechanism 12 via a gear 46. The output shaft 40a includes an output gear 45, a transmission gear 46, an input shaft 12a of the rear wheel differential mechanism 12, a transmission gear 48a provided so as to be rotatable integrally with the input shaft 12a, and a front wheel that is engaged with the transmission gear 48a. The output shaft 47 is linked to the input shaft 13 a of the front wheel differential mechanism 13 through a transmission gear 48 that is provided so as to be rotatable integrally with the output shaft 47, a front wheel output shaft 47, and a rotating shaft 49.

１速レンジ設定部４０Ａ及び２速レンジ設定部４０Ｂは、リングギヤ連動の合成力出力軸３８ａあるいはサンギヤ連動の合成力出力軸３８ｂの回転速度を１／２の速度に減速して出力軸４０ａに伝達するように構成してある。３速レンジ設定部４０Ｃ及び４速レンジ設定部４０Ｄは、キャリヤ連動の合成力出力軸３８ｃあるいはサンギヤ連動の合成力出力軸３８ｂの回転速度を２倍の速度に増速して出力軸４０ａに伝達するように構成してある。 The first-speed range setting unit 40A and the second-speed range setting unit 40B reduce the rotational speed of the ring gear-linked composite force output shaft 38a or the sun gear-linked combined force output shaft 38b to a half speed and transmit it to the output shaft 40a. It is comprised so that it may do. The 3rd speed range setting unit 40C and the 4th speed range setting unit 40D increase the rotational speed of the combined force output shaft 38c associated with the carrier or the combined force output shaft 38b associated with the sun gear to twice the speed and transmit it to the output shaft 40a. It is comprised so that it may do.

従って、速度レンジ設定部４０は、１速クラッチ４１ｃが入り状態に切換え制御され、２速クラッチ４２ｃと３速クラッチ４３ｃと４速クラッチ４４ｃが切り状態に切換え制御されることにより、遊星伝動部３０がリングギヤ連動の合成力出力軸３８ａから出力する前進用の駆動力（一定の回転方向の駆動力）を１速レンジ設定部４０Ａによって出力軸４０ａに伝達して出力軸４０ａの後端部から後輪差動機構１２及び前輪差動機構１３に向けて前進用の駆動力のままで出力するように１速レンジ設定状態になる。 Accordingly, the speed range setting unit 40 is controlled to switch the first-speed clutch 41c to the on state and the second-speed clutch 42c, the third-speed clutch 43c, and the fourth-speed clutch 44c are controlled to be switched off, so that the planetary transmission unit 30 after There the rear end portion of the forward driving force (constant rotation direction of the driving force) of the first speed range setting unit 40A by the output shaft 40a is transmitted to the output shaft 40a to output the synthesized power output shaft 38a of the ring gear interlocked The first speed range setting state is set so that the forward driving force is output to the wheel differential mechanism 12 and the front wheel differential mechanism 13 with the forward driving force.

速度レンジ設定部４０は、２速クラッチ４２ｃが入り状態に切換え制御され、１速クラッチ４１ｃと３速クラッチ４３ｃと４速クラッチ４４ｃが切り状態に切換え制御されることにより、遊星伝動部３０がサンギヤ連動の合成力出力軸３８ｂから出力する前進用の駆動力（一定の回転方向の駆動力）を２速レンジ設定部４０Ｂによって出力軸４０ａに伝達して出力軸４０ａの後端部から後輪差動機構１２及び前輪差動機構１３に向けて前進用の駆動力のままで出力するように２速レンジ設定状態になる。 The speed range setting unit 40 is controlled to switch the second speed clutch 42c to the engaged state, and the first speed clutch 41c, the third speed clutch 43c and the fourth speed clutch 44c are controlled to be switched to the disconnected state, so that the planetary transmission unit 30 The forward driving force ( driving force in a constant rotational direction) output from the interlocked combined force output shaft 38b is transmitted to the output shaft 40a by the second speed range setting unit 40B, and the rear wheel difference from the rear end of the output shaft 40a. The second speed range setting state is set so that the forward driving force remains output toward the moving mechanism 12 and the front wheel differential mechanism 13.

速度レンジ設定部４０は、３速クラッチ４３ｃが入り状態に切換え制御され、１速クラッチ４１ｃと２速クラッチ４２ｃと４速クラッチ４４ｃが切り状態に切換え制御されることにより、遊星伝動部３０がキャリヤ連動の合成力出力軸３８ｃから出力する前進用の駆動力（一定の回転方向の駆動力）を３速レンジ設定部４０Ｃによって出力軸４０ａに伝達して出力軸４０ａの後端部から後輪差動機構１２及び前輪差動機構１３に向けて前進用の駆動力のままで出力するように３速レンジ設定状態になる。 The speed range setting unit 40 is controlled to switch the third speed clutch 43c to the engaged state, and the first speed clutch 41c, the second speed clutch 42c and the fourth speed clutch 44c are controlled to be switched to the disengaged state, so that the planetary transmission unit 30 becomes the carrier. The forward driving force ( a driving force in a constant rotational direction) output from the interlocking combined force output shaft 38c is transmitted to the output shaft 40a by the third speed range setting unit 40C, and the rear wheel difference from the rear end portion of the output shaft 40a. A three-speed range setting state is set so that the forward drive force remains output toward the moving mechanism 12 and the front wheel differential mechanism 13.

速度レンジ設定部４０は、４速クラッチ４４ｃが入り状態に切換え制御され、１速クラッチ４１ｃと２速クラッチ４２ｃと３速クラッチ４３ｃが切り状態に切換え制御されることにより、遊星伝動部３０がサンギヤ連動の合成力出力軸３８ｂから出力する前進用の駆動力を４速レンジ設定部４０Ｄによって出力軸４０ａに伝達して出力軸４０ａの後端部から後輪差動機構１２及び前輪差動機構１３に向けて前進用の駆動力のままで出力するように４速レンジ設定状態になる。 The speed range setting unit 40 is controlled to switch the 4-speed clutch 44c to the engaged state, and the first-speed clutch 41c, the 2-speed clutch 42c, and the 3-speed clutch 43c are controlled to be switched to the disengaged state. The forward driving force output from the interlocking combined force output shaft 38b is transmitted to the output shaft 40a by the 4-speed range setting unit 40D, and the rear wheel differential mechanism 12 and the front wheel differential mechanism 13 are transmitted from the rear end of the output shaft 40a. The 4th speed range is set so that the forward driving force is output as it is.

速度レンジ設定部４０は、１速クラッチ４１ｃと２速クラッチ４２ｃと３速クラッチ４３ｃと４速クラッチ４４ｃが切り状態に切換え制御されることにより、出力軸４０ａに対する伝動を停止するよう中立状態になる。 The speed range setting unit 40 is in a neutral state to stop transmission to the output shaft 40a when the first speed clutch 41c, the second speed clutch 42c, the third speed clutch 43c, and the fourth speed clutch 44c are controlled to be switched off. .

走行伝動部Ｓを構成する後進伝動部５０は、リングギヤ連動の合成力出力軸３８ａに一体回転自在に設けた入力ギヤ５１と、この入力ギヤ５１に噛合う逆転ギヤ５２と、この逆転ギヤ５２に噛合うことによって逆転ギヤ５２を介してリングギヤ連動の合成力出力軸３８ａに連動する状態にあり、この連動状態で出力軸４０ａに相対回転自在に支持される後進伝動ギヤ５３と、この後進伝動ギヤ５３と出力軸４０ａにわたって設けた多板式で油圧操作式の摩擦クラッチで成る後進伝動クラッチ５４を備えて構成してある。 The reverse transmission unit 50 that constitutes the traveling transmission unit S includes an input gear 51 that is provided so as to be rotatable integrally with the ring gear-linked composite force output shaft 38 a, a reverse gear 52 that meshes with the input gear 51, and the reverse gear 52. By meshing, the reverse transmission gear 52 is linked to the ring gear-linked synthetic force output shaft 38a, and in this linked state, the reverse transmission gear 53 is rotatably supported on the output shaft 40a, and the reverse transmission gear. 53 and a reverse transmission clutch 54 which is a multi-plate hydraulically operated friction clutch provided over the output shaft 40a.

後進伝動部５０は、後進伝動クラッチ５４が入り状態に切換え操作されることにより、遊星伝動部３０がリングギヤ連動の合成力出力軸３８ａから出力する前進用の駆動力（一定の回転方向の駆動力）を後進用の駆動力に変換して出力軸４０ａに伝達して出力軸４０ａから後輪差動機構１２及び前輪差動機構１３に向けて出力するよう伝動状態になる。
When the reverse transmission clutch 54 is switched to the engaged state, the reverse transmission unit 50 is driven forward by the planetary transmission unit 30 from the ring gear-linked composite force output shaft 38a ( a driving force in a constant rotational direction). ) Is converted into a reverse driving force, transmitted to the output shaft 40a, and transmitted to the rear wheel differential mechanism 12 and the front wheel differential mechanism 13 from the output shaft 40a.

後進伝動部５０は、後進伝動クラッチ５４が切り状態に切換え操作されることにより、出力軸４０ａに対する伝動を停止するよう中立状態になる。 The reverse transmission unit 50 is in a neutral state to stop transmission to the output shaft 40a when the reverse transmission clutch 54 is switched to the disengaged state.

図４は、エンジン３が一定速度の駆動力を出力するようにアクセルセットされた状態における静油圧式無段変速部１１の変速状態と自走車の走行速度（車速）の関係を示す説明図である。図４の横軸は、静油圧式無段変速部１１の変速状態を示し、横軸の「Ｎ」は、静油圧式無段変速部１１の中立位置を示し、横軸の「＋ｍａｘ」は、静油圧式無段変速部１１の正回転変速状態での最高速位置を示し、横軸の「−ｍａｘ」は、静油圧式無段変速部１１の逆回転変速状態での最高速位置を示す。図４の縦軸は、車速を示し、縦軸の「０」は、車速の零を示し、縦軸の「０」よりも上側の部分は前進車速を示し、縦軸の「０」よりも下側の部分は、後進車速を示す。 FIG. 4 is an explanatory diagram showing the relationship between the shifting state of the hydrostatic continuously variable transmission unit 11 and the traveling speed (vehicle speed) of the self-propelled vehicle when the engine 3 is accelerator-set so as to output a driving force at a constant speed. It is. The horizontal axis of FIG. 4 indicates the speed change state of the hydrostatic continuously variable transmission unit 11, the horizontal axis “N” indicates the neutral position of the hydrostatic continuously variable transmission unit 11, and the horizontal axis “+ max” indicates “+ max”. The maximum speed position of the hydrostatic continuously variable transmission unit 11 in the forward rotational speed change state is shown, and the horizontal axis “−max” indicates the maximum speed position of the hydrostatic continuously variable transmission unit 11 in the reverse rotational speed change state. Show. The vertical axis in FIG. 4 represents the vehicle speed, “0” on the vertical axis represents the vehicle speed zero, the portion above “0” on the vertical axis represents the forward vehicle speed, and the vertical axis represents “0”. The lower part shows the reverse vehicle speed.

図４に示す実線Ｆ１は、自走車を前進走行させる場合の１速レンジにおける車速変化を示し、図４に示す実線Ｆ２は、自走車を前進走行させる場合の２速レンジにおける車速変化を示し、図４に示す実線Ｆ３は、自走車を前進走行させる場合の３速レンジにおける車速変化を示し、図４に示す実線Ｆ４は、自走車を前進走行させる場合の４速レンジにおける車速変化を示す。図４に示す実線Ｒは、自走車を後進走行させる場合の後進レンジにおける車速変化を示す。 A solid line F1 shown in FIG. 4 indicates a change in the vehicle speed in the first speed range when the self-propelled vehicle travels forward, and a solid line F2 shown in FIG. 4 indicates a vehicle speed change in the second speed range when the self-propelled vehicle travels forward. A solid line F3 shown in FIG. 4 indicates a change in the vehicle speed in the third speed range when the self-propelled vehicle travels forward, and a solid line F4 shown in FIG. 4 indicates the vehicle speed in the fourth speed range when the self-propelled vehicle travels forward. Showing change. A solid line R shown in FIG. 4 indicates a change in vehicle speed in the reverse range when the self-propelled vehicle travels backward.

図５は、後進伝動クラッチ５４、１速クラッチ４１ｃ、２速クラッチ４２ｃ、３速クラッチ４３ｃ及び４速クラッチ４４ｃの操作状態と自走車の走行方向及び速度レンジとの関係を示す説明図である。図５に示す「入」は、後進伝動クラッチ５４、１速クラッチ４１ｃ、２速クラッチ４２ｃ、３速クラッチ４３ｃ、４速クラッチ４４ｃの入り状態を示し、図５に示す「切り」は、後進伝動クラッチ５４、１速クラッチ４１ｃ、２速クラッチ４２ｃ、３速クラッチ４３ｃ、４速クラッチ４４ｃの切り状態を示す。 FIG. 5 is an explanatory diagram showing the relationship between the operating state of the reverse transmission clutch 54, the first speed clutch 41c, the second speed clutch 42c, the third speed clutch 43c and the fourth speed clutch 44c and the traveling direction and speed range of the own vehicle. . “ON” shown in FIG. 5 indicates the engaged state of the reverse transmission clutch 54, the first speed clutch 41c, the second speed clutch 42c, the third speed clutch 43c, and the fourth speed clutch 44c, and “OFF” shown in FIG. 5 indicates the reverse transmission. The disengagement state of the clutch 54, the first speed clutch 41c, the second speed clutch 42c, the third speed clutch 43c, and the fourth speed clutch 44c is shown.

図４，５に示すように、後進伝動クラッチ５４が切り状態「切」に操作されると、１速クラッチ４１ｃ、２速クラッチ４２ｃ、３速クラッチ４３ｃ及び４速クラッチ４３ｃの切換え制御が行なわれる。後進伝動クラッチ５４が切り状態「切」に操作された状態において、１速クラッチ４１ｃが入り状態「入」に切換え制御され、２速クラッチ４２ｃ、３速クラッチ４３ｃ及び４速クラッチ４４ｃが切り状態「切」に切換え制御され、１速クラッチ４１ｃが入り状態「入」に維持され、かつ２速クラッチ４２ｃと３速クラッチ４３ｃと４速クラッチ４４ｃが切り状態「切」に維持されたままで、静油圧式無段変速部１１が逆回転変速状態の最高速位置「−ｍａｘ」から正回転変速状態の最高速位置「＋ｍａｘ」に向けて変速制御されることにより、前進車速が零「０」から１速レンジ（Ｆ１）で無段階に増速していく。静油圧式無段変速部１１が正回転変速状態の最高速位置「＋ｍａｘ」に至ると、前進車速が「ｆ１」になる。 As shown in FIGS. 4 and 5, when the reverse transmission clutch 54 is operated to the disengaged state “disengaged”, switching control of the first speed clutch 41c, the second speed clutch 42c, the third speed clutch 43c and the fourth speed clutch 43c is performed. . In a state where the reverse transmission clutch 54 is operated to the disengaged state “disengaged”, the first speed clutch 41c is controlled to be switched to the engaged state “on”, and the second speed clutch 42c, the third speed clutch 43c and the fourth speed clutch 44c are disengaged. The first-speed clutch 41c is maintained in the engaged state “on”, and the second-speed clutch 42c, the third-speed clutch 43c, and the fourth-speed clutch 44c are maintained in the disconnected state “off”. The stepless speed change unit 11 is controlled to shift from the highest speed position “−max” in the reverse rotation speed change state to the highest speed position “+ max” in the forward rotation speed change state. The speed increases steplessly in the speed range (F1). When the hydrostatic continuously variable transmission 11 reaches the maximum speed position “+ max” in the forward rotation speed change state, the forward vehicle speed becomes “f1”.

静油圧式無段変速部１１が正回転変速状態の最高速位置「＋ｍａｘ」になると、１速レンジと２速レンジを切換える切換え点「Ｔ１」になる。切換え点「Ｔ１」になると同時に、１速クラッチ４１ｃが切り状態「切」に切換え制御されるとともに２速クラッチ４２ｃが入り状態「入」に切換え制御される。切換え点「Ｔ１」では、出力途切れが発生しないように１速クラッチ４１ｃ及び２速クラッチ４２ｃを共に入り状態「入」にする過程を経て、１速クラッチ４１ｃが切り状態「切」に切換え制御され、２速クラッチ４２ｃが入り状態「入」に切換え制御される。この後、２速クラッチ４２ｃが入り状態「入」に維持され、かつ１速クラッチ４１ｃ、３速クラッチ４３ｃ、４速クラッチ４４ｃが切り状態「切」に維持されたままで、静油圧式無段変速部１１が正回転変速状態の最高速位置「＋ｍａｘ」から逆回転変速状態の最高速位置「−ｍａｘ」に向けて変速制御されることにより、前進車速が「ｆ１」から２速レンジ（Ｆ２）で無段階に増速していく。静油圧式無段変速部１１が逆回転変速状態の最高速位置「−ｍａｘ」に至ると、前進車速が「ｆ２」になる。 When the hydrostatic continuously variable transmission unit 11 reaches the maximum speed position “+ max” in the forward rotation speed change state, a switching point “T1” for switching between the first speed range and the second speed range is obtained. At the same time as the switching point “T1” is reached, the first speed clutch 41c is controlled to be switched to the disconnected state “OFF” and the second speed clutch 42c is switched to the engaged state “ON”. At the switching point “T1”, the first-speed clutch 41c is controlled to be switched to the “off” state through the process of entering both the first-speed clutch 41c and the second-speed clutch 42c into the “on” state so that output interruption does not occur. The second speed clutch 42c is controlled to be switched to the engaged state “ON”. Thereafter, the second-speed clutch 42c is maintained in the engaged state “ON”, and the first-speed clutch 41c, the third-speed clutch 43c, and the fourth-speed clutch 44c are maintained in the disconnected state “OFF”. The speed of the forward vehicle is changed from “f1” to the second speed range (F2) when the portion 11 is shift-controlled from the highest speed position “+ max” in the forward rotation speed change state to the highest speed position “−max” in the reverse rotation speed change state. The speed will increase steplessly. When the hydrostatic continuously variable transmission 11 reaches the maximum speed position “−max” in the reverse rotation speed change state, the forward vehicle speed becomes “f2”.

静油圧式無段変速部１１が逆回転変速状態の最高速位置「−ｍａｘ」になると、２速レンジと３速レンジを切換える切換え点「Ｔ２」になる。切換え点「Ｔ２」になると同時に、２速クラッチ４２ｃが切り状態「切」に切換え制御されるとともに３速クラッチ４３ｃが入り状態「入」に切換え制御される。切換え点「Ｔ２」では、出力途切れが発生しないように２速クラッチ４２ｃ及び３速クラッチ４３ｃを共に入り状態「入」にする過程を経て、２速クラッチ４２ｃが切り状態「切」に切換え制御され、３速クラッチ４３ｃが入り状態「入」に切換え制御される。この後、３速クラッチ４３ｃが入り状態「入」に維持され、かつ１速クラッチ４１ｃ、２速クラッチ４２ｃ、４速クラッチ４３ｃが切り状態「切」に維持されたままで、静油圧式無段変速部１１が逆回転変速状態の最高速位置「−ｍａｘ」から正回転変速状態の最高速位置「＋ｍａｘ」に向けて変速制御されることにより、前進車速が「ｆ２」から３速レンジ（Ｆ３）で無段階に増速していく。静油圧式無段変速部１１が正回転変速状態の最高速位置「＋ｍａｘ」に至ると、前進車速が「ｆ３」になる。 When the hydrostatic continuously variable transmission unit 11 reaches the maximum speed position “−max” in the reverse rotation speed change state, the switching point “T2” for switching between the second speed range and the third speed range is reached. Simultaneously with the switching point “T2”, the second speed clutch 42c is controlled to be switched to the disconnected state “OFF”, and the third speed clutch 43c is switched to the engaged state “ON”. At the switching point “T2”, the second speed clutch 42c is controlled to be switched to the disconnected state “OFF” through the process of bringing the second speed clutch 42c and the third speed clutch 43c together into the “ON” state so that output interruption does not occur. The third speed clutch 43c is controlled to be switched to the engaged state “ON”. Thereafter, the hydrostatic continuously variable transmission is performed while the third speed clutch 43c is maintained in the engaged state "on" and the first speed clutch 41c, the second speed clutch 42c and the fourth speed clutch 43c are maintained in the disengaged state "off". The speed of the forward vehicle is changed from “f2” to the third speed range (F3) when the portion 11 is shift-controlled from the highest speed position “−max” in the reverse rotation speed change state to the highest speed position “+ max” in the forward rotation speed change state. The speed will increase steplessly. When the hydrostatic continuously variable transmission 11 reaches the maximum speed position “+ max” in the forward rotation speed change state, the forward vehicle speed becomes “f3”.

静油圧式無段変速部１１が正回転変速状態の最高速位置「＋ｍａｘ」になると、３速レンジと４速レンジを切換える切換え点「Ｔ３」になる。切換え点「Ｔ３」になると同時に、３速クラッチ４３ｃが切り状態「切」に切換え制御されるとともに４速クラッチ４４ｃが入り状態「入」に切換え制御される。切換え点「Ｔ３」では、出力途切れが発生しないように３速クラッチ４３ｃ及び４速クラッチ４４ｃを共に入り状態「入」にする過程を経て、３速クラッチ４３ｃが切り状態「切」に切換え制御され、４速クラッチ４４ｃが入り状態「入」に切換え制御される。この後、４速クラッチ４４ｃが入り状態「入」に維持され、かつ１速クラッチ４１ｃ、２速クラッチ４２ｃ、３速クラッチ４３ｃが切り状態「切」に維持されたままで、静油圧式無段変速部１１が正回転変速状態の最高速位置「＋ｍａｘ」から逆回転変速状態の最高速位置「−ｍａｘ」に向けて変速制御されることにより、前進車速が「ｆ３」から４速レンジ（Ｆ４）で無段階に増速していく。静油圧式無段変速部１１が逆回転変速状態の最高速位置「−ｍａｘ」に至ると、前進車速が最高車速の「ｆ４」になる。 When the hydrostatic continuously variable transmission unit 11 reaches the maximum speed position “+ max” in the forward rotation speed change state, a switching point “T3” for switching between the 3rd speed range and the 4th speed range is obtained. Simultaneously with the switching point “T3”, the third speed clutch 43c is controlled to be switched to the disconnected state “OFF” and the fourth speed clutch 44c is switched to the engaged state “ON”. At the switching point “T3”, the third speed clutch 43c is controlled to be switched to the disconnected state “OFF” through the process of entering the state “ON” together with the third speed clutch 43c and the fourth speed clutch 44c so that the output is not interrupted. The 4-speed clutch 44c is controlled to be switched to the engaged state “ON”. Thereafter, the hydrostatic continuously variable transmission is performed while the fourth speed clutch 44c is maintained in the engaged state "on" and the first speed clutch 41c, the second speed clutch 42c, and the third speed clutch 43c are maintained in the disengaged state "off". The speed of the forward vehicle is changed from “f3” to the fourth speed range (F4) by the gear 11 being controlled to shift from the highest speed position “+ max” in the forward rotation speed change state to the highest speed position “−max” in the reverse rotation speed change state. The speed will increase steplessly. When the hydrostatic continuously variable transmission 11 reaches the maximum speed position “−max” in the reverse rotation speed change state, the forward vehicle speed becomes “f4” which is the maximum vehicle speed.

図４，５に示すように、後進伝動クラッチ５４が入り状態「入」に操作されると、１速クラッチ４１ｃ、２速クラッチ４２ｃ、３速クラッチ４３ｃ及び４速クラッチ４４ｃが切り状態「切」に維持制御される。後進伝動クラッチ５４が入り状態「入」に操作された状態において、静油圧式無段変速部１１が逆回転変速状態の最高速位置「−ｍａｘ」から正回転変速状態の最高速位置「＋ｍａｘ」に向けて変速制御されることにより、後進車速が零「０」から後進レンジ（Ｒ）で無段階に増速していく。静油圧式無段変速部１１が正回転変速状態の最高速位置「＋ｍａｘ」に至ると、後進車速が最高車速の「ｒ」になる。 As shown in FIGS. 4 and 5, when the reverse transmission clutch 54 is operated to the engaged state “ON”, the first speed clutch 41c, the second speed clutch 42c, the third speed clutch 43c and the fourth speed clutch 44c are disconnected “OFF”. Is maintained and controlled. In a state where the reverse transmission clutch 54 is operated to the engaged state “on”, the hydrostatic continuously variable transmission 11 changes from the maximum speed position “−max” in the reverse rotation speed change state to the maximum speed position “+ max” in the forward rotation speed change state. As a result, the reverse vehicle speed is continuously increased from zero “0” in the reverse range (R). When the hydrostatic continuously variable transmission unit 11 reaches the maximum speed position “+ max” in the forward rotation speed change state, the reverse vehicle speed becomes the maximum vehicle speed “r”.

後進伝動部５０において合成力出力軸３８ａの回転を減速して出力軸４０ａに伝達する減速比を、１速レンジ設定部４０Ａにおいて合成力出力軸３８ａの回転を減速して出力軸４０ａに伝達する減速比よりも小に設定してあり、後進車速の最高車速「ｒ」は、前進の１速レンジにおける最高車速「ｆ１」よりも高速になる。 The reverse transmission unit 50 decelerates the rotation of the resultant force output shaft 38a and transmits it to the output shaft 40a. The first speed range setting unit 40A reduces the rotation of the resultant force output shaft 38a and transmits it to the output shaft 40a. The maximum vehicle speed “r” of the reverse vehicle speed is higher than the maximum vehicle speed “f1” in the forward first speed range.

図６は、走行用の伝動装置部Ｄ１を変速操作する変速操作装置７０を示すブロック図である。この図に示すように、変速操作装置７０は、静油圧式無段変速部１１に油圧ポンプ１１Ｐの斜板角変更を行なうように備えられた変速操作部７１、１速クラッチ４１ｃの切換え操作部（図示せず）、２速クラッチ４２ｃの切換え操作部（図示せず）、３速クラッチ４３ｃの切換え操作部（図示せず）、４速クラッチ４４ｃの切換え操作部（図示せず）、後進伝動クラッチ５４の切換え操作部（図示）のそれぞれに連係された制御装置７２と、変速レバー７３と、エンジン３の出力速度を検出するエンジン回転センサ７４と、前後進レバー７５とを備えている。 FIG. 6 is a block diagram showing a speed change operation device 70 that performs a speed change operation on the traveling transmission device D1. As shown in this figure, the speed change operating device 70 includes a speed change operation portion 71 and a speed change operation portion for the first speed clutch 41c provided to the hydrostatic continuously variable transmission portion 11 to change the swash plate angle of the hydraulic pump 11P. (Not shown) switching operation part (not shown) of the second speed clutch 42c, switching operation part (not shown) of the third speed clutch 43c, switching operation part (not shown) of the fourth speed clutch 44c, reverse transmission A control device 72, a transmission lever 73, an engine rotation sensor 74 that detects the output speed of the engine 3, and a forward / reverse lever 75 are provided that are linked to each of the switching operation portions (illustrated) of the clutch 54.

変速レバー７３は、変速レバー７３に連係された変速検出センサ７３ａを介して制御装置７２に連係されている。変速検出センサ７３ａは、変速レバー７３に回転操作部が連動された回転ポテンショメータによって構成してあり、変速レバー７３の操作位置を検出してこの検出結果を制御装置７２に出力する。 The shift lever 73 is linked to the control device 72 via a shift detection sensor 73 a linked to the shift lever 73. The shift detection sensor 73 a is configured by a rotary potentiometer in which a rotation operation unit is linked to the shift lever 73, detects the operation position of the shift lever 73, and outputs the detection result to the control device 72.

前後進レバー７５は、前後進レバー７５に連係された前後進検出センサ７５ａを介して制御装置７２に連係されている。前後進検出センサ７５ａは、前後進レバー７５に回転操作部が連動された回転ポテンショメータによって構成してあり、前後進レバー７５の操作位置を検出してこの検出結果を制御装置７２に出力する。 The forward / reverse lever 75 is linked to the control device 72 via a forward / backward detection sensor 75 a linked to the forward / reverse lever 75. The forward / reverse detection sensor 75 a is configured by a rotary potentiometer whose rotational operation unit is linked to the forward / reverse lever 75, detects the operation position of the forward / reverse lever 75, and outputs the detection result to the control device 72.

制御装置７２は、マイクロコンピュータを利用して構成してあり、主変速制御手段７７及び前後進切換え手段７８を備えている。 The control device 72 is configured using a microcomputer and includes a main transmission control means 77 and a forward / reverse switching means 78.

主変速制御手段７７は、エンジン回転センサ７４による検出情報を基にエンジン３がアクセルセットされた状態でのエンジン３の出力速度を検出し、変速検出センサ７３ａによる検出情報を基に変速レバー７３の操作位置を判断し、検出したエンジン３の出力速度と判断した変速レバー７３の操作位置と前後進検出センサ７５ａからの指令とを基に、変速レバー７３及び前後進レバー７５の操作位置に対応した所定の前進車速あるいは後進車速が現出されるように静油圧式無段変速部１１を自動的に変速制御し、かつ１速クラッチ４１ｃ、２速クラッチ４２ｃ、３速クラッチ４３ｃ及び４速クラッチ４４ｃを自動的に切換え制御する。 The main shift control means 77 detects the output speed of the engine 3 when the engine 3 is accelerator-set based on information detected by the engine rotation sensor 74, and based on the detection information detected by the shift detection sensor 73a. The operation position is determined, and the detected output speed of the engine 3 and the determined operation position of the shift lever 73 and the command from the forward / reverse detection sensor 75a correspond to the operation positions of the shift lever 73 and the forward / reverse lever 75. The hydrostatic continuously variable transmission portion 11 is automatically controlled so that a predetermined forward vehicle speed or reverse vehicle speed appears, and the first speed clutch 41c, the second speed clutch 42c, the third speed clutch 43c, and the fourth speed clutch 44c. Is automatically switched and controlled.

前後進切換え手段７８は、前後進レバー７５が前進位置「前」に操作されると、前後進検出センサ７５ａによる検出情報を基に後進伝動クラッチ５４を切り状態「切」に自動的に切換え操作し、前後進レバー７５が後進位置「後」に操作されると、前後進検出センサ７５ａによる検出情報を基に後進伝動クラッチ５４を入り状態「入」に自動的に切換え操作する。 When the forward / reverse lever 75 is operated to the forward position “forward”, the forward / reverse switching means 78 automatically switches the reverse transmission clutch 54 to the disconnected state “off” based on the detection information by the forward / reverse detection sensor 75a. When the forward / reverse lever 75 is operated to the reverse position “rear”, the reverse transmission clutch 54 is automatically switched to the engaged state “on” based on the information detected by the forward / reverse detection sensor 75a.

〔別実施例〕
（１）上記した実施例では、１速レンジＦ１と２速レンジＦ２の切換え、２速レンジＦ２と３速レンジＦ３の切換え、３速レンジＦ３と４速レンジＦ４の切換え、前進と後進の切換えを摩擦式クラッチの切換えによってよりスムーズにかつ機敏に行えるように、１速クラッチ４１ｃ、２速クラッチ４２ｃ、３速クラッチ４３ｃ、４速クラッチ４４ｃ及び後進伝動クラッチ５４を摩擦式のクラッチによって構成した例を示したが、噛み合い式のクラッチによって構成してもよい。また、これらのクラッチのうちのいずれか１つ以上を摩擦クラッチによって構成し、その他のクラッチを噛み合い式のクラッチによって構成してもよい。 [Another Example]
(1) In the above-described embodiment, switching between the first speed range F1 and the second speed range F2, switching between the second speed range F2 and the third speed range F3, switching between the third speed range F3 and the fourth speed range F4, switching between forward and reverse. The first-speed clutch 41c, the second-speed clutch 42c, the third-speed clutch 43c, the fourth-speed clutch 44c, and the reverse transmission clutch 54 are configured by friction-type clutches so that the friction-type clutch can be switched more smoothly and quickly. However, it may be constituted by a meshing clutch. Further, any one or more of these clutches may be constituted by friction clutches, and the other clutches may be constituted by meshing clutches.

（２）上記した実施例では、遊星伝動部３０を複合遊星ギヤ機構によって構成した例を示したが、多段にギヤ機構を並べた普通型の遊星ギヤ機構によって構成してもよい。 (2) In the above-described embodiment, an example in which the planetary transmission unit 30 is configured by a compound planetary gear mechanism has been described, but it may be configured by a normal planetary gear mechanism in which gear mechanisms are arranged in multiple stages.

（３）上記した実施例では、前車輪１及び後車輪２を走行装置として備えた例を示したが、車輪に替えてクローラ式走行装置を備えてもよい。 (3) In the above-described embodiment, an example in which the front wheels 1 and the rear wheels 2 are provided as travel devices has been described, but a crawler travel device may be provided instead of the wheels.

本発明は、車体後部に作業装置が連結されるトラクタに設けられる伝動装置の他、車体の前後輪間あるいは車体の前部に草刈装置などの作業装置が連結されるトラクタに設けられる伝動装置にも利用可能である。 The present invention relates to a transmission device provided in a tractor in which a working device such as a mowing device is connected between front and rear wheels of the vehicle body or a front portion of the vehicle body, in addition to a transmission device provided in a tractor in which a work device is connected to the rear portion of the vehicle body. Is also available.

１，２走行装置
３エンジン
１１静油圧式無段変速部
１１Ｐポンプ
１１Ｍモータ
３０遊星伝動部
３３ｂリングギヤ
３４ｂサンギヤ
３６キャリヤ
３８ａ、３８ｂ、３８ｃ合成力出力軸
４０速度レンジ設定部
４０ａ出力軸
４１ｂ前進１速伝動ギヤ
４１ｃ１速クラッチ
４２ｂ前進２速伝動ギヤ
４２ｃ２速クラッチ
４３ｂ前進３速伝動ギヤ
４３ｃ３速クラッチ
４４ｂ前進４速伝動機構
４４ｃ４速クラッチ
５０後進伝動部
５２逆転ギヤ
５３後進伝動ギヤ
５４後進伝動クラッチ
Ｓ走行伝動部 DESCRIPTION OF SYMBOLS 1, 2 Traveling apparatus 3 Engine 11 Hydrostatic continuously variable transmission part 11P Pump 11M Motor 30 Planetary transmission part 33b Ring gear 34b Sun gear 36 Carrier 38a, 38b, 38c Composite force output shaft 40 Speed range setting part 40a Output shaft 41b 1st forward speed Transmission gear 41c 1st speed clutch 42b Forward 2nd speed transmission gear 42c 2nd speed clutch 43b Forward 3rd speed transmission gear 43c 3rd speed clutch 44b Forward 4th speed transmission mechanism 44c 4th speed clutch 50 Reverse transmission part 52 Reverse gear 53 Reverse transmission gear 54 Reverse transmission Clutch S Driving transmission

Claims

エンジンからの駆動力を入力する静油圧式無段変速部と、前記静油圧式無段変速部が出力する駆動力とエンジンからの駆動力を合成して出力する遊星伝動部と、前記遊星伝動部の出力を走行装置に伝動する走行伝動部とを備えたトラクタの伝動装置であって、
前記遊星伝動部を、前記静油圧式無段変速部を構成するポンプ及びモータに対して伝動方向下手側に配置するとともに前記静油圧式無段変速部が正回転方向の駆動力を出力する正回転変速状態と逆回転方向の駆動力を出力する逆回転変速状態のいずれに変速された状態においても一定の回転方向の駆動力を出力するように構成し、
前記走行伝動部に、前記遊星伝動部が出力する一定の回転方向の駆動力を複数段の速度レンジに段階分けして出力する複数段の変速伝動状態と伝動を停止する中立状態とに変速操作自在な速度レンジ設定部、及び、前記遊星伝動部が出力する一定の回転方向の駆動力を後進用の駆動力に変換して出力する後進伝動状態と伝動を停止する中立状態とに切換え操作自在な後進伝動部を設け、
前記遊星伝動部を構成するサンギヤ、キャリヤ及びリングギヤに各別に連動されたサンギヤ連動の合成力出力軸、キャリヤ連動の合成力出力軸及びリングギヤ連動の合成力出力軸を、前記遊星伝動部から前記静油圧式無段変速部が位置する側とは反対側に向けて同一の軸芯まわりに相対回転自在に延出させ、
前記リングギヤ連動の合成力出力軸に一体回転自在に設けた１速入力ギヤと、その１速入力ギヤに噛み合う前進１速伝動ギヤと、前記サンギヤ連動の合成力出力軸に一体回転自在に設けた２速入力ギヤと、その２速入力ギヤに噛み合う前進２速伝動ギヤと、前記キャリヤ連動の合成力出力軸に一体回転自在に設けた３速入力ギヤと、その３速入力ギヤに噛み合う前進３速伝動ギヤと、前記前進１速伝動ギヤ、前記前進２速伝動ギヤ及び前記前進３速伝動ギヤの回転軸芯が一直線状に並ぶ状態で前記前進１速伝動ギヤ、前記前進２速伝動ギヤ及び前記前進３速伝動ギヤを相対回転自在に支持する出力軸と、前記前進１速伝動ギヤを前記出力軸に一体回転自在に連結する１速クラッチと、前記前進２速伝動ギヤを前記出力軸に一体回転自在に連結する２速クラッチと、前記前進３速伝動ギヤを前記出力軸に一体回転自在に連結する３速クラッチとを備えて、前記速度レンジ設定部を構成し、
前記リングギヤ連動の合成力出力軸に一体回転自在に設けた入力ギヤと、その入力ギヤに逆転ギヤを介して連動される後進伝動ギヤとを備え、前記後進伝動ギヤを、この後進伝動ギヤの回転軸芯が前記前進１速伝動ギヤ、前記前進２速伝動ギヤ及び前記前進３速伝動ギヤの回転軸芯と一直線状に並ぶ状態で前記出力軸に相対回転自在に支持させて、かつ前記後進伝動ギヤを前記出力軸に一体回転自在に連結する後進伝動クラッチを備えて、前記後進伝動部を構成してあるトラクタの伝動装置。 A hydrostatic continuously variable transmission unit that inputs driving force from the engine, a planetary transmission unit that combines and outputs the driving force output from the hydrostatic continuously variable transmission unit and the driving force from the engine, and the planetary transmission A tractor transmission device comprising a traveling transmission unit for transmitting the output of the unit to the traveling device,
The planetary transmission unit is disposed on the lower side in the transmission direction with respect to the pump and motor constituting the hydrostatic continuously variable transmission unit, and the hydrostatic continuously variable transmission unit outputs a driving force in the forward rotation direction. It is configured to output a driving force in a constant rotational direction in either the rotational speed changing state or the reverse rotational speed changing state in which the driving force in the reverse rotational direction is output.
A shift operation is performed on the traveling transmission unit between a multi-stage shift transmission state in which the driving force in the constant rotational direction output from the planetary transmission unit is output in stages into a plurality of speed ranges and a neutral state in which the transmission is stopped. Flexible speed range setting unit, and can be switched between a reverse transmission state in which the driving force in the constant rotation direction output from the planetary transmission unit is converted into a reverse driving force and a neutral state in which the transmission is stopped A reverse gearing,
A sun gear interlocking combined force output shaft, a carrier interlocking combined force output shaft, and a ring gear interlocking combined force output shaft that are individually linked to the sun gear, the carrier, and the ring gear constituting the planetary transmission unit are connected to the static transmission unit from the static transmission unit. Extending relative to the same axis about the side opposite to the side where the hydraulic continuously variable transmission is located,
A first-speed input gear provided integrally with the ring gear-linked synthetic force output shaft, a forward first-speed transmission gear meshing with the first-speed input gear, and a sun gear-linked synthetic force output shaft provided integrally rotatable. A two-speed input gear, a forward two-speed transmission gear meshing with the two-speed input gear, a three-speed input gear provided integrally with the combined force output shaft coupled with the carrier, and a forward three meshing with the three-speed input gear speed and transmission gear, the first forward speed transmission gear, the forward second speed transmission gear and the forward third speed transmission gear of the rotation axis is the forward first speed transmission gear in a state arranged in a straight line, the forward second speed transmission gear and an output shaft for supporting the forward third speed transmission gear relatively rotatably, a first speed clutch integrally rotatably connected to the forward first speed transmission gear to the output shaft, the second forward speed transmission gear to said output shaft Integrally rotatable That a second speed clutch, and a third speed clutch integrally rotatably connected to the forward third speed transmission gear to said output shaft, constitute the speed range setting unit,
An input gear provided integrally with the ring gear interlocking force output shaft and a reverse transmission gear linked to the input gear via a reverse gear, and the reverse transmission gear is rotated by the reverse transmission gear. The shaft is supported by the output shaft so as to be relatively rotatable in a state where the shaft is aligned with the rotation shafts of the forward first speed transmission gear, the forward second speed transmission gear, and the forward third speed transmission gear, and the reverse transmission. A transmission device for a tractor comprising a reverse transmission clutch for connecting a gear to the output shaft so as to be integrally rotatable, and constituting the reverse transmission portion.

前記サンギヤ連動の合成力出力軸に一体回転自在に設けた４速入力ギヤと、その４速入力ギヤに噛み合い前記出力軸に相対回転自在に支持された前進４速伝動ギヤと、この前進４速伝動ギヤを前記出力軸に一体回転自在に連結する４速クラッチを、前記速度レンジ設定部に備えてある請求項１記載のトラクタの伝動装置。 A four-speed input gear provided rotatably on the sun gear-linked composite force output shaft, a forward four-speed transmission gear meshed with the four-speed input gear and supported relative to the output shaft, and the forward fourth speed 2. The transmission device for a tractor according to claim 1 , wherein a four-speed clutch that connects a transmission gear to the output shaft so as to be integrally rotatable is provided in the speed range setting section.