JPH06469B2 - Four-wheel drive work vehicle - Google Patents
Four-wheel drive work vehicleInfo
- Publication number
- JPH06469B2 JPH06469B2 JP5819287A JP5819287A JPH06469B2 JP H06469 B2 JPH06469 B2 JP H06469B2 JP 5819287 A JP5819287 A JP 5819287A JP 5819287 A JP5819287 A JP 5819287A JP H06469 B2 JPH06469 B2 JP H06469B2
- Authority
- JP
- Japan
- Prior art keywords
- speed
- drive
- front wheel
- wheel
- transmission
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
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- Arrangement And Driving Of Transmission Devices (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、四輪駆動型作業車の前輪変速構造に関する。Description: TECHNICAL FIELD The present invention relates to a front wheel shift structure for a four-wheel drive work vehicle.
通常の四輪駆動型の作業車においては前輪と後輪の駆動
速度は略等しいものであるが、近年では前輪への動力を
変速する前輪変速装置を装備したものが農用トラクタに
現れてきており、この構成の一例が特開昭61-150830号
公報に開示されている。In a normal four-wheel drive type work vehicle, the driving speeds of the front wheels and the rear wheels are substantially equal, but in recent years, agricultural tractors have been equipped with front wheel transmissions that shift the power to the front wheels. An example of this structure is disclosed in JP-A-61-150830.
開示されている前輪変速装置は、後輪駆動速度と略等し
い駆動速度で伝動する標準駆動状態と、後輪駆動速度よ
り大きい駆動速度で伝動する増速駆動状態の2状態に切
換可能に構成されており、通常の直進時には標準駆動状
態で走行する。そして、旋回時に前輪変速装置を増速駆
動側に切換操作すると機体前部が旋回方向に積極的に引
張られて行き、軟弱な地面でも比較的容易に急旋回が行
えるのである。The disclosed front wheel transmission is configured to be switchable between two states: a standard drive state in which a drive speed is substantially equal to the rear wheel drive speed and a speed-up drive state in which a drive speed is higher than the rear wheel drive speed. Therefore, the vehicle runs in the standard drive state when the vehicle goes straight normally. When the front wheel transmission is switched to the speed-increasing drive side during turning, the front part of the machine body is positively pulled in the turning direction, and a sharp turn can be relatively easily performed even on soft ground.
農用トラクタで走行する作業地面の状況は畑地、乾田、
湿田、芝地、等のように多種多様なものであると共に、
作業中での旋回半径も一定ではない。しかしながら、前
述の構成では増速駆動状態における前輪の後輪に対する
変速比が一定のものである為、前輪の駆動速度と機体前
部の旋回速度がうまく適合せず、前輪で作業地面を荒し
てしまう場合があった。The condition of the working ground traveling on the agricultural tractor is
There are a wide variety of things like wetlands, turf, etc.,
The turning radius during work is also not constant. However, in the above-mentioned configuration, since the gear ratio of the front wheels to the rear wheels in the speed-up drive state is constant, the drive speed of the front wheels and the turning speed of the front part of the aircraft do not match well, and the front wheels roughen the work ground. There were times when it ended up.
ここで本発明は前述の問題に着目して、作業地面を特に
荒さずに急旋回が行えるように構成することを目的とし
ている。In view of the above-mentioned problems, the present invention has an object to provide a structure capable of making a sharp turn without particularly roughening the work ground.
本発明の特徴は先に述べたような四輪駆動型作業車にお
いて、後輪の駆動速度よりも大きい駆動速度に無段階に
増速する前輪変速装置を操向自在な前輪への伝動系に設
けると共に、左右後輪の各々の回転数を検出する回転数
検出センサーを設けて、前記回転数検出センサーからの
検出に基づき左右後輪の回転数差の増大に応じて前記前
輪変速装置を増速操作する制御装置を備えてあることに
あり、その作用及び効果は次のとおりである。A feature of the present invention is that in a four-wheel drive type work vehicle as described above, a front wheel transmission that continuously increases to a drive speed higher than the drive speed of the rear wheels is used as a transmission system for steerable front wheels. A rotation speed detection sensor for detecting the rotation speed of each of the left and right rear wheels is provided, and the front wheel transmission is increased according to an increase in the rotation speed difference between the left and right rear wheels based on the detection by the rotation speed detection sensor. It is provided with a control device that operates at high speed, and its operation and effect are as follows.
直進状態から前輪を操向操作し機体が旋回を始めて左右
後輪の両回転数に差が生じ始めると、この回転数差の増
大に応じて前輪が次第に増速されて行く。この状態では
前輪の操向角度に比べて旋回半径は大きいのであるが前
輪増速作用に伴って機体前部が旋回方向に引張られて行
き、前輪の駆動状態が前輪の操向角度に対応した旋回半
径での旋回状態に達する。その後は前輪の操向角度、つ
まり機体前部の旋回速度に適した駆動速度で前輪が駆動
されて行くのである。When the front wheels are steered from the straight ahead state to start turning and the difference in the rotational speeds of the left and right rear wheels begins to occur, the front wheels are gradually accelerated in accordance with the increase in the rotational speed difference. In this state, the turning radius is larger than the steering angle of the front wheels, but the front part of the aircraft is pulled in the turning direction as the front wheels accelerate, and the driving state of the front wheels corresponds to the steering angle of the front wheels. Reaching a turning condition with a turning radius. After that, the front wheels are driven at a driving speed suitable for the steering angle of the front wheels, that is, the turning speed of the front part of the body.
以上のように、左右後輪の回転数差に応じて前輪を機体
前部の旋回速度に適した駆動速度に増速させることがで
きるようになって、作業地面を特に荒らすことなく急旋
回が行えるようになった。As described above, it becomes possible to increase the front wheels to the drive speed suitable for the turning speed of the front part of the machine body in accordance with the difference in the rotational speeds of the left and right rear wheels, and the sharp turning can be performed without particularly roughening the work ground. I can do it now.
以下、本発明の実施例の1つである四輪駆動型の農用ト
ラクタについて図面に基づいて説明する。A four-wheel drive agricultural tractor, which is one of the embodiments of the present invention, will be described below with reference to the drawings.
第3図に示すように、左右一対の操向型の前輪(1)及び
後輪(2)の各々を駆動自在に支持した機体フレーム(3)に
エンジン(4)、主クラッチ(5)、ミッションケース(6)及
び操縦部(7)を搭載し、機体後部にロータリー耕耘装置
等の各種作業装置を昇降自在に連結するリフトアーム
(8)、及び作業装置に動力を伝達するPTO軸(9)を備え
て四輪駆動型の農用トラクタを構成している。As shown in FIG. 3, an engine (4), a main clutch (5), and a main clutch (5) are mounted on a machine body frame (3) that rotatably supports a pair of left and right steering type front wheels (1) and rear wheels (2). A lift arm that mounts a mission case (6) and a control unit (7), and connects various working devices such as a rotary tiller to the rear of the machine in a vertically movable manner.
(8) and the PTO shaft (9) for transmitting power to the working device constitute a four-wheel drive agricultural tractor.
農用トラクタの動力伝達系について述べると、第3図及
び第2図に示すように、エンジン(4)からの動力は主ク
ラッチ(5)を介してミッションケース(6)内の主変速装置
及び副変速装置(以上、図示せず)に伝達されて、後輪
デフ駆動軸(12)から後輪デフ機構(2a)に伝達されると共
に、後輪デフ駆動軸(12)から分岐した動力は前輪変速装
置(10)に伝達され、前輪出力軸(15)を介して前輪デフ機
構(1a)に伝達されるものである。Referring to the power transmission system of the agricultural tractor, as shown in FIGS. 3 and 2, the power from the engine (4) is transmitted through the main clutch (5) to the main transmission and the sub transmission in the transmission case (6). The power transmitted to the transmission (above, not shown) is transmitted from the rear wheel differential drive shaft (12) to the rear wheel differential drive mechanism (2a), and the power branched from the rear wheel differential drive shaft (12) is applied to the front wheels. It is transmitted to the transmission (10) and is transmitted to the front wheel differential mechanism (1a) via the front wheel output shaft (15).
前記前輪変速装置(10)は第2図に示すように、前記後輪
デフ駆動軸(12)に前輪出力軸(15)が並設され、この後輪
デフ駆動軸(12)に第1・第2駆動ギヤ(13),(14)が固定
されている。そして、前記第1・第2駆動ギヤ(13),(1
4)の各々と咬合う第1・第2従動ギヤ(16),(17)が前輪
出力軸(15)に遊転外嵌されており、第1従動ギヤ(16)と
前輪出力軸(15)との間に第1油圧クラッチ(18)、第2従
動ギヤ(17)と前輪出力軸(15)との間に第2油圧クラッチ
(19)が構成されている。そして、第1図に示すように、
前記第1・第2油圧クラッチ(18),(19)に対して圧油給
排を行う電磁式で、且つ中立復帰型の制御弁(24)が設け
られ、この制御弁(24)に操作信号を発する制御装置(23)
が備えられている。As shown in FIG. 2, in the front wheel transmission (10), a front wheel output shaft (15) is arranged in parallel with the rear wheel differential drive shaft (12), and the rear wheel differential drive shaft (12) is provided with the first and second. The second drive gears (13), (14) are fixed. Then, the first and second drive gears (13), (1
The first and second driven gears (16), (17) that engage with each of (4) are fitted onto the front wheel output shaft (15) by idling, and the first driven gear (16) and the front wheel output shaft (15) ) Between the first hydraulic clutch (18) and the second driven gear (17) and the front wheel output shaft (15) between the second hydraulic clutch.
(19) is configured. Then, as shown in FIG.
An electromagnetic control valve (24) for supplying / discharging pressure oil to / from the first and second hydraulic clutches (18), (19) is provided, and a control valve (24) for operating the control valve (24) is provided. Controllers that emit signals (23)
Is provided.
これに対し、第1図に示すように左右後輪(2)に対して
各々の回転数を検出する回転数検出センサー(11a),(11
b)が設けてあり、回転数検出センサー(11a),(11b)から
の信号が前記制御装置(23)に入力されている。そして、
前記回転数検出センサー(11a),(11b)の検出値に基づい
て算出される左右後輪(2)の各々の周速度(VRa),(VRb)の
差が設定範囲内であれば、制御装置(23)は機体が直進状
態に在ると判断して前記制御弁(24)を第1油圧クラッチ
(18)圧油供給側に操作し、この第1油圧クラッチ(18)を
入り状態とする。この状態では、動力は前後輪(1),(2)
の平均周速度が略等しい標準駆動状態で前輪(1)に伝達
されて行く。On the other hand, as shown in FIG. 1, rotation speed detection sensors (11a), (11) for detecting the respective rotation speeds of the left and right rear wheels (2).
b) is provided, and signals from the rotation speed detection sensors (11a) and (11b) are input to the control device (23). And
If the difference between the peripheral speeds (VRa), (VRb) of the left and right rear wheels (2) calculated based on the detection values of the rotation speed detection sensors (11a), (11b) is within a set range, control is performed. The device (23) determines that the aircraft is in a straight traveling state and sets the control valve (24) to the first hydraulic clutch.
(18) Operate the pressure oil supply side to put the first hydraulic clutch (18) into the engaged state. In this state, power is applied to the front and rear wheels (1), (2)
Are transmitted to the front wheels (1) in a standard drive state in which the average peripheral velocities of are substantially equal.
次に、旋回時の状態について詳述すると同図に示すよう
に、前記回転数検出センサー(11a),(11b)の検出に基づ
いて算出される左右後輪(2)の周速度(VRa),(VRb)には第
1式(C1)のような関係が成立する。Next, detailed description will be given of the state at the time of turning, as shown in the figure, the peripheral speed (VRa) of the left and right rear wheels (2) calculated based on the detection of the rotation speed detection sensors (11a), (11b). , (VRb) has a relation as in the first equation (C 1 ).
VRa:VRb=(R1−B):(R1+B) …………(C1) R1:左右後輪の平均旋回半径 B:トレッドの1/2 故に、 又、前輪(1)の平均旋回半径(R2)とホイルベース(A)及び
後輪(2)の平均旋回半径(R1)は次式(C3)のような関係を
有している。VRa: VRb = (R 1 −B): (R 1 + B) ………… (C 1 ) R 1 : The average turning radius of the left and right rear wheels B: 1/2 of the tread The average turning radius (R 1) of the average turning radius (R 2) and a wheel base of the front wheel (1) (A) and the rear wheel (2) has a relationship as follows (C 3).
R2 2=A2+R1 2 …………………………(C3 故に、旋回時における後輪(2)に対する前輪(1)の増速比
(α)は次式(C4)で表される。R 2 2 = A 2 + R 1 2 …………………… (C 3 Therefore, the speed increase ratio (α) of the front wheel (1) to the rear wheel (2) during turning is calculated by the following equation (C 4 ).
この式(C4)に前式(C2)を代入すると 以上のような式(C5)で増速比(α)が得られる。 Substituting the previous expression (C 2 ) into this expression (C 4 ) The speed increasing ratio (α) is obtained by the above equation (C 5 ).
次に、前輪(1)を無段階に増速する構成について述べる
と、第4図(イ)に示すように制御弁(24)に対して第2油
圧クラッチ(19)圧油供給側に操作する信号を制御装置(2
3)から発振し続ければ、第2油圧クラッチ(19)は完全に
入り状態となって、後輪デフ駆動軸(12)からの動力は第
2駆動・従動ギヤ(14),(17)及び第2油圧クラッチ(19)
を通つて、第1油圧クラッチ(18)を入り操作する前記標
準駆動状態よりも増速された増速駆動状態で前輪(1)に
伝達されて行く。この増速駆動状態の増速比はギヤ比に
よって一義的に定まるものである。Next, the structure for continuously increasing the speed of the front wheel (1) will be described. As shown in Fig. 4 (a), the second hydraulic clutch (19) is operated to the pressure oil supply side with respect to the control valve (24). Signal to control device (2
If it continues to oscillate from 3), the second hydraulic clutch (19) will be completely in the engaged state, and the power from the rear wheel differential drive shaft (12) will be the second drive / driven gears (14), (17) and Second hydraulic clutch (19)
The first hydraulic clutch (18) is transmitted to the front wheels (1) in a speed-up drive state in which the speed is higher than the standard drive state in which the first hydraulic clutch (18) is turned on and operated. The speed increasing ratio in this speed increasing drive state is uniquely determined by the gear ratio.
これに対し、第4図(ロ),(ハ)に示すように制御弁(24)を
第2油圧クラッチ(19)圧油供給側に操作する信号を間欠
的に発振し、制御弁(24)を間欠的に開閉操作すると、第
2油圧クラッチ(19)を完全に入り状態に保持しておくだ
けの圧力が第2油圧クラッチ(19)に作用しなくなる。こ
のような状態となると、第2油圧クラッチ(19)でスリッ
プが発生して、第2油圧クラッチ(19)が完全に入り状態
となった場合での前記増速駆動状態よりも減速された状
態で動力が伝達されて行く。従って、設定時間(t)内で
第2油圧クラッチ(19)入り側への発振時間の総和を変更
操作することにより、第2油圧クラッチ(19)のスリップ
の程度を変更でき前記標準駆動状態と増速駆動状態との
間で無段階に前輪(1)を変速操作することができるので
ある。On the other hand, as shown in FIGS. 4B and 4C, a signal for operating the control valve (24) to the pressure oil supply side of the second hydraulic clutch (19) is intermittently oscillated, and the control valve (24 ) Is intermittently opened and closed, the pressure sufficient to keep the second hydraulic clutch (19) completely in the closed state does not act on the second hydraulic clutch (19). In such a state, slippage occurs in the second hydraulic clutch (19) and the second hydraulic clutch (19) is decelerated more than the speed-up drive state in the fully entered state. Power is transmitted by. Therefore, the degree of slippage of the second hydraulic clutch (19) can be changed by changing the total sum of the oscillation times to the entry side of the second hydraulic clutch (19) within the set time (t). The front wheels (1) can be continuously operated to change gears during the speed-up drive state.
そして、第1図に示すように前輪変速装置(10)から下手
側の前輪出力軸(15)及び後輪デフ駆動軸(12)に回転数検
出センサー(20),(21)が取付けられ、制御装置(23)に接
続されている。そして、前記回転数検出センサー(20),
(21)の検出に基づいて算出される前輪(1)の平均周速度
(VF)及び後輪(2)の平均周速度(VR)とが、旋回中に、 VF=αVR α=増速比 となるように制御装置(23)が制御弁(24)を先に述べたよ
うに間欠的に操作するのである。Then, as shown in FIG. 1, rotation speed detection sensors (20), (21) are attached to the front wheel output shaft (15) and the rear wheel differential drive shaft (12) on the lower side from the front wheel transmission (10), It is connected to the control unit (23). And the rotation speed detection sensor (20),
Average peripheral speed of front wheel (1) calculated based on detection of (21)
The control device (23) controls the control valve (24) so that (V F ) and the average peripheral velocity (V R ) of the rear wheels (2) are such that V F = αV R α = gear increase ratio during turning. Is operated intermittently as described above.
前述の実施例では前輪変速装置の増速系を油圧操作式と
したが、ベルト式等の摩擦式無段変速装置に構成する構
造も採用できる。In the above-described embodiment, the speed increasing system of the front wheel transmission is hydraulically operated, but a structure of a friction type continuously variable transmission such as a belt type may be adopted.
尚、特許請求の範囲の項に図面との対照を便利にする為
に符号を記すが、該記入により本発明は添付図面の構造
に限定されるものではない。It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.
図面は本発明に係る四輪駆動型作業車の実施例を示し、
第1図は前輪変速装置の制御系統を示す概略平面図、第
2図は前輪変速装置の側面図、第3図は農用トラクタの
全体側面図、第4図(イ),(ロ),(ハ)は制御装置から制御
弁に対しての第2油圧クラッチ圧油供給側への信号の発
振状態を示す図である。 (1)……前輪、(2)……後輪、(10)……前輪変速装置、(1
1a),(11b)……回転数検出センサー、(23)……制御装
置。The drawings show an embodiment of a four-wheel drive type working vehicle according to the present invention,
FIG. 1 is a schematic plan view showing a control system of a front wheel transmission, FIG. 2 is a side view of the front wheel transmission, FIG. 3 is an overall side view of an agricultural tractor, and FIGS. 4 (a), (b), ( (C) is a diagram showing an oscillating state of a signal from the control device to the second hydraulic clutch pressure oil supply side to the control valve. (1) …… Front wheel, (2) …… Rear wheel, (10) …… Front wheel transmission, (1
1a), (11b) ... Rotation speed detection sensor, (23) ... Control device.
Claims (1)
に無段階に増速する前輪変速装置(10)を操向自在な前輪
(1)への伝動系に設けると共に、左右後輪(2)の各々の回
転数を検出する回転数検出センサー(11a),(11b)を設け
て、前記回転数検出センサー(11a),(11b)からの検出に
基づき左右後輪(2)の回転数差の増大に応じて前記前輪
変速装置(10)を増速操作する制御装置(23)を備えてある
四輪駆動型作業車。1. A front wheel capable of steering a front wheel transmission (10) which continuously increases to a driving speed higher than that of the rear wheel (2).
Provided with a transmission system to (1), provided with a rotation speed detection sensor (11a), (11b) for detecting the rotation speed of each of the left and right rear wheels (2), the rotation speed detection sensor (11a), ( A four-wheel drive work vehicle provided with a control device (23) for increasing the speed of the front wheel transmission (10) according to an increase in the rotational speed difference between the left and right rear wheels (2) based on the detection from 11b).
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5819287A JPH06469B2 (en) | 1987-03-12 | 1987-03-12 | Four-wheel drive work vehicle |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5819287A JPH06469B2 (en) | 1987-03-12 | 1987-03-12 | Four-wheel drive work vehicle |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS63222928A JPS63222928A (en) | 1988-09-16 |
JPH06469B2 true JPH06469B2 (en) | 1994-01-05 |
Family
ID=13077155
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP5819287A Expired - Lifetime JPH06469B2 (en) | 1987-03-12 | 1987-03-12 | Four-wheel drive work vehicle |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH06469B2 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP7129814B2 (en) * | 2018-04-26 | 2022-09-02 | 株式会社小松製作所 | Working machine and its control method |
-
1987
- 1987-03-12 JP JP5819287A patent/JPH06469B2/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
JPS63222928A (en) | 1988-09-16 |
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